* 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
*/
*/
//#define DEBUG
+//#define ASSERT_LEVEL 2
-#include "libavcore/audioconvert.h"
+#include <stdint.h>
+
+#include "libavutil/audioconvert.h"
+#include "libavutil/avassert.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"
+
+#ifndef CONFIG_AC3ENC_FLOAT
+#define CONFIG_AC3ENC_FLOAT 0
+#endif
-#define MDCT_NBITS 9
-#define MDCT_SAMPLES (1 << MDCT_NBITS)
/** Maximum number of exponent groups. +1 for separate DC exponent. */
#define AC3_MAX_EXP_GROUPS 85
-/** Scale a float value by 2^bits and convert to an integer. */
-#define SCALE_FLOAT(a, bits) lrintf((a) * (float)(1 << (bits)))
-
-/** 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))
+#if CONFIG_AC3ENC_FLOAT
+#define MAC_COEF(d,a,b) ((d)+=(a)*(b))
+typedef float SampleType;
+typedef float CoefType;
+typedef float CoefSumType;
+#else
+#define MAC_COEF(d,a,b) MAC64(d,a,b)
+typedef int16_t SampleType;
+typedef int32_t CoefType;
+typedef int64_t CoefSumType;
+#endif
+typedef struct AC3MDCTContext {
+ const SampleType *window; ///< MDCT window function
+ FFTContext fft; ///< FFT context for MDCT calculation
+} AC3MDCTContext;
/**
- * Compex number.
- * Used in fixed-point MDCT calculation.
+ * Encoding Options used by AVOption.
*/
-typedef struct IComplex {
- int16_t re,im;
-} IComplex;
-
-typedef struct AC3MDCTContext {
- AVCodecContext *avctx; ///< parent context for av_log()
- int16_t *rot_tmp; ///< temp buffer for pre-rotated samples
- IComplex *cplx_tmp; ///< temp buffer for complex pre-rotated samples
-} AC3MDCTContext;
+typedef struct AC3EncOptions {
+ /* AC-3 metadata options*/
+ int dialogue_level;
+ int bitstream_mode;
+ float center_mix_level;
+ float surround_mix_level;
+ int dolby_surround_mode;
+ int audio_production_info;
+ int mixing_level;
+ int room_type;
+ int copyright;
+ int original;
+ int extended_bsi_1;
+ int preferred_stereo_downmix;
+ float ltrt_center_mix_level;
+ float ltrt_surround_mix_level;
+ float loro_center_mix_level;
+ float loro_surround_mix_level;
+ int extended_bsi_2;
+ int dolby_surround_ex_mode;
+ int dolby_headphone_mode;
+ int ad_converter_type;
+
+ /* other encoding options */
+ int allow_per_frame_metadata;
+ int stereo_rematrixing;
+} AC3EncOptions;
/**
* Data for a single audio block.
*/
typedef struct AC3Block {
uint8_t **bap; ///< bit allocation pointers (bap)
- int32_t **mdct_coef; ///< MDCT coefficients
+ CoefType **mdct_coef; ///< MDCT coefficients
+ int32_t **fixed_coef; ///< fixed-point MDCT coefficients
uint8_t **exp; ///< original exponents
uint8_t **grouped_exp; ///< grouped exponents
int16_t **psd; ///< psd per frequency bin
int16_t **band_psd; ///< psd per critical band
int16_t **mask; ///< masking curve
uint16_t **qmant; ///< quantized mantissas
- uint8_t num_exp_groups[AC3_MAX_CHANNELS]; ///< number of exponent groups
- uint8_t exp_strategy[AC3_MAX_CHANNELS]; ///< exponent strategies
- int8_t exp_shift[AC3_MAX_CHANNELS]; ///< exponent shift values
+ uint8_t coeff_shift[AC3_MAX_CHANNELS]; ///< fixed-point coefficient shift values
+ uint8_t new_rematrixing_strategy; ///< send new rematrixing flags in this block
+ uint8_t rematrixing_flags[4]; ///< rematrixing flags
+ struct AC3Block *exp_ref_block[AC3_MAX_CHANNELS]; ///< reference blocks for EXP_REUSE
} AC3Block;
/**
* AC-3 encoder private context.
*/
typedef struct AC3EncodeContext {
+ AVClass *av_class; ///< AVClass used for AVOption
+ AC3EncOptions options; ///< encoding options
PutBitContext pb; ///< bitstream writer context
DSPContext dsp;
+ AC3DSPContext ac3dsp; ///< AC-3 optimized functions
AC3MDCTContext mdct; ///< MDCT context
AC3Block blocks[AC3_MAX_BLOCKS]; ///< per-block info
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)
+ uint16_t crc_inv[2];
int bits_written; ///< bit count (used to avg. bitrate)
int samples_written; ///< sample count (used to avg. bitrate)
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 has_center; ///< indicates if there is a center channel
+ int has_surround; ///< indicates if there are one or more surround channels
int channel_mode; ///< channel mode (acmod)
const uint8_t *channel_map; ///< channel map used to reorder channels
+ int center_mix_level; ///< center mix level code
+ int surround_mix_level; ///< surround mix level code
+ int ltrt_center_mix_level; ///< Lt/Rt center mix level code
+ int ltrt_surround_mix_level; ///< Lt/Rt surround mix level code
+ int loro_center_mix_level; ///< Lo/Ro center mix level code
+ int loro_surround_mix_level; ///< Lo/Ro surround mix level code
+
+ int cutoff; ///< user-specified cutoff frequency, in Hz
int bandwidth_code[AC3_MAX_CHANNELS]; ///< bandwidth code (0 to 60) (chbwcod)
int nb_coefs[AC3_MAX_CHANNELS];
+ int rematrixing_enabled; ///< stereo rematrixing enabled
+ int num_rematrixing_bands; ///< number of rematrixing bands
+
/* bitrate allocation control */
int slow_gain_code; ///< slow gain code (sgaincod)
int slow_decay_code; ///< slow decay code (sdcycod)
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)
+ int frame_bits_fixed; ///< number of non-coefficient bits for fixed parameters
int frame_bits; ///< all frame bits except exponents and mantissas
int exponent_bits; ///< number of bits used for exponents
- /* mantissa encoding */
- int mant1_cnt, mant2_cnt, mant4_cnt; ///< mantissa counts for bap=1,2,4
- uint16_t *qmant1_ptr, *qmant2_ptr, *qmant4_ptr; ///< mantissa pointers for bap=1,2,4
-
- int16_t **planar_samples;
+ SampleType **planar_samples;
uint8_t *bap_buffer;
uint8_t *bap1_buffer;
- int32_t *mdct_coef_buffer;
+ CoefType *mdct_coef_buffer;
+ int32_t *fixed_coef_buffer;
uint8_t *exp_buffer;
uint8_t *grouped_exp_buffer;
int16_t *psd_buffer;
int16_t *mask_buffer;
uint16_t *qmant_buffer;
- DECLARE_ALIGNED(16, int16_t, windowed_samples)[AC3_WINDOW_SIZE];
