/*
* The simplest AC-3 encoder
* Copyright (c) 2000 Fabrice Bellard
+ * Copyright (c) 2006-2010 Justin Ruggles <justin.ruggles@gmail.com>
+ * Copyright (c) 2006-2010 Prakash Punnoor <prakash@punnoor.de>
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
* The simplest AC-3 encoder.
*/
-//#define DEBUG
+//#define ASSERT_LEVEL 2
-#include "libavcore/audioconvert.h"
+#include <stdint.h>
+
+#include "libavutil/audioconvert.h"
+#include "libavutil/avassert.h"
+#include "libavutil/avstring.h"
#include "libavutil/crc.h"
+#include "libavutil/opt.h"
#include "avcodec.h"
#include "put_bits.h"
+#include "dsputil.h"
+#include "ac3dsp.h"
#include "ac3.h"
#include "audioconvert.h"
+#include "fft.h"
+#include "ac3enc.h"
+#include "eac3enc.h"
+typedef struct AC3Mant {
+ int16_t *qmant1_ptr, *qmant2_ptr, *qmant4_ptr; ///< mantissa pointers for bap=1,2,4
+ int mant1_cnt, mant2_cnt, mant4_cnt; ///< mantissa counts for bap=1,2,4
+} AC3Mant;
-#define MDCT_NBITS 9
-#define MDCT_SAMPLES (1 << MDCT_NBITS)
-
-/** Scale a float value by 2^bits and convert to an integer. */
-#define SCALE_FLOAT(a, bits) lrintf((a) * (float)(1 << (bits)))
+#define CMIXLEV_NUM_OPTIONS 3
+static const float cmixlev_options[CMIXLEV_NUM_OPTIONS] = {
+ LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB
+};
-/** Scale a float value by 2^15, convert to an integer, and clip to int16_t range. */
-#define FIX15(a) av_clip_int16(SCALE_FLOAT(a, 15))
+#define SURMIXLEV_NUM_OPTIONS 3
+static const float surmixlev_options[SURMIXLEV_NUM_OPTIONS] = {
+ LEVEL_MINUS_3DB, LEVEL_MINUS_6DB, LEVEL_ZERO
+};
+#define EXTMIXLEV_NUM_OPTIONS 8
+static const float extmixlev_options[EXTMIXLEV_NUM_OPTIONS] = {
+ LEVEL_PLUS_3DB, LEVEL_PLUS_1POINT5DB, LEVEL_ONE, LEVEL_MINUS_4POINT5DB,
+ LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB, LEVEL_ZERO
+};
-/**
- * Compex number.
- * Used in fixed-point MDCT calculation.
- */
-typedef struct IComplex {
- int16_t re,im;
-} IComplex;
/**
- * AC-3 encoder private context.
+ * LUT for number of exponent groups.
+ * exponent_group_tab[coupling][exponent strategy-1][number of coefficients]
*/
-typedef struct AC3EncodeContext {
- PutBitContext pb; ///< bitstream writer context
-
- int bitstream_id; ///< bitstream id (bsid)
- int bitstream_mode; ///< bitstream mode (bsmod)
-
- int bit_rate; ///< target bit rate, in bits-per-second
- int sample_rate; ///< sampling frequency, in Hz
-
- int frame_size_min; ///< minimum frame size in case rounding is necessary
- int frame_size; ///< current frame size in bytes
- int frame_size_code; ///< frame size code (frmsizecod)
- int bits_written; ///< bit count (used to avg. bitrate)
- int samples_written; ///< sample count (used to avg. bitrate)
-
- int fbw_channels; ///< number of full-bandwidth channels (nfchans)
- int channels; ///< total number of channels (nchans)
- int lfe_on; ///< indicates if there is an LFE channel (lfeon)
- int lfe_channel; ///< channel index of the LFE channel
- int channel_mode; ///< channel mode (acmod)
- const uint8_t *channel_map; ///< channel map used to reorder channels
-
- int bandwidth_code[AC3_MAX_CHANNELS]; ///< bandwidth code (0 to 60) (chbwcod)
- int nb_coefs[AC3_MAX_CHANNELS];
-
- /* bitrate allocation control */
- int slow_gain_code; ///< slow gain code (sgaincod)
- int slow_decay_code; ///< slow decay code (sdcycod)
- int fast_decay_code; ///< fast decay code (fdcycod)
- int db_per_bit_code; ///< dB/bit code (dbpbcod)
- int floor_code; ///< floor code (floorcod)
- AC3BitAllocParameters bit_alloc; ///< bit allocation parameters
- int coarse_snr_offset; ///< coarse SNR offsets (csnroffst)
- int fast_gain_code[AC3_MAX_CHANNELS]; ///< fast gain codes (signal-to-mask ratio) (fgaincod)
- int fine_snr_offset[AC3_MAX_CHANNELS]; ///< fine SNR offsets (fsnroffst)
-
- /* mantissa encoding */
- int mant1_cnt, mant2_cnt, mant4_cnt; ///< mantissa counts for bap=1,2,4
-
- int16_t last_samples[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]; ///< last 256 samples from previous frame
-} AC3EncodeContext;
-
-
-/** MDCT and FFT tables */
-static int16_t costab[64];
-static int16_t sintab[64];
-static int16_t xcos1[128];
-static int16_t xsin1[128];
+static uint8_t exponent_group_tab[2][3][256];
/**
- * Initialize FFT tables.
- * @param ln log2(FFT size)
+ * List of supported channel layouts.
*/
-static av_cold void fft_init(int ln)
-{
- int i, n, n2;
- float alpha;
-
- n = 1 << ln;
- n2 = n >> 1;
-
- for (i = 0; i < n2; i++) {
- alpha = 2.0 * M_PI * i / n;
- costab[i] = FIX15(cos(alpha));
- sintab[i] = FIX15(sin(alpha));
- }
-}
+const uint64_t ff_ac3_channel_layouts[19] = {
+ AV_CH_LAYOUT_MONO,
+ AV_CH_LAYOUT_STEREO,
+ AV_CH_LAYOUT_2_1,
+ AV_CH_LAYOUT_SURROUND,
+ AV_CH_LAYOUT_2_2,
+ AV_CH_LAYOUT_QUAD,
+ AV_CH_LAYOUT_4POINT0,
+ AV_CH_LAYOUT_5POINT0,
+ AV_CH_LAYOUT_5POINT0_BACK,
+ (AV_CH_LAYOUT_MONO | AV_CH_LOW_FREQUENCY),
+ (AV_CH_LAYOUT_STEREO | AV_CH_LOW_FREQUENCY),
+ (AV_CH_LAYOUT_2_1 | AV_CH_LOW_FREQUENCY),
+ (AV_CH_LAYOUT_SURROUND | AV_CH_LOW_FREQUENCY),
+ (AV_CH_LAYOUT_2_2 | AV_CH_LOW_FREQUENCY),
+ (AV_CH_LAYOUT_QUAD | AV_CH_LOW_FREQUENCY),
+ (AV_CH_LAYOUT_4POINT0 | AV_CH_LOW_FREQUENCY),
+ AV_CH_LAYOUT_5POINT1,
+ AV_CH_LAYOUT_5POINT1_BACK,
+ 0
+};
/**
- * Initialize MDCT tables.
- * @param nbits log2(MDCT size)
+ * LUT to select the bandwidth code based on the bit rate, sample rate, and
+ * number of full-bandwidth channels.
+ * bandwidth_tab[fbw_channels-1][sample rate code][bit rate code]
*/
-static av_cold void mdct_init(int nbits)
-{
- int i, n, n4;
+static const uint8_t ac3_bandwidth_tab[5][3][19] = {
+// 32 40 48 56 64 80 96 112 128 160 192 224 256 320 384 448 512 576 640
- n = 1 << nbits;
- n4 = n >> 2;
+ { { 0, 0, 0, 12, 16, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
+ { 0, 0, 0, 16, 20, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
+ { 0, 0, 0, 32, 40, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
- fft_init(nbits - 2);
+ { { 0, 0, 0, 0, 0, 0, 0, 20, 24, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
+ { 0, 0, 0, 0, 0, 0, 4, 24, 28, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
+ { 0, 0, 0, 0, 0, 0, 20, 44, 52, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
- for (i = 0; i < n4; i++) {
- float alpha = 2.0 * M_PI * (i + 1.0 / 8.0) / n;
- xcos1[i] = FIX15(-cos(alpha));
- xsin1[i] = FIX15(-sin(alpha));
- }
-}
+ { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 24, 32, 40, 48, 48, 48, 48, 48, 48 },
+ { 0, 0, 0, 0, 0, 0, 0, 0, 4, 20, 28, 36, 44, 56, 56, 56, 56, 56, 56 },
+ { 0, 0, 0, 0, 0, 0, 0, 0, 20, 40, 48, 60, 60, 60, 60, 60, 60, 60, 60 } },
+ { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 24, 32, 48, 48, 48, 48, 48, 48 },
+ { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 28, 36, 56, 56, 56, 56, 56, 56 },
+ { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 32, 48, 60, 60, 60, 60, 60, 60, 60 } },
-/** Butterfly op */
-#define BF(pre, pim, qre, qim, pre1, pim1, qre1, qim1) \
-{ \
- int ax, ay, bx, by; \
- bx = pre1; \
- by = pim1; \
- ax = qre1; \
- ay = qim1; \
- pre = (bx + ax) >> 1; \
- pim = (by + ay) >> 1; \
- qre = (bx - ax) >> 1; \
- qim = (by - ay) >> 1; \
-}
+ { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 20, 32, 40, 48, 48, 48, 48 },
+ { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 24, 36, 44, 56, 56, 56, 56 },
+ { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 28, 44, 60, 60, 60, 60, 60, 60 } }
+};
-/** Complex multiply */
-#define CMUL(pre, pim, are, aim, bre, bim) \
-{ \
- pre = (MUL16(are, bre) - MUL16(aim, bim)) >> 15; \
- pim = (MUL16(are, bim) + MUL16(bre, aim)) >> 15; \
-}
+/**
+ * LUT to select the coupling start band based on the bit rate, sample rate, and
+ * number of full-bandwidth channels. -1 = coupling off
+ * ac3_coupling_start_tab[channel_mode-2][sample rate code][bit rate code]
+ *
+ * TODO: more testing for optimal parameters.
+ * multi-channel tests at 44.1kHz and 32kHz.
+ */
+static const int8_t ac3_coupling_start_tab[6][3][19] = {
+// 32 40 48 56 64 80 96 112 128 160 192 224 256 320 384 448 512 576 640
+
+ // 2/0
+ { { 0, 0, 0, 0, 0, 0, 0, 1, 1, 7, 8, 11, 12, -1, -1, -1, -1, -1, -1 },
+ { 0, 0, 0, 0, 0, 0, 1, 3, 5, 7, 10, 12, 13, -1, -1, -1, -1, -1, -1 },
+ { 0, 0, 0, 0, 1, 2, 2, 9, 13, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
+
+ // 3/0
+ { { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
+ { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
+ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
+
+ // 2/1 - untested
+ { { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
+ { 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 9, 11, 12, 13, -1, -1, -1, -1 },
+ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
+
+ // 3/1
+ { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
+ { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
+ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
+
+ // 2/2 - untested
+ { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
+ { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 2, 10, 11, 11, 12, 12, 14, -1 },
+ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
+
+ // 3/2
+ { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 6, 8, 11, 12, 12, -1, -1 },
+ { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 6, 8, 11, 12, 12, -1, -1 },
+ { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
+};
/**
- * Calculate a 2^n point complex FFT on 2^ln points.
- * @param z complex input/output samples
- * @param ln log2(FFT size)
+ * Adjust the frame size to make the average bit rate match the target bit rate.
+ * This is only needed for 11025, 22050, and 44100 sample rates or any E-AC-3.
+ *
+ * @param s AC-3 encoder private context
*/
-static void fft(IComplex *z, int ln)
+void ff_ac3_adjust_frame_size(AC3EncodeContext *s)
{
- int j, l, np, np2;
- int nblocks, nloops;
- register IComplex *p,*q;
- int tmp_re, tmp_im;
-
- np = 1 << ln;
-
- /* reverse */
- for (j = 0; j < np; j++) {
- int k = av_reverse[j] >> (8 - ln);
- if (k < j)
- FFSWAP(IComplex, z[k], z[j]);
- }
-
- /* pass 0 */
-
- p = &z[0];
- j = np >> 1;
- do {
- BF(p[0].re, p[0].im, p[1].re, p[1].im,
- p[0].re, p[0].im, p[1].re, p[1].im);
- p += 2;
- } while (--j);
-
- /* pass 1 */
-
- p = &z[0];
- j = np >> 2;
- do {
- BF(p[0].re, p[0].im, p[2].re, p[2].im,
- p[0].re, p[0].im, p[2].re, p[2].im);
- BF(p[1].re, p[1].im, p[3].re, p[3].im,
- p[1].re, p[1].im, p[3].im, -p[3].re);
- p+=4;
- } while (--j);
-
- /* pass 2 .. ln-1 */
-
- nblocks = np >> 3;
- nloops = 1 << 2;
- np2 = np >> 1;
- do {
- p = z;
- q = z + nloops;
- for (j = 0; j < nblocks; j++) {
- BF(p->re, p->im, q->re, q->im,
- p->re, p->im, q->re, q->im);
- p++;
- q++;
- for(l = nblocks; l < np2; l += nblocks) {
- CMUL(tmp_re, tmp_im, costab[l], -sintab[l], q->re, q->im);
- BF(p->re, p->im, q->re, q->im,
- p->re, p->im, tmp_re, tmp_im);
- p++;
- q++;
- }
- p += nloops;
- q += nloops;
- }
- nblocks = nblocks >> 1;
- nloops = nloops << 1;
- } while (nblocks);
+ while (s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
+ s->bits_written -= s->bit_rate;
+ s->samples_written -= s->sample_rate;
+ }
+ s->frame_size = s->frame_size_min +
+ 2 * (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate);
+ s->bits_written += s->frame_size * 8;
+ s->samples_written += AC3_BLOCK_SIZE * s->num_blocks;
}
/**
- * Calculate a 512-point MDCT
- * @param out 256 output frequency coefficients
- * @param in 512 windowed input audio samples
+ * Set the initial coupling strategy parameters prior to coupling analysis.
+ *
+ * @param s AC-3 encoder private context
*/
-static void mdct512(int32_t *out, int16_t *in)
+void ff_ac3_compute_coupling_strategy(AC3EncodeContext *s)
{
- int i, re, im, re1, im1;
- int16_t rot[MDCT_SAMPLES];
- IComplex x[MDCT_SAMPLES/4];
-
- /* shift to simplify computations */
- for (i = 0; i < MDCT_SAMPLES/4; i++)
- rot[i] = -in[i + 3*MDCT_SAMPLES/4];
- for (;i < MDCT_SAMPLES; i++)
- rot[i] = in[i - MDCT_SAMPLES/4];
-
- /* pre rotation */
- for (i = 0; i < MDCT_SAMPLES/4; i++) {
- re = ((int)rot[ 2*i] - (int)rot[MDCT_SAMPLES -1-2*i]) >> 1;
- im = -((int)rot[MDCT_SAMPLES/2+2*i] - (int)rot[MDCT_SAMPLES/2-1-2*i]) >> 1;
- CMUL(x[i].re, x[i].im, re, im, -xcos1[i], xsin1[i]);
+ int blk, ch;
+ int got_cpl_snr;
+ int num_cpl_blocks;
+
+ /* set coupling use flags for each block/channel */
+ /* TODO: turn coupling on/off and adjust start band based on bit usage */
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ for (ch = 1; ch <= s->fbw_channels; ch++)
+ block->channel_in_cpl[ch] = s->cpl_on;
}
- fft(x, MDCT_NBITS - 2);
+ /* enable coupling for each block if at least 2 channels have coupling
+ enabled for that block */
+ got_cpl_snr = 0;
+ num_cpl_blocks = 0;
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ block->num_cpl_channels = 0;
+ for (ch = 1; ch <= s->fbw_channels; ch++)
+ block->num_cpl_channels += block->channel_in_cpl[ch];
+ block->cpl_in_use = block->num_cpl_channels > 1;
+ num_cpl_blocks += block->cpl_in_use;
+ if (!block->cpl_in_use) {
+ block->num_cpl_channels = 0;
+ for (ch = 1; ch <= s->fbw_channels; ch++)
+ block->channel_in_cpl[ch] = 0;
+ }
- /* post rotation */
- for (i = 0; i < MDCT_SAMPLES/4; i++) {
- re = x[i].re;
- im = x[i].im;
- CMUL(re1, im1, re, im, xsin1[i], xcos1[i]);
- out[ 2*i] = im1;
- out[MDCT_SAMPLES/2-1-2*i] = re1;
+ block->new_cpl_strategy = !blk;
+ if (blk) {
+ for (ch = 1; ch <= s->fbw_channels; ch++) {
+ if (block->channel_in_cpl[ch] != s->blocks[blk-1].channel_in_cpl[ch]) {
+ block->new_cpl_strategy = 1;
+ break;
+ }
+ }
+ }
+ block->new_cpl_leak = block->new_cpl_strategy;
+
+ if (!blk || (block->cpl_in_use && !got_cpl_snr)) {
+ block->new_snr_offsets = 1;
+ if (block->cpl_in_use)
+ got_cpl_snr = 1;
+ } else {
+ block->new_snr_offsets = 0;
+ }
+ }
+ if (!num_cpl_blocks)
+ s->cpl_on = 0;
+
+ /* set bandwidth for each channel */
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ for (ch = 1; ch <= s->fbw_channels; ch++) {
+ if (block->channel_in_cpl[ch])
+ block->end_freq[ch] = s->start_freq[CPL_CH];
+ else
+ block->end_freq[ch] = s->bandwidth_code * 3 + 73;
+ }
}
}
/**
- * Calculate the log2() of the maximum absolute value in an array.
