/*
* AC-3 Audio Decoder
- * This code is developed as part of Google Summer of Code 2006 Program.
+ * This code was developed as part of Google Summer of Code 2006.
+ * E-AC-3 support was added as part of Google Summer of Code 2007.
*
- * Copyright (c) 2006 Kartikey Mahendra BHATT (bhattkm at gmail dot com).
- * Copyright (c) 2007 Justin Ruggles
- *
- * Portions of this code are derived from liba52
- * http://liba52.sourceforge.net
- * Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org>
- * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
+ * Copyright (c) 2006 Kartikey Mahendra BHATT (bhattkm at gmail dot com)
+ * Copyright (c) 2007-2008 Bartlomiej Wolowiec <bartek.wolowiec@gmail.com>
+ * Copyright (c) 2007 Justin Ruggles <justin.ruggles@gmail.com>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
+ * modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
- * General Public License for more details.
+ * Lesser General Public License for more details.
*
- * You should have received a copy of the GNU General Public
+ * You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <math.h>
#include <string.h>
-#include "avcodec.h"
+#include "libavutil/crc.h"
+#include "internal.h"
+#include "aac_ac3_parser.h"
#include "ac3_parser.h"
-#include "bitstream.h"
-#include "dsputil.h"
-#include "random.h"
+#include "ac3dec.h"
+#include "ac3dec_data.h"
-/**
- * Table of bin locations for rematrixing bands
- * reference: Section 7.5.2 Rematrixing : Frequency Band Definitions
- */
-static const uint8_t rematrix_band_tab[5] = { 13, 25, 37, 61, 253 };
+/** Large enough for maximum possible frame size when the specification limit is ignored */
+#define AC3_FRAME_BUFFER_SIZE 32768
/**
- * table for exponent to scale_factor mapping
- * scale_factors[i] = 2 ^ -i
+ * table for ungrouping 3 values in 7 bits.
+ * used for exponents and bap=2 mantissas
*/
-static float scale_factors[25];
-
-/** table for grouping exponents */
-static uint8_t exp_ungroup_tab[128][3];
+static uint8_t ungroup_3_in_7_bits_tab[128][3];
/** tables for ungrouping mantissas */
-static float b1_mantissas[32][3];
-static float b2_mantissas[128][3];
-static float b3_mantissas[8];
-static float b4_mantissas[128][2];
-static float b5_mantissas[16];
+static int b1_mantissas[32][3];
+static int b2_mantissas[128][3];
+static int b3_mantissas[8];
+static int b4_mantissas[128][2];
+static int b5_mantissas[16];
/**
* Quantization table: levels for symmetric. bits for asymmetric.
* reference: Table 7.18 Mapping of bap to Quantizer
*/
-static const uint8_t qntztab[16] = {
+static const uint8_t quantization_tab[16] = {
0, 3, 5, 7, 11, 15,
5, 6, 7, 8, 9, 10, 11, 12, 14, 16
};
/** dynamic range table. converts codes to scale factors. */
-static float dynrng_tab[256];
-
-/** dialogue normalization table */
-static float dialnorm_tab[32];
+static float dynamic_range_tab[256];
/** Adjustments in dB gain */
+#define LEVEL_PLUS_3DB 1.4142135623730950
+#define LEVEL_PLUS_1POINT5DB 1.1892071150027209
+#define LEVEL_MINUS_1POINT5DB 0.8408964152537145
#define LEVEL_MINUS_3DB 0.7071067811865476
#define LEVEL_MINUS_4POINT5DB 0.5946035575013605
#define LEVEL_MINUS_6DB 0.5000000000000000
#define LEVEL_ZERO 0.0000000000000000
#define LEVEL_ONE 1.0000000000000000
-static const float gain_levels[6] = {
- LEVEL_ZERO,
+static const float gain_levels[9] = {
+ LEVEL_PLUS_3DB,
+ LEVEL_PLUS_1POINT5DB,
LEVEL_ONE,
+ LEVEL_MINUS_1POINT5DB,
LEVEL_MINUS_3DB,
LEVEL_MINUS_4POINT5DB,
LEVEL_MINUS_6DB,
+ LEVEL_ZERO,
LEVEL_MINUS_9DB
};
* Table for center mix levels
* reference: Section 5.4.2.4 cmixlev
*/
-static const uint8_t clevs[4] = { 2, 3, 4, 3 };
+static const uint8_t center_levels[4] = { 4, 5, 6, 5 };
/**
* Table for surround mix levels
* reference: Section 5.4.2.5 surmixlev
*/
-static const uint8_t slevs[4] = { 2, 4, 0, 4 };
+static const uint8_t surround_levels[4] = { 4, 6, 7, 6 };
/**
* Table for default stereo downmixing coefficients
* reference: Section 7.8.2 Downmixing Into Two Channels
*/
static const uint8_t ac3_default_coeffs[8][5][2] = {
- { { 1, 0 }, { 0, 1 }, },
- { { 2, 2 }, },
- { { 1, 0 }, { 0, 1 }, },
- { { 1, 0 }, { 3, 3 }, { 0, 1 }, },
- { { 1, 0 }, { 0, 1 }, { 4, 4 }, },
- { { 1, 0 }, { 3, 3 }, { 0, 1 }, { 5, 5 }, },
- { { 1, 0 }, { 0, 1 }, { 4, 0 }, { 0, 4 }, },
- { { 1, 0 }, { 3, 3 }, { 0, 1 }, { 4, 0 }, { 0, 4 }, },
+ { { 2, 7 }, { 7, 2 }, },
+ { { 4, 4 }, },
+ { { 2, 7 }, { 7, 2 }, },
+ { { 2, 7 }, { 5, 5 }, { 7, 2 }, },
+ { { 2, 7 }, { 7, 2 }, { 6, 6 }, },
+ { { 2, 7 }, { 5, 5 }, { 7, 2 }, { 8, 8 }, },
+ { { 2, 7 }, { 7, 2 }, { 6, 7 }, { 7, 6 }, },
+ { { 2, 7 }, { 5, 5 }, { 7, 2 }, { 6, 7 }, { 7, 6 }, },
};
-/* override ac3.h to include coupling channel */
-#undef AC3_MAX_CHANNELS
-#define AC3_MAX_CHANNELS 7
-#define CPL_CH 0
-
-#define AC3_OUTPUT_LFEON 8
-
-typedef struct {
- int acmod; ///< audio coding mode
- int dsurmod; ///< dolby surround mode
- int blksw[AC3_MAX_CHANNELS]; ///< block switch flags
- int dithflag[AC3_MAX_CHANNELS]; ///< dither flags
- int dither_all; ///< true if all channels are dithered
- int cplinu; ///< coupling in use
- int chincpl[AC3_MAX_CHANNELS]; ///< channel in coupling
- int phsflginu; ///< phase flags in use
- int cplbndstrc[18]; ///< coupling band structure
- int rematstr; ///< rematrixing strategy
- int nrematbnd; ///< number of rematrixing bands
- int rematflg[4]; ///< rematrixing flags
- int expstr[AC3_MAX_CHANNELS]; ///< exponent strategies
- int snroffst[AC3_MAX_CHANNELS]; ///< signal-to-noise ratio offsets
- int fgain[AC3_MAX_CHANNELS]; ///< fast gain values (signal-to-mask ratio)
- int deltbae[AC3_MAX_CHANNELS]; ///< delta bit allocation exists
- int deltnseg[AC3_MAX_CHANNELS]; ///< number of delta segments
- uint8_t deltoffst[AC3_MAX_CHANNELS][8]; ///< delta segment offsets
- uint8_t deltlen[AC3_MAX_CHANNELS][8]; ///< delta segment lengths
- uint8_t deltba[AC3_MAX_CHANNELS][8]; ///< delta values for each segment
-
- int sampling_rate; ///< sample frequency, in Hz
- int bit_rate; ///< stream bit rate, in bits-per-second
- int frame_size; ///< current frame size, in bytes
-
- int nchans; ///< number of total channels
- int nfchans; ///< number of full-bandwidth channels
- int lfeon; ///< lfe channel in use
- int lfe_ch; ///< index of LFE channel
- int output_mode; ///< output channel configuration
- int out_channels; ///< number of output channels
-
- float downmix_coeffs[AC3_MAX_CHANNELS][2]; ///< stereo downmix coefficients
- float dialnorm[2]; ///< dialogue normalization
- float dynrng[2]; ///< dynamic range
- float cplco[AC3_MAX_CHANNELS][18]; ///< coupling coordinates
- int ncplbnd; ///< number of coupling bands