+ uint8_t exp_strategy[AC3_MAX_CHANNELS][AC3_MAX_BLOCKS]; ///< exponent strategies
+
+ DECLARE_ALIGNED(32, SampleType, windowed_samples)[AC3_WINDOW_SIZE];
} AC3EncodeContext;
+typedef struct AC3Mant {
+ uint16_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 CMIXLEV_NUM_OPTIONS 3
+static const float cmixlev_options[CMIXLEV_NUM_OPTIONS] = {
+ LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB
+};
+
+#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
+};
+
+
+#define OFFSET(param) offsetof(AC3EncodeContext, options.param)
+#define AC3ENC_PARAM (AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM)
+
+static const AVOption options[] = {
+/* Metadata Options */
+{"per_frame_metadata", "Allow Changing Metadata Per-Frame", OFFSET(allow_per_frame_metadata), FF_OPT_TYPE_INT, 0, 0, 1, AC3ENC_PARAM},
+/* downmix levels */
+{"center_mixlev", "Center Mix Level", OFFSET(center_mix_level), FF_OPT_TYPE_FLOAT, LEVEL_MINUS_4POINT5DB, 0.0, 1.0, AC3ENC_PARAM},
+{"surround_mixlev", "Surround Mix Level", OFFSET(surround_mix_level), FF_OPT_TYPE_FLOAT, LEVEL_MINUS_6DB, 0.0, 1.0, AC3ENC_PARAM},
+/* audio production information */
+{"mixing_level", "Mixing Level", OFFSET(mixing_level), FF_OPT_TYPE_INT, -1, -1, 111, AC3ENC_PARAM},
+{"room_type", "Room Type", OFFSET(room_type), FF_OPT_TYPE_INT, -1, -1, 2, AC3ENC_PARAM, "room_type"},
+ {"notindicated", "Not Indicated (default)", 0, FF_OPT_TYPE_CONST, 0, INT_MIN, INT_MAX, AC3ENC_PARAM, "room_type"},
+ {"large", "Large Room", 0, FF_OPT_TYPE_CONST, 1, INT_MIN, INT_MAX, AC3ENC_PARAM, "room_type"},
+ {"small", "Small Room", 0, FF_OPT_TYPE_CONST, 2, INT_MIN, INT_MAX, AC3ENC_PARAM, "room_type"},
+/* other metadata options */
+{"copyright", "Copyright Bit", OFFSET(copyright), FF_OPT_TYPE_INT, 0, 0, 1, AC3ENC_PARAM},
+{"dialnorm", "Dialogue Level (dB)", OFFSET(dialogue_level), FF_OPT_TYPE_INT, -31, -31, -1, AC3ENC_PARAM},
+{"dsur_mode", "Dolby Surround Mode", OFFSET(dolby_surround_mode), FF_OPT_TYPE_INT, 0, 0, 2, AC3ENC_PARAM, "dsur_mode"},
+ {"notindicated", "Not Indicated (default)", 0, FF_OPT_TYPE_CONST, 0, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsur_mode"},
+ {"on", "Dolby Surround Encoded", 0, FF_OPT_TYPE_CONST, 1, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsur_mode"},
+ {"off", "Not Dolby Surround Encoded", 0, FF_OPT_TYPE_CONST, 2, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsur_mode"},
+{"original", "Original Bit Stream", OFFSET(original), FF_OPT_TYPE_INT, 1, 0, 1, AC3ENC_PARAM},
+/* extended bitstream information */
+{"dmix_mode", "Preferred Stereo Downmix Mode", OFFSET(preferred_stereo_downmix), FF_OPT_TYPE_INT, -1, -1, 2, AC3ENC_PARAM, "dmix_mode"},
+ {"notindicated", "Not Indicated (default)", 0, FF_OPT_TYPE_CONST, 0, INT_MIN, INT_MAX, AC3ENC_PARAM, "dmix_mode"},
+ {"ltrt", "Lt/Rt Downmix Preferred", 0, FF_OPT_TYPE_CONST, 1, INT_MIN, INT_MAX, AC3ENC_PARAM, "dmix_mode"},
+ {"loro", "Lo/Ro Downmix Preferred", 0, FF_OPT_TYPE_CONST, 2, INT_MIN, INT_MAX, AC3ENC_PARAM, "dmix_mode"},
+{"ltrt_cmixlev", "Lt/Rt Center Mix Level", OFFSET(ltrt_center_mix_level), FF_OPT_TYPE_FLOAT, -1.0, -1.0, 2.0, AC3ENC_PARAM},
+{"ltrt_surmixlev", "Lt/Rt Surround Mix Level", OFFSET(ltrt_surround_mix_level), FF_OPT_TYPE_FLOAT, -1.0, -1.0, 2.0, AC3ENC_PARAM},
+{"loro_cmixlev", "Lo/Ro Center Mix Level", OFFSET(loro_center_mix_level), FF_OPT_TYPE_FLOAT, -1.0, -1.0, 2.0, AC3ENC_PARAM},
+{"loro_surmixlev", "Lo/Ro Surround Mix Level", OFFSET(loro_surround_mix_level), FF_OPT_TYPE_FLOAT, -1.0, -1.0, 2.0, AC3ENC_PARAM},
+{"dsurex_mode", "Dolby Surround EX Mode", OFFSET(dolby_surround_ex_mode), FF_OPT_TYPE_INT, -1, -1, 2, AC3ENC_PARAM, "dsurex_mode"},
+ {"notindicated", "Not Indicated (default)", 0, FF_OPT_TYPE_CONST, 0, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsurex_mode"},
+ {"on", "Dolby Surround EX Encoded", 0, FF_OPT_TYPE_CONST, 1, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsurex_mode"},
+ {"off", "Not Dolby Surround EX Encoded", 0, FF_OPT_TYPE_CONST, 2, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsurex_mode"},
+{"dheadphone_mode", "Dolby Headphone Mode", OFFSET(dolby_headphone_mode), FF_OPT_TYPE_INT, -1, -1, 2, AC3ENC_PARAM, "dheadphone_mode"},
+ {"notindicated", "Not Indicated (default)", 0, FF_OPT_TYPE_CONST, 0, INT_MIN, INT_MAX, AC3ENC_PARAM, "dheadphone_mode"},
+ {"on", "Dolby Headphone Encoded", 0, FF_OPT_TYPE_CONST, 1, INT_MIN, INT_MAX, AC3ENC_PARAM, "dheadphone_mode"},
+ {"off", "Not Dolby Headphone Encoded", 0, FF_OPT_TYPE_CONST, 2, INT_MIN, INT_MAX, AC3ENC_PARAM, "dheadphone_mode"},
+{"ad_conv_type", "A/D Converter Type", OFFSET(ad_converter_type), FF_OPT_TYPE_INT, -1, -1, 1, AC3ENC_PARAM, "ad_conv_type"},
+ {"standard", "Standard (default)", 0, FF_OPT_TYPE_CONST, 0, INT_MIN, INT_MAX, AC3ENC_PARAM, "ad_conv_type"},
+ {"hdcd", "HDCD", 0, FF_OPT_TYPE_CONST, 1, INT_MIN, INT_MAX, AC3ENC_PARAM, "ad_conv_type"},
+/* Other Encoding Options */
+{"stereo_rematrixing", "Stereo Rematrixing", OFFSET(stereo_rematrixing), FF_OPT_TYPE_INT, 1, 0, 1, AC3ENC_PARAM},
+{NULL}
+};
+
+#if CONFIG_AC3ENC_FLOAT
+static AVClass ac3enc_class = { "AC-3 Encoder", av_default_item_name,
+ options, LIBAVUTIL_VERSION_INT };
+#else
+static AVClass ac3enc_class = { "Fixed-Point AC-3 Encoder", av_default_item_name,
+ options, LIBAVUTIL_VERSION_INT };
+#endif
+
+
+/* prototypes for functions in ac3enc_fixed.c and ac3enc_float.c */
-/** 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 av_cold void mdct_end(AC3MDCTContext *mdct);
+
+static av_cold int mdct_init(AVCodecContext *avctx, AC3MDCTContext *mdct,
+ int nbits);
+
+static void apply_window(DSPContext *dsp, SampleType *output, const SampleType *input,
+ const SampleType *window, unsigned int len);
+
+static int normalize_samples(AC3EncodeContext *s);
+
+static void scale_coefficients(AC3EncodeContext *s);
+
+
+/**
+ * LUT for number of exponent groups.