- * @param tab input array
- * @param n number of values in the array
- * @return log2(max(abs(tab[])))
+ * Apply stereo rematrixing to coefficients based on rematrixing flags.
+ *
+ * @param s AC-3 encoder private context
*/
-static int log2_tab(int16_t *tab, int n)
+void ff_ac3_apply_rematrixing(AC3EncodeContext *s)
{
- int i, v;
+ int nb_coefs;
+ int blk, bnd, i;
+ int start, end;
+ uint8_t *flags;
- v = 0;
- for (i = 0; i < n; i++)
- v |= abs(tab[i]);
+ if (!s->rematrixing_enabled)
+ return;
- return av_log2(v);
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ if (block->new_rematrixing_strategy)
+ flags = block->rematrixing_flags;
+ nb_coefs = FFMIN(block->end_freq[1], block->end_freq[2]);
+ for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++) {
+ if (flags[bnd]) {
+ start = ff_ac3_rematrix_band_tab[bnd];
+ end = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
+ for (i = start; i < end; i++) {
+ int32_t lt = block->fixed_coef[1][i];
+ int32_t rt = block->fixed_coef[2][i];
+ block->fixed_coef[1][i] = (lt + rt) >> 1;
+ block->fixed_coef[2][i] = (lt - rt) >> 1;
+ }
+ }
+ }
+ }
}
-/**
- * Left-shift each value in an array by a specified amount.
- * @param tab input array
- * @param n number of values in the array
- * @param lshift left shift amount. a negative value means right shift.
+/*
+ * Initialize exponent tables.
*/
-static void lshift_tab(int16_t *tab, int n, int lshift)
+static av_cold void exponent_init(AC3EncodeContext *s)
{
- int i;
+ int expstr, i, grpsize;
- if (lshift > 0) {
- for(i = 0; i < n; i++)
- tab[i] <<= lshift;
- } else if (lshift < 0) {
- lshift = -lshift;
- for (i = 0; i < n; i++)
- tab[i] >>= lshift;
+ for (expstr = EXP_D15-1; expstr <= EXP_D45-1; expstr++) {
+ grpsize = 3 << expstr;
+ for (i = 12; i < 256; i++) {
+ exponent_group_tab[0][expstr][i] = (i + grpsize - 4) / grpsize;
+ exponent_group_tab[1][expstr][i] = (i ) / grpsize;
+ }
}
+ /* LFE */
+ exponent_group_tab[0][0][7] = 2;
+
+ if (CONFIG_EAC3_ENCODER && s->eac3)
+ ff_eac3_exponent_init();
}
-/**
- * Calculate the sum of absolute differences (SAD) between 2 sets of exponents.
+/*
+ * Extract exponents from the MDCT coefficients.
*/
-static int calc_exp_diff(uint8_t *exp1, uint8_t *exp2, int n)
+static void extract_exponents(AC3EncodeContext *s)
{
- int sum, i;
- sum = 0;
- for (i = 0; i < n; i++)
- sum += abs(exp1[i] - exp2[i]);
- return sum;
+ int ch = !s->cpl_on;
+ int chan_size = AC3_MAX_COEFS * s->num_blocks * (s->channels - ch + 1);
+ AC3Block *block = &s->blocks[0];
+
+ s->ac3dsp.extract_exponents(block->exp[ch], block->fixed_coef[ch], chan_size);
}
* Exponent Difference Threshold.
* New exponents are sent if their SAD exceed this number.
*/
-#define EXP_DIFF_THRESHOLD 1000
-
+#define EXP_DIFF_THRESHOLD 500
/**
- * Calculate exponent strategies for all blocks in a single channel.
+ * Table used to select exponent strategy based on exponent reuse block interval.
+ */
+static const uint8_t exp_strategy_reuse_tab[4][6] = {
+ { EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
+ { EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
+ { EXP_D25, EXP_D25, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
+ { EXP_D45, EXP_D25, EXP_D25, EXP_D15, EXP_D15, EXP_D15 }
+};
+
+/*
+ * Calculate exponent strategies for all channels.
+ * Array arrangement is reversed to simplify the per-channel calculation.
*/
-static void compute_exp_strategy_ch(uint8_t exp_strategy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS],
- uint8_t exp[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
- int ch, int is_lfe)
+static void compute_exp_strategy(AC3EncodeContext *s)
{
- int blk, blk1;
- int exp_diff;
-
- /* estimate if the exponent variation & decide if they should be
- reused in the next frame */
- exp_strategy[0][ch] = EXP_NEW;
- for (blk = 1; blk < AC3_MAX_BLOCKS; blk++) {
- exp_diff = calc_exp_diff(exp[blk][ch], exp[blk-1][ch], AC3_MAX_COEFS);
- if (exp_diff > EXP_DIFF_THRESHOLD)
- exp_strategy[blk][ch] = EXP_NEW;
- else
- exp_strategy[blk][ch] = EXP_REUSE;
- }
- if (is_lfe)
- return;
+ int ch, blk, blk1;
+
+ for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) {
+ uint8_t *exp_strategy = s->exp_strategy[ch];
+ uint8_t *exp = s->blocks[0].exp[ch];
+ int exp_diff;
+
+ /* estimate if the exponent variation & decide if they should be
+ reused in the next frame */
+ exp_strategy[0] = EXP_NEW;
+ exp += AC3_MAX_COEFS;
+ for (blk = 1; blk < s->num_blocks; blk++, exp += AC3_MAX_COEFS) {
+ if (ch == CPL_CH) {
+ if (!s->blocks[blk-1].cpl_in_use) {
+ exp_strategy[blk] = EXP_NEW;
+ continue;
+ } else if (!s->blocks[blk].cpl_in_use) {
+ exp_strategy[blk] = EXP_REUSE;
+ continue;
+ }
+ } else if (s->blocks[blk].channel_in_cpl[ch] != s->blocks[blk-1].channel_in_cpl[ch]) {
+ exp_strategy[blk] = EXP_NEW;
+ continue;
+ }
+ exp_diff = s->dsp.sad[0](NULL, exp, exp - AC3_MAX_COEFS, 16, 16);
+ exp_strategy[blk] = EXP_REUSE;
+ if (ch == CPL_CH && exp_diff > (EXP_DIFF_THRESHOLD * (s->blocks[blk].end_freq[ch] - s->start_freq[ch]) / AC3_MAX_COEFS))
+ exp_strategy[blk] = EXP_NEW;
+ else if (ch > CPL_CH && exp_diff > EXP_DIFF_THRESHOLD)
+ exp_strategy[blk] = EXP_NEW;
+ }
- /* now select the encoding strategy type : if exponents are often
- recoded, we use a coarse encoding */
- blk = 0;
- while (blk < AC3_MAX_BLOCKS) {
- blk1 = blk + 1;
- while (blk1 < AC3_MAX_BLOCKS && exp_strategy[blk1][ch] == EXP_REUSE)
- blk1++;
- switch (blk1 - blk) {
- case 1: exp_strategy[blk][ch] = EXP_D45; break;
- case 2:
- case 3: exp_strategy[blk][ch] = EXP_D25; break;
- default: exp_strategy[blk][ch] = EXP_D15; break;
+ /* now select the encoding strategy type : if exponents are often
+ recoded, we use a coarse encoding */
+ blk = 0;
+ while (blk < s->num_blocks) {
+ blk1 = blk + 1;
+ while (blk1 < s->num_blocks && exp_strategy[blk1] == EXP_REUSE)
+ blk1++;
+ exp_strategy[blk] = exp_strategy_reuse_tab[s->num_blks_code][blk1-blk-1];
+ blk = blk1;
}
- blk = blk1;
}
-}
-
-
-/**
- * Set each encoded exponent in a block to the minimum of itself and the
- * exponent in the same frequency bin of a following block.
- * exp[i] = min(exp[i], exp1[i]
- */
-static void exponent_min(uint8_t exp[AC3_MAX_COEFS], uint8_t exp1[AC3_MAX_COEFS], int n)
-{
- int i;
- for (i = 0; i < n; i++) {
- if (exp1[i] < exp[i])
- exp[i] = exp1[i];
+ if (s->lfe_on) {
+ ch = s->lfe_channel;
+ s->exp_strategy[ch][0] = EXP_D15;
+ for (blk = 1; blk < s->num_blocks; blk++)
+ s->exp_strategy[ch][blk] = EXP_REUSE;
}
+
+ /* for E-AC-3, determine frame exponent strategy */
+ if (CONFIG_EAC3_ENCODER && s->eac3)
+ ff_eac3_get_frame_exp_strategy(s);
}
/**
* Update the exponents so that they are the ones the decoder will decode.
- * @return the number of bits used to encode the exponents.
+ *
+ * @param[in,out] exp array of exponents for 1 block in 1 channel
+ * @param nb_exps number of exponents in active bandwidth
+ * @param exp_strategy exponent strategy for the block
+ * @param cpl indicates if the block is in the coupling channel
*/
-static int encode_exponents_blk_ch(uint8_t encoded_exp[AC3_MAX_COEFS],
- uint8_t exp[AC3_MAX_COEFS],
- int nb_exps, int exp_strategy)
+static void encode_exponents_blk_ch(uint8_t *exp, int nb_exps, int exp_strategy,
+ int cpl)
{
- int group_size, nb_groups, i, j, k, exp_min;
- uint8_t exp1[AC3_MAX_COEFS];
+ int nb_groups, i, k;
- group_size = exp_strategy + (exp_strategy == EXP_D45);
- nb_groups = ((nb_exps + (group_size * 3) - 4) / (3 * group_size)) * 3;
+ nb_groups = exponent_group_tab[cpl][exp_strategy-1][nb_exps] * 3;
/* for each group, compute the minimum exponent */
- exp1[0] = exp[0]; /* DC exponent is handled separately */
- k = 1;
- for (i = 1; i <= nb_groups; i++) {
- exp_min = exp[k];
- assert(exp_min >= 0 && exp_min <= 24);
- for (j = 1; j < group_size; j++) {
- if (exp[k+j] < exp_min)
- exp_min = exp[k+j];
+ switch(exp_strategy) {
+ case EXP_D25:
+ for (i = 1, k = 1-cpl; i <= nb_groups; i++) {
+ uint8_t exp_min = exp[k];
+ if (exp[k+1] < exp_min)
+ exp_min = exp[k+1];
+ exp[i-cpl] = exp_min;
+ k += 2;
+ }
+ break;
+ case EXP_D45:
+ for (i = 1, k = 1-cpl; i <= nb_groups; i++) {
+ uint8_t exp_min = exp[k];
+ if (exp[k+1] < exp_min)
+ exp_min = exp[k+1];
+ if (exp[k+2] < exp_min)
+ exp_min = exp[k+2];
+ if (exp[k+3] < exp_min)
+ exp_min = exp[k+3];
+ exp[i-cpl] = exp_min;
+ k += 4;
}
- exp1[i] = exp_min;
- k += group_size;
+ break;
}
/* constraint for DC exponent */
- if (exp1[0] > 15)
- exp1[0] = 15;
+ if (!cpl && exp[0] > 15)
+ exp[0] = 15;
/* decrease the delta between each groups to within 2 so that they can be
differentially encoded */
for (i = 1; i <= nb_groups; i++)
- exp1[i] = FFMIN(exp1[i], exp1[i-1] + 2);
- for (i = nb_groups-1; i >= 0; i--)
- exp1[i] = FFMIN(exp1[i], exp1[i+1] + 2);
+ exp[i] = FFMIN(exp[i], exp[i-1] + 2);
+ i--;
+ while (--i >= 0)
+ exp[i] = FFMIN(exp[i], exp[i+1] + 2);
+
+ if (cpl)
+ exp[-1] = exp[0] & ~1;
/* now we have the exponent values the decoder will see */
- encoded_exp[0] = exp1[0];
- k = 1;
- for (i = 1; i <= nb_groups; i++) {
- for (j = 0; j < group_size; j++)
- encoded_exp[k+j] = exp1[i];
- k += group_size;
+ switch (exp_strategy) {
+ case EXP_D25:
+ for (i = nb_groups, k = (nb_groups * 2)-cpl; i > 0; i--) {
+ uint8_t exp1 = exp[i-cpl];
+ exp[k--] = exp1;
+ exp[k--] = exp1;
+ }
+ break;
+ case EXP_D45:
+ for (i = nb_groups, k = (nb_groups * 4)-cpl; i > 0; i--) {
+ exp[k] = exp[k-1] = exp[k-2] = exp[k-3] = exp[i-cpl];
+ k -= 4;
+ }
+ break;
+ }
+}
+
+
+/*
+ * Encode exponents from original extracted form to what the decoder will see.
+ * This copies and groups exponents based on exponent strategy and reduces
+ * deltas between adjacent exponent groups so that they can be differentially
+ * encoded.
+ */
+static void encode_exponents(AC3EncodeContext *s)
+{
+ int blk, blk1, ch, cpl;
+ uint8_t *exp, *exp_strategy;
+ int nb_coefs, num_reuse_blocks;
+
+ for (ch = !s->cpl_on; ch <= s->channels; ch++) {
+ exp = s->blocks[0].exp[ch] + s->start_freq[ch];
+ exp_strategy = s->exp_strategy[ch];
+
+ cpl = (ch == CPL_CH);
+ blk = 0;
+ while (blk < s->num_blocks) {
+ AC3Block *block = &s->blocks[blk];
+ if (cpl && !block->cpl_in_use) {
+ exp += AC3_MAX_COEFS;
+ blk++;
+ continue;
+ }
+ nb_coefs = block->end_freq[ch] - s->start_freq[ch];
+ blk1 = blk + 1;
+
+ /* count the number of EXP_REUSE blocks after the current block
+ and set exponent reference block numbers */
+ s->exp_ref_block[ch][blk] = blk;
+ while (blk1 < s->num_blocks && exp_strategy[blk1] == EXP_REUSE) {
+ s->exp_ref_block[ch][blk1] = blk;
+ blk1++;
+ }
+ num_reuse_blocks = blk1 - blk - 1;
+
+ /* for the EXP_REUSE case we select the min of the exponents */
+ s->ac3dsp.ac3_exponent_min(exp-s->start_freq[ch], num_reuse_blocks,
+ AC3_MAX_COEFS);
+
+ encode_exponents_blk_ch(exp, nb_coefs, exp_strategy[blk], cpl);
+
+ exp += AC3_MAX_COEFS * (num_reuse_blocks + 1);
+ blk = blk1;
+ }
}
- return 4 + (nb_groups / 3) * 7;
+ /* reference block numbers have been changed, so reset ref_bap_set */
+ s->ref_bap_set = 0;
}
-/**
- * Calculate the number of bits needed to encode a set of mantissas.
+/*
+ * Count exponent bits based on bandwidth, coupling, and exponent strategies.
*/
-static int compute_mantissa_size(AC3EncodeContext *s, uint8_t *m, int nb_coefs)
+static int count_exponent_bits(AC3EncodeContext *s)
{
- int bits, mant, i;
+ int blk, ch;
+ int nb_groups, bit_count;
- bits = 0;
- for (i = 0; i < nb_coefs; i++) {
- mant = m[i];
- switch (mant) {
- case 0:
- /* nothing */
- break;
- case 1:
- /* 3 mantissa in 5 bits */
- if (s->mant1_cnt == 0)
- bits += 5;
- if (++s->mant1_cnt == 3)
- s->mant1_cnt = 0;
- break;
- case 2:
- /* 3 mantissa in 7 bits */
- if (s->mant2_cnt == 0)
- bits += 7;
- if (++s->mant2_cnt == 3)
- s->mant2_cnt = 0;
- break;
- case 3:
- bits += 3;
- break;
- case 4:
- /* 2 mantissa in 7 bits */
- if (s->mant4_cnt == 0)
- bits += 7;
- if (++s->mant4_cnt == 2)
- s->mant4_cnt = 0;
- break;
- case 14:
- bits += 14;
- break;
- case 15:
- bits += 16;
- break;
- default:
- bits += mant - 1;
- break;
+ bit_count = 0;
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
+ int exp_strategy = s->exp_strategy[ch][blk];
+ int cpl = (ch == CPL_CH);
+ int nb_coefs = block->end_freq[ch] - s->start_freq[ch];
+
+ if (exp_strategy == EXP_REUSE)
+ continue;
+
+ nb_groups = exponent_group_tab[cpl][exp_strategy-1][nb_coefs];
+ bit_count += 4 + (nb_groups * 7);
}
}
- return bits;
+
+ return bit_count;
}
/**
- * Calculate masking curve based on the final exponents.