- int ncplsubnd; ///< number of coupling sub bands
- int startmant[AC3_MAX_CHANNELS]; ///< start frequency bin
- int endmant[AC3_MAX_CHANNELS]; ///< end frequency bin
- AC3BitAllocParameters bit_alloc_params; ///< bit allocation parameters
-
- int8_t dexps[AC3_MAX_CHANNELS][256]; ///< decoded exponents
- uint8_t bap[AC3_MAX_CHANNELS][256]; ///< bit allocation pointers
- int16_t psd[AC3_MAX_CHANNELS][256]; ///< scaled exponents
- int16_t bndpsd[AC3_MAX_CHANNELS][50]; ///< interpolated exponents
- int16_t mask[AC3_MAX_CHANNELS][50]; ///< masking curve values
-
- DECLARE_ALIGNED_16(float, transform_coeffs[AC3_MAX_CHANNELS][256]); ///< transform coefficients
-
- /* For IMDCT. */
- MDCTContext imdct_512; ///< for 512 sample IMDCT
- MDCTContext imdct_256; ///< for 256 sample IMDCT
- DSPContext dsp; ///< for optimization
- float add_bias; ///< offset for float_to_int16 conversion
- float mul_bias; ///< scaling for float_to_int16 conversion
-
- DECLARE_ALIGNED_16(float, output[AC3_MAX_CHANNELS-1][256]); ///< output after imdct transform and windowing
- DECLARE_ALIGNED_16(short, int_output[AC3_MAX_CHANNELS-1][256]); ///< final 16-bit integer output
- DECLARE_ALIGNED_16(float, delay[AC3_MAX_CHANNELS-1][256]); ///< delay - added to the next block
- DECLARE_ALIGNED_16(float, tmp_imdct[256]); ///< temporary storage for imdct transform
- DECLARE_ALIGNED_16(float, tmp_output[512]); ///< temporary storage for output before windowing
- DECLARE_ALIGNED_16(float, window[256]); ///< window coefficients
-
- /* Miscellaneous. */
- GetBitContext gb; ///< bitstream reader
- AVRandomState dith_state; ///< for dither generation
- AVCodecContext *avctx; ///< parent context
-} AC3DecodeContext;
-
-/**
- * Generate a Kaiser-Bessel Derived Window.
- */
-static void ac3_window_init(float *window)
-{
- int i, j;
- double sum = 0.0, bessel, tmp;
- double local_window[256];
- double alpha2 = (5.0 * M_PI / 256.0) * (5.0 * M_PI / 256.0);
-
- for (i = 0; i < 256; i++) {
- tmp = i * (256 - i) * alpha2;
- bessel = 1.0;
- for (j = 100; j > 0; j--) /* default to 100 iterations */
- bessel = bessel * tmp / (j * j) + 1;
- sum += bessel;
- local_window[i] = sum;
- }
-
- sum++;
- for (i = 0; i < 256; i++)
- window[i] = sqrt(local_window[i] / sum);
-}
-
/**
* Symmetrical Dequantization
* reference: Section 7.3.3 Expansion of Mantissas for Symmetrical Quantization
* Tables 7.19 to 7.23
*/
-static inline float
+static inline int
symmetric_dequant(int code, int levels)
{
- return (code - (levels >> 1)) * (2.0f / levels);
+ return ((code - (levels >> 1)) << 24) / levels;
}
/*
* Initialize tables at runtime.
*/
-static void ac3_tables_init(void)
+static av_cold void ac3_tables_init(void)
{
int i;
+ /* generate table for ungrouping 3 values in 7 bits
+ reference: Section 7.1.3 Exponent Decoding */
+ for(i=0; i<128; i++) {
+ ungroup_3_in_7_bits_tab[i][0] = i / 25;
+ ungroup_3_in_7_bits_tab[i][1] = (i % 25) / 5;
+ ungroup_3_in_7_bits_tab[i][2] = (i % 25) % 5;
+ }
+
/* generate grouped mantissa tables
reference: Section 7.3.5 Ungrouping of Mantissas */
for(i=0; i<32; i++) {
/* bap=1 mantissas */
- b1_mantissas[i][0] = symmetric_dequant( i / 9 , 3);
- b1_mantissas[i][1] = symmetric_dequant((i % 9) / 3, 3);
- b1_mantissas[i][2] = symmetric_dequant((i % 9) % 3, 3);
+ b1_mantissas[i][0] = symmetric_dequant(ff_ac3_ungroup_3_in_5_bits_tab[i][0], 3);
+ b1_mantissas[i][1] = symmetric_dequant(ff_ac3_ungroup_3_in_5_bits_tab[i][1], 3);
+ b1_mantissas[i][2] = symmetric_dequant(ff_ac3_ungroup_3_in_5_bits_tab[i][2], 3);
}
for(i=0; i<128; i++) {
/* bap=2 mantissas */
- b2_mantissas[i][0] = symmetric_dequant( i / 25 , 5);
- b2_mantissas[i][1] = symmetric_dequant((i % 25) / 5, 5);
- b2_mantissas[i][2] = symmetric_dequant((i % 25) % 5, 5);
+ b2_mantissas[i][0] = symmetric_dequant(ungroup_3_in_7_bits_tab[i][0], 5);
+ b2_mantissas[i][1] = symmetric_dequant(ungroup_3_in_7_bits_tab[i][1], 5);
+ b2_mantissas[i][2] = symmetric_dequant(ungroup_3_in_7_bits_tab[i][2], 5);
/* bap=4 mantissas */
b4_mantissas[i][0] = symmetric_dequant(i / 11, 11);
reference: Section 7.7.1 Dynamic Range Control */
for(i=0; i<256; i++) {
int v = (i >> 5) - ((i >> 7) << 3) - 5;
- dynrng_tab[i] = powf(2.0f, v) * ((i & 0x1F) | 0x20);
- }
-
- /* generate dialogue normalization table
- references: Section 5.4.2.8 dialnorm
- Section 7.6 Dialogue Normalization */
- for(i=1; i<32; i++) {
- dialnorm_tab[i] = expf((i-31) * M_LN10 / 20.0f);
- }
- dialnorm_tab[0] = dialnorm_tab[31];
-
- /* generate scale factors for exponents and asymmetrical dequantization
- reference: Section 7.3.2 Expansion of Mantissas for Asymmetric Quantization */
- for (i = 0; i < 25; i++)
- scale_factors[i] = pow(2.0, -i);
-
- /* generate exponent tables
- reference: Section 7.1.3 Exponent Decoding */
- for(i=0; i<128; i++) {
- exp_ungroup_tab[i][0] = i / 25;
- exp_ungroup_tab[i][1] = (i % 25) / 5;
- exp_ungroup_tab[i][2] = (i % 25) % 5;
+ dynamic_range_tab[i] = powf(2.0f, v) * ((i & 0x1F) | 0x20);
}
}
/**
* AVCodec initialization
*/
-static int ac3_decode_init(AVCodecContext *avctx)
+static av_cold int ac3_decode_init(AVCodecContext *avctx)
{
- AC3DecodeContext *ctx = avctx->priv_data;
- ctx->avctx = avctx;
+ AC3DecodeContext *s = avctx->priv_data;
+ s->avctx = avctx;
ac3_common_init();
ac3_tables_init();
- ff_mdct_init(&ctx->imdct_256, 8, 1);
- ff_mdct_init(&ctx->imdct_512, 9, 1);
- ac3_window_init(ctx->window);
- dsputil_init(&ctx->dsp, avctx);
- av_init_random(0, &ctx->dith_state);
+ ff_mdct_init(&s->imdct_256, 8, 1, 1.0);
+ ff_mdct_init(&s->imdct_512, 9, 1, 1.0);
+ ff_kbd_window_init(s->window, 5.0, 256);
+ dsputil_init(&s->dsp, avctx);
+ av_lfg_init(&s->dith_state, 0);
/* set bias values for float to int16 conversion */
- if(ctx->dsp.float_to_int16 == ff_float_to_int16_c) {
- ctx->add_bias = 385.0f;
- ctx->mul_bias = 1.0f;
+ if(s->dsp.float_to_int16_interleave == ff_float_to_int16_interleave_c) {
+ s->add_bias = 385.0f;
+ s->mul_bias = 1.0f;
} else {
- ctx->add_bias = 0.0f;
- ctx->mul_bias = 32767.0f;
+ s->add_bias = 0.0f;
+ s->mul_bias = 32767.0f;
+ }
+
+ /* allow downmixing to stereo or mono */
+ if (avctx->channels > 0 && avctx->request_channels > 0 &&
+ avctx->request_channels < avctx->channels &&
+ avctx->request_channels <= 2) {
+ avctx->channels = avctx->request_channels;
}
+ s->downmixed = 1;
+ /* allocate context input buffer */
+ if (avctx->error_recognition >= FF_ER_CAREFUL) {
+ s->input_buffer = av_mallocz(AC3_FRAME_BUFFER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
+ if (!s->input_buffer)
+ return AVERROR_NOMEM;
+ }
+
+ avctx->sample_fmt = SAMPLE_FMT_S16;
return 0;
}
/**
* Parse the 'sync info' and 'bit stream info' from the AC-3 bitstream.