+ * exponent_group_tab[exponent strategy-1][number of coefficients]
+ */
+static uint8_t exponent_group_tab[3][256];
+
+
+/**
+ * List of supported channel layouts.
+ */
+static const int64_t ac3_channel_layouts[] = {
+ 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
+};
+
+
+/**
+ * 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 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
+
+ { { 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 } },
+
+ { { 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 } },
+
+ { { 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 } },
+
+ { { 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 } }
+};
/**
/**
* Deinterleave input samples.
- * Channels are reordered from FFmpeg's default order to AC-3 order.
+ * Channels are reordered from Libav's default order to AC-3 order.
*/
static void deinterleave_input_samples(AC3EncodeContext *s,
- const int16_t *samples)
+ const SampleType *samples)
{
int ch, i;
/* deinterleave and remap input samples */
for (ch = 0; ch < s->channels; ch++) {
- const int16_t *sptr;
+ const SampleType *sptr;
int sinc;
/* copy last 256 samples of previous frame to the start of the current frame */
/**
- * Finalize MDCT and free allocated memory.
+ * Apply the MDCT to input samples to generate frequency coefficients.
+ * This applies the KBD window and normalizes the input to reduce precision
+ * loss due to fixed-point calculations.
*/
-static av_cold void mdct_end(AC3MDCTContext *mdct)
+static void apply_mdct(AC3EncodeContext *s)
{
- av_freep(&mdct->rot_tmp);
- av_freep(&mdct->cplx_tmp);
-}
-
+ int blk, ch;
+ for (ch = 0; ch < s->channels; ch++) {
+ for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ const SampleType *input_samples = &s->planar_samples[ch][blk * AC3_BLOCK_SIZE];
-/**
- * Initialize FFT tables.
- * @param ln log2(FFT size)
- */
-static av_cold void fft_init(int ln)
-{
- int i, n, n2;
- float alpha;
+ apply_window(&s->dsp, s->windowed_samples, input_samples, s->mdct.window, AC3_WINDOW_SIZE);
- n = 1 << ln;
- n2 = n >> 1;
+ block->coeff_shift[ch] = normalize_samples(s);
- for (i = 0; i < n2; i++) {
- alpha = 2.0 * M_PI * i / n;
- costab[i] = FIX15(cos(alpha));
- sintab[i] = FIX15(sin(alpha));
+ s->mdct.fft.mdct_calcw(&s->mdct.fft, block->mdct_coef[ch],
+ s->windowed_samples);
+ }
}
}
/**
- * Initialize MDCT tables.
- * @param nbits log2(MDCT size)
+ * Determine rematrixing flags for each block and band.
*/
-static av_cold int mdct_init(AC3MDCTContext *mdct, int nbits)
+static void compute_rematrixing_strategy(AC3EncodeContext *s)
{
- int i, n, n4;
-
- n = 1 << nbits;
- n4 = n >> 2;
-
- fft_init(nbits - 2);
-
- FF_ALLOC_OR_GOTO(mdct->avctx, mdct->rot_tmp, n * sizeof(*mdct->rot_tmp),
- mdct_alloc_fail);
- FF_ALLOC_OR_GOTO(mdct->avctx, mdct->cplx_tmp, n4 * sizeof(*mdct->cplx_tmp),
- mdct_alloc_fail);
-
- 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));
- }
-
- return 0;
-mdct_alloc_fail:
- return AVERROR(ENOMEM);
-}
+ int nb_coefs;
+ int blk, bnd, i;
+ AC3Block *block, *block0;
+ if (s->channel_mode != AC3_CHMODE_STEREO)
+ return;
-/** 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; \
-}
+ s->num_rematrixing_bands = 4;
+ nb_coefs = FFMIN(s->nb_coefs[0], s->nb_coefs[1]);
-/** 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; \
-}
+ for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
+ block = &s->blocks[blk];
+ block->new_rematrixing_strategy = !blk;
+ if (!s->rematrixing_enabled)
+ continue;
+ for (bnd = 0; bnd < s->num_rematrixing_bands; bnd++) {
+ /* calculate calculate sum of squared coeffs for one band in one block */
+ int start = ff_ac3_rematrix_band_tab[bnd];
+ int end = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
+ CoefSumType sum[4] = {0,};
+ for (i = start; i < end; i++) {
+ CoefType lt = block->mdct_coef[0][i];
+ CoefType rt = block->mdct_coef[1][i];
+ CoefType md = lt + rt;
+ CoefType sd = lt - rt;
+ MAC_COEF(sum[0], lt, lt);
+ MAC_COEF(sum[1], rt, rt);
+ MAC_COEF(sum[2], md, md);
+ MAC_COEF(sum[3], sd, sd);
+ }
+ /* compare sums to determine if rematrixing will be used for this band */
+ if (FFMIN(sum[2], sum[3]) < FFMIN(sum[0], sum[1]))
+ block->rematrixing_flags[bnd] = 1;
+ else
+ block->rematrixing_flags[bnd] = 0;
-/**
- * Calculate a 2^n point complex FFT on 2^ln points.
- * @param z complex input/output samples
- * @param ln log2(FFT size)
- */
-static void fft(IComplex *z, int ln)
-{
- 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++;
+ /* determine if new rematrixing flags will be sent */
+ if (blk &&
+ block->rematrixing_flags[bnd] != block0->rematrixing_flags[bnd]) {
+ block->new_rematrixing_strategy = 1;
}
- p += nloops;
- q += nloops;
}
- nblocks = nblocks >> 1;
- nloops = nloops << 1;
- } while (nblocks);
-}
-
-
-/**
- * Calculate a 512-point MDCT
- * @param out 256 output frequency coefficients
- * @param in 512 windowed input audio samples
- */
-static void mdct512(AC3MDCTContext *mdct, int32_t *out, int16_t *in)
-{
- int i, re, im;
- int16_t *rot = mdct->rot_tmp;
- IComplex *x = mdct->cplx_tmp;
-
- /* shift to simplify computations */
- for (i = 0; i < MDCT_SAMPLES/4; i++)
- rot[i] = -in[i + 3*MDCT_SAMPLES/4];
- memcpy(&rot[MDCT_SAMPLES/4], &in[0], 3*MDCT_SAMPLES/4*sizeof(*in));
-
- /* 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]);
- }
-
- fft(x, MDCT_NBITS - 2);
-
- /* post rotation */
- for (i = 0; i < MDCT_SAMPLES/4; i++) {
- re = x[i].re;
- im = x[i].im;
- CMUL(out[MDCT_SAMPLES/2-1-2*i], out[2*i], re, im, xsin1[i], xcos1[i]);
+ block0 = block;
}
}
/**
- * Apply KBD window to input samples prior to MDCT.
+ * Apply stereo rematrixing to coefficients based on rematrixing flags.
*/
-static void apply_window(int16_t *output, const int16_t *input,
- const int16_t *window, int n)
+static void apply_rematrixing(AC3EncodeContext *s)
{
- int i;
- int n2 = n >> 1;
-
- for (i = 0; i < n2; i++) {
- output[i] = MUL16(input[i], window[i]) >> 15;
- output[n-i-1] = MUL16(input[n-i-1], window[i]) >> 15;
- }
-}
-
-
-/**
- * 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[])))
- */
-static int log2_tab(int16_t *tab, int n)
-{
- int i, v;
-
- v = 0;
- for (i = 0; i < n; i++)
- v |= abs(tab[i]);
-
- return av_log2(v);
-}
+ int nb_coefs;
+ int blk, bnd, i;
+ int start, end;
+ uint8_t *flags;
+ if (!s->rematrixing_enabled)
+ return;
-/**
- * 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.