- * Also calculate the power spectral densities to use in future calculations.
+ * Group exponents.
+ * 3 delta-encoded exponents are in each 7-bit group. The number of groups
+ * varies depending on exponent strategy and bandwidth.
+ *
+ * @param s AC-3 encoder private context
*/
-static void bit_alloc_masking(AC3EncodeContext *s,
- uint8_t encoded_exp[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
- uint8_t exp_strategy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS],
- int16_t psd[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
- int16_t mask[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS])
+void ff_ac3_group_exponents(AC3EncodeContext *s)
{
- int blk, ch;
- int16_t band_psd[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS];
+ int blk, ch, i, cpl;
+ int group_size, nb_groups;
+ uint8_t *p;
+ int delta0, delta1, delta2;
+ int exp0, exp1;
- for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
- for (ch = 0; ch < s->channels; ch++) {
- if(exp_strategy[blk][ch] == EXP_REUSE) {
- memcpy(psd[blk][ch], psd[blk-1][ch], AC3_MAX_COEFS*sizeof(psd[0][0][0]));
- memcpy(mask[blk][ch], mask[blk-1][ch], AC3_CRITICAL_BANDS*sizeof(mask[0][0][0]));
- } else {
- ff_ac3_bit_alloc_calc_psd(encoded_exp[blk][ch], 0,
- s->nb_coefs[ch],
- psd[blk][ch], band_psd[blk][ch]);
- ff_ac3_bit_alloc_calc_mask(&s->bit_alloc, band_psd[blk][ch],
- 0, s->nb_coefs[ch],
- ff_ac3_fast_gain_tab[s->fast_gain_code[ch]],
- ch == s->lfe_channel,
- DBA_NONE, 0, NULL, NULL, NULL,
- mask[blk][ch]);
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
+ int exp_strategy = s->exp_strategy[ch][blk];
+ if (exp_strategy == EXP_REUSE)
+ continue;
+ cpl = (ch == CPL_CH);
+ group_size = exp_strategy + (exp_strategy == EXP_D45);
+ nb_groups = exponent_group_tab[cpl][exp_strategy-1][block->end_freq[ch]-s->start_freq[ch]];
+ p = block->exp[ch] + s->start_freq[ch] - cpl;
+
+ /* DC exponent */
+ exp1 = *p++;
+ block->grouped_exp[ch][0] = exp1;
+
+ /* remaining exponents are delta encoded */
+ for (i = 1; i <= nb_groups; i++) {
+ /* merge three delta in one code */
+ exp0 = exp1;
+ exp1 = p[0];
+ p += group_size;
+ delta0 = exp1 - exp0 + 2;
+ av_assert2(delta0 >= 0 && delta0 <= 4);
+
+ exp0 = exp1;
+ exp1 = p[0];
+ p += group_size;
+ delta1 = exp1 - exp0 + 2;
+ av_assert2(delta1 >= 0 && delta1 <= 4);
+
+ exp0 = exp1;
+ exp1 = p[0];
+ p += group_size;
+ delta2 = exp1 - exp0 + 2;
+ av_assert2(delta2 >= 0 && delta2 <= 4);
+
+ block->grouped_exp[ch][i] = ((delta0 * 5 + delta1) * 5) + delta2;
}
}
}
/**
- * Run the bit allocation with a given SNR offset.
- * This calculates the bit allocation pointers that will be used to determine
- * the quantization of each mantissa.
- * @return the number of remaining bits (positive or negative) if the given
- * SNR offset is used to quantize the mantissas.
+ * Calculate final exponents from the supplied MDCT coefficients and exponent shift.
+ * Extract exponents from MDCT coefficients, calculate exponent strategies,
+ * and encode final exponents.
+ *
+ * @param s AC-3 encoder private context
*/
-static int bit_alloc(AC3EncodeContext *s,
- int16_t mask[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS],
- int16_t psd[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
- uint8_t bap[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
- int frame_bits, int coarse_snr_offset, int fine_snr_offset)
+void ff_ac3_process_exponents(AC3EncodeContext *s)
{
- int blk, ch;
- int snr_offset;
+ extract_exponents(s);
- snr_offset = (((coarse_snr_offset - 15) << 4) + fine_snr_offset) << 2;
+ compute_exp_strategy(s);
- for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
- s->mant1_cnt = 0;
- s->mant2_cnt = 0;
- s->mant4_cnt = 0;
- for (ch = 0; ch < s->channels; ch++) {
- ff_ac3_bit_alloc_calc_bap(mask[blk][ch], psd[blk][ch], 0,
- s->nb_coefs[ch], snr_offset,
- s->bit_alloc.floor, ff_ac3_bap_tab,
- bap[blk][ch]);
- frame_bits += compute_mantissa_size(s, bap[blk][ch], s->nb_coefs[ch]);
- }
- }
- return 8 * s->frame_size - frame_bits;
-}
+ encode_exponents(s);
+ emms_c();
+}
-#define SNR_INC1 4
-/**
- * Perform bit allocation search.
- * Finds the SNR offset value that maximizes quality and fits in the specified
- * frame size. Output is the SNR offset and a set of bit allocation pointers
- * used to quantize the mantissas.
+/*
+ * Count frame bits that are based solely on fixed parameters.
+ * This only has to be run once when the encoder is initialized.
*/
-static int compute_bit_allocation(AC3EncodeContext *s,
- uint8_t bap[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
- uint8_t encoded_exp[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
- uint8_t exp_strategy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS],
- int frame_bits)
+static void count_frame_bits_fixed(AC3EncodeContext *s)
{
- int blk, ch;
- int coarse_snr_offset, fine_snr_offset;
- uint8_t bap1[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS];
- int16_t psd[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS];
- int16_t mask[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS];
static const int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
+ int blk;
+ int frame_bits;
+
+ /* assumptions:
+ * no dynamic range codes
+ * bit allocation parameters do not change between blocks
+ * no delta bit allocation
+ * no skipped data
+ * no auxilliary data
+ * no E-AC-3 metadata
+ */
+
+ /* header */
+ frame_bits = 16; /* sync info */
+ if (s->eac3) {
+ /* bitstream info header */
+ frame_bits += 35;
+ frame_bits += 1 + 1;
+ if (s->num_blocks != 0x6)
+ frame_bits++;
+ frame_bits++;
+ /* audio frame header */
+ if (s->num_blocks == 6)
+ frame_bits += 2;
+ frame_bits += 10;
+ /* exponent strategy */
+ if (s->use_frame_exp_strategy)
+ frame_bits += 5 * s->fbw_channels;
+ else
+ frame_bits += s->num_blocks * 2 * s->fbw_channels;
+ if (s->lfe_on)
+ frame_bits += s->num_blocks;
+ /* converter exponent strategy */
+ if (s->num_blks_code != 0x3)
+ frame_bits++;
+ else
+ frame_bits += s->fbw_channels * 5;
+ /* snr offsets */
+ frame_bits += 10;
+ /* block start info */
+ if (s->num_blocks != 1)
+ frame_bits++;
+ } else {
+ frame_bits += 49;
+ frame_bits += frame_bits_inc[s->channel_mode];
+ }
+
+ /* audio blocks */
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ if (!s->eac3) {
+ /* block switch flags */
+ frame_bits += s->fbw_channels;
+
+ /* dither flags */
+ frame_bits += s->fbw_channels;
+ }
+
+ /* dynamic range */
+ frame_bits++;
+
+ /* spectral extension */
+ if (s->eac3)
+ frame_bits++;
+
+ if (!s->eac3) {
+ /* exponent strategy */
+ frame_bits += 2 * s->fbw_channels;
+ if (s->lfe_on)
+ frame_bits++;
+
+ /* bit allocation params */
+ frame_bits++;
+ if (!blk)
+ frame_bits += 2 + 2 + 2 + 2 + 3;
+ }
+
+ /* converter snr offset */
+ if (s->eac3)
+ frame_bits++;
+
+ if (!s->eac3) {
+ /* delta bit allocation */
+ frame_bits++;
+
+ /* skipped data */
+ frame_bits++;
+ }
+ }
+
+ /* auxiliary data */
+ frame_bits++;
+
+ /* CRC */
+ frame_bits += 1 + 16;
+
+ s->frame_bits_fixed = frame_bits;
+}
+
+
+/*
+ * Initialize bit allocation.
+ * Set default parameter codes and calculate parameter values.
+ */
+static void bit_alloc_init(AC3EncodeContext *s)
+{
+ int ch;
/* init default parameters */
s->slow_decay_code = 2;
s->fast_decay_code = 1;
s->slow_gain_code = 1;
- s->db_per_bit_code = 2;
- s->floor_code = 4;
- for (ch = 0; ch < s->channels; ch++)
+ s->db_per_bit_code = s->eac3 ? 2 : 3;
+ s->floor_code = 7;
+ for (ch = 0; ch <= s->channels; ch++)
s->fast_gain_code[ch] = 4;
+ /* initial snr offset */
+ s->coarse_snr_offset = 40;
+
/* compute real values */
+ /* currently none of these values change during encoding, so we can just
+ set them once at initialization */
s->bit_alloc.slow_decay = ff_ac3_slow_decay_tab[s->slow_decay_code] >> s->bit_alloc.sr_shift;
s->bit_alloc.fast_decay = ff_ac3_fast_decay_tab[s->fast_decay_code] >> s->bit_alloc.sr_shift;
s->bit_alloc.slow_gain = ff_ac3_slow_gain_tab[s->slow_gain_code];
s->bit_alloc.db_per_bit = ff_ac3_db_per_bit_tab[s->db_per_bit_code];
s->bit_alloc.floor = ff_ac3_floor_tab[s->floor_code];
+ s->bit_alloc.cpl_fast_leak = 0;
+ s->bit_alloc.cpl_slow_leak = 0;
+
+ count_frame_bits_fixed(s);
+}
- /* header size */
- frame_bits += 65;
- // if (s->channel_mode == 2)
- // frame_bits += 2;
- frame_bits += frame_bits_inc[s->channel_mode];
+
+/*
+ * Count the bits used to encode the frame, minus exponents and mantissas.
+ * Bits based on fixed parameters have already been counted, so now we just
+ * have to add the bits based on parameters that change during encoding.
+ */
+static void count_frame_bits(AC3EncodeContext *s)
+{
+ AC3EncOptions *opt = &s->options;
+ int blk, ch;
+ int frame_bits = 0;
+
+ /* header */
+ if (s->eac3) {
+ if (opt->eac3_mixing_metadata) {
+ if (s->channel_mode > AC3_CHMODE_STEREO)
+ frame_bits += 2;
+ if (s->has_center)
+ frame_bits += 6;
+ if (s->has_surround)
+ frame_bits += 6;
+ frame_bits += s->lfe_on;
+ frame_bits += 1 + 1 + 2;
+ if (s->channel_mode < AC3_CHMODE_STEREO)
+ frame_bits++;
+ frame_bits++;
+ }
+ if (opt->eac3_info_metadata) {
+ frame_bits += 3 + 1 + 1;
+ if (s->channel_mode == AC3_CHMODE_STEREO)
+ frame_bits += 2 + 2;
+ if (s->channel_mode >= AC3_CHMODE_2F2R)
+ frame_bits += 2;
+ frame_bits++;
+ if (opt->audio_production_info)
+ frame_bits += 5 + 2 + 1;
+ frame_bits++;
+ }
+ /* coupling */
+ if (s->channel_mode > AC3_CHMODE_MONO) {
+ frame_bits++;
+ for (blk = 1; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ frame_bits++;
+ if (block->new_cpl_strategy)
+ frame_bits++;
+ }
+ }
+ /* coupling exponent strategy */
+ if (s->cpl_on) {
+ if (s->use_frame_exp_strategy) {
+ frame_bits += 5 * s->cpl_on;
+ } else {
+ for (blk = 0; blk < s->num_blocks; blk++)
+ frame_bits += 2 * s->blocks[blk].cpl_in_use;
+ }
+ }
+ } else {
+ if (opt->audio_production_info)
+ frame_bits += 7;
+ if (s->bitstream_id == 6) {
+ if (opt->extended_bsi_1)
+ frame_bits += 14;
+ if (opt->extended_bsi_2)
+ frame_bits += 14;
+ }
+ }
/* audio blocks */
- for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
- frame_bits += s->fbw_channels * 2 + 2; /* blksw * c, dithflag * c, dynrnge, cplstre */
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+
+ /* coupling strategy */
+ if (!s->eac3)
+ frame_bits++;
+ if (block->new_cpl_strategy) {
+ if (!s->eac3)
+ frame_bits++;
+ if (block->cpl_in_use) {
+ if (s->eac3)
+ frame_bits++;
+ if (!s->eac3 || s->channel_mode != AC3_CHMODE_STEREO)
+ frame_bits += s->fbw_channels;
+ if (s->channel_mode == AC3_CHMODE_STEREO)
+ frame_bits++;
+ frame_bits += 4 + 4;
+ if (s->eac3)
+ frame_bits++;
+ else
+ frame_bits += s->num_cpl_subbands - 1;
+ }
+ }
+
+ /* coupling coordinates */
+ if (block->cpl_in_use) {
+ for (ch = 1; ch <= s->fbw_channels; ch++) {
+ if (block->channel_in_cpl[ch]) {
+ if (!s->eac3 || block->new_cpl_coords[ch] != 2)
+ frame_bits++;
+ if (block->new_cpl_coords[ch]) {
+ frame_bits += 2;
+ frame_bits += (4 + 4) * s->num_cpl_bands;
+ }
+ }
+ }
+ }
+
+ /* stereo rematrixing */
if (s->channel_mode == AC3_CHMODE_STEREO) {
- frame_bits++; /* rematstr */
- if (!blk)
- frame_bits += 4;
+ if (!s->eac3 || blk > 0)
+ frame_bits++;
+ if (s->blocks[blk].new_rematrixing_strategy)
+ frame_bits += block->num_rematrixing_bands;
}
- frame_bits += 2 * s->fbw_channels; /* chexpstr[2] * c */
- if (s->lfe_on)
- frame_bits++; /* lfeexpstr */
- for (ch = 0; ch < s->fbw_channels; ch++) {
- if (exp_strategy[blk][ch] != EXP_REUSE)
- frame_bits += 6 + 2; /* chbwcod[6], gainrng[2] */
+
+ /* bandwidth codes & gain range */
+ for (ch = 1; ch <= s->fbw_channels; ch++) {
+ if (s->exp_strategy[ch][blk] != EXP_REUSE) {
+ if (!block->channel_in_cpl[ch])
+ frame_bits += 6;
+ frame_bits += 2;
+ }
+ }
+
+ /* coupling exponent strategy */
+ if (!s->eac3 && block->cpl_in_use)
+ frame_bits += 2;
+
+ /* snr offsets and fast gain codes */
+ if (!s->eac3) {
+ frame_bits++;
+ if (block->new_snr_offsets)
+ frame_bits += 6 + (s->channels + block->cpl_in_use) * (4 + 3);
+ }
+
+ /* coupling leak info */
+ if (block->cpl_in_use) {
+ if (!s->eac3 || block->new_cpl_leak != 2)
+ frame_bits++;
+ if (block->new_cpl_leak)
+ frame_bits += 3 + 3;
}
- frame_bits++; /* baie */
- frame_bits++; /* snr */
- frame_bits += 2; /* delta / skip */
}
- frame_bits++; /* cplinu for block 0 */
- /* bit alloc info */
- /* sdcycod[2], fdcycod[2], sgaincod[2], dbpbcod[2], floorcod[3] */
- /* csnroffset[6] */
- /* (fsnoffset[4] + fgaincod[4]) * c */
- frame_bits += 2*4 + 3 + 6 + s->channels * (4 + 3);
- /* auxdatae, crcrsv */
- frame_bits += 2;
+ s->frame_bits = s->frame_bits_fixed + frame_bits;
+}
- /* CRC */
- frame_bits += 16;
- /* calculate psd and masking curve before doing bit allocation */
- bit_alloc_masking(s, encoded_exp, exp_strategy, psd, mask);
+/*
+ * Calculate masking curve based on the final exponents.
+ * Also calculate the power spectral densities to use in future calculations.