* GetBitContext within AC3DecodeContext must point to
- * start of the synchronized ac3 bitstream.
+ * the start of the synchronized AC-3 bitstream.
*/
-static int ac3_parse_header(AC3DecodeContext *ctx)
+static int ac3_parse_header(AC3DecodeContext *s)
{
- AC3HeaderInfo hdr;
- GetBitContext *gb = &ctx->gb;
- float cmixlev, surmixlev;
- int err, i;
-
- err = ff_ac3_parse_header(gb->buffer, &hdr);
- if(err)
- return err;
-
- /* get decoding parameters from header info */
- ctx->bit_alloc_params.fscod = hdr.fscod;
- ctx->acmod = hdr.acmod;
- cmixlev = gain_levels[clevs[hdr.cmixlev]];
- surmixlev = gain_levels[slevs[hdr.surmixlev]];
- ctx->dsurmod = hdr.dsurmod;
- ctx->lfeon = hdr.lfeon;
- ctx->bit_alloc_params.halfratecod = hdr.halfratecod;
- ctx->sampling_rate = hdr.sample_rate;
- ctx->bit_rate = hdr.bit_rate;
- ctx->nchans = hdr.channels;
- ctx->nfchans = ctx->nchans - ctx->lfeon;
- ctx->lfe_ch = ctx->nfchans + 1;
- ctx->frame_size = hdr.frame_size;
-
- /* set default output to all source channels */
- ctx->out_channels = ctx->nchans;
- ctx->output_mode = ctx->acmod;
- if(ctx->lfeon)
- ctx->output_mode |= AC3_OUTPUT_LFEON;
-
- /* skip over portion of header which has already been read */
- skip_bits(gb, 16); // skip the sync_word
- skip_bits(gb, 16); // skip crc1
- skip_bits(gb, 8); // skip fscod and frmsizecod
- skip_bits(gb, 11); // skip bsid, bsmod, and acmod
- if(ctx->acmod == AC3_ACMOD_STEREO) {
- skip_bits(gb, 2); // skip dsurmod
- } else {
- if((ctx->acmod & 1) && ctx->acmod != AC3_ACMOD_MONO)
- skip_bits(gb, 2); // skip cmixlev
- if(ctx->acmod & 4)
- skip_bits(gb, 2); // skip surmixlev
- }
- skip_bits1(gb); // skip lfeon
+ GetBitContext *gbc = &s->gbc;
+ int i;
/* read the rest of the bsi. read twice for dual mono mode. */
- i = !(ctx->acmod);
+ i = !(s->channel_mode);
do {
- ctx->dialnorm[i] = dialnorm_tab[get_bits(gb, 5)]; // dialogue normalization
- if (get_bits1(gb))
- skip_bits(gb, 8); //skip compression
- if (get_bits1(gb))
- skip_bits(gb, 8); //skip language code
- if (get_bits1(gb))
- skip_bits(gb, 7); //skip audio production information
+ skip_bits(gbc, 5); // skip dialog normalization
+ if (get_bits1(gbc))
+ skip_bits(gbc, 8); //skip compression
+ if (get_bits1(gbc))
+ skip_bits(gbc, 8); //skip language code
+ if (get_bits1(gbc))
+ skip_bits(gbc, 7); //skip audio production information
} while (i--);
- skip_bits(gb, 2); //skip copyright bit and original bitstream bit
+ skip_bits(gbc, 2); //skip copyright bit and original bitstream bit
/* skip the timecodes (or extra bitstream information for Alternate Syntax)
TODO: read & use the xbsi1 downmix levels */
- if (get_bits1(gb))
- skip_bits(gb, 14); //skip timecode1 / xbsi1
- if (get_bits1(gb))
- skip_bits(gb, 14); //skip timecode2 / xbsi2
+ if (get_bits1(gbc))
+ skip_bits(gbc, 14); //skip timecode1 / xbsi1
+ if (get_bits1(gbc))
+ skip_bits(gbc, 14); //skip timecode2 / xbsi2
/* skip additional bitstream info */
- if (get_bits1(gb)) {
- i = get_bits(gb, 6);
+ if (get_bits1(gbc)) {
+ i = get_bits(gbc, 6);
do {
- skip_bits(gb, 8);
+ skip_bits(gbc, 8);
} while(i--);
}
- /* set stereo downmixing coefficients
- reference: Section 7.8.2 Downmixing Into Two Channels */
- for(i=0; i<ctx->nfchans; i++) {
- ctx->downmix_coeffs[i][0] = gain_levels[ac3_default_coeffs[ctx->acmod][i][0]];
- ctx->downmix_coeffs[i][1] = gain_levels[ac3_default_coeffs[ctx->acmod][i][1]];
+ return 0;
+}
+
+/**
+ * Common function to parse AC-3 or E-AC-3 frame header
+ */
+static int parse_frame_header(AC3DecodeContext *s)
+{
+ AC3HeaderInfo hdr;
+ int err;
+
+ err = ff_ac3_parse_header(&s->gbc, &hdr);
+ if(err)
+ return err;
+
+ /* get decoding parameters from header info */
+ s->bit_alloc_params.sr_code = hdr.sr_code;
+ s->channel_mode = hdr.channel_mode;
+ s->channel_layout = hdr.channel_layout;
+ s->lfe_on = hdr.lfe_on;
+ s->bit_alloc_params.sr_shift = hdr.sr_shift;
+ s->sample_rate = hdr.sample_rate;
+ s->bit_rate = hdr.bit_rate;
+ s->channels = hdr.channels;
+ s->fbw_channels = s->channels - s->lfe_on;
+ s->lfe_ch = s->fbw_channels + 1;
+ s->frame_size = hdr.frame_size;
+ s->center_mix_level = hdr.center_mix_level;
+ s->surround_mix_level = hdr.surround_mix_level;
+ s->num_blocks = hdr.num_blocks;
+ s->frame_type = hdr.frame_type;
+ s->substreamid = hdr.substreamid;
+
+ if(s->lfe_on) {
+ s->start_freq[s->lfe_ch] = 0;
+ s->end_freq[s->lfe_ch] = 7;
+ s->num_exp_groups[s->lfe_ch] = 2;
+ s->channel_in_cpl[s->lfe_ch] = 0;
+ }
+
+ if (hdr.bitstream_id <= 10) {
+ s->eac3 = 0;
+ s->snr_offset_strategy = 2;
+ s->block_switch_syntax = 1;
+ s->dither_flag_syntax = 1;
+ s->bit_allocation_syntax = 1;
+ s->fast_gain_syntax = 0;
+ s->first_cpl_leak = 0;
+ s->dba_syntax = 1;
+ s->skip_syntax = 1;
+ memset(s->channel_uses_aht, 0, sizeof(s->channel_uses_aht));
+ return ac3_parse_header(s);
+ } else if (CONFIG_EAC3_DECODER) {
+ s->eac3 = 1;
+ return ff_eac3_parse_header(s);
+ } else {
+ av_log(s->avctx, AV_LOG_ERROR, "E-AC-3 support not compiled in\n");
+ return -1;
+ }
+}
+
+/**
+ * Set stereo downmixing coefficients based on frame header info.