- */
-static void lshift_tab(int16_t *tab, int n, int lshift)
-{
- int i;
+ nb_coefs = FFMIN(s->nb_coefs[0], s->nb_coefs[1]);
- 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 (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ if (block->new_rematrixing_strategy)
+ flags = block->rematrixing_flags;
+ for (bnd = 0; bnd < s->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[0][i];
+ int32_t rt = block->fixed_coef[1][i];
+ block->fixed_coef[0][i] = (lt + rt) >> 1;
+ block->fixed_coef[1][i] = (lt - rt) >> 1;
+ }
+ }
+ }
}
}
/**
- * Normalize the input samples to use the maximum available precision.
- * This assumes signed 16-bit input samples. Exponents are reduced by 9 to
- * match the 24-bit internal precision for MDCT coefficients.
- *
- * @return exponent shift
- */
-static int normalize_samples(AC3EncodeContext *s)
-{
- int v = 14 - log2_tab(s->windowed_samples, AC3_WINDOW_SIZE);
- v = FFMAX(0, v);
- lshift_tab(s->windowed_samples, AC3_WINDOW_SIZE, v);
- return v - 9;
-}
-
-
-/**
- * Apply the MDCT to input samples to generate frequency coefficients.
- * This applies the KBD window and normalizes the input to reduce precision
- * loss due to fixed-point calculations.
+ * Initialize exponent tables.
*/
-static void apply_mdct(AC3EncodeContext *s)
+static av_cold void exponent_init(AC3EncodeContext *s)
{
- int blk, ch;
-
- for (ch = 0; ch < s->channels; ch++) {
- for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
- AC3Block *block = &s->blocks[blk];
- const int16_t *input_samples = &s->planar_samples[ch][blk * AC3_BLOCK_SIZE];
+ int expstr, i, grpsize;
- apply_window(s->windowed_samples, input_samples, ff_ac3_window, AC3_WINDOW_SIZE);
-
- block->exp_shift[ch] = normalize_samples(s);
-
- mdct512(&s->mdct, block->mdct_coef[ch], s->windowed_samples);
+ for (expstr = EXP_D15-1; expstr <= EXP_D45-1; expstr++) {
+ grpsize = 3 << expstr;
+ for (i = 73; i < 256; i++) {
+ exponent_group_tab[expstr][i] = (i + grpsize - 4) / grpsize;
}
}
+ /* LFE */
+ exponent_group_tab[0][7] = 2;
}
*/
static void extract_exponents(AC3EncodeContext *s)
{
- int blk, ch, i;
+ int blk, ch;
for (ch = 0; ch < s->channels; ch++) {
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
AC3Block *block = &s->blocks[blk];
- for (i = 0; i < AC3_MAX_COEFS; i++) {
- int e;
- int v = abs(block->mdct_coef[ch][i]);
- if (v == 0)
- e = 24;
- else {
- e = 23 - av_log2(v) + block->exp_shift[ch];
- if (e >= 24) {
- e = 24;
- block->mdct_coef[ch][i] = 0;
- }
- }
- block->exp[ch][i] = e;
- }
+ s->ac3dsp.extract_exponents(block->exp[ch], block->fixed_coef[ch],
+ AC3_MAX_COEFS);
}
}
}
* 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.
*/
-static void compute_exp_strategy_ch(AC3EncodeContext *s, uint8_t *exp_strategy, uint8_t **exp)
+static void compute_exp_strategy_ch(AC3EncodeContext *s, uint8_t *exp_strategy,
+ uint8_t *exp)
{
int blk, blk1;
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 < AC3_MAX_BLOCKS; blk++) {
- exp_diff = s->dsp.sad[0](NULL, exp[blk], exp[blk-1], 16, 16);
+ exp_diff = s->dsp.sad[0](NULL, exp, exp - AC3_MAX_COEFS, 16, 16);
if (exp_diff > EXP_DIFF_THRESHOLD)
exp_strategy[blk] = EXP_NEW;
else
exp_strategy[blk] = EXP_REUSE;
+ exp += AC3_MAX_COEFS;
}
/* now select the encoding strategy type : if exponents are often
*/
static void compute_exp_strategy(AC3EncodeContext *s)
{
- uint8_t *exp1[AC3_MAX_CHANNELS][AC3_MAX_BLOCKS];
- uint8_t exp_str1[AC3_MAX_CHANNELS][AC3_MAX_BLOCKS];
int ch, blk;
for (ch = 0; ch < s->fbw_channels; ch++) {
- for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
- exp1[ch][blk] = s->blocks[blk].exp[ch];
- exp_str1[ch][blk] = s->blocks[blk].exp_strategy[ch];
- }
-
- compute_exp_strategy_ch(s, exp_str1[ch], exp1[ch]);
-
- for (blk = 0; blk < AC3_MAX_BLOCKS; blk++)
- s->blocks[blk].exp_strategy[ch] = exp_str1[ch][blk];
+ compute_exp_strategy_ch(s, s->exp_strategy[ch], s->blocks[0].exp[ch]);
}
if (s->lfe_on) {
ch = s->lfe_channel;
- s->blocks[0].exp_strategy[ch] = EXP_D15;
+ s->exp_strategy[ch][0] = EXP_D15;
for (blk = 1; blk < AC3_MAX_BLOCKS; blk++)
- s->blocks[blk].exp_strategy[ch] = EXP_REUSE;
- }
-}
-
-
-/**
- * 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, uint8_t *exp1, int n)
-{
- int i;
- for (i = 0; i < n; i++) {
- if (exp1[i] < exp[i])
- exp[i] = exp1[i];
+ s->exp_strategy[ch][blk] = EXP_REUSE;
}
}
/**
* Update the exponents so that they are the ones the decoder will decode.