+ */
+static void bit_alloc_masking(AC3EncodeContext *s)
+{
+ int blk, ch;
- /* now the big work begins : do the bit allocation. Modify the snr
- offset until we can pack everything in the requested frame size */
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
+ /* We only need psd and mask for calculating bap.
+ Since we currently do not calculate bap when exponent
+ strategy is EXP_REUSE we do not need to calculate psd or mask. */
+ if (s->exp_strategy[ch][blk] != EXP_REUSE) {
+ ff_ac3_bit_alloc_calc_psd(block->exp[ch], s->start_freq[ch],
+ block->end_freq[ch], block->psd[ch],
+ block->band_psd[ch]);
+ ff_ac3_bit_alloc_calc_mask(&s->bit_alloc, block->band_psd[ch],
+ s->start_freq[ch], block->end_freq[ch],
+ ff_ac3_fast_gain_tab[s->fast_gain_code[ch]],
+ ch == s->lfe_channel,
+ DBA_NONE, 0, NULL, NULL, NULL,
+ block->mask[ch]);
+ }
+ }
+ }
+}
- coarse_snr_offset = s->coarse_snr_offset;
- while (coarse_snr_offset >= 0 &&
- bit_alloc(s, mask, psd, bap, frame_bits, coarse_snr_offset, 0) < 0)
- coarse_snr_offset -= SNR_INC1;
- if (coarse_snr_offset < 0) {
- av_log(NULL, AV_LOG_ERROR, "Bit allocation failed. Try increasing the bitrate.\n");
- return -1;
+
+/*
+ * Ensure that bap for each block and channel point to the current bap_buffer.
+ * They may have been switched during the bit allocation search.
+ */
+static void reset_block_bap(AC3EncodeContext *s)
+{
+ int blk, ch;
+ uint8_t *ref_bap;
+
+ if (s->ref_bap[0][0] == s->bap_buffer && s->ref_bap_set)
+ return;
+
+ ref_bap = s->bap_buffer;
+ for (ch = 0; ch <= s->channels; ch++) {
+ for (blk = 0; blk < s->num_blocks; blk++)
+ s->ref_bap[ch][blk] = ref_bap + AC3_MAX_COEFS * s->exp_ref_block[ch][blk];
+ ref_bap += AC3_MAX_COEFS * s->num_blocks;
+ }
+ s->ref_bap_set = 1;
+}
+
+
+/**
+ * Initialize mantissa counts.
+ * These are set so that they are padded to the next whole group size when bits
+ * are counted in compute_mantissa_size.
+ *
+ * @param[in,out] mant_cnt running counts for each bap value for each block
+ */
+static void count_mantissa_bits_init(uint16_t mant_cnt[AC3_MAX_BLOCKS][16])
+{
+ int blk;
+
+ for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
+ memset(mant_cnt[blk], 0, sizeof(mant_cnt[blk]));
+ mant_cnt[blk][1] = mant_cnt[blk][2] = 2;
+ mant_cnt[blk][4] = 1;
+ }
+}
+
+
+/**
+ * Update mantissa bit counts for all blocks in 1 channel in a given bandwidth
+ * range.
+ *
+ * @param s AC-3 encoder private context
+ * @param ch channel index
+ * @param[in,out] mant_cnt running counts for each bap value for each block
+ * @param start starting coefficient bin
+ * @param end ending coefficient bin
+ */
+static void count_mantissa_bits_update_ch(AC3EncodeContext *s, int ch,
+ uint16_t mant_cnt[AC3_MAX_BLOCKS][16],
+ int start, int end)
+{
+ int blk;
+
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ if (ch == CPL_CH && !block->cpl_in_use)
+ continue;
+ s->ac3dsp.update_bap_counts(mant_cnt[blk],
+ s->ref_bap[ch][blk] + start,
+ FFMIN(end, block->end_freq[ch]) - start);
}
- while (coarse_snr_offset + SNR_INC1 <= 63 &&
- bit_alloc(s, mask, psd, bap1, frame_bits,
- coarse_snr_offset + SNR_INC1, 0) >= 0) {
- coarse_snr_offset += SNR_INC1;
- memcpy(bap, bap1, sizeof(bap1));
+}
+
+
+/*
+ * Count the number of mantissa bits in the frame based on the bap values.
+ */
+static int count_mantissa_bits(AC3EncodeContext *s)
+{
+ int ch, max_end_freq;
+ LOCAL_ALIGNED_16(uint16_t, mant_cnt, [AC3_MAX_BLOCKS], [16]);
+
+ count_mantissa_bits_init(mant_cnt);
+
+ max_end_freq = s->bandwidth_code * 3 + 73;
+ for (ch = !s->cpl_enabled; ch <= s->channels; ch++)
+ count_mantissa_bits_update_ch(s, ch, mant_cnt, s->start_freq[ch],
+ max_end_freq);
+
+ return s->ac3dsp.compute_mantissa_size(mant_cnt);
+}
+
+
+/**
+ * Run the bit allocation with a given SNR offset.
+ * This calculates the bit allocation pointers that will be used to determine
+ * the quantization of each mantissa.
+ *
+ * @param s AC-3 encoder private context
+ * @param snr_offset SNR offset, 0 to 1023
+ * @return the number of bits needed for mantissas if the given SNR offset is
+ * is used.
+ */
+static int bit_alloc(AC3EncodeContext *s, int snr_offset)
+{
+ int blk, ch;
+
+ snr_offset = (snr_offset - 240) << 2;
+
+ reset_block_bap(s);
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+
+ for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
+ /* Currently the only bit allocation parameters which vary across
+ blocks within a frame are the exponent values. We can take
+ advantage of that by reusing the bit allocation pointers
+ whenever we reuse exponents. */
+ if (s->exp_strategy[ch][blk] != EXP_REUSE) {
+ s->ac3dsp.bit_alloc_calc_bap(block->mask[ch], block->psd[ch],
+ s->start_freq[ch], block->end_freq[ch],
+ snr_offset, s->bit_alloc.floor,
+ ff_ac3_bap_tab, s->ref_bap[ch][blk]);
+ }
+ }
}
- while (coarse_snr_offset + 1 <= 63 &&
- bit_alloc(s, mask, psd, bap1, frame_bits, coarse_snr_offset + 1, 0) >= 0) {
- coarse_snr_offset++;
- memcpy(bap, bap1, sizeof(bap1));
+ return count_mantissa_bits(s);
+}
+
+
+/*
+ * Constant bitrate bit allocation search.
+ * Find the largest SNR offset that will allow data to fit in the frame.
+ */
+static int cbr_bit_allocation(AC3EncodeContext *s)
+{
+ int ch;
+ int bits_left;
+ int snr_offset, snr_incr;
+
+ bits_left = 8 * s->frame_size - (s->frame_bits + s->exponent_bits);
+ if (bits_left < 0)
+ return AVERROR(EINVAL);
+
+ snr_offset = s->coarse_snr_offset << 4;
+
+ /* if previous frame SNR offset was 1023, check if current frame can also
+ use SNR offset of 1023. if so, skip the search. */
+ if ((snr_offset | s->fine_snr_offset[1]) == 1023) {
+ if (bit_alloc(s, 1023) <= bits_left)
+ return 0;
}
- fine_snr_offset = 0;
- while (fine_snr_offset + SNR_INC1 <= 15 &&
- bit_alloc(s, mask, psd, bap1, frame_bits,
- coarse_snr_offset, fine_snr_offset + SNR_INC1) >= 0) {
- fine_snr_offset += SNR_INC1;
- memcpy(bap, bap1, sizeof(bap1));
+ while (snr_offset >= 0 &&
+ bit_alloc(s, snr_offset) > bits_left) {
+ snr_offset -= 64;
}
- while (fine_snr_offset + 1 <= 15 &&
- bit_alloc(s, mask, psd, bap1, frame_bits,
- coarse_snr_offset, fine_snr_offset + 1) >= 0) {
- fine_snr_offset++;
- memcpy(bap, bap1, sizeof(bap1));
+ if (snr_offset < 0)
+ return AVERROR(EINVAL);
+
+ FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
+ for (snr_incr = 64; snr_incr > 0; snr_incr >>= 2) {
+ while (snr_offset + snr_incr <= 1023 &&
+ bit_alloc(s, snr_offset + snr_incr) <= bits_left) {
+ snr_offset += snr_incr;
+ FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
+ }
}
+ FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
+ reset_block_bap(s);
- s->coarse_snr_offset = coarse_snr_offset;
- for (ch = 0; ch < s->channels; ch++)
- s->fine_snr_offset[ch] = fine_snr_offset;
+ s->coarse_snr_offset = snr_offset >> 4;
+ for (ch = !s->cpl_on; ch <= s->channels; ch++)
+ s->fine_snr_offset[ch] = snr_offset & 0xF;
return 0;
}
-/**
- * Write the AC-3 frame header to the output bitstream.
+/*
+ * Perform bit allocation search.
+ * Finds the SNR offset value that maximizes quality and fits in the specified
+ * frame size. Output is the SNR offset and a set of bit allocation pointers
+ * used to quantize the mantissas.
*/
-static void output_frame_header(AC3EncodeContext *s, unsigned char *frame)
+int ff_ac3_compute_bit_allocation(AC3EncodeContext *s)
{
- init_put_bits(&s->pb, frame, AC3_MAX_CODED_FRAME_SIZE);
+ count_frame_bits(s);
- put_bits(&s->pb, 16, 0x0b77); /* frame header */
- put_bits(&s->pb, 16, 0); /* crc1: will be filled later */
- put_bits(&s->pb, 2, s->bit_alloc.sr_code);
- put_bits(&s->pb, 6, s->frame_size_code + (s->frame_size - s->frame_size_min) / 2);
- put_bits(&s->pb, 5, s->bitstream_id);
- put_bits(&s->pb, 3, s->bitstream_mode);
- put_bits(&s->pb, 3, s->channel_mode);
- if ((s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO)
- put_bits(&s->pb, 2, 1); /* XXX -4.5 dB */
- if (s->channel_mode & 0x04)
- put_bits(&s->pb, 2, 1); /* XXX -6 dB */
- if (s->channel_mode == AC3_CHMODE_STEREO)
- put_bits(&s->pb, 2, 0); /* surround not indicated */
- put_bits(&s->pb, 1, s->lfe_on); /* LFE */
- put_bits(&s->pb, 5, 31); /* dialog norm: -31 db */
- put_bits(&s->pb, 1, 0); /* no compression control word */
- put_bits(&s->pb, 1, 0); /* no lang code */
- put_bits(&s->pb, 1, 0); /* no audio production info */
- put_bits(&s->pb, 1, 0); /* no copyright */
- put_bits(&s->pb, 1, 1); /* original bitstream */
- put_bits(&s->pb, 1, 0); /* no time code 1 */
- put_bits(&s->pb, 1, 0); /* no time code 2 */
- put_bits(&s->pb, 1, 0); /* no additional bit stream info */
+ s->exponent_bits = count_exponent_bits(s);
+
+ bit_alloc_masking(s);
+
+ return cbr_bit_allocation(s);
}
/**
* Symmetric quantization on 'levels' levels.
+ *
+ * @param c unquantized coefficient
+ * @param e exponent
+ * @param levels number of quantization levels
+ * @return quantized coefficient
*/
static inline int sym_quant(int c, int e, int levels)
{
- int v;
-
- if (c >= 0) {
- v = (levels * (c << e)) >> 24;
- v = (v + 1) >> 1;
- v = (levels >> 1) + v;
- } else {
- v = (levels * ((-c) << e)) >> 24;
- v = (v + 1) >> 1;
- v = (levels >> 1) - v;
- }
- assert (v >= 0 && v < levels);
+ int v = (((levels * c) >> (24 - e)) + levels) >> 1;
+ av_assert2(v >= 0 && v < levels);
return v;
}
/**
* Asymmetric quantization on 2^qbits levels.
+ *
+ * @param c unquantized coefficient
+ * @param e exponent
+ * @param qbits number of quantization bits
+ * @return quantized coefficient
*/
static inline int asym_quant(int c, int e, int qbits)
{
- int lshift, m, v;
+ int m;
- lshift = e + qbits - 24;
- if (lshift >= 0)
- v = c << lshift;
- else
- v = c >> (-lshift);
- /* rounding */
- v = (v + 1) >> 1;
+ c = (((c << e) >> (24 - qbits)) + 1) >> 1;
m = (1 << (qbits-1));
- if (v >= m)
- v = m - 1;
- assert(v >= -m);
- return v & ((1 << qbits)-1);
+ if (c >= m)
+ c = m - 1;
+ av_assert2(c >= -m);
+ return c;
+}
+
+
+/**
+ * Quantize a set of mantissas for a single channel in a single block.
+ *
+ * @param s Mantissa count context
+ * @param fixed_coef unquantized fixed-point coefficients
+ * @param exp exponents
+ * @param bap bit allocation pointer indices
+ * @param[out] qmant quantized coefficients
+ * @param start_freq starting coefficient bin
+ * @param end_freq ending coefficient bin
+ */
+static void quantize_mantissas_blk_ch(AC3Mant *s, int32_t *fixed_coef,
+ uint8_t *exp, uint8_t *bap,
+ int16_t *qmant, int start_freq,
+ int end_freq)
+{
+ int i;
+
+ for (i = start_freq; i < end_freq; i++) {
+ int v;
+ int c = fixed_coef[i];
+ int e = exp[i];
+ int b = bap[i];
+ switch (b) {
+ case 0:
+ v = 0;
+ break;
+ case 1:
+ v = sym_quant(c, e, 3);
+ switch (s->mant1_cnt) {
+ case 0:
+ s->qmant1_ptr = &qmant[i];
+ v = 9 * v;
+ s->mant1_cnt = 1;
+ break;
+ case 1:
+ *s->qmant1_ptr += 3 * v;
+ s->mant1_cnt = 2;
+ v = 128;
+ break;
+ default:
+ *s->qmant1_ptr += v;
+ s->mant1_cnt = 0;
+ v = 128;
+ break;
+ }
+ break;
+ case 2:
+ v = sym_quant(c, e, 5);
+ switch (s->mant2_cnt) {
+ case 0:
+ s->qmant2_ptr = &qmant[i];
+ v = 25 * v;
+ s->mant2_cnt = 1;
+ break;
+ case 1:
+ *s->qmant2_ptr += 5 * v;
+ s->mant2_cnt = 2;
+ v = 128;
+ break;
+ default:
+ *s->qmant2_ptr += v;
+ s->mant2_cnt = 0;
+ v = 128;
+ break;
+ }
+ break;
+ case 3:
+ v = sym_quant(c, e, 7);
+ break;
+ case 4:
+ v = sym_quant(c, e, 11);
+ switch (s->mant4_cnt) {
+ case 0:
+ s->qmant4_ptr = &qmant[i];
+ v = 11 * v;
+ s->mant4_cnt = 1;
+ break;
+ default:
+ *s->qmant4_ptr += v;
+ s->mant4_cnt = 0;
+ v = 128;
+ break;
+ }
+ break;
+ case 5:
+ v = sym_quant(c, e, 15);
+ break;
+ case 14:
+ v = asym_quant(c, e, 14);
+ break;
+ case 15:
+ v = asym_quant(c, e, 16);
+ break;
+ default:
+ v = asym_quant(c, e, b - 1);
+ break;
+ }
+ qmant[i] = v;
+ }
+}
+
+
+/**
+ * Quantize mantissas using coefficients, exponents, and bit allocation pointers.
+ *
+ * @param s AC-3 encoder private context
+ */
+void ff_ac3_quantize_mantissas(AC3EncodeContext *s)
+{
+ int blk, ch, ch0=0, got_cpl;
+
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ AC3Mant m = { 0 };
+
+ got_cpl = !block->cpl_in_use;
+ for (ch = 1; ch <= s->channels; ch++) {
+ if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {
+ ch0 = ch - 1;
+ ch = CPL_CH;
+ got_cpl = 1;
+ }
+ quantize_mantissas_blk_ch(&m, block->fixed_coef[ch],
+ s->blocks[s->exp_ref_block[ch][blk]].exp[ch],
+ s->ref_bap[ch][blk], block->qmant[ch],
+ s->start_freq[ch], block->end_freq[ch]);
+ if (ch == CPL_CH)
+ ch = ch0;
+ }
+ }
+}
+
+
+/*
+ * Write the AC-3 frame header to the output bitstream.