+ * reference: Section 7.8.2 Downmixing Into Two Channels
+ */
+static void set_downmix_coeffs(AC3DecodeContext *s)
+{
+ int i;
+ float cmix = gain_levels[center_levels[s->center_mix_level]];
+ float smix = gain_levels[surround_levels[s->surround_mix_level]];
+ float norm0, norm1;
+
+ for(i=0; i<s->fbw_channels; i++) {
+ s->downmix_coeffs[i][0] = gain_levels[ac3_default_coeffs[s->channel_mode][i][0]];
+ s->downmix_coeffs[i][1] = gain_levels[ac3_default_coeffs[s->channel_mode][i][1]];
}
- if(ctx->acmod > 1 && ctx->acmod & 1) {
- ctx->downmix_coeffs[1][0] = ctx->downmix_coeffs[1][1] = cmixlev;
+ if(s->channel_mode > 1 && s->channel_mode & 1) {
+ s->downmix_coeffs[1][0] = s->downmix_coeffs[1][1] = cmix;
}
- if(ctx->acmod == AC3_ACMOD_2F1R || ctx->acmod == AC3_ACMOD_3F1R) {
- int nf = ctx->acmod - 2;
- ctx->downmix_coeffs[nf][0] = ctx->downmix_coeffs[nf][1] = surmixlev * LEVEL_MINUS_3DB;
+ if(s->channel_mode == AC3_CHMODE_2F1R || s->channel_mode == AC3_CHMODE_3F1R) {
+ int nf = s->channel_mode - 2;
+ s->downmix_coeffs[nf][0] = s->downmix_coeffs[nf][1] = smix * LEVEL_MINUS_3DB;
}
- if(ctx->acmod == AC3_ACMOD_2F2R || ctx->acmod == AC3_ACMOD_3F2R) {
- int nf = ctx->acmod - 4;
- ctx->downmix_coeffs[nf][0] = ctx->downmix_coeffs[nf+1][1] = surmixlev;
+ if(s->channel_mode == AC3_CHMODE_2F2R || s->channel_mode == AC3_CHMODE_3F2R) {
+ int nf = s->channel_mode - 4;
+ s->downmix_coeffs[nf][0] = s->downmix_coeffs[nf+1][1] = smix;
}
- return 0;
+ /* renormalize */
+ norm0 = norm1 = 0.0;
+ for(i=0; i<s->fbw_channels; i++) {
+ norm0 += s->downmix_coeffs[i][0];
+ norm1 += s->downmix_coeffs[i][1];
+ }
+ norm0 = 1.0f / norm0;
+ norm1 = 1.0f / norm1;
+ for(i=0; i<s->fbw_channels; i++) {
+ s->downmix_coeffs[i][0] *= norm0;
+ s->downmix_coeffs[i][1] *= norm1;
+ }
+
+ if(s->output_mode == AC3_CHMODE_MONO) {
+ for(i=0; i<s->fbw_channels; i++)
+ s->downmix_coeffs[i][0] = (s->downmix_coeffs[i][0] + s->downmix_coeffs[i][1]) * LEVEL_MINUS_3DB;
+ }
}
/**
* Decode the grouped exponents according to exponent strategy.
* reference: Section 7.1.3 Exponent Decoding
*/
-static void decode_exponents(GetBitContext *gb, int expstr, int ngrps,
- uint8_t absexp, int8_t *dexps)
+static int decode_exponents(GetBitContext *gbc, int exp_strategy, int ngrps,
+ uint8_t absexp, int8_t *dexps)
{
- int i, j, grp, grpsize;
+ int i, j, grp, group_size;
int dexp[256];
int expacc, prevexp;
/* unpack groups */
- grpsize = expstr + (expstr == EXP_D45);
+ group_size = exp_strategy + (exp_strategy == EXP_D45);
for(grp=0,i=0; grp<ngrps; grp++) {
- expacc = get_bits(gb, 7);
- dexp[i++] = exp_ungroup_tab[expacc][0];
- dexp[i++] = exp_ungroup_tab[expacc][1];
- dexp[i++] = exp_ungroup_tab[expacc][2];
+ expacc = get_bits(gbc, 7);
+ dexp[i++] = ungroup_3_in_7_bits_tab[expacc][0];
+ dexp[i++] = ungroup_3_in_7_bits_tab[expacc][1];
+ dexp[i++] = ungroup_3_in_7_bits_tab[expacc][2];
}
/* convert to absolute exps and expand groups */
prevexp = absexp;
- for(i=0; i<ngrps*3; i++) {
- prevexp = av_clip(prevexp + dexp[i]-2, 0, 24);
- for(j=0; j<grpsize; j++) {
- dexps[(i*grpsize)+j] = prevexp;
+ for(i=0,j=0; i<ngrps*3; i++) {
+ prevexp += dexp[i] - 2;
+ if (prevexp > 24U)
+ return -1;
+ switch (group_size) {
+ case 4: dexps[j++] = prevexp;
+ dexps[j++] = prevexp;
+ case 2: dexps[j++] = prevexp;
+ case 1: dexps[j++] = prevexp;
}
}
+ return 0;
}
/**
* range using the coupling coefficients and coupling coordinates.