*/
-static void encode_exponents_blk_ch(uint8_t *exp,
- int nb_exps, int exp_strategy,
- uint8_t *num_exp_groups)
+static void encode_exponents_blk_ch(uint8_t *exp, int nb_exps, int exp_strategy)
{
- int group_size, nb_groups, i, k;
+ int nb_groups, i, k;
- group_size = exp_strategy + (exp_strategy == EXP_D45);
- *num_exp_groups = (nb_exps + (group_size * 3) - 4) / (3 * group_size);
- nb_groups = *num_exp_groups * 3;
+ nb_groups = exponent_group_tab[exp_strategy-1][nb_exps] * 3;
/* for each group, compute the minimum exponent */
switch(exp_strategy) {
*/
static void encode_exponents(AC3EncodeContext *s)
{
- int blk, blk1, blk2, ch;
- AC3Block *block, *block1, *block2;
+ int blk, blk1, ch;
+ uint8_t *exp, *exp_strategy;
+ int nb_coefs, num_reuse_blocks;
for (ch = 0; ch < s->channels; ch++) {
+ exp = s->blocks[0].exp[ch];
+ exp_strategy = s->exp_strategy[ch];
+ nb_coefs = s->nb_coefs[ch];
+
blk = 0;
- block = &s->blocks[0];
while (blk < AC3_MAX_BLOCKS) {
blk1 = blk + 1;
- block1 = block + 1;
- /* for the EXP_REUSE case we select the min of the exponents */
- while (blk1 < AC3_MAX_BLOCKS && block1->exp_strategy[ch] == EXP_REUSE) {
- exponent_min(block->exp[ch], block1->exp[ch], s->nb_coefs[ch]);
+
+ /* count the number of EXP_REUSE blocks after the current block
+ and set exponent reference block pointers */
+ s->blocks[blk].exp_ref_block[ch] = &s->blocks[blk];
+ while (blk1 < AC3_MAX_BLOCKS && exp_strategy[blk1] == EXP_REUSE) {
+ s->blocks[blk1].exp_ref_block[ch] = &s->blocks[blk];
blk1++;
- block1++;
- }
- encode_exponents_blk_ch(block->exp[ch], s->nb_coefs[ch],
- block->exp_strategy[ch],
- &block->num_exp_groups[ch]);
- /* copy encoded exponents for reuse case */
- block2 = block + 1;
- for (blk2 = blk+1; blk2 < blk1; blk2++, block2++) {
- memcpy(block2->exp[ch], block->exp[ch],
- s->nb_coefs[ch] * sizeof(uint8_t));
}
+ num_reuse_blocks = blk1 - blk - 1;
+
+ /* for the EXP_REUSE case we select the min of the exponents */
+ s->ac3dsp.ac3_exponent_min(exp, num_reuse_blocks, nb_coefs);
+
+ encode_exponents_blk_ch(exp, nb_coefs, exp_strategy[blk]);
+
+ exp += AC3_MAX_COEFS * (num_reuse_blocks + 1);
blk = blk1;
- block = block1;
}
}
}
static void group_exponents(AC3EncodeContext *s)
{
int blk, ch, i;
- int group_size, bit_count;
+ int group_size, nb_groups, bit_count;
uint8_t *p;
int delta0, delta1, delta2;
int exp0, exp1;
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
AC3Block *block = &s->blocks[blk];
for (ch = 0; ch < s->channels; ch++) {
- if (block->exp_strategy[ch] == EXP_REUSE) {
- block->num_exp_groups[ch] = 0;
+ int exp_strategy = s->exp_strategy[ch][blk];
+ if (exp_strategy == EXP_REUSE)
continue;
- }
- group_size = block->exp_strategy[ch] + (block->exp_strategy[ch] == EXP_D45);
- bit_count += 4 + (block->num_exp_groups[ch] * 7);
+ group_size = exp_strategy + (exp_strategy == EXP_D45);
+ nb_groups = exponent_group_tab[exp_strategy-1][s->nb_coefs[ch]];
+ bit_count += 4 + (nb_groups * 7);
p = block->exp[ch];
/* DC exponent */
block->grouped_exp[ch][0] = exp1;
/* remaining exponents are delta encoded */
- for (i = 1; i <= block->num_exp_groups[ch]; i++) {
+ 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;
}
encode_exponents(s);
group_exponents(s);
+
+ emms_c();
+}
+
+
+/**
+ * Count frame bits that are based solely on fixed parameters.
+ * This only has to be run once when the encoder is initialized.
+ */
+static void count_frame_bits_fixed(AC3EncodeContext *s)
+{
+ 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
+ * no channel coupling
+ * bit allocation parameters do not change between blocks
+ * SNR offsets do not change between blocks
+ * no delta bit allocation
+ * no skipped data
+ * no auxilliary data
+ */
+
+ /* header size */
+ frame_bits = 65;
+ frame_bits += frame_bits_inc[s->channel_mode];
+
+ /* audio blocks */
+ for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
+ frame_bits += s->fbw_channels * 2 + 2; /* blksw * c, dithflag * c, dynrnge, cplstre */
+ if (s->channel_mode == AC3_CHMODE_STEREO) {
+ frame_bits++; /* rematstr */
+ }
+ frame_bits += 2 * s->fbw_channels; /* chexpstr[2] * c */
+ if (s->lfe_on)
+ frame_bits++; /* lfeexpstr */
+ 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;
+
+ /* CRC */
+ frame_bits += 16;
+
+ s->frame_bits_fixed = frame_bits;
}
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;
+ s->db_per_bit_code = 3;
+ s->floor_code = 7;
for (ch = 0; ch < s->channels; ch++)
s->fast_gain_code[ch] = 4;
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];
+
+ count_frame_bits_fixed(s);
}
/**
* 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)
{
- static const int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
+ AC3EncOptions *opt = &s->options;
int blk, ch;
- int frame_bits;
-
- /* header size */
- frame_bits = 65;
- frame_bits += frame_bits_inc[s->channel_mode];
+ int frame_bits = 0;
+
+ 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 */
- if (s->channel_mode == AC3_CHMODE_STEREO) {
- frame_bits++; /* rematstr */
- if (!blk)
- frame_bits += 4;
+ /* stereo rematrixing */
+ if (s->channel_mode == AC3_CHMODE_STEREO &&
+ s->blocks[blk].new_rematrixing_strategy) {
+ frame_bits += s->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 (s->blocks[blk].exp_strategy[ch] != EXP_REUSE)
+ if (s->exp_strategy[ch][blk] != EXP_REUSE)
frame_bits += 6 + 2; /* chbwcod[6], gainrng[2] */
}
- 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;
-
- /* CRC */
- frame_bits += 16;
-
- s->frame_bits = frame_bits;
+ s->frame_bits = s->frame_bits_fixed + frame_bits;
}
/**
- * Calculate the number of bits needed to encode a set of mantissas.
+ * Finalize the mantissa bit count by adding in the grouped mantissas.
*/
-static int compute_mantissa_size(AC3EncodeContext *s, uint8_t *bap, int nb_coefs)
+static int compute_mantissa_size_final(int mant_cnt[5])
{
- int bits, b, i;
-
- bits = 0;
- for (i = 0; i < nb_coefs; i++) {
- b = bap[i];
- switch (b) {
- case 0:
- /* bap=0 mantissas are not encoded */
- break;
- case 1:
- /* 3 mantissas in 5 bits */
- if (s->mant1_cnt == 0)
- bits += 5;
- if (++s->mant1_cnt == 3)
- s->mant1_cnt = 0;
- break;
- case 2:
- /* 3 mantissas 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 mantissas 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 += b - 1;
- break;
- }
- }
+ // bap=1 : 3 mantissas in 5 bits
+ int bits = (mant_cnt[1] / 3) * 5;
+ // bap=2 : 3 mantissas in 7 bits
+ // bap=4 : 2 mantissas in 7 bits
+ bits += ((mant_cnt[2] / 3) + (mant_cnt[4] >> 1)) * 7;
+ // bap=3 : each mantissa is 3 bits
+ bits += mant_cnt[3] * 3;
return bits;
}
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
AC3Block *block = &s->blocks[blk];
for (ch = 0; ch < s->channels; ch++) {
- if (block->exp_strategy[ch] == EXP_REUSE) {
- AC3Block *block1 = &s->blocks[blk-1];
- memcpy(block->psd[ch], block1->psd[ch], AC3_MAX_COEFS*sizeof(block->psd[0][0]));
- memcpy(block->mask[ch], block1->mask[ch], AC3_CRITICAL_BANDS*sizeof(block->mask[0][0]));
- } else {
+ /* 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], 0,
s->nb_coefs[ch],
block->psd[ch], block->band_psd[ch]);
* @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)
+static int bit_alloc(AC3EncodeContext *s, int snr_offset)
{
int blk, ch;
int mantissa_bits;
+ int mant_cnt[5];
snr_offset = (snr_offset - 240) << 2;
mantissa_bits = 0;
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
AC3Block *block = &s->blocks[blk];
- s->mant1_cnt = 0;
- s->mant2_cnt = 0;
- s->mant4_cnt = 0;
+ AC3Block *ref_block;
+ // initialize grouped mantissa counts. these are set so that they are
+ // padded to the next whole group size when bits are counted in
+ // compute_mantissa_size_final
+ mant_cnt[0] = mant_cnt[3] = 0;
+ mant_cnt[1] = mant_cnt[2] = 2;
+ mant_cnt[4] = 1;
for (ch = 0; ch < s->channels; ch++) {
- ff_ac3_bit_alloc_calc_bap(block->mask[ch], block->psd[ch], 0,
- s->nb_coefs[ch], snr_offset,
- s->bit_alloc.floor, ff_ac3_bap_tab,
- block->bap[ch]);
- mantissa_bits += compute_mantissa_size(s, block->bap[ch], s->nb_coefs[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. */
+ ref_block = block->exp_ref_block[ch];
+ if (s->exp_strategy[ch][blk] != EXP_REUSE) {
+ s->ac3dsp.bit_alloc_calc_bap(ref_block->mask[ch],
+ ref_block->psd[ch], 0,
+ s->nb_coefs[ch], snr_offset,
+ s->bit_alloc.floor, ff_ac3_bap_tab,
+ ref_block->bap[ch]);
+ }
+ mantissa_bits += s->ac3dsp.compute_mantissa_size(mant_cnt,
+ ref_block->bap[ch],
+ s->nb_coefs[ch]);
}
+ mantissa_bits += compute_mantissa_size_final(mant_cnt);
}
return mantissa_bits;
}
{
int ch;
int bits_left;
- int snr_offset;
+ int snr_offset, snr_incr;
bits_left = 8 * s->frame_size - (s->frame_bits + s->exponent_bits);
+ av_assert2(bits_left >= 0);
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[0]) == 1023) {
+ if (bit_alloc(s, 1023) <= bits_left)
+ return 0;
+ }
+
while (snr_offset >= 0 &&
bit_alloc(s, snr_offset) > bits_left) {
snr_offset -= 64;
return AVERROR(EINVAL);
FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
- while (snr_offset + 64 <= 1023 &&
- bit_alloc(s, snr_offset + 64) <= bits_left) {
- snr_offset += 64;
- FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
- }
- while (snr_offset + 16 <= 1023 &&
- bit_alloc(s, snr_offset + 16) <= bits_left) {
- snr_offset += 16;
- FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
- }
- while (snr_offset + 4 <= 1023 &&
- bit_alloc(s, snr_offset + 4) <= bits_left) {
- snr_offset += 4;
- FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
- }
- while (snr_offset + 1 <= 1023 &&
- bit_alloc(s, snr_offset + 1) <= bits_left) {
- snr_offset++;
- 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);
}
+/**
+ * Downgrade exponent strategies to reduce the bits used by the exponents.
+ * This is a fallback for when bit allocation fails with the normal exponent
+ * strategies. Each time this function is run it only downgrades the
+ * strategy in 1 channel of 1 block.
+ * @return non-zero if downgrade was unsuccessful
+ */
+static int downgrade_exponents(AC3EncodeContext *s)
+{
+ int ch, blk;
+
+ for (ch = 0; ch < s->fbw_channels; ch++) {
+ for (blk = AC3_MAX_BLOCKS-1; blk >= 0; blk--) {
+ if (s->exp_strategy[ch][blk] == EXP_D15) {
+ s->exp_strategy[ch][blk] = EXP_D25;
+ return 0;
+ }
+ }
+ }
+ for (ch = 0; ch < s->fbw_channels; ch++) {
+ for (blk = AC3_MAX_BLOCKS-1; blk >= 0; blk--) {
+ if (s->exp_strategy[ch][blk] == EXP_D25) {
+ s->exp_strategy[ch][blk] = EXP_D45;
+ return 0;
+ }
+ }
+ }
+ for (ch = 0; ch < s->fbw_channels; ch++) {
+ /* block 0 cannot reuse exponents, so only downgrade D45 to REUSE if
+ the block number > 0 */
+ for (blk = AC3_MAX_BLOCKS-1; blk > 0; blk--) {
+ if (s->exp_strategy[ch][blk] > EXP_REUSE) {
+ s->exp_strategy[ch][blk] = EXP_REUSE;
+ return 0;
+ }
+ }
+ }
+ return -1;
+}
+
+
+/**
+ * Reduce the bandwidth to reduce the number of bits used for a given SNR offset.
+ * This is a second fallback for when bit allocation still fails after exponents
+ * have been downgraded.
+ * @return non-zero if bandwidth reduction was unsuccessful
+ */
+static int reduce_bandwidth(AC3EncodeContext *s, int min_bw_code)
+{
+ int ch;
+
+ if (s->bandwidth_code[0] > min_bw_code) {
+ for (ch = 0; ch < s->fbw_channels; ch++) {
+ s->bandwidth_code[ch]--;
+ s->nb_coefs[ch] = s->bandwidth_code[ch] * 3 + 73;
+ }
+ return 0;
+ }
+ return -1;
+}
+
+
/**
* Perform bit allocation search.
* Finds the SNR offset value that maximizes quality and fits in the specified
*/
static int compute_bit_allocation(AC3EncodeContext *s)
{
+ int ret;
+
count_frame_bits(s);
bit_alloc_masking(s);
- return cbr_bit_allocation(s);
+ ret = cbr_bit_allocation(s);
+ while (ret) {
+ /* fallback 1: downgrade exponents */
+ if (!downgrade_exponents(s)) {
+ extract_exponents(s);
+ encode_exponents(s);
+ group_exponents(s);
+ ret = compute_bit_allocation(s);
+ continue;
+ }
+
+ /* fallback 2: reduce bandwidth */
+ /* only do this if the user has not specified a specific cutoff
+ frequency */
+ if (!s->cutoff && !reduce_bandwidth(s, 0)) {
+ process_exponents(s);
+ ret = compute_bit_allocation(s);
+ continue;
+ }
+
+ /* fallbacks were not enough... */
+ break;
+ }
+
+ return ret;
}
*/
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;
}
m = (1 << (qbits-1));
if (v >= m)
v = m - 1;
- assert(v >= -m);
+ av_assert2(v >= -m);
return v & ((1 << qbits)-1);
}
/**
* Quantize a set of mantissas for a single channel in a single block.