+ */
+static void ac3_output_frame_header(AC3EncodeContext *s)
+{
+ AC3EncOptions *opt = &s->options;
+
+ put_bits(&s->pb, 16, 0x0b77); /* frame header */
+ put_bits(&s->pb, 16, 0); /* crc1: will be filled later */
+ put_bits(&s->pb, 2, s->bit_alloc.sr_code);
+ put_bits(&s->pb, 6, s->frame_size_code + (s->frame_size - s->frame_size_min) / 2);
+ put_bits(&s->pb, 5, s->bitstream_id);
+ put_bits(&s->pb, 3, s->bitstream_mode);
+ put_bits(&s->pb, 3, s->channel_mode);
+ if ((s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO)
+ put_bits(&s->pb, 2, s->center_mix_level);
+ if (s->channel_mode & 0x04)
+ put_bits(&s->pb, 2, s->surround_mix_level);
+ if (s->channel_mode == AC3_CHMODE_STEREO)
+ put_bits(&s->pb, 2, opt->dolby_surround_mode);
+ put_bits(&s->pb, 1, s->lfe_on); /* LFE */
+ put_bits(&s->pb, 5, -opt->dialogue_level);
+ put_bits(&s->pb, 1, 0); /* no compression control word */
+ put_bits(&s->pb, 1, 0); /* no lang code */
+ put_bits(&s->pb, 1, opt->audio_production_info);
+ if (opt->audio_production_info) {
+ put_bits(&s->pb, 5, opt->mixing_level - 80);
+ put_bits(&s->pb, 2, opt->room_type);
+ }
+ put_bits(&s->pb, 1, opt->copyright);
+ put_bits(&s->pb, 1, opt->original);
+ if (s->bitstream_id == 6) {
+ /* alternate bit stream syntax */
+ put_bits(&s->pb, 1, opt->extended_bsi_1);
+ if (opt->extended_bsi_1) {
+ put_bits(&s->pb, 2, opt->preferred_stereo_downmix);
+ put_bits(&s->pb, 3, s->ltrt_center_mix_level);
+ put_bits(&s->pb, 3, s->ltrt_surround_mix_level);
+ put_bits(&s->pb, 3, s->loro_center_mix_level);
+ put_bits(&s->pb, 3, s->loro_surround_mix_level);
+ }
+ put_bits(&s->pb, 1, opt->extended_bsi_2);
+ if (opt->extended_bsi_2) {
+ put_bits(&s->pb, 2, opt->dolby_surround_ex_mode);
+ put_bits(&s->pb, 2, opt->dolby_headphone_mode);
+ put_bits(&s->pb, 1, opt->ad_converter_type);
+ put_bits(&s->pb, 9, 0); /* xbsi2 and encinfo : reserved */
+ }
+ } else {
+ put_bits(&s->pb, 1, 0); /* no time code 1 */
+ put_bits(&s->pb, 1, 0); /* no time code 2 */
+ }
+ put_bits(&s->pb, 1, 0); /* no additional bit stream info */
}
-/**
+/*
* Write one audio block to the output bitstream.
*/
-static void output_audio_block(AC3EncodeContext *s,
- uint8_t exp_strategy[AC3_MAX_CHANNELS],
- uint8_t encoded_exp[AC3_MAX_CHANNELS][AC3_MAX_COEFS],
- uint8_t bap[AC3_MAX_CHANNELS][AC3_MAX_COEFS],
- int32_t mdct_coef[AC3_MAX_CHANNELS][AC3_MAX_COEFS],
- int8_t exp_shift[AC3_MAX_CHANNELS],
- int block_num)
+static void output_audio_block(AC3EncodeContext *s, int blk)
{
- int ch, nb_groups, group_size, i, baie, rbnd;
- uint8_t *p;
- uint16_t qmant[AC3_MAX_CHANNELS][AC3_MAX_COEFS];
- int exp0, exp1;
- int mant1_cnt, mant2_cnt, mant4_cnt;
- uint16_t *qmant1_ptr, *qmant2_ptr, *qmant4_ptr;
- int delta0, delta1, delta2;
+ int ch, i, baie, bnd, got_cpl;
+ int av_uninit(ch0);
+ AC3Block *block = &s->blocks[blk];
- for (ch = 0; ch < s->fbw_channels; ch++)
- put_bits(&s->pb, 1, 0); /* no block switching */
- for (ch = 0; ch < s->fbw_channels; ch++)
- put_bits(&s->pb, 1, 1); /* no dither */
- put_bits(&s->pb, 1, 0); /* no dynamic range */
- if (!block_num) {
- put_bits(&s->pb, 1, 1); /* coupling strategy present */
- put_bits(&s->pb, 1, 0); /* no coupling strategy */
- } else {
- put_bits(&s->pb, 1, 0); /* no new coupling strategy */
+ /* block switching */
+ if (!s->eac3) {
+ for (ch = 0; ch < s->fbw_channels; ch++)
+ put_bits(&s->pb, 1, 0);
}
- if (s->channel_mode == AC3_CHMODE_STEREO) {
- if (!block_num) {
- /* first block must define rematrixing (rematstr) */
+ /* dither flags */
+ if (!s->eac3) {
+ for (ch = 0; ch < s->fbw_channels; ch++)
put_bits(&s->pb, 1, 1);
+ }
- /* dummy rematrixing rematflg(1:4)=0 */
- for (rbnd = 0; rbnd < 4; rbnd++)
- put_bits(&s->pb, 1, 0);
- } else {
- /* no matrixing (but should be used in the future) */
- put_bits(&s->pb, 1, 0);
+ /* dynamic range codes */
+ put_bits(&s->pb, 1, 0);
+
+ /* spectral extension */
+ if (s->eac3)
+ put_bits(&s->pb, 1, 0);
+
+ /* channel coupling */
+ if (!s->eac3)
+ put_bits(&s->pb, 1, block->new_cpl_strategy);
+ if (block->new_cpl_strategy) {
+ if (!s->eac3)
+ put_bits(&s->pb, 1, block->cpl_in_use);
+ if (block->cpl_in_use) {
+ int start_sub, end_sub;
+ if (s->eac3)
+ put_bits(&s->pb, 1, 0); /* enhanced coupling */
+ if (!s->eac3 || s->channel_mode != AC3_CHMODE_STEREO) {
+ for (ch = 1; ch <= s->fbw_channels; ch++)
+ put_bits(&s->pb, 1, block->channel_in_cpl[ch]);
+ }
+ if (s->channel_mode == AC3_CHMODE_STEREO)
+ put_bits(&s->pb, 1, 0); /* phase flags in use */
+ start_sub = (s->start_freq[CPL_CH] - 37) / 12;
+ end_sub = (s->cpl_end_freq - 37) / 12;
+ put_bits(&s->pb, 4, start_sub);
+ put_bits(&s->pb, 4, end_sub - 3);
+ /* coupling band structure */
+ if (s->eac3) {
+ put_bits(&s->pb, 1, 0); /* use default */
+ } else {
+ for (bnd = start_sub+1; bnd < end_sub; bnd++)
+ put_bits(&s->pb, 1, ff_eac3_default_cpl_band_struct[bnd]);
+ }
}
}
- /* exponent strategy */
- for (ch = 0; ch < s->fbw_channels; ch++)
- put_bits(&s->pb, 2, exp_strategy[ch]);
+ /* coupling coordinates */
+ if (block->cpl_in_use) {
+ for (ch = 1; ch <= s->fbw_channels; ch++) {
+ if (block->channel_in_cpl[ch]) {
+ if (!s->eac3 || block->new_cpl_coords[ch] != 2)
+ put_bits(&s->pb, 1, block->new_cpl_coords[ch]);
+ if (block->new_cpl_coords[ch]) {
+ put_bits(&s->pb, 2, block->cpl_master_exp[ch]);
+ for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
+ put_bits(&s->pb, 4, block->cpl_coord_exp [ch][bnd]);
+ put_bits(&s->pb, 4, block->cpl_coord_mant[ch][bnd]);
+ }
+ }
+ }
+ }
+ }
- if (s->lfe_on)
- put_bits(&s->pb, 1, exp_strategy[s->lfe_channel]);
+ /* stereo rematrixing */
+ if (s->channel_mode == AC3_CHMODE_STEREO) {
+ if (!s->eac3 || blk > 0)
+ put_bits(&s->pb, 1, block->new_rematrixing_strategy);
+ if (block->new_rematrixing_strategy) {
+ /* rematrixing flags */
+ for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++)
+ put_bits(&s->pb, 1, block->rematrixing_flags[bnd]);
+ }
+ }
+
+ /* exponent strategy */
+ if (!s->eac3) {
+ for (ch = !block->cpl_in_use; ch <= s->fbw_channels; ch++)
+ put_bits(&s->pb, 2, s->exp_strategy[ch][blk]);
+ if (s->lfe_on)
+ put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]);
+ }
/* bandwidth */
- for (ch = 0; ch < s->fbw_channels; ch++) {
- if (exp_strategy[ch] != EXP_REUSE)
- put_bits(&s->pb, 6, s->bandwidth_code[ch]);
+ for (ch = 1; ch <= s->fbw_channels; ch++) {
+ if (s->exp_strategy[ch][blk] != EXP_REUSE && !block->channel_in_cpl[ch])
+ put_bits(&s->pb, 6, s->bandwidth_code);
}
/* exponents */
- for (ch = 0; ch < s->channels; ch++) {
- if (exp_strategy[ch] == EXP_REUSE)
- continue;
- group_size = exp_strategy[ch] + (exp_strategy[ch] == EXP_D45);
- nb_groups = (s->nb_coefs[ch] + (group_size * 3) - 4) / (3 * group_size);
- p = encoded_exp[ch];
-
- /* first exponent */
- exp1 = *p++;
- put_bits(&s->pb, 4, exp1);
+ for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
+ int nb_groups;
+ int cpl = (ch == CPL_CH);
- /* next ones are delta encoded */
- for (i = 0; i < nb_groups; i++) {
- /* merge three delta in one code */
- exp0 = exp1;
- exp1 = p[0];
- p += group_size;
- delta0 = exp1 - exp0 + 2;
-
- exp0 = exp1;
- exp1 = p[0];
- p += group_size;
- delta1 = exp1 - exp0 + 2;
+ if (s->exp_strategy[ch][blk] == EXP_REUSE)
+ continue;
- exp0 = exp1;
- exp1 = p[0];
- p += group_size;
- delta2 = exp1 - exp0 + 2;
+ /* DC exponent */
+ put_bits(&s->pb, 4, block->grouped_exp[ch][0] >> cpl);
- put_bits(&s->pb, 7, ((delta0 * 5 + delta1) * 5) + delta2);
- }
+ /* exponent groups */
+ nb_groups = exponent_group_tab[cpl][s->exp_strategy[ch][blk]-1][block->end_freq[ch]-s->start_freq[ch]];
+ for (i = 1; i <= nb_groups; i++)
+ put_bits(&s->pb, 7, block->grouped_exp[ch][i]);
- if (ch != s->lfe_channel)
- put_bits(&s->pb, 2, 0); /* no gain range info */
+ /* gain range info */
+ if (ch != s->lfe_channel && !cpl)
+ put_bits(&s->pb, 2, 0);
}
/* bit allocation info */
- baie = (block_num == 0);
- put_bits(&s->pb, 1, baie);
- if (baie) {
- put_bits(&s->pb, 2, s->slow_decay_code);
- put_bits(&s->pb, 2, s->fast_decay_code);
- put_bits(&s->pb, 2, s->slow_gain_code);
- put_bits(&s->pb, 2, s->db_per_bit_code);
- put_bits(&s->pb, 3, s->floor_code);
+ if (!s->eac3) {
+ baie = (blk == 0);
+ put_bits(&s->pb, 1, baie);
+ if (baie) {
+ put_bits(&s->pb, 2, s->slow_decay_code);
+ put_bits(&s->pb, 2, s->fast_decay_code);
+ put_bits(&s->pb, 2, s->slow_gain_code);
+ put_bits(&s->pb, 2, s->db_per_bit_code);
+ put_bits(&s->pb, 3, s->floor_code);
+ }
}
/* snr offset */
- put_bits(&s->pb, 1, baie);
- if (baie) {
- put_bits(&s->pb, 6, s->coarse_snr_offset);
- for (ch = 0; ch < s->channels; ch++) {
- put_bits(&s->pb, 4, s->fine_snr_offset[ch]);
- put_bits(&s->pb, 3, s->fast_gain_code[ch]);
+ if (!s->eac3) {
+ put_bits(&s->pb, 1, block->new_snr_offsets);
+ if (block->new_snr_offsets) {
+ put_bits(&s->pb, 6, s->coarse_snr_offset);
+ for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
+ put_bits(&s->pb, 4, s->fine_snr_offset[ch]);
+ put_bits(&s->pb, 3, s->fast_gain_code[ch]);
+ }
}
+ } else {
+ put_bits(&s->pb, 1, 0); /* no converter snr offset */
}
- put_bits(&s->pb, 1, 0); /* no delta bit allocation */
- put_bits(&s->pb, 1, 0); /* no data to skip */
-
- /* mantissa encoding : we use two passes to handle the grouping. A
- one pass method may be faster, but it would necessitate to
- modify the output stream. */
-
- /* first pass: quantize */
- mant1_cnt = mant2_cnt = mant4_cnt = 0;
- qmant1_ptr = qmant2_ptr = qmant4_ptr = NULL;
-
- for (ch = 0; ch < s->channels; ch++) {
- int b, c, e, v;
-
- for (i = 0; i < s->nb_coefs[ch]; i++) {
- c = mdct_coef[ch][i];
- e = encoded_exp[ch][i] - exp_shift[ch];
- b = bap[ch][i];
- switch (b) {
- case 0:
- v = 0;
- break;
- case 1:
- v = sym_quant(c, e, 3);
- switch (mant1_cnt) {
- case 0:
- qmant1_ptr = &qmant[ch][i];
- v = 9 * v;
- mant1_cnt = 1;
- break;
- case 1:
- *qmant1_ptr += 3 * v;
- mant1_cnt = 2;
- v = 128;
- break;
- default:
- *qmant1_ptr += v;
- mant1_cnt = 0;
- v = 128;
- break;
- }
- break;
- case 2:
- v = sym_quant(c, e, 5);
- switch (mant2_cnt) {
- case 0:
- qmant2_ptr = &qmant[ch][i];
- v = 25 * v;
- mant2_cnt = 1;
- break;
- case 1:
- *qmant2_ptr += 5 * v;
- mant2_cnt = 2;
- v = 128;
- break;
- default:
- *qmant2_ptr += v;
- mant2_cnt = 0;
- v = 128;
- break;
- }
- break;
- case 3:
- v = sym_quant(c, e, 7);
- break;
- case 4:
- v = sym_quant(c, e, 11);
- switch (mant4_cnt) {
- case 0:
- qmant4_ptr = &qmant[ch][i];
- v = 11 * v;
- mant4_cnt = 1;
- break;
- default:
- *qmant4_ptr += v;
- mant4_cnt = 0;
- v = 128;
- break;
- }
- break;
- case 5:
- v = sym_quant(c, e, 15);
- break;
- case 14:
- v = asym_quant(c, e, 14);
- break;
- case 15:
- v = asym_quant(c, e, 16);
- break;
- default:
- v = asym_quant(c, e, b - 1);
- break;
- }
- qmant[ch][i] = v;
+ /* coupling leak */
+ if (block->cpl_in_use) {
+ if (!s->eac3 || block->new_cpl_leak != 2)
+ put_bits(&s->pb, 1, block->new_cpl_leak);
+ if (block->new_cpl_leak) {
+ put_bits(&s->pb, 3, s->bit_alloc.cpl_fast_leak);
+ put_bits(&s->pb, 3, s->bit_alloc.cpl_slow_leak);
}
}
- /* second pass : output the values */
- for (ch = 0; ch < s->channels; ch++) {
+ if (!s->eac3) {
+ put_bits(&s->pb, 1, 0); /* no delta bit allocation */
+ put_bits(&s->pb, 1, 0); /* no data to skip */
+ }
+
+ /* mantissas */
+ got_cpl = !block->cpl_in_use;
+ for (ch = 1; ch <= s->channels; ch++) {
int b, q;
- for (i = 0; i < s->nb_coefs[ch]; i++) {
- q = qmant[ch][i];
- b = bap[ch][i];
+ if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {
+ ch0 = ch - 1;
+ ch = CPL_CH;
+ got_cpl = 1;
+ }
+ for (i = s->start_freq[ch]; i < block->end_freq[ch]; i++) {
+ q = block->qmant[ch][i];
+ b = s->ref_bap[ch][blk][i];
switch (b) {
- case 0: break;
- case 1: if (q != 128) put_bits(&s->pb, 5, q); break;
- case 2: if (q != 128) put_bits(&s->pb, 7, q); break;
- case 3: put_bits(&s->pb, 3, q); break;
- case 4: if (q != 128) put_bits(&s->pb, 7, q); break;
- case 14: put_bits(&s->pb, 14, q); break;
- case 15: put_bits(&s->pb, 16, q); break;
- default: put_bits(&s->pb, b-1, q); break;
+ case 0: break;
+ case 1: if (q != 128) put_bits (&s->pb, 5, q); break;
+ case 2: if (q != 128) put_bits (&s->pb, 7, q); break;
+ case 3: put_sbits(&s->pb, 3, q); break;
+ case 4: if (q != 128) put_bits (&s->pb, 7, q); break;
+ case 14: put_sbits(&s->pb, 14, q); break;
+ case 15: put_sbits(&s->pb, 16, q); break;
+ default: put_sbits(&s->pb, b-1, q); break;
}
}
+ if (ch == CPL_CH)
+ ch = ch0;
}
}
}
-/**
+/*
* Fill the end of the frame with 0's and compute the two CRCs.