* reference: Section 7.4.3 Coupling Coordinate Format
*/
-static void uncouple_channels(AC3DecodeContext *ctx)
+static void calc_transform_coeffs_cpl(AC3DecodeContext *s)
{
- int i, j, ch, bnd, subbnd;
-
- subbnd = -1;
- i = ctx->startmant[CPL_CH];
- for(bnd=0; bnd<ctx->ncplbnd; bnd++) {
- do {
- subbnd++;
- for(j=0; j<12; j++) {
- for(ch=1; ch<=ctx->nfchans; ch++) {
- if(ctx->chincpl[ch])
- ctx->transform_coeffs[ch][i] = ctx->transform_coeffs[CPL_CH][i] * ctx->cplco[ch][bnd] * 8.0f;
+ int bin, band, ch;
+
+ bin = s->start_freq[CPL_CH];
+ for (band = 0; band < s->num_cpl_bands; band++) {
+ int band_start = bin;
+ int band_end = bin + s->cpl_band_sizes[band];
+ for (ch = 1; ch <= s->fbw_channels; ch++) {
+ if (s->channel_in_cpl[ch]) {
+ int64_t cpl_coord = s->cpl_coords[ch][band];
+ for (bin = band_start; bin < band_end; bin++) {
+ s->fixed_coeffs[ch][bin] = ((int64_t)s->fixed_coeffs[CPL_CH][bin] *
+ cpl_coord) >> 23;
+ }
+ if (ch == 2 && s->phase_flags[band]) {
+ for (bin = band_start; bin < band_end; bin++)
+ s->fixed_coeffs[2][bin] = -s->fixed_coeffs[2][bin];
}
- i++;
}
- } while(ctx->cplbndstrc[subbnd]);
+ }
+ bin = band_end;
}
}
* Grouped mantissas for 3-level 5-level and 11-level quantization
*/
typedef struct {
- float b1_mant[3];
- float b2_mant[3];
- float b4_mant[2];
- int b1ptr;
- int b2ptr;
- int b4ptr;
+ int b1_mant[2];
+ int b2_mant[2];
+ int b4_mant;
+ int b1;
+ int b2;
+ int b4;
} mant_groups;
/**
- * Get the transform coefficients for a particular channel
+ * Decode the transform coefficients for a particular channel
* reference: Section 7.3 Quantization and Decoding of Mantissas
*/
-static int get_transform_coeffs_ch(AC3DecodeContext *ctx, int ch_index, mant_groups *m)
+static void ac3_decode_transform_coeffs_ch(AC3DecodeContext *s, int ch_index, mant_groups *m)
{
- GetBitContext *gb = &ctx->gb;
- int i, gcode, tbap, start, end;
- uint8_t *exps;
- uint8_t *bap;
- float *coeffs;
-
- exps = ctx->dexps[ch_index];
- bap = ctx->bap[ch_index];
- coeffs = ctx->transform_coeffs[ch_index];
- start = ctx->startmant[ch_index];
- end = ctx->endmant[ch_index];
-
- for (i = start; i < end; i++) {
- tbap = bap[i];
- switch (tbap) {
+ int start_freq = s->start_freq[ch_index];
+ int end_freq = s->end_freq[ch_index];
+ uint8_t *baps = s->bap[ch_index];
+ int8_t *exps = s->dexps[ch_index];
+ int *coeffs = s->fixed_coeffs[ch_index];
+ int dither = (ch_index == CPL_CH) || s->dither_flag[ch_index];
+ GetBitContext *gbc = &s->gbc;
+ int freq;
+
+ for(freq = start_freq; freq < end_freq; freq++){
+ int bap = baps[freq];
+ int mantissa;
+ switch(bap){
case 0:
- coeffs[i] = ((av_random(&ctx->dith_state) & 0xFFFF) / 65535.0f) - 0.5f;
+ if (dither)
+ mantissa = (av_lfg_get(&s->dith_state) & 0x7FFFFF) - 0x400000;
+ else
+ mantissa = 0;
break;
-
case 1:
- if(m->b1ptr > 2) {
- gcode = get_bits(gb, 5);
- m->b1_mant[0] = b1_mantissas[gcode][0];
- m->b1_mant[1] = b1_mantissas[gcode][1];
- m->b1_mant[2] = b1_mantissas[gcode][2];
- m->b1ptr = 0;
+ if(m->b1){
+ m->b1--;
+ mantissa = m->b1_mant[m->b1];
+ }
+ else{
+ int bits = get_bits(gbc, 5);
+ mantissa = b1_mantissas[bits][0];
+ m->b1_mant[1] = b1_mantissas[bits][1];
+ m->b1_mant[0] = b1_mantissas[bits][2];
+ m->b1 = 2;
}
- coeffs[i] = m->b1_mant[m->b1ptr++];
break;
-
case 2:
- if(m->b2ptr > 2) {
- gcode = get_bits(gb, 7);
- m->b2_mant[0] = b2_mantissas[gcode][0];
- m->b2_mant[1] = b2_mantissas[gcode][1];
- m->b2_mant[2] = b2_mantissas[gcode][2];
- m->b2ptr = 0;
+ if(m->b2){
+ m->b2--;
+ mantissa = m->b2_mant[m->b2];
+ }
+ else{
+ int bits = get_bits(gbc, 7);
+ mantissa = b2_mantissas[bits][0];
+ m->b2_mant[1] = b2_mantissas[bits][1];
+ m->b2_mant[0] = b2_mantissas[bits][2];
+ m->b2 = 2;
}
- coeffs[i] = m->b2_mant[m->b2ptr++];
break;
-
case 3:
- coeffs[i] = b3_mantissas[get_bits(gb, 3)];
+ mantissa = b3_mantissas[get_bits(gbc, 3)];
break;
-
case 4:
- if(m->b4ptr > 1) {
- gcode = get_bits(gb, 7);
- m->b4_mant[0] = b4_mantissas[gcode][0];
- m->b4_mant[1] = b4_mantissas[gcode][1];
- m->b4ptr = 0;
+ if(m->b4){
+ m->b4 = 0;
+ mantissa = m->b4_mant;
+ }
+ else{
+ int bits = get_bits(gbc, 7);
+ mantissa = b4_mantissas[bits][0];
+ m->b4_mant = b4_mantissas[bits][1];
+ m->b4 = 1;
}
- coeffs[i] = m->b4_mant[m->b4ptr++];
break;
-
case 5:
- coeffs[i] = b5_mantissas[get_bits(gb, 4)];
+ mantissa = b5_mantissas[get_bits(gbc, 4)];
break;
-
- default:
- /* asymmetric dequantization */
- coeffs[i] = get_sbits(gb, qntztab[tbap]) * scale_factors[qntztab[tbap]-1];
+ default: /* 6 to 15 */
+ mantissa = get_bits(gbc, quantization_tab[bap]);
+ /* Shift mantissa and sign-extend it. */
+ mantissa = (mantissa << (32-quantization_tab[bap]))>>8;
break;
}
- coeffs[i] *= scale_factors[exps[i]];
+ coeffs[freq] = mantissa >> exps[freq];
}
-
- return 0;
}
/**
- * Remove random dithering from coefficients with zero-bit mantissas
+ * Remove random dithering from coupling range coefficients with zero-bit
+ * mantissas for coupled channels which do not use dithering.
* reference: Section 7.3.4 Dither for Zero Bit Mantissas (bap=0)
*/
-static void remove_dithering(AC3DecodeContext *ctx) {
+static void remove_dithering(AC3DecodeContext *s) {
int ch, i;
- int end=0;
- float *coeffs;
- uint8_t *bap;
-
- for(ch=1; ch<=ctx->nfchans; ch++) {
- if(!ctx->dithflag[ch]) {
- coeffs = ctx->transform_coeffs[ch];
- bap = ctx->bap[ch];
- if(ctx->chincpl[ch])
- end = ctx->startmant[CPL_CH];
- else
- end = ctx->endmant[ch];
- for(i=0; i<end; i++) {
- if(bap[i] == 0)
- coeffs[i] = 0.0f;
- }
- if(ctx->chincpl[ch]) {
- bap = ctx->bap[CPL_CH];
- for(; i<ctx->endmant[CPL_CH]; i++) {
- if(bap[i] == 0)
- coeffs[i] = 0.0f;
- }
+
+ for(ch=1; ch<=s->fbw_channels; ch++) {
+ if(!s->dither_flag[ch] && s->channel_in_cpl[ch]) {
+ for(i = s->start_freq[CPL_CH]; i<s->end_freq[CPL_CH]; i++) {
+ if(!s->bap[CPL_CH][i])
+ s->fixed_coeffs[ch][i] = 0;
}
}
}
}
+static void decode_transform_coeffs_ch(AC3DecodeContext *s, int blk, int ch,
+ mant_groups *m)
+{
+ if (!s->channel_uses_aht[ch]) {
+ ac3_decode_transform_coeffs_ch(s, ch, m);
+ } else {
+ /* if AHT is used, mantissas for all blocks are encoded in the first
+ block of the frame. */
+ int bin;
+ if (!blk && CONFIG_EAC3_DECODER)
+ ff_eac3_decode_transform_coeffs_aht_ch(s, ch);
+ for (bin = s->start_freq[ch]; bin < s->end_freq[ch]; bin++) {
+ s->fixed_coeffs[ch][bin] = s->pre_mantissa[ch][bin][blk] >> s->dexps[ch][bin];
+ }
+ }
+}
+
/**
- * Get the transform coefficients.
+ * Decode the transform coefficients.