*/
-static void quantize_mantissas_blk_ch(AC3EncodeContext *s,
- int32_t *mdct_coef, int8_t exp_shift,
- uint8_t *exp, uint8_t *bap,
- uint16_t *qmant, int n)
+static void quantize_mantissas_blk_ch(AC3Mant *s, int32_t *fixed_coef,
+ uint8_t *exp,
+ uint8_t *bap, uint16_t *qmant, int n)
{
int i;
for (i = 0; i < n; i++) {
int v;
- int c = mdct_coef[i];
- int e = exp[i] - exp_shift;
+ int c = fixed_coef[i];
+ int e = exp[i];
int b = bap[i];
switch (b) {
case 0:
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
AC3Block *block = &s->blocks[blk];
- s->mant1_cnt = s->mant2_cnt = s->mant4_cnt = 0;
- s->qmant1_ptr = s->qmant2_ptr = s->qmant4_ptr = NULL;
+ AC3Block *ref_block;
+ AC3Mant m = { 0 };
for (ch = 0; ch < s->channels; ch++) {
- quantize_mantissas_blk_ch(s, block->mdct_coef[ch], block->exp_shift[ch],
- block->exp[ch], block->bap[ch],
+ ref_block = block->exp_ref_block[ch];
+ quantize_mantissas_blk_ch(&m, block->fixed_coef[ch],
+ ref_block->exp[ch], ref_block->bap[ch],
block->qmant[ch], s->nb_coefs[ch]);
}
}
*/
static void 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, 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 */
+ put_bits(&s->pb, 2, s->center_mix_level);
if (s->channel_mode & 0x04)
- put_bits(&s->pb, 2, 1); /* XXX -6 dB */
+ put_bits(&s->pb, 2, s->surround_mix_level);
if (s->channel_mode == AC3_CHMODE_STEREO)
- put_bits(&s->pb, 2, 0); /* surround not indicated */
+ put_bits(&s->pb, 2, opt->dolby_surround_mode);
put_bits(&s->pb, 1, s->lfe_on); /* LFE */
- put_bits(&s->pb, 5, 31); /* dialog norm: -31 db */
+ 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, 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, 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,
- int block_num)
+static void output_audio_block(AC3EncodeContext *s, int blk)
{
int ch, i, baie, rbnd;
- AC3Block *block = &s->blocks[block_num];
+ AC3Block *block = &s->blocks[blk];
/* block switching */
for (ch = 0; ch < s->fbw_channels; ch++)
put_bits(&s->pb, 1, 0);
/* channel coupling */
- if (!block_num) {
+ if (!blk) {
put_bits(&s->pb, 1, 1); /* coupling strategy present */
put_bits(&s->pb, 1, 0); /* no coupling strategy */
} else {
/* stereo rematrixing */
if (s->channel_mode == AC3_CHMODE_STEREO) {
- if (!block_num) {
- /* first block must define rematrixing (rematstr) */
- 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);
+ put_bits(&s->pb, 1, block->new_rematrixing_strategy);
+ if (block->new_rematrixing_strategy) {
+ /* rematrixing flags */
+ for (rbnd = 0; rbnd < s->num_rematrixing_bands; rbnd++)
+ put_bits(&s->pb, 1, block->rematrixing_flags[rbnd]);
}
}
/* exponent strategy */
for (ch = 0; ch < s->fbw_channels; ch++)
- put_bits(&s->pb, 2, block->exp_strategy[ch]);
+ put_bits(&s->pb, 2, s->exp_strategy[ch][blk]);
if (s->lfe_on)
- put_bits(&s->pb, 1, block->exp_strategy[s->lfe_channel]);
+ put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]);
/* bandwidth */
for (ch = 0; ch < s->fbw_channels; ch++) {
- if (block->exp_strategy[ch] != EXP_REUSE)
+ if (s->exp_strategy[ch][blk] != EXP_REUSE)
put_bits(&s->pb, 6, s->bandwidth_code[ch]);
}
/* exponents */
for (ch = 0; ch < s->channels; ch++) {
- if (block->exp_strategy[ch] == EXP_REUSE)
+ int nb_groups;
+
+ if (s->exp_strategy[ch][blk] == EXP_REUSE)
continue;
/* DC exponent */
put_bits(&s->pb, 4, block->grouped_exp[ch][0]);
/* exponent groups */
- for (i = 1; i <= block->num_exp_groups[ch]; i++)
+ nb_groups = exponent_group_tab[s->exp_strategy[ch][blk]-1][s->nb_coefs[ch]];
+ for (i = 1; i <= nb_groups; i++)
put_bits(&s->pb, 7, block->grouped_exp[ch][i]);
/* gain range info */
}
/* bit allocation info */
- baie = (block_num == 0);
+ baie = (blk == 0);
put_bits(&s->pb, 1, baie);
if (baie) {
put_bits(&s->pb, 2, s->slow_decay_code);
/* mantissas */
for (ch = 0; ch < s->channels; ch++) {
int b, q;
+ AC3Block *ref_block = block->exp_ref_block[ch];
for (i = 0; i < s->nb_coefs[ch]; i++) {
q = block->qmant[ch][i];
- b = block->bap[ch][i];
+ b = ref_block->bap[ch][i];
switch (b) {
case 0: break;
case 1: if (q != 128) put_bits(&s->pb, 5, q); break;
*/
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_58 = ((frame_size >> 2) + (frame_size >> 4)) << 1;
+ 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);
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);
/* compute crc1 */
/* this is not so easy because it is at the beginning of the data... */
- 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);
+ 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);
/* compute crc2 */
- 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);
+ 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);
}
/**
* Write the frame to the output bitstream.
*/
-static void output_frame(AC3EncodeContext *s,
- unsigned char *frame)
+static void output_frame(AC3EncodeContext *s, unsigned char *frame)
{
int blk;
}
+static void dprint_options(AVCodecContext *avctx)
+{
+#ifdef DEBUG
+ AC3EncodeContext *s = avctx->priv_data;
+ AC3EncOptions *opt = &s->options;
+ char strbuf[32];
+
+ switch (s->bitstream_id) {
+ case 6: strncpy(strbuf, "AC-3 (alt syntax)", 32); break;
+ case 8: strncpy(strbuf, "AC-3 (standard)", 32); break;
+ case 9: strncpy(strbuf, "AC-3 (dnet half-rate)", 32); break;
+ case 10: strncpy(strbuf, "AC-3 (dnet quater-rate", 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);
+ 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 0: strncpy(strbuf, "notindicated", 32); break;
+ case 1: strncpy(strbuf, "large", 32); break;
+ case 2: strncpy(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 0: strncpy(strbuf, "notindicated", 32); break;
+ case 1: strncpy(strbuf, "on", 32); break;
+ case 2: strncpy(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 0: strncpy(strbuf, "notindicated", 32); break;
+ case 1: strncpy(strbuf, "ltrt", 32); break;
+ case 2: strncpy(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 0: strncpy(strbuf, "notindicated", 32); break;
+ case 1: strncpy(strbuf, "on", 32); break;
+ case 2: strncpy(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 0: strncpy(strbuf, "notindicated", 32); break;
+ case 1: strncpy(strbuf, "on", 32); break;
+ case 2: strncpy(strbuf, "off", 32); break;
+ default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_headphone_mode);
+ }
+ av_dlog(avctx, "dheadphone_mode: %s\n", strbuf);
+
+ switch (opt->ad_converter_type) {
+ case 0: strncpy(strbuf, "standard", 32); break;
+ case 1: strncpy(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
+}
+
+
+#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;
+}
+
+
+/**
+ * Validate metadata options as set by AVOption system.
+ * These values can optionally be changed per-frame.
+ */
+static int validate_metadata(AVCodecContext *avctx)
+{
+ AC3EncodeContext *s = avctx->priv_data;
+ AC3EncOptions *opt = &s->options;
+
+ /* validate mixing levels */
+ 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);
+ }
+
+ /* set audio production info flag */
+ if (opt->mixing_level >= 0 || opt->room_type >= 0) {
+ if (opt->mixing_level < 0) {
+ 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 < 0)
+ opt->room_type = 0;
+ opt->audio_production_info = 1;
+ } else {
+ opt->audio_production_info = 0;
+ }
+
+ /* set extended bsi 1 flag */
+ if ((s->has_center || s->has_surround) &&
+ (opt->preferred_stereo_downmix >= 0 ||
+ opt->ltrt_center_mix_level >= 0 ||
+ opt->ltrt_surround_mix_level >= 0 ||
+ opt->loro_center_mix_level >= 0 ||
+ opt->loro_surround_mix_level >= 0)) {
+ /* default preferred stereo downmix */
+ if (opt->preferred_stereo_downmix < 0)
+ opt->preferred_stereo_downmix = 0;
+ /* 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 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 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);
+ /* 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);
+ opt->extended_bsi_1 = 1;
+ } else {
+ opt->extended_bsi_1 = 0;
+ }
+
+ /* set extended bsi 2 flag */
+ if (opt->dolby_surround_ex_mode >= 0 ||
+ opt->dolby_headphone_mode >= 0 ||
+ opt->ad_converter_type >= 0) {
+ /* default dolby surround ex mode */
+ if (opt->dolby_surround_ex_mode < 0)
+ opt->dolby_surround_ex_mode = 0;
+ /* default dolby headphone mode */
+ if (opt->dolby_headphone_mode < 0)
+ opt->dolby_headphone_mode = 0;
+ /* default A/D converter type */
+ if (opt->ad_converter_type < 0)
+ opt->ad_converter_type = 0;
+ opt->extended_bsi_2 = 1;
+ } else {
+ opt->extended_bsi_2 = 0;
+ }
+
+ /* set bitstream id for alternate bitstream syntax */
+ if (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;
+ }
+ }
+
+ return 0;
+}
+
+
/**
* Encode a single AC-3 frame.