*/
static void output_frame_end(AC3EncodeContext *s)
{
- int frame_size, frame_size_58, pad_bytes, crc1, crc2, crc_inv;
+ const AVCRC *crc_ctx = av_crc_get_table(AV_CRC_16_ANSI);
+ int frame_size_58, pad_bytes, crc1, crc2_partial, crc2, crc_inv;
uint8_t *frame;
- frame_size = s->frame_size; /* frame size in words */
- /* align to 8 bits */
+ frame_size_58 = ((s->frame_size >> 2) + (s->frame_size >> 4)) << 1;
+
+ /* pad the remainder of the frame with zeros */
+ av_assert2(s->frame_size * 8 - put_bits_count(&s->pb) >= 18);
flush_put_bits(&s->pb);
- /* add zero bytes to reach the frame size */
frame = s->pb.buf;
pad_bytes = s->frame_size - (put_bits_ptr(&s->pb) - frame) - 2;
- assert(pad_bytes >= 0);
+ av_assert2(pad_bytes >= 0);
if (pad_bytes > 0)
memset(put_bits_ptr(&s->pb), 0, pad_bytes);
- /* Now we must compute both crcs : this is not so easy for crc1
- because it is at the beginning of the data... */
- frame_size_58 = ((frame_size >> 2) + (frame_size >> 4)) << 1;
-
- crc1 = av_bswap16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0,
- frame + 4, frame_size_58 - 4));
-
- /* XXX: could precompute crc_inv */
- crc_inv = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
+ if (s->eac3) {
+ /* compute crc2 */
+ crc2_partial = av_crc(crc_ctx, 0, frame + 2, s->frame_size - 5);
+ } else {
+ /* compute crc1 */
+ /* this is not so easy because it is at the beginning of the data... */
+ crc1 = av_bswap16(av_crc(crc_ctx, 0, frame + 4, frame_size_58 - 4));
+ crc_inv = s->crc_inv[s->frame_size > s->frame_size_min];
crc1 = mul_poly(crc_inv, crc1, CRC16_POLY);
AV_WB16(frame + 2, crc1);
- crc2 = av_bswap16(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0,
- frame + frame_size_58,
- frame_size - frame_size_58 - 2));
- AV_WB16(frame + frame_size - 2, crc2);
+ /* compute crc2 */
+ crc2_partial = av_crc(crc_ctx, 0, frame + frame_size_58,
+ s->frame_size - frame_size_58 - 3);
+ }
+ crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
+ /* ensure crc2 does not match sync word by flipping crcrsv bit if needed */
+ if (crc2 == 0x770B) {
+ frame[s->frame_size - 3] ^= 0x1;
+ crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
+ }
+ crc2 = av_bswap16(crc2);
+ AV_WB16(frame + s->frame_size - 2, crc2);
}
/**
- * Encode a single AC-3 frame.
+ * Write the frame to the output bitstream.
+ *
+ * @param s AC-3 encoder private context
+ * @param frame output data buffer
*/
-static int ac3_encode_frame(AVCodecContext *avctx,
- unsigned char *frame, int buf_size, void *data)
+void ff_ac3_output_frame(AC3EncodeContext *s, unsigned char *frame)
{
- AC3EncodeContext *s = avctx->priv_data;
- const int16_t *samples = data;
- int v;
- int blk, blk1, blk2, ch, i;
- int16_t input_samples[AC3_WINDOW_SIZE];
- int32_t mdct_coef[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS];
- uint8_t exp[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS];
- uint8_t exp_strategy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS];
- uint8_t encoded_exp[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS];
- uint8_t bap[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS];
- int8_t exp_shift[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS];
- int frame_bits;
+ int blk;
- frame_bits = 0;
- for (ch = 0; ch < s->channels; ch++) {
- int ich = s->channel_map[ch];
- /* fixed mdct to the six sub blocks & exponent computation */
- for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
- const int16_t *sptr;
- int sinc;
-
- /* compute input samples */
- memcpy(input_samples, s->last_samples[ich], AC3_BLOCK_SIZE * sizeof(int16_t));
- sinc = s->channels;
- sptr = samples + (sinc * AC3_BLOCK_SIZE * blk) + ich;
- for (i = 0; i < AC3_BLOCK_SIZE; i++) {
- v = *sptr;
- input_samples[i + AC3_BLOCK_SIZE] = v;
- s->last_samples[ich][i] = v;
- sptr += sinc;
- }
+ init_put_bits(&s->pb, frame, AC3_MAX_CODED_FRAME_SIZE);
+
+ s->output_frame_header(s);
+
+ for (blk = 0; blk < s->num_blocks; blk++)
+ output_audio_block(s, blk);
+
+ output_frame_end(s);
+}
- /* apply the MDCT window */
- for (i = 0; i < AC3_BLOCK_SIZE; i++) {
- input_samples[i] = MUL16(input_samples[i],
- ff_ac3_window[i]) >> 15;
- input_samples[AC3_WINDOW_SIZE-i-1] = MUL16(input_samples[AC3_WINDOW_SIZE-i-1],
- ff_ac3_window[i]) >> 15;
+
+static void dprint_options(AC3EncodeContext *s)
+{
+#ifdef DEBUG
+ AVCodecContext *avctx = s->avctx;
+ AC3EncOptions *opt = &s->options;
+ char strbuf[32];
+
+ switch (s->bitstream_id) {
+ case 6: av_strlcpy(strbuf, "AC-3 (alt syntax)", 32); break;
+ case 8: av_strlcpy(strbuf, "AC-3 (standard)", 32); break;
+ case 9: av_strlcpy(strbuf, "AC-3 (dnet half-rate)", 32); break;
+ case 10: av_strlcpy(strbuf, "AC-3 (dnet quater-rate)", 32); break;
+ case 16: av_strlcpy(strbuf, "E-AC-3 (enhanced)", 32); break;
+ default: snprintf(strbuf, 32, "ERROR");
+ }
+ av_dlog(avctx, "bitstream_id: %s (%d)\n", strbuf, s->bitstream_id);
+ av_dlog(avctx, "sample_fmt: %s\n", av_get_sample_fmt_name(avctx->sample_fmt));
+ av_get_channel_layout_string(strbuf, 32, s->channels, avctx->channel_layout);
+ av_dlog(avctx, "channel_layout: %s\n", strbuf);
+ av_dlog(avctx, "sample_rate: %d\n", s->sample_rate);
+ av_dlog(avctx, "bit_rate: %d\n", s->bit_rate);
+ av_dlog(avctx, "blocks/frame: %d (code=%d)\n", s->num_blocks, s->num_blks_code);
+ if (s->cutoff)
+ av_dlog(avctx, "cutoff: %d\n", s->cutoff);
+
+ av_dlog(avctx, "per_frame_metadata: %s\n",
+ opt->allow_per_frame_metadata?"on":"off");
+ if (s->has_center)
+ av_dlog(avctx, "center_mixlev: %0.3f (%d)\n", opt->center_mix_level,
+ s->center_mix_level);
+ else
+ av_dlog(avctx, "center_mixlev: {not written}\n");
+ if (s->has_surround)
+ av_dlog(avctx, "surround_mixlev: %0.3f (%d)\n", opt->surround_mix_level,
+ s->surround_mix_level);
+ else
+ av_dlog(avctx, "surround_mixlev: {not written}\n");
+ if (opt->audio_production_info) {
+ av_dlog(avctx, "mixing_level: %ddB\n", opt->mixing_level);
+ switch (opt->room_type) {
+ case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
+ case AC3ENC_OPT_LARGE_ROOM: av_strlcpy(strbuf, "large", 32); break;
+ case AC3ENC_OPT_SMALL_ROOM: av_strlcpy(strbuf, "small", 32); break;
+ default: snprintf(strbuf, 32, "ERROR (%d)", opt->room_type);
+ }
+ av_dlog(avctx, "room_type: %s\n", strbuf);
+ } else {
+ av_dlog(avctx, "mixing_level: {not written}\n");
+ av_dlog(avctx, "room_type: {not written}\n");
+ }
+ av_dlog(avctx, "copyright: %s\n", opt->copyright?"on":"off");
+ av_dlog(avctx, "dialnorm: %ddB\n", opt->dialogue_level);
+ if (s->channel_mode == AC3_CHMODE_STEREO) {
+ switch (opt->dolby_surround_mode) {
+ case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
+ case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
+ case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
+ default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_mode);
+ }
+ av_dlog(avctx, "dsur_mode: %s\n", strbuf);
+ } else {
+ av_dlog(avctx, "dsur_mode: {not written}\n");
+ }
+ av_dlog(avctx, "original: %s\n", opt->original?"on":"off");
+
+ if (s->bitstream_id == 6) {
+ if (opt->extended_bsi_1) {
+ switch (opt->preferred_stereo_downmix) {
+ case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
+ case AC3ENC_OPT_DOWNMIX_LTRT: av_strlcpy(strbuf, "ltrt", 32); break;
+ case AC3ENC_OPT_DOWNMIX_LORO: av_strlcpy(strbuf, "loro", 32); break;
+ default: snprintf(strbuf, 32, "ERROR (%d)", opt->preferred_stereo_downmix);
+ }
+ av_dlog(avctx, "dmix_mode: %s\n", strbuf);
+ av_dlog(avctx, "ltrt_cmixlev: %0.3f (%d)\n",
+ opt->ltrt_center_mix_level, s->ltrt_center_mix_level);
+ av_dlog(avctx, "ltrt_surmixlev: %0.3f (%d)\n",
+ opt->ltrt_surround_mix_level, s->ltrt_surround_mix_level);
+ av_dlog(avctx, "loro_cmixlev: %0.3f (%d)\n",
+ opt->loro_center_mix_level, s->loro_center_mix_level);
+ av_dlog(avctx, "loro_surmixlev: %0.3f (%d)\n",
+ opt->loro_surround_mix_level, s->loro_surround_mix_level);
+ } else {
+ av_dlog(avctx, "extended bitstream info 1: {not written}\n");
+ }
+ if (opt->extended_bsi_2) {
+ switch (opt->dolby_surround_ex_mode) {
+ case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
+ case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
+ case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
+ default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_ex_mode);
+ }
+ av_dlog(avctx, "dsurex_mode: %s\n", strbuf);
+ switch (opt->dolby_headphone_mode) {
+ case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
+ case AC3ENC_OPT_MODE_ON: av_strlcpy(strbuf, "on", 32); break;
+ case AC3ENC_OPT_MODE_OFF: av_strlcpy(strbuf, "off", 32); break;
+ default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_headphone_mode);
}
+ av_dlog(avctx, "dheadphone_mode: %s\n", strbuf);
- /* Normalize the samples to use the maximum available precision */
- v = 14 - log2_tab(input_samples, AC3_WINDOW_SIZE);
- if (v < 0)
- v = 0;
- exp_shift[blk][ch] = v - 9;
- lshift_tab(input_samples, AC3_WINDOW_SIZE, v);
-
- /* do the MDCT */
- mdct512(mdct_coef[blk][ch], input_samples);
-
- /* compute "exponents". We take into account the normalization there */
- for (i = 0; i < AC3_MAX_COEFS; i++) {
- int e;
- v = abs(mdct_coef[blk][ch][i]);
- if (v == 0)
- e = 24;
- else {
- e = 23 - av_log2(v) + exp_shift[blk][ch];
- if (e >= 24) {
- e = 24;
- mdct_coef[blk][ch][i] = 0;
- }
- }
- exp[blk][ch][i] = e;
+ switch (opt->ad_converter_type) {
+ case AC3ENC_OPT_ADCONV_STANDARD: av_strlcpy(strbuf, "standard", 32); break;
+ case AC3ENC_OPT_ADCONV_HDCD: av_strlcpy(strbuf, "hdcd", 32); break;
+ default: snprintf(strbuf, 32, "ERROR (%d)", opt->ad_converter_type);
}
+ av_dlog(avctx, "ad_conv_type: %s\n", strbuf);
+ } else {
+ av_dlog(avctx, "extended bitstream info 2: {not written}\n");
}
+ }
+#endif
+}
- compute_exp_strategy_ch(exp_strategy, exp, ch, ch == s->lfe_channel);
- /* compute the exponents as the decoder will see them. The
- EXP_REUSE case must be handled carefully : we select the
- min of the exponents */
- blk = 0;
- while (blk < AC3_MAX_BLOCKS) {
- blk1 = blk + 1;
- while (blk1 < AC3_MAX_BLOCKS && exp_strategy[blk1][ch] == EXP_REUSE) {
- exponent_min(exp[blk][ch], exp[blk1][ch], s->nb_coefs[ch]);
- blk1++;
- }
- frame_bits += encode_exponents_blk_ch(encoded_exp[blk][ch],
- exp[blk][ch], s->nb_coefs[ch],
- exp_strategy[blk][ch]);
- /* copy encoded exponents for reuse case */
- for (blk2 = blk+1; blk2 < blk1; blk2++) {
- memcpy(encoded_exp[blk2][ch], encoded_exp[blk][ch],
- s->nb_coefs[ch] * sizeof(uint8_t));
- }
- blk = blk1;
+#define FLT_OPTION_THRESHOLD 0.01
+
+static int validate_float_option(float v, const float *v_list, int v_list_size)
+{
+ int i;
+
+ for (i = 0; i < v_list_size; i++) {
+ if (v < (v_list[i] + FLT_OPTION_THRESHOLD) &&
+ v > (v_list[i] - FLT_OPTION_THRESHOLD))
+ break;
+ }
+ if (i == v_list_size)
+ return -1;
+
+ return i;
+}
+
+
+static void validate_mix_level(void *log_ctx, const char *opt_name,
+ float *opt_param, const float *list,
+ int list_size, int default_value, int min_value,
+ int *ctx_param)
+{
+ int mixlev = validate_float_option(*opt_param, list, list_size);
+ if (mixlev < min_value) {
+ mixlev = default_value;
+ if (*opt_param >= 0.0) {
+ av_log(log_ctx, AV_LOG_WARNING, "requested %s is not valid. using "
+ "default value: %0.3f\n", opt_name, list[mixlev]);
}
}
+ *opt_param = list[mixlev];
+ *ctx_param = mixlev;
+}
- /* adjust for fractional frame sizes */
- while (s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
- s->bits_written -= s->bit_rate;
- s->samples_written -= s->sample_rate;
+
+/**
+ * Validate metadata options as set by AVOption system.
+ * These values can optionally be changed per-frame.