*/
-static int get_transform_coeffs(AC3DecodeContext * ctx)
+static void decode_transform_coeffs(AC3DecodeContext *s, int blk)
{
int ch, end;
int got_cplchan = 0;
mant_groups m;
- m.b1ptr = m.b2ptr = m.b4ptr = 3;
+ m.b1 = m.b2 = m.b4 = 0;
- for (ch = 1; ch <= ctx->nchans; ch++) {
+ for (ch = 1; ch <= s->channels; ch++) {
/* transform coefficients for full-bandwidth channel */
- if (get_transform_coeffs_ch(ctx, ch, &m))
- return -1;
+ decode_transform_coeffs_ch(s, blk, ch, &m);
/* tranform coefficients for coupling channel come right after the
coefficients for the first coupled channel*/
- if (ctx->chincpl[ch]) {
+ if (s->channel_in_cpl[ch]) {
if (!got_cplchan) {
- if (get_transform_coeffs_ch(ctx, CPL_CH, &m)) {
- av_log(ctx->avctx, AV_LOG_ERROR, "error in decoupling channels\n");
- return -1;
- }
- uncouple_channels(ctx);
+ decode_transform_coeffs_ch(s, blk, CPL_CH, &m);
+ calc_transform_coeffs_cpl(s);
got_cplchan = 1;
}
- end = ctx->endmant[CPL_CH];
+ end = s->end_freq[CPL_CH];
} else {
- end = ctx->endmant[ch];
+ end = s->end_freq[ch];
}
do
- ctx->transform_coeffs[ch][end] = 0;
+ s->fixed_coeffs[ch][end] = 0;
while(++end < 256);
}
- /* if any channel doesn't use dithering, zero appropriate coefficients */
- if(!ctx->dither_all)
- remove_dithering(ctx);
-
- return 0;
+ /* zero the dithered coefficients for appropriate channels */
+ remove_dithering(s);
}
/**
* Stereo rematrixing.
* reference: Section 7.5.4 Rematrixing : Decoding Technique
*/
-static void do_rematrixing(AC3DecodeContext *ctx)
+static void do_rematrixing(AC3DecodeContext *s)
{
int bnd, i;
int end, bndend;
- float tmp0, tmp1;
-
- end = FFMIN(ctx->endmant[1], ctx->endmant[2]);
-
- for(bnd=0; bnd<ctx->nrematbnd; bnd++) {
- if(ctx->rematflg[bnd]) {
- bndend = FFMIN(end, rematrix_band_tab[bnd+1]);
- for(i=rematrix_band_tab[bnd]; i<bndend; i++) {
- tmp0 = ctx->transform_coeffs[1][i];
- tmp1 = ctx->transform_coeffs[2][i];
- ctx->transform_coeffs[1][i] = tmp0 + tmp1;
- ctx->transform_coeffs[2][i] = tmp0 - tmp1;
- }
- }
- }
-}
-
-/**
- * Perform the 256-point IMDCT
- */
-static void do_imdct_256(AC3DecodeContext *ctx, int chindex)
-{
- int i, k;
- DECLARE_ALIGNED_16(float, x[128]);
- FFTComplex z[2][64];
- float *o_ptr = ctx->tmp_output;
-
- for(i=0; i<2; i++) {
- /* de-interleave coefficients */
- for(k=0; k<128; k++) {
- x[k] = ctx->transform_coeffs[chindex][2*k+i];
- }
- /* run standard IMDCT */
- ctx->imdct_256.fft.imdct_calc(&ctx->imdct_256, o_ptr, x, ctx->tmp_imdct);
+ end = FFMIN(s->end_freq[1], s->end_freq[2]);
- /* reverse the post-rotation & reordering from standard IMDCT */
- for(k=0; k<32; k++) {
- z[i][32+k].re = -o_ptr[128+2*k];
- z[i][32+k].im = -o_ptr[2*k];
- z[i][31-k].re = o_ptr[2*k+1];
- z[i][31-k].im = o_ptr[128+2*k+1];
+ for(bnd=0; bnd<s->num_rematrixing_bands; bnd++) {
+ if(s->rematrixing_flags[bnd]) {
+ bndend = FFMIN(end, ff_ac3_rematrix_band_tab[bnd+1]);
+ for(i=ff_ac3_rematrix_band_tab[bnd]; i<bndend; i++) {
+ int tmp0 = s->fixed_coeffs[1][i];
+ s->fixed_coeffs[1][i] += s->fixed_coeffs[2][i];
+ s->fixed_coeffs[2][i] = tmp0 - s->fixed_coeffs[2][i];
+ }
}
}
-
- /* apply AC-3 post-rotation & reordering */
- for(k=0; k<64; k++) {
- o_ptr[ 2*k ] = -z[0][ k].im;
- o_ptr[ 2*k+1] = z[0][63-k].re;
- o_ptr[128+2*k ] = -z[0][ k].re;
- o_ptr[128+2*k+1] = z[0][63-k].im;
- o_ptr[256+2*k ] = -z[1][ k].re;
- o_ptr[256+2*k+1] = z[1][63-k].im;
- o_ptr[384+2*k ] = z[1][ k].im;
- o_ptr[384+2*k+1] = -z[1][63-k].re;
- }
}
/**
* Convert frequency domain coefficients to time-domain audio samples.
* reference: Section 7.9.4 Transformation Equations
*/
-static inline void do_imdct(AC3DecodeContext *ctx)
+static inline void do_imdct(AC3DecodeContext *s, int channels)
{
int ch;
- int nchans;
-
- /* Don't perform the IMDCT on the LFE channel unless it's used in the output */
- nchans = ctx->nfchans;
- if(ctx->output_mode & AC3_OUTPUT_LFEON)
- nchans++;
-
- for (ch=1; ch<=nchans; ch++) {
- if (ctx->blksw[ch]) {
- do_imdct_256(ctx, ch);
+ float add_bias = s->add_bias;
+ if(s->out_channels==1 && channels>1)
+ add_bias *= LEVEL_MINUS_3DB; // compensate for the gain in downmix
+
+ for (ch=1; ch<=channels; ch++) {
+ if (s->block_switch[ch]) {
+ int i;
+ float *x = s->tmp_output+128;
+ for(i=0; i<128; i++)
+ x[i] = s->transform_coeffs[ch][2*i];
+ ff_imdct_half(&s->imdct_256, s->tmp_output, x);
+ s->dsp.vector_fmul_window(s->output[ch-1], s->delay[ch-1], s->tmp_output, s->window, add_bias, 128);
+ for(i=0; i<128; i++)
+ x[i] = s->transform_coeffs[ch][2*i+1];
+ ff_imdct_half(&s->imdct_256, s->delay[ch-1], x);
} else {
- ctx->imdct_512.fft.imdct_calc(&ctx->imdct_512, ctx->tmp_output,
- ctx->transform_coeffs[ch],
- ctx->tmp_imdct);
+ ff_imdct_half(&s->imdct_512, s->tmp_output, s->transform_coeffs[ch]);
+ s->dsp.vector_fmul_window(s->output[ch-1], s->delay[ch-1], s->tmp_output, s->window, add_bias, 128);
+ memcpy(s->delay[ch-1], s->tmp_output+128, 128*sizeof(float));
}
- /* For the first half of the block, apply the window, add the delay
- from the previous block, and send to output */
- ctx->dsp.vector_fmul_add_add(ctx->output[ch-1], ctx->tmp_output,
- ctx->window, ctx->delay[ch-1], 0, 256, 1);
- /* For the second half of the block, apply the window and store the
- samples to delay, to be combined with the next block */
- ctx->dsp.vector_fmul_reverse(ctx->delay[ch-1], ctx->tmp_output+256,
- ctx->window, 256);
}
}
/**
* Downmix the output to mono or stereo.