*/
-static int ac3_encode_frame(AVCodecContext *avctx,
- unsigned char *frame, int buf_size, void *data)
+static int ac3_encode_frame(AVCodecContext *avctx, unsigned char *frame,
+ int buf_size, void *data)
{
AC3EncodeContext *s = avctx->priv_data;
- const int16_t *samples = data;
+ const SampleType *samples = data;
int ret;
+ if (s->options.allow_per_frame_metadata) {
+ ret = validate_metadata(avctx);
+ if (ret)
+ return ret;
+ }
+
if (s->bit_alloc.sr_code == 1)
adjust_frame_size(s);
apply_mdct(s);
+ scale_coefficients(s);
+
+ compute_rematrixing_strategy(s);
+
+ apply_rematrixing(s);
+
process_exponents(s);
ret = compute_bit_allocation(s);
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);
AC3Block *block = &s->blocks[blk];
av_freep(&block->bap);
av_freep(&block->mdct_coef);
+ av_freep(&block->fixed_coef);
av_freep(&block->exp);
av_freep(&block->grouped_exp);
av_freep(&block->psd);
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;
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;
s->sample_rate = avctx->sample_rate;
s->bit_alloc.sr_shift = i % 3;
s->bit_alloc.sr_code = i / 3;
+ s->bitstream_id = 8 + s->bit_alloc.sr_shift;
/* validate bit rate */
for (i = 0; i < 19; i++) {
s->bit_rate = avctx->bit_rate;
s->frame_size_code = i << 1;
+ /* validate cutoff */
+ if (avctx->cutoff < 0) {
+ av_log(avctx, AV_LOG_ERROR, "invalid cutoff frequency\n");
+ return AVERROR(EINVAL);
+ }
+ s->cutoff = avctx->cutoff;
+ if (s->cutoff > (s->sample_rate >> 1))
+ s->cutoff = s->sample_rate >> 1;
+
+ /* 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);
+ }
+
+ ret = validate_metadata(avctx);
+ if (ret)
+ return ret;
+
+ s->rematrixing_enabled = s->options.stereo_rematrixing &&
+ (s->channel_mode == AC3_CHMODE_STEREO);
+
return 0;
}
* 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;
- 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;
+ fbw_coeffs = s->cutoff * 2 * AC3_MAX_COEFS / s->sample_rate;
bw_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;
+ bw_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 */
alloc_fail);
for (ch = 0; ch < s->channels; ch++) {
+ /* arrangement: block, channel, coeff */
block->bap[ch] = &s->bap_buffer [AC3_MAX_COEFS * (blk * s->channels + ch)];
block->mdct_coef[ch] = &s->mdct_coef_buffer [AC3_MAX_COEFS * (blk * s->channels + ch)];
- block->exp[ch] = &s->exp_buffer [AC3_MAX_COEFS * (blk * s->channels + ch)];
block->grouped_exp[ch] = &s->grouped_exp_buffer[128 * (blk * s->channels + ch)];
block->psd[ch] = &s->psd_buffer [AC3_MAX_COEFS * (blk * s->channels + ch)];
block->band_psd[ch] = &s->band_psd_buffer [64 * (blk * s->channels + ch)];
block->mask[ch] = &s->mask_buffer [64 * (blk * s->channels + ch)];
block->qmant[ch] = &s->qmant_buffer [AC3_MAX_COEFS * (blk * s->channels + ch)];
+
+ /* arrangement: channel, block, coeff */
+ block->exp[ch] = &s->exp_buffer [AC3_MAX_COEFS * (AC3_MAX_BLOCKS * ch + blk)];
+ }
+ }
+
+ if (CONFIG_AC3ENC_FLOAT) {
+ FF_ALLOC_OR_GOTO(avctx, s->fixed_coef_buffer, AC3_MAX_BLOCKS * s->channels *
+ AC3_MAX_COEFS * sizeof(*s->fixed_coef_buffer), alloc_fail);
+ for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ FF_ALLOCZ_OR_GOTO(avctx, block->fixed_coef, s->channels *
+ sizeof(*block->fixed_coef), alloc_fail);
+ for (ch = 0; ch < s->channels; ch++)
+ block->fixed_coef[ch] = &s->fixed_coef_buffer[AC3_MAX_COEFS * (blk * s->channels + ch)];
+ }
+ } else {
+ for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
+ AC3Block *block = &s->blocks[blk];
+ FF_ALLOCZ_OR_GOTO(avctx, block->fixed_coef, s->channels *
+ sizeof(*block->fixed_coef), alloc_fail);
+ for (ch = 0; ch < s->channels; ch++)
+ block->fixed_coef[ch] = (int32_t *)block->mdct_coef[ch];
}
}
static av_cold int ac3_encode_init(AVCodecContext *avctx)
{
AC3EncodeContext *s = avctx->priv_data;
- int ret;
+ int ret, frame_size_58;
avctx->frame_size = AC3_FRAME_SIZE;
- ac3_common_init();
+ ff_ac3_common_init();
ret = validate_options(avctx, s);
if (ret)
return ret;
- s->bitstream_id = 8 + s->bit_alloc.sr_shift;
- s->bitstream_mode = 0; /* complete main audio service */
+ s->bitstream_mode = avctx->audio_service_type;
+ if (s->bitstream_mode == AV_AUDIO_SERVICE_TYPE_KARAOKE)
+ s->bitstream_mode = 0x7;
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);
+ /* 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);
+ }
+
+ set_bandwidth(s);
+
+ exponent_init(s);
bit_alloc_init(s);
- s->mdct.avctx = avctx;
- ret = mdct_init(&s->mdct, 9);
+ ret = mdct_init(avctx, &s->mdct, 9);
if (ret)
goto init_fail;
avctx->coded_frame= avcodec_alloc_frame();
dsputil_init(&s->dsp, avctx);
+ ff_ac3dsp_init(&s->ac3dsp, avctx->flags & CODEC_FLAG_BITEXACT);
+
+ dprint_options(avctx);
return 0;
init_fail:
ac3_encode_close(avctx);
return ret;
}
-
-
-#ifdef TEST
-/*************************************************************************/
-/* TEST */
-
-#include "libavutil/lfg.h"
-
-#define FN (MDCT_SAMPLES/4)
-
-
-static void fft_test(AVLFG *lfg)
-{
- IComplex in[FN], in1[FN];
- int k, n, i;
- float sum_re, sum_im, a;
-
- 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);
-
- /* 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);
- }
-}
-
-
-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;
-
- for (i = 0; i < MDCT_SAMPLES; i++) {
- input[i] = (av_lfg_get(lfg) % 65535 - 32767) * 9 / 10;
- input1[i] = input[i];
- }
-
- mdct512(output, input);
-
- /* 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;
- }
-
- 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);
-}
-
-
-int main(void)
-{
- AVLFG lfg;
-
- av_log_set_level(AV_LOG_DEBUG);
- mdct_init(9);
-
- fft_test(&lfg);
- mdct_test(&lfg);
-
- return 0;
-}
-#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 },
-};