+ *
+ * @param s AC-3 encoder private context
+ */
+int ff_ac3_validate_metadata(AC3EncodeContext *s)
+{
+ AVCodecContext *avctx = s->avctx;
+ AC3EncOptions *opt = &s->options;
+
+ opt->audio_production_info = 0;
+ opt->extended_bsi_1 = 0;
+ opt->extended_bsi_2 = 0;
+ opt->eac3_mixing_metadata = 0;
+ opt->eac3_info_metadata = 0;
+
+ /* determine mixing metadata / xbsi1 use */
+ if (s->channel_mode > AC3_CHMODE_STEREO && opt->preferred_stereo_downmix != AC3ENC_OPT_NONE) {
+ opt->extended_bsi_1 = 1;
+ opt->eac3_mixing_metadata = 1;
+ }
+ if (s->has_center &&
+ (opt->ltrt_center_mix_level >= 0 || opt->loro_center_mix_level >= 0)) {
+ opt->extended_bsi_1 = 1;
+ opt->eac3_mixing_metadata = 1;
+ }
+ if (s->has_surround &&
+ (opt->ltrt_surround_mix_level >= 0 || opt->loro_surround_mix_level >= 0)) {
+ opt->extended_bsi_1 = 1;
+ opt->eac3_mixing_metadata = 1;
}
- s->frame_size = s->frame_size_min + 2 * (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate);
- s->bits_written += s->frame_size * 8;
- s->samples_written += AC3_FRAME_SIZE;
- compute_bit_allocation(s, bap, encoded_exp, exp_strategy, frame_bits);
- /* everything is known... let's output the frame */
- output_frame_header(s, frame);
+ if (s->eac3) {
+ /* determine info metadata use */
+ if (avctx->audio_service_type != AV_AUDIO_SERVICE_TYPE_MAIN)
+ opt->eac3_info_metadata = 1;
+ if (opt->copyright != AC3ENC_OPT_NONE || opt->original != AC3ENC_OPT_NONE)
+ opt->eac3_info_metadata = 1;
+ if (s->channel_mode == AC3_CHMODE_STEREO &&
+ (opt->dolby_headphone_mode != AC3ENC_OPT_NONE || opt->dolby_surround_mode != AC3ENC_OPT_NONE))
+ opt->eac3_info_metadata = 1;
+ if (s->channel_mode >= AC3_CHMODE_2F2R && opt->dolby_surround_ex_mode != AC3ENC_OPT_NONE)
+ opt->eac3_info_metadata = 1;
+ if (opt->mixing_level != AC3ENC_OPT_NONE || opt->room_type != AC3ENC_OPT_NONE ||
+ opt->ad_converter_type != AC3ENC_OPT_NONE) {
+ opt->audio_production_info = 1;
+ opt->eac3_info_metadata = 1;
+ }
+ } else {
+ /* determine audio production info use */
+ if (opt->mixing_level != AC3ENC_OPT_NONE || opt->room_type != AC3ENC_OPT_NONE)
+ opt->audio_production_info = 1;
+
+ /* determine xbsi2 use */
+ if (s->channel_mode >= AC3_CHMODE_2F2R && opt->dolby_surround_ex_mode != AC3ENC_OPT_NONE)
+ opt->extended_bsi_2 = 1;
+ if (s->channel_mode == AC3_CHMODE_STEREO && opt->dolby_headphone_mode != AC3ENC_OPT_NONE)
+ opt->extended_bsi_2 = 1;
+ if (opt->ad_converter_type != AC3ENC_OPT_NONE)
+ opt->extended_bsi_2 = 1;
+ }
- for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
- output_audio_block(s, exp_strategy[blk], encoded_exp[blk],
- bap[blk], mdct_coef[blk], exp_shift[blk], blk);
+ /* validate AC-3 mixing levels */
+ if (!s->eac3) {
+ if (s->has_center) {
+ validate_mix_level(avctx, "center_mix_level", &opt->center_mix_level,
+ cmixlev_options, CMIXLEV_NUM_OPTIONS, 1, 0,
+ &s->center_mix_level);
+ }
+ if (s->has_surround) {
+ validate_mix_level(avctx, "surround_mix_level", &opt->surround_mix_level,
+ surmixlev_options, SURMIXLEV_NUM_OPTIONS, 1, 0,
+ &s->surround_mix_level);
+ }
+ }
+
+ /* validate extended bsi 1 / mixing metadata */
+ if (opt->extended_bsi_1 || opt->eac3_mixing_metadata) {
+ /* default preferred stereo downmix */
+ if (opt->preferred_stereo_downmix == AC3ENC_OPT_NONE)
+ opt->preferred_stereo_downmix = AC3ENC_OPT_NOT_INDICATED;
+ if (!s->eac3 || s->has_center) {
+ /* validate Lt/Rt center mix level */
+ validate_mix_level(avctx, "ltrt_center_mix_level",
+ &opt->ltrt_center_mix_level, extmixlev_options,
+ EXTMIXLEV_NUM_OPTIONS, 5, 0,
+ &s->ltrt_center_mix_level);
+ /* validate Lo/Ro center mix level */
+ validate_mix_level(avctx, "loro_center_mix_level",
+ &opt->loro_center_mix_level, extmixlev_options,
+ EXTMIXLEV_NUM_OPTIONS, 5, 0,
+ &s->loro_center_mix_level);
+ }
+ if (!s->eac3 || s->has_surround) {
+ /* validate Lt/Rt surround mix level */
+ validate_mix_level(avctx, "ltrt_surround_mix_level",
+ &opt->ltrt_surround_mix_level, extmixlev_options,
+ EXTMIXLEV_NUM_OPTIONS, 6, 3,
+ &s->ltrt_surround_mix_level);
+ /* validate Lo/Ro surround mix level */
+ validate_mix_level(avctx, "loro_surround_mix_level",
+ &opt->loro_surround_mix_level, extmixlev_options,
+ EXTMIXLEV_NUM_OPTIONS, 6, 3,
+ &s->loro_surround_mix_level);
+ }
+ }
+
+ /* validate audio service type / channels combination */
+ if ((avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_KARAOKE &&
+ avctx->channels == 1) ||
+ ((avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_COMMENTARY ||
+ avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_EMERGENCY ||
+ avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_VOICE_OVER)
+ && avctx->channels > 1)) {
+ av_log(avctx, AV_LOG_ERROR, "invalid audio service type for the "
+ "specified number of channels\n");
+ return AVERROR(EINVAL);
+ }
+
+ /* validate extended bsi 2 / info metadata */
+ if (opt->extended_bsi_2 || opt->eac3_info_metadata) {
+ /* default dolby headphone mode */
+ if (opt->dolby_headphone_mode == AC3ENC_OPT_NONE)
+ opt->dolby_headphone_mode = AC3ENC_OPT_NOT_INDICATED;
+ /* default dolby surround ex mode */
+ if (opt->dolby_surround_ex_mode == AC3ENC_OPT_NONE)
+ opt->dolby_surround_ex_mode = AC3ENC_OPT_NOT_INDICATED;
+ /* default A/D converter type */
+ if (opt->ad_converter_type == AC3ENC_OPT_NONE)
+ opt->ad_converter_type = AC3ENC_OPT_ADCONV_STANDARD;
+ }
+
+ /* copyright & original defaults */
+ if (!s->eac3 || opt->eac3_info_metadata) {
+ /* default copyright */
+ if (opt->copyright == AC3ENC_OPT_NONE)
+ opt->copyright = AC3ENC_OPT_OFF;
+ /* default original */
+ if (opt->original == AC3ENC_OPT_NONE)
+ opt->original = AC3ENC_OPT_ON;
+ }
+
+ /* dolby surround mode default */
+ if (!s->eac3 || opt->eac3_info_metadata) {
+ if (opt->dolby_surround_mode == AC3ENC_OPT_NONE)
+ opt->dolby_surround_mode = AC3ENC_OPT_NOT_INDICATED;
+ }
+
+ /* validate audio production info */
+ if (opt->audio_production_info) {
+ if (opt->mixing_level == AC3ENC_OPT_NONE) {
+ av_log(avctx, AV_LOG_ERROR, "mixing_level must be set if "
+ "room_type is set\n");
+ return AVERROR(EINVAL);
+ }
+ if (opt->mixing_level < 80) {
+ av_log(avctx, AV_LOG_ERROR, "invalid mixing level. must be between "
+ "80dB and 111dB\n");
+ return AVERROR(EINVAL);
+ }
+ /* default room type */
+ if (opt->room_type == AC3ENC_OPT_NONE)
+ opt->room_type = AC3ENC_OPT_NOT_INDICATED;
+ }
+
+ /* set bitstream id for alternate bitstream syntax */
+ if (!s->eac3 && (opt->extended_bsi_1 || opt->extended_bsi_2)) {
+ if (s->bitstream_id > 8 && s->bitstream_id < 11) {
+ static int warn_once = 1;
+ if (warn_once) {
+ av_log(avctx, AV_LOG_WARNING, "alternate bitstream syntax is "
+ "not compatible with reduced samplerates. writing of "
+ "extended bitstream information will be disabled.\n");
+ warn_once = 0;
+ }
+ } else {
+ s->bitstream_id = 6;
+ }
}
- output_frame_end(s);
- return s->frame_size;
+ return 0;
}
/**
* Finalize encoding and free any memory allocated by the encoder.
+ *
+ * @param avctx Codec context
*/
-static av_cold int ac3_encode_close(AVCodecContext *avctx)
+av_cold int ff_ac3_encode_close(AVCodecContext *avctx)
{
+ int blk, ch;
+ AC3EncodeContext *s = avctx->priv_data;
+
+ av_freep(&s->windowed_samples);
+ for (ch = 0; ch < s->channels; ch++)
+ av_freep(&s->planar_samples[ch]);
+ av_freep(&s->planar_samples);
+ av_freep(&s->bap_buffer);
+ av_freep(&s->bap1_buffer);
+ av_freep(&s->mdct_coef_buffer);
+ av_freep(&s->fixed_coef_buffer);
+ av_freep(&s->exp_buffer);
+ av_freep(&s->grouped_exp_buffer);
+ av_freep(&s->psd_buffer);
+ av_freep(&s->band_psd_buffer);
+ av_freep(&s->mask_buffer);
+ av_freep(&s->qmant_buffer);
+ av_freep(&s->cpl_coord_exp_buffer);
+ av_freep(&s->cpl_coord_mant_buffer);
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ av_freep(&block->mdct_coef);
+ av_freep(&block->fixed_coef);
+ av_freep(&block->exp);
+ av_freep(&block->grouped_exp);
+ av_freep(&block->psd);
+ av_freep(&block->band_psd);
+ av_freep(&block->mask);
+ av_freep(&block->qmant);
+ av_freep(&block->cpl_coord_exp);
+ av_freep(&block->cpl_coord_mant);
+ }
+
+ s->mdct_end(s);
+
av_freep(&avctx->coded_frame);
return 0;
}
-/**
+/*
* Set channel information during initialization.
*/
static av_cold int set_channel_info(AC3EncodeContext *s, int channels,
- int64_t *channel_layout)
+ uint64_t *channel_layout)
{
int ch_layout;
if (channels < 1 || channels > AC3_MAX_CHANNELS)
return AVERROR(EINVAL);
- if ((uint64_t)*channel_layout > 0x7FF)
+ if (*channel_layout > 0x7FF)
return AVERROR(EINVAL);
ch_layout = *channel_layout;
if (!ch_layout)
ch_layout = avcodec_guess_channel_layout(channels, CODEC_ID_AC3, NULL);
- if (av_get_channel_layout_nb_channels(ch_layout) != channels)
- return AVERROR(EINVAL);
s->lfe_on = !!(ch_layout & AV_CH_LOW_FREQUENCY);
s->channels = channels;
s->fbw_channels = channels - s->lfe_on;
- s->lfe_channel = s->lfe_on ? s->fbw_channels : -1;
+ s->lfe_channel = s->lfe_on ? s->fbw_channels + 1 : -1;
if (s->lfe_on)
ch_layout -= AV_CH_LOW_FREQUENCY;
default:
return AVERROR(EINVAL);
}
+ s->has_center = (s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO;
+ s->has_surround = s->channel_mode & 0x04;
s->channel_map = ff_ac3_enc_channel_map[s->channel_mode][s->lfe_on];
*channel_layout = ch_layout;
}
-static av_cold int validate_options(AVCodecContext *avctx, AC3EncodeContext *s)
+static av_cold int validate_options(AC3EncodeContext *s)
{
- int i, ret;
+ AVCodecContext *avctx = s->avctx;
+ int i, ret, max_sr;
+ /* validate channel layout */
if (!avctx->channel_layout) {
av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The "
"encoder will guess the layout, but it "
return ret;
}
- /* frequency */
- for (i = 0; i < 9; i++) {
- if ((ff_ac3_sample_rate_tab[i / 3] >> (i % 3)) == avctx->sample_rate)
+ /* validate sample rate */
+ /* note: max_sr could be changed from 2 to 5 for E-AC-3 once we find a
+ decoder that supports half sample rate so we can validate that
+ the generated files are correct. */
+ max_sr = s->eac3 ? 2 : 8;
+ for (i = 0; i <= max_sr; i++) {
+ if ((ff_ac3_sample_rate_tab[i % 3] >> (i / 3)) == avctx->sample_rate)
break;
}
- if (i == 9) {
+ if (i > max_sr) {
av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");
return AVERROR(EINVAL);
}
s->sample_rate = avctx->sample_rate;
- s->bit_alloc.sr_shift = i % 3;
- s->bit_alloc.sr_code = i / 3;
+ s->bit_alloc.sr_shift = i / 3;
+ s->bit_alloc.sr_code = i % 3;
+ s->bitstream_id = s->eac3 ? 16 : 8 + s->bit_alloc.sr_shift;
+
+ /* validate bit rate */
+ if (s->eac3) {
+ int max_br, min_br, wpf, min_br_dist, min_br_code;
+ int num_blks_code, num_blocks, frame_samples;
+
+ /* calculate min/max bitrate */
+ /* TODO: More testing with 3 and 2 blocks. All E-AC-3 samples I've
+ found use either 6 blocks or 1 block, even though 2 or 3 blocks
+ would work as far as the bit rate is concerned. */
+ for (num_blks_code = 3; num_blks_code >= 0; num_blks_code--) {
+ num_blocks = ((int[]){ 1, 2, 3, 6 })[num_blks_code];
+ frame_samples = AC3_BLOCK_SIZE * num_blocks;
+ max_br = 2048 * s->sample_rate / frame_samples * 16;
+ min_br = ((s->sample_rate + (frame_samples-1)) / frame_samples) * 16;
+ if (avctx->bit_rate <= max_br)
+ break;
+ }
+ if (avctx->bit_rate < min_br || avctx->bit_rate > max_br) {
+ av_log(avctx, AV_LOG_ERROR, "invalid bit rate. must be %d to %d "
+ "for this sample rate\n", min_br, max_br);
+ return AVERROR(EINVAL);
+ }
+ s->num_blks_code = num_blks_code;
+ s->num_blocks = num_blocks;
+
+ /* calculate words-per-frame for the selected bitrate */
+ wpf = (avctx->bit_rate / 16) * frame_samples / s->sample_rate;
+ av_assert1(wpf > 0 && wpf <= 2048);
+
+ /* find the closest AC-3 bitrate code to the selected bitrate.
+ this is needed for lookup tables for bandwidth and coupling
+ parameter selection */
+ min_br_code = -1;
+ min_br_dist = INT_MAX;
+ for (i = 0; i < 19; i++) {
+ int br_dist = abs(ff_ac3_bitrate_tab[i] * 1000 - avctx->bit_rate);
+ if (br_dist < min_br_dist) {
+ min_br_dist = br_dist;
+ min_br_code = i;
+ }
+ }
- /* bitrate & frame size */
- for (i = 0; i < 19; i++) {
- if ((ff_ac3_bitrate_tab[i] >> s->bit_alloc.sr_shift)*1000 == avctx->bit_rate)
- break;
+ /* make sure the minimum frame size is below the average frame size */
+ s->frame_size_code = min_br_code << 1;
+ while (wpf > 1 && wpf * s->sample_rate / AC3_FRAME_SIZE * 16 > avctx->bit_rate)
+ wpf--;
+ s->frame_size_min = 2 * wpf;
+ } else {
+ for (i = 0; i < 19; i++) {
+ if ((ff_ac3_bitrate_tab[i] >> s->bit_alloc.sr_shift)*1000 == avctx->bit_rate)
+ break;
+ }
+ if (i == 19) {
+ av_log(avctx, AV_LOG_ERROR, "invalid bit rate\n");
+ return AVERROR(EINVAL);
+ }
+ s->frame_size_code = i << 1;
+ s->frame_size_min = 2 * ff_ac3_frame_size_tab[s->frame_size_code][s->bit_alloc.sr_code];
+ s->num_blks_code = 0x3;
+ s->num_blocks = 6;
}
- if (i == 19) {
- av_log(avctx, AV_LOG_ERROR, "invalid bit rate\n");
+ s->bit_rate = avctx->bit_rate;
+ s->frame_size = s->frame_size_min;
+
+ /* validate cutoff */
+ if (avctx->cutoff < 0) {
+ av_log(avctx, AV_LOG_ERROR, "invalid cutoff frequency\n");
return AVERROR(EINVAL);
}
- s->bit_rate = avctx->bit_rate;
- s->frame_size_code = i << 1;
+ s->cutoff = avctx->cutoff;
+ if (s->cutoff > (s->sample_rate >> 1))
+ s->cutoff = s->sample_rate >> 1;
+
+ ret = ff_ac3_validate_metadata(s);
+ if (ret)
+ return ret;
+
+ s->rematrixing_enabled = s->options.stereo_rematrixing &&
+ (s->channel_mode == AC3_CHMODE_STEREO);
+
+ s->cpl_enabled = s->options.channel_coupling &&
+ s->channel_mode >= AC3_CHMODE_STEREO;
return 0;
}
-/**
+/*
* Set bandwidth for all channels.
* The user can optionally supply a cutoff frequency. Otherwise an appropriate
* default value will be used.