*/
-static void ac3_downmix(float samples[AC3_MAX_CHANNELS][256], int nfchans,
- int output_mode, float coef[AC3_MAX_CHANNELS][2])
+void ff_ac3_downmix_c(float (*samples)[256], float (*matrix)[2], int out_ch, int in_ch, int len)
{
int i, j;
- float v0, v1, s0, s1;
-
- for(i=0; i<256; i++) {
- v0 = v1 = s0 = s1 = 0.0f;
- for(j=0; j<nfchans; j++) {
- v0 += samples[j][i] * coef[j][0];
- v1 += samples[j][i] * coef[j][1];
- s0 += coef[j][0];
- s1 += coef[j][1];
- }
- v0 /= s0;
- v1 /= s1;
- if(output_mode == AC3_ACMOD_MONO) {
- samples[0][i] = (v0 + v1) * LEVEL_MINUS_3DB;
- } else if(output_mode == AC3_ACMOD_STEREO) {
+ float v0, v1;
+ if(out_ch == 2) {
+ for(i=0; i<len; i++) {
+ v0 = v1 = 0.0f;
+ for(j=0; j<in_ch; j++) {
+ v0 += samples[j][i] * matrix[j][0];
+ v1 += samples[j][i] * matrix[j][1];
+ }
samples[0][i] = v0;
samples[1][i] = v1;
}
+ } else if(out_ch == 1) {
+ for(i=0; i<len; i++) {
+ v0 = 0.0f;
+ for(j=0; j<in_ch; j++)
+ v0 += samples[j][i] * matrix[j][0];
+ samples[0][i] = v0;
+ }
}
}
/**
- * Parse an audio block from AC-3 bitstream.
+ * Upmix delay samples from stereo to original channel layout.
*/
-static int ac3_parse_audio_block(AC3DecodeContext *ctx, int blk)
+static void ac3_upmix_delay(AC3DecodeContext *s)
{
- int nfchans = ctx->nfchans;
- int acmod = ctx->acmod;
+ int channel_data_size = sizeof(s->delay[0]);
+ switch(s->channel_mode) {
+ case AC3_CHMODE_DUALMONO:
+ case AC3_CHMODE_STEREO:
+ /* upmix mono to stereo */
+ memcpy(s->delay[1], s->delay[0], channel_data_size);
+ break;
+ case AC3_CHMODE_2F2R:
+ memset(s->delay[3], 0, channel_data_size);
+ case AC3_CHMODE_2F1R:
+ memset(s->delay[2], 0, channel_data_size);
+ break;
+ case AC3_CHMODE_3F2R:
+ memset(s->delay[4], 0, channel_data_size);
+ case AC3_CHMODE_3F1R:
+ memset(s->delay[3], 0, channel_data_size);
+ case AC3_CHMODE_3F:
+ memcpy(s->delay[2], s->delay[1], channel_data_size);
+ memset(s->delay[1], 0, channel_data_size);
+ break;
+ }
+}
+
+/**
+ * Decode band structure for coupling, spectral extension, or enhanced coupling.
+ * The band structure defines how many subbands are in each band. For each
+ * subband in the range, 1 means it is combined with the previous band, and 0
+ * means that it starts a new band.
+ *
+ * @param[in] gbc bit reader context
+ * @param[in] blk block number
+ * @param[in] eac3 flag to indicate E-AC-3
+ * @param[in] ecpl flag to indicate enhanced coupling
+ * @param[in] start_subband subband number for start of range
+ * @param[in] end_subband subband number for end of range
+ * @param[in] default_band_struct default band structure table
+ * @param[out] num_bands number of bands (optionally NULL)
+ * @param[out] band_sizes array containing the number of bins in each band (optionally NULL)
+ */
+static void decode_band_structure(GetBitContext *gbc, int blk, int eac3,
+ int ecpl, int start_subband, int end_subband,
+ const uint8_t *default_band_struct,
+ int *num_bands, uint8_t *band_sizes)
+{
+ int subbnd, bnd, n_subbands, n_bands=0;
+ uint8_t bnd_sz[22];
+ uint8_t coded_band_struct[22];
+ const uint8_t *band_struct;
+
+ n_subbands = end_subband - start_subband;
+
+ /* decode band structure from bitstream or use default */
+ if (!eac3 || get_bits1(gbc)) {
+ for (subbnd = 0; subbnd < n_subbands - 1; subbnd++) {
+ coded_band_struct[subbnd] = get_bits1(gbc);
+ }
+ band_struct = coded_band_struct;
+ } else if (!blk) {
+ band_struct = &default_band_struct[start_subband+1];
+ } else {
+ /* no change in band structure */
+ return;
+ }
+
+ /* calculate number of bands and band sizes based on band structure.
+ note that the first 4 subbands in enhanced coupling span only 6 bins
+ instead of 12. */
+ if (num_bands || band_sizes ) {
+ n_bands = n_subbands;
+ bnd_sz[0] = ecpl ? 6 : 12;
+ for (bnd = 0, subbnd = 1; subbnd < n_subbands; subbnd++) {
+ int subbnd_size = (ecpl && subbnd < 4) ? 6 : 12;
+ if (band_struct[subbnd-1]) {
+ n_bands--;
+ bnd_sz[bnd] += subbnd_size;
+ } else {
+ bnd_sz[++bnd] = subbnd_size;
+ }
+ }
+ }
+
+ /* set optional output params */
+ if (num_bands)
+ *num_bands = n_bands;
+ if (band_sizes)
+ memcpy(band_sizes, bnd_sz, n_bands);
+}
+
+/**
+ * Decode a single audio block from the AC-3 bitstream.
+ */
+static int decode_audio_block(AC3DecodeContext *s, int blk)
+{
+ int fbw_channels = s->fbw_channels;
+ int channel_mode = s->channel_mode;
int i, bnd, seg, ch;
- GetBitContext *gb = &ctx->gb;
+ int different_transforms;
+ int downmix_output;
+ int cpl_in_use;
+ GetBitContext *gbc = &s->gbc;
uint8_t bit_alloc_stages[AC3_MAX_CHANNELS];
memset(bit_alloc_stages, 0, AC3_MAX_CHANNELS);
/* block switch flags */
- for (ch = 1; ch <= nfchans; ch++)
- ctx->blksw[ch] = get_bits1(gb);
+ different_transforms = 0;
+ if (s->block_switch_syntax) {
+ for (ch = 1; ch <= fbw_channels; ch++) {
+ s->block_switch[ch] = get_bits1(gbc);
+ if(ch > 1 && s->block_switch[ch] != s->block_switch[1])
+ different_transforms = 1;
+ }
+ }
/* dithering flags */
- ctx->dither_all = 1;
- for (ch = 1; ch <= nfchans; ch++) {
- ctx->dithflag[ch] = get_bits1(gb);
- if(!ctx->dithflag[ch])
- ctx->dither_all = 0;
+ if (s->dither_flag_syntax) {
+ for (ch = 1; ch <= fbw_channels; ch++) {
+ s->dither_flag[ch] = get_bits1(gbc);
+ }
}
/* dynamic range */
- i = !(ctx->acmod);
+ i = !(s->channel_mode);
do {
- if(get_bits1(gb)) {
- ctx->dynrng[i] = dynrng_tab[get_bits(gb, 8)];
+ if(get_bits1(gbc)) {
+ s->dynamic_range[i] = ((dynamic_range_tab[get_bits(gbc, 8)]-1.0) *
+ s->avctx->drc_scale)+1.0;
} else if(blk == 0) {
- ctx->dynrng[i] = 1.0f;
+ s->dynamic_range[i] = 1.0f;
}
} while(i--);
+ /* spectral extension strategy */
+ if (s->eac3 && (!blk || get_bits1(gbc))) {
+ if (get_bits1(gbc)) {
+ av_log_missing_feature(s->avctx, "Spectral extension", 1);
+ return -1;
+ }
+ /* TODO: parse spectral extension strategy info */
+ }
+
+ /* TODO: spectral extension coordinates */
+
/* coupling strategy */
- if (get_bits1(gb)) {
+ if (s->eac3 ? s->cpl_strategy_exists[blk] : get_bits1(gbc)) {
memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
- ctx->cplinu = get_bits1(gb);
- if (ctx->cplinu) {
+ if (!s->eac3)
+ s->cpl_in_use[blk] = get_bits1(gbc);
+ if (s->cpl_in_use[blk]) {
/* coupling in use */
- int cplbegf, cplendf;
+ int cpl_start_subband, cpl_end_subband;
+
+ if (channel_mode < AC3_CHMODE_STEREO) {
+ av_log(s->avctx, AV_LOG_ERROR, "coupling not allowed in mono or dual-mono\n");
+ return -1;
+ }
+
+ /* check for enhanced coupling */
+ if (s->eac3 && get_bits1(gbc)) {
+ /* TODO: parse enhanced coupling strategy info */
+ av_log_missing_feature(s->avctx, "Enhanced coupling", 1);
+ return -1;
+ }
/* determine which channels are coupled */
- for (ch = 1; ch <= nfchans; ch++)
- ctx->chincpl[ch] = get_bits1(gb);
+ if (s->eac3 && s->channel_mode == AC3_CHMODE_STEREO) {
+ s->channel_in_cpl[1] = 1;
+ s->channel_in_cpl[2] = 1;
+ } else {
+ for (ch = 1; ch <= fbw_channels; ch++)
+ s->channel_in_cpl[ch] = get_bits1(gbc);
+ }
/* phase flags in use */
- if (acmod == AC3_ACMOD_STEREO)
- ctx->phsflginu = get_bits1(gb);
-
- /* coupling frequency range and band structure */
- cplbegf = get_bits(gb, 4);
- cplendf = get_bits(gb, 4);
- if (3 + cplendf - cplbegf < 0) {
- av_log(ctx->avctx, AV_LOG_ERROR, "cplendf = %d < cplbegf = %d\n", cplendf, cplbegf);
+ if (channel_mode == AC3_CHMODE_STEREO)
+ s->phase_flags_in_use = get_bits1(gbc);
+
+ /* coupling frequency range */
+ /* TODO: modify coupling end freq if spectral extension is used */
+ cpl_start_subband = get_bits(gbc, 4);
+ cpl_end_subband = get_bits(gbc, 4) + 3;
+ if (cpl_start_subband >= cpl_end_subband) {
+ av_log(s->avctx, AV_LOG_ERROR, "invalid coupling range (%d >= %d)\n",
+ cpl_start_subband, cpl_end_subband);
return -1;
}
- ctx->ncplbnd = ctx->ncplsubnd = 3 + cplendf - cplbegf;
- ctx->startmant[CPL_CH] = cplbegf * 12 + 37;
- ctx->endmant[CPL_CH] = cplendf * 12 + 73;
- for (bnd = 0; bnd < ctx->ncplsubnd - 1; bnd++) {
- if (get_bits1(gb)) {
- ctx->cplbndstrc[bnd] = 1;
- ctx->ncplbnd--;
- }
- }
+ s->start_freq[CPL_CH] = cpl_start_subband * 12 + 37;
+ s->end_freq[CPL_CH] = cpl_end_subband * 12 + 37;
+
+ decode_band_structure(gbc, blk, s->eac3, 0, cpl_start_subband,
+ cpl_end_subband,
+ ff_eac3_default_cpl_band_struct,
+ &s->num_cpl_bands, s->cpl_band_sizes);
} else {
/* coupling not in use */
- for (ch = 1; ch <= nfchans; ch++)
- ctx->chincpl[ch] = 0;
+ for (ch = 1; ch <= fbw_channels; ch++) {
+ s->channel_in_cpl[ch] = 0;
+ s->first_cpl_coords[ch] = 1;
+ }
+ s->first_cpl_leak = s->eac3;
+ s->phase_flags_in_use = 0;
+ }
+ } else if (!s->eac3) {
+ if(!blk) {
+ av_log(s->avctx, AV_LOG_ERROR, "new coupling strategy must be present in block 0\n");
+ return -1;
+ } else {
+ s->cpl_in_use[blk] = s->cpl_in_use[blk-1];
}
}
+ cpl_in_use = s->cpl_in_use[blk];
/* coupling coordinates */
- if (ctx->cplinu) {
- int cplcoe = 0;
-
- for (ch = 1; ch <= nfchans; ch++) {
- if (ctx->chincpl[ch]) {
- if (get_bits1(gb)) {
- int mstrcplco, cplcoexp, cplcomant;
- cplcoe = 1;
- mstrcplco = 3 * get_bits(gb, 2);
- for (bnd = 0; bnd < ctx->ncplbnd; bnd++) {
- cplcoexp = get_bits(gb, 4);
- cplcomant = get_bits(gb, 4);
- if (cplcoexp == 15)
- ctx->cplco[ch][bnd] = cplcomant / 16.0f;
+ if (cpl_in_use) {
+ int cpl_coords_exist = 0;
+
+ for (ch = 1; ch <= fbw_channels; ch++) {
+ if (s->channel_in_cpl[ch]) {
+ if ((s->eac3 && s->first_cpl_coords[ch]) || get_bits1(gbc)) {
+ int master_cpl_coord, cpl_coord_exp, cpl_coord_mant;
+ s->first_cpl_coords[ch] = 0;
+ cpl_coords_exist = 1;
+ master_cpl_coord = 3 * get_bits(gbc, 2);
+ for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
+ cpl_coord_exp = get_bits(gbc, 4);
+ cpl_coord_mant = get_bits(gbc, 4);
+ if (cpl_coord_exp == 15)
+ s->cpl_coords[ch][bnd] = cpl_coord_mant << 22;
else
- ctx->cplco[ch][bnd] = (cplcomant + 16.0f) / 32.0f;
- ctx->cplco[ch][bnd] *= scale_factors[cplcoexp + mstrcplco];
+ s->cpl_coords[ch][bnd] = (cpl_coord_mant + 16) << 21;
+ s->cpl_coords[ch][bnd] >>= (cpl_coord_exp + master_cpl_coord);
}
+ } else if (!blk) {
+ av_log(s->avctx, AV_LOG_ERROR, "new coupling coordinates must be present in block 0\n");
+ return -1;
}
+ } else {
+ /* channel not in coupling */
+ s->first_cpl_coords[ch] = 1;
}
}
/* phase flags */
- if (acmod == AC3_ACMOD_STEREO && ctx->phsflginu && cplcoe) {
- for (bnd = 0; bnd < ctx->ncplbnd; bnd++) {
- if (get_bits1(gb))
- ctx->cplco[2][bnd] = -ctx->cplco[2][bnd];
+ if (channel_mode == AC3_CHMODE_STEREO && cpl_coords_exist) {
+ for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
+ s->phase_flags[bnd] = s->phase_flags_in_use? get_bits1(gbc) : 0;
}
}
}
/* stereo rematrixing strategy and band structure */
- if (acmod == AC3_ACMOD_STEREO) {
- ctx->rematstr = get_bits1(gb);
- if (ctx->rematstr) {
- ctx->nrematbnd = 4;
- if(ctx->cplinu && ctx->startmant[CPL_CH] <= 61)
- ctx->nrematbnd -= 1 + (ctx->startmant[CPL_CH] == 37);
- for(bnd=0; bnd<ctx->nrematbnd; bnd++)
- ctx->rematflg[bnd] = get_bits1(gb);
+ if (channel_mode == AC3_CHMODE_STEREO) {
+ if ((s->eac3 && !blk) || get_bits1(gbc)) {
+ s->num_rematrixing_bands = 4;
+ if(cpl_in_use && s->start_freq[CPL_CH] <= 61)
+ s->num_rematrixing_bands -= 1 + (s->start_freq[CPL_CH] == 37);
+ for(bnd=0; bnd<s->num_rematrixing_bands; bnd++)
+ s->rematrixing_flags[bnd] = get_bits1(gbc);
+ } else if (!blk) {
+ av_log(s->avctx, AV_LOG_WARNING, "Warning: new rematrixing strategy not present in block 0\n");
+ s->num_rematrixing_bands = 0;
}
}
/* exponent strategies for each channel */
- ctx->expstr[CPL_CH] = EXP_REUSE;
- ctx->expstr[ctx->lfe_ch] = EXP_REUSE;
- for (ch = !ctx->cplinu; ch <= ctx->nchans; ch++) {
- if(ch == ctx->lfe_ch)
- ctx->expstr[ch] = get_bits(gb, 1);
- else
- ctx->expstr[ch] = get_bits(gb, 2);
- if(ctx->expstr[ch] != EXP_REUSE)
+ for (ch = !cpl_in_use; ch <= s->channels; ch++) {
+ if (!s->eac3)
+ s->exp_strategy[blk][ch] = get_