*/
-static av_cold void set_bandwidth(AC3EncodeContext *s, int cutoff)
+static av_cold void set_bandwidth(AC3EncodeContext *s)
{
- int ch, bw_code;
+ int blk, ch;
+ int av_uninit(cpl_start);
- if (cutoff) {
+ if (s->cutoff) {
/* calculate bandwidth based on user-specified cutoff frequency */
int fbw_coeffs;
- cutoff = av_clip(cutoff, 1, s->sample_rate >> 1);
- fbw_coeffs = cutoff * 2 * AC3_MAX_COEFS / s->sample_rate;
- bw_code = av_clip((fbw_coeffs - 73) / 3, 0, 60);
+ fbw_coeffs = s->cutoff * 2 * AC3_MAX_COEFS / s->sample_rate;
+ s->bandwidth_code = av_clip((fbw_coeffs - 73) / 3, 0, 60);
} else {
/* use default bandwidth setting */
- /* XXX: should compute the bandwidth according to the frame
- size, so that we avoid annoying high frequency artifacts */
- bw_code = 50;
+ s->bandwidth_code = ac3_bandwidth_tab[s->fbw_channels-1][s->bit_alloc.sr_code][s->frame_size_code/2];
}
/* set number of coefficients for each channel */
- for (ch = 0; ch < s->fbw_channels; ch++) {
- s->bandwidth_code[ch] = bw_code;
- s->nb_coefs[ch] = bw_code * 3 + 73;
+ for (ch = 1; ch <= s->fbw_channels; ch++) {
+ s->start_freq[ch] = 0;
+ for (blk = 0; blk < s->num_blocks; blk++)
+ s->blocks[blk].end_freq[ch] = s->bandwidth_code * 3 + 73;
+ }
+ /* LFE channel always has 7 coefs */
+ if (s->lfe_on) {
+ s->start_freq[s->lfe_channel] = 0;
+ for (blk = 0; blk < s->num_blocks; blk++)
+ s->blocks[blk].end_freq[ch] = 7;
}
- if (s->lfe_on)
- s->nb_coefs[s->lfe_channel] = 7; /* LFE channel always has 7 coefs */
-}
-
-/**
- * Initialize the encoder.
- */
-static av_cold int ac3_encode_init(AVCodecContext *avctx)
-{
- AC3EncodeContext *s = avctx->priv_data;
- int ret;
+ /* initialize coupling strategy */
+ if (s->cpl_enabled) {
+ if (s->options.cpl_start != AC3ENC_OPT_AUTO) {
+ cpl_start = s->options.cpl_start;
+ } else {
+ cpl_start = ac3_coupling_start_tab[s->channel_mode-2][s->bit_alloc.sr_code][s->frame_size_code/2];
+ if (cpl_start < 0) {
+ if (s->options.channel_coupling == AC3ENC_OPT_AUTO)
+ s->cpl_enabled = 0;
+ else
+ cpl_start = 15;
+ }
+ }
+ }
+ if (s->cpl_enabled) {
+ int i, cpl_start_band, cpl_end_band;
+ uint8_t *cpl_band_sizes = s->cpl_band_sizes;
- avctx->frame_size = AC3_FRAME_SIZE;
+ cpl_end_band = s->bandwidth_code / 4 + 3;
+ cpl_start_band = av_clip(cpl_start, 0, FFMIN(cpl_end_band-1, 15));
- ac3_common_init();
+ s->num_cpl_subbands = cpl_end_band - cpl_start_band;
- ret = validate_options(avctx, s);
- if (ret)
- return ret;
+ s->num_cpl_bands = 1;
+ *cpl_band_sizes = 12;
+ for (i = cpl_start_band + 1; i < cpl_end_band; i++) {
+ if (ff_eac3_default_cpl_band_struct[i]) {
+ *cpl_band_sizes += 12;
+ } else {
+ s->num_cpl_bands++;
+ cpl_band_sizes++;
+ *cpl_band_sizes = 12;
+ }
+ }
- s->bitstream_id = 8 + s->bit_alloc.sr_shift;
- s->bitstream_mode = 0; /* complete main audio service */
+ s->start_freq[CPL_CH] = cpl_start_band * 12 + 37;
+ s->cpl_end_freq = cpl_end_band * 12 + 37;
+ for (blk = 0; blk < s->num_blocks; blk++)
+ s->blocks[blk].end_freq[CPL_CH] = s->cpl_end_freq;
+ }
+}
- s->frame_size_min = 2 * ff_ac3_frame_size_tab[s->frame_size_code][s->bit_alloc.sr_code];
- s->bits_written = 0;
- s->samples_written = 0;
- s->frame_size = s->frame_size_min;
- set_bandwidth(s, avctx->cutoff);
+static av_cold int allocate_buffers(AC3EncodeContext *s)
+{
+ AVCodecContext *avctx = s->avctx;
+ int blk, ch;
+ int channels = s->channels + 1; /* includes coupling channel */
+ int channel_blocks = channels * s->num_blocks;
+ int total_coefs = AC3_MAX_COEFS * channel_blocks;
+
+ if (s->allocate_sample_buffers(s))
+ goto alloc_fail;
+
+ FF_ALLOC_OR_GOTO(avctx, s->bap_buffer, total_coefs *
+ sizeof(*s->bap_buffer), alloc_fail);
+ FF_ALLOC_OR_GOTO(avctx, s->bap1_buffer, total_coefs *
+ sizeof(*s->bap1_buffer), alloc_fail);
+ FF_ALLOCZ_OR_GOTO(avctx, s->mdct_coef_buffer, total_coefs *
+ sizeof(*s->mdct_coef_buffer), alloc_fail);
+ FF_ALLOC_OR_GOTO(avctx, s->exp_buffer, total_coefs *
+ sizeof(*s->exp_buffer), alloc_fail);
+ FF_ALLOC_OR_GOTO(avctx, s->grouped_exp_buffer, channel_blocks * 128 *
+ sizeof(*s->grouped_exp_buffer), alloc_fail);
+ FF_ALLOC_OR_GOTO(avctx, s->psd_buffer, total_coefs *
+ sizeof(*s->psd_buffer), alloc_fail);
+ FF_ALLOC_OR_GOTO(avctx, s->band_psd_buffer, channel_blocks * 64 *
+ sizeof(*s->band_psd_buffer), alloc_fail);
+ FF_ALLOC_OR_GOTO(avctx, s->mask_buffer, channel_blocks * 64 *
+ sizeof(*s->mask_buffer), alloc_fail);
+ FF_ALLOC_OR_GOTO(avctx, s->qmant_buffer, total_coefs *
+ sizeof(*s->qmant_buffer), alloc_fail);
+ if (s->cpl_enabled) {
+ FF_ALLOC_OR_GOTO(avctx, s->cpl_coord_exp_buffer, channel_blocks * 16 *
+ sizeof(*s->cpl_coord_exp_buffer), alloc_fail);
+ FF_ALLOC_OR_GOTO(avctx, s->cpl_coord_mant_buffer, channel_blocks * 16 *
+ sizeof(*s->cpl_coord_mant_buffer), alloc_fail);
+ }
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ FF_ALLOCZ_OR_GOTO(avctx, block->mdct_coef, channels * sizeof(*block->mdct_coef),
+ alloc_fail);
+ FF_ALLOCZ_OR_GOTO(avctx, block->exp, channels * sizeof(*block->exp),
+ alloc_fail);
+ FF_ALLOCZ_OR_GOTO(avctx, block->grouped_exp, channels * sizeof(*block->grouped_exp),
+ alloc_fail);
+ FF_ALLOCZ_OR_GOTO(avctx, block->psd, channels * sizeof(*block->psd),
+ alloc_fail);
+ FF_ALLOCZ_OR_GOTO(avctx, block->band_psd, channels * sizeof(*block->band_psd),
+ alloc_fail);
+ FF_ALLOCZ_OR_GOTO(avctx, block->mask, channels * sizeof(*block->mask),
+ alloc_fail);
+ FF_ALLOCZ_OR_GOTO(avctx, block->qmant, channels * sizeof(*block->qmant),
+ alloc_fail);
+ if (s->cpl_enabled) {
+ FF_ALLOCZ_OR_GOTO(avctx, block->cpl_coord_exp, channels * sizeof(*block->cpl_coord_exp),
+ alloc_fail);
+ FF_ALLOCZ_OR_GOTO(avctx, block->cpl_coord_mant, channels * sizeof(*block->cpl_coord_mant),
+ alloc_fail);
+ }
- /* initial snr offset */
- s->coarse_snr_offset = 40;
+ for (ch = 0; ch < channels; ch++) {
+ /* arrangement: block, channel, coeff */
+ block->grouped_exp[ch] = &s->grouped_exp_buffer[128 * (blk * channels + ch)];
+ block->psd[ch] = &s->psd_buffer [AC3_MAX_COEFS * (blk * channels + ch)];
+ block->band_psd[ch] = &s->band_psd_buffer [64 * (blk * channels + ch)];
+ block->mask[ch] = &s->mask_buffer [64 * (blk * channels + ch)];
+ block->qmant[ch] = &s->qmant_buffer [AC3_MAX_COEFS * (blk * channels + ch)];
+ if (s->cpl_enabled) {
+ block->cpl_coord_exp[ch] = &s->cpl_coord_exp_buffer [16 * (blk * channels + ch)];
+ block->cpl_coord_mant[ch] = &s->cpl_coord_mant_buffer[16 * (blk * channels + ch)];
+ }
- mdct_init(9);
+ /* arrangement: channel, block, coeff */
+ block->exp[ch] = &s->exp_buffer [AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
+ block->mdct_coef[ch] = &s->mdct_coef_buffer [AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
+ }
+ }
- avctx->coded_frame= avcodec_alloc_frame();
- avctx->coded_frame->key_frame= 1;
+ if (!s->fixed_point) {
+ FF_ALLOCZ_OR_GOTO(avctx, s->fixed_coef_buffer, total_coefs *
+ sizeof(*s->fixed_coef_buffer), alloc_fail);
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ FF_ALLOCZ_OR_GOTO(avctx, block->fixed_coef, channels *
+ sizeof(*block->fixed_coef), alloc_fail);
+ for (ch = 0; ch < channels; ch++)
+ block->fixed_coef[ch] = &s->fixed_coef_buffer[AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
+ }
+ } else {
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ FF_ALLOCZ_OR_GOTO(avctx, block->fixed_coef, channels *
+ sizeof(*block->fixed_coef), alloc_fail);
+ for (ch = 0; ch < channels; ch++)
+ block->fixed_coef[ch] = (int32_t *)block->mdct_coef[ch];
+ }
+ }
return 0;
+alloc_fail:
+ return AVERROR(ENOMEM);
}
-#ifdef TEST
-/*************************************************************************/
-/* TEST */
+av_cold int ff_ac3_encode_init(AVCodecContext *avctx)
+{
+ AC3EncodeContext *s = avctx->priv_data;
+ int ret, frame_size_58;
-#include "libavutil/lfg.h"
+ s->avctx = avctx;
-#define FN (MDCT_SAMPLES/4)
+ s->eac3 = avctx->codec_id == CODEC_ID_EAC3;
+ ff_ac3_common_init();
-static void fft_test(AVLFG *lfg)
-{
- IComplex in[FN], in1[FN];
- int k, n, i;
- float sum_re, sum_im, a;
+ ret = validate_options(s);
+ if (ret)
+ return ret;
- for (i = 0; i < FN; i++) {
- in[i].re = av_lfg_get(lfg) % 65535 - 32767;
- in[i].im = av_lfg_get(lfg) % 65535 - 32767;
- in1[i] = in[i];
- }
- fft(in, 7);
+ avctx->frame_size = AC3_BLOCK_SIZE * s->num_blocks;
- /* do it by hand */
- for (k = 0; k < FN; k++) {
- sum_re = 0;
- sum_im = 0;
- for (n = 0; n < FN; n++) {
- a = -2 * M_PI * (n * k) / FN;
- sum_re += in1[n].re * cos(a) - in1[n].im * sin(a);
- sum_im += in1[n].re * sin(a) + in1[n].im * cos(a);
- }
- av_log(NULL, AV_LOG_DEBUG, "%3d: %6d,%6d %6.0f,%6.0f\n",
- k, in[k].re, in[k].im, sum_re / FN, sum_im / FN);
- }
-}
+ s->bitstream_mode = avctx->audio_service_type;
+ if (s->bitstream_mode == AV_AUDIO_SERVICE_TYPE_KARAOKE)
+ s->bitstream_mode = 0x7;
+ s->bits_written = 0;
+ s->samples_written = 0;
-static void mdct_test(AVLFG *lfg)
-{
- int16_t input[MDCT_SAMPLES];
- int32_t output[AC3_MAX_COEFS];
- float input1[MDCT_SAMPLES];
- float output1[AC3_MAX_COEFS];
- float s, a, err, e, emax;
- int i, k, n;
+ /* calculate crc_inv for both possible frame sizes */
+ frame_size_58 = (( s->frame_size >> 2) + ( s->frame_size >> 4)) << 1;
+ s->crc_inv[0] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
+ if (s->bit_alloc.sr_code == 1) {
+ frame_size_58 = (((s->frame_size+2) >> 2) + ((s->frame_size+2) >> 4)) << 1;
+ s->crc_inv[1] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
+ }
- for (i = 0; i < MDCT_SAMPLES; i++) {
- input[i] = (av_lfg_get(lfg) % 65535 - 32767) * 9 / 10;
- input1[i] = input[i];
+ /* set function pointers */
+ if (CONFIG_AC3_FIXED_ENCODER && s->fixed_point) {
+ s->mdct_end = ff_ac3_fixed_mdct_end;
+ s->mdct_init = ff_ac3_fixed_mdct_init;
+ s->allocate_sample_buffers = ff_ac3_fixed_allocate_sample_buffers;
+ } else if (CONFIG_AC3_ENCODER || CONFIG_EAC3_ENCODER) {
+ s->mdct_end = ff_ac3_float_mdct_end;
+ s->mdct_init = ff_ac3_float_mdct_init;
+ s->allocate_sample_buffers = ff_ac3_float_allocate_sample_buffers;
}
+ if (CONFIG_EAC3_ENCODER && s->eac3)
+ s->output_frame_header = ff_eac3_output_frame_header;
+ else
+ s->output_frame_header = ac3_output_frame_header;
- mdct512(output, input);
+ set_bandwidth(s);
- /* do it by hand */
- for (k = 0; k < AC3_MAX_COEFS; k++) {
- s = 0;
- for (n = 0; n < MDCT_SAMPLES; n++) {
- a = (2*M_PI*(2*n+1+MDCT_SAMPLES/2)*(2*k+1) / (4 * MDCT_SAMPLES));
- s += input1[n] * cos(a);
- }
- output1[k] = -2 * s / MDCT_SAMPLES;
- }
+ exponent_init(s);
- err = 0;
- emax = 0;
- for (i = 0; i < AC3_MAX_COEFS; i++) {
- av_log(NULL, AV_LOG_DEBUG, "%3d: %7d %7.0f\n", i, output[i], output1[i]);
- e = output[i] - output1[i];
- if (e > emax)
- emax = e;
- err += e * e;
- }
- av_log(NULL, AV_LOG_DEBUG, "err2=%f emax=%f\n", err / AC3_MAX_COEFS, emax);
-}
+ bit_alloc_init(s);
+ ret = s->mdct_init(s);
+ if (ret)
+ goto init_fail;
-int main(void)
-{
- AVLFG lfg;
+ ret = allocate_buffers(s);
+ if (ret)
+ goto init_fail;
+
+ avctx->coded_frame= avcodec_alloc_frame();
- av_log_set_level(AV_LOG_DEBUG);
- mdct_init(9);
+ dsputil_init(&s->dsp, avctx);
+ ff_ac3dsp_init(&s->ac3dsp, avctx->flags & CODEC_FLAG_BITEXACT);
- fft_test(&lfg);
- mdct_test(&lfg);
+ dprint_options(s);
return 0;
+init_fail:
+ ff_ac3_encode_close(avctx);
+ return ret;
}
-#endif /* TEST */
-
-
-AVCodec ac3_encoder = {
- "ac3",
- AVMEDIA_TYPE_AUDIO,
- CODEC_ID_AC3,
- sizeof(AC3EncodeContext),
- ac3_encode_init,
- ac3_encode_frame,
- ac3_encode_close,
- NULL,
- .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},
- .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
- .channel_layouts = (const int64_t[]){
- AV_CH_LAYOUT_MONO,
- AV_CH_LAYOUT_STEREO,
- AV_CH_LAYOUT_2_1,
- AV_CH_LAYOUT_SURROUND,
- AV_CH_LAYOUT_2_2,
- AV_CH_LAYOUT_QUAD,
- AV_CH_LAYOUT_4POINT0,
- AV_CH_LAYOUT_5POINT0,
- AV_CH_LAYOUT_5POINT0_BACK,
- (AV_CH_LAYOUT_MONO | AV_CH_LOW_FREQUENCY),
- (AV_CH_LAYOUT_STEREO | AV_CH_LOW_FREQUENCY),
- (AV_CH_LAYOUT_2_1 | AV_CH_LOW_FREQUENCY),
- (AV_CH_LAYOUT_SURROUND | AV_CH_LOW_FREQUENCY),
- (AV_CH_LAYOUT_2_2 | AV_CH_LOW_FREQUENCY),
- (AV_CH_LAYOUT_QUAD | AV_CH_LOW_FREQUENCY),
- (AV_CH_LAYOUT_4POINT0 | AV_CH_LOW_FREQUENCY),
- AV_CH_LAYOUT_5POINT1,
- AV_CH_LAYOUT_5POINT1_BACK,
- 0 },
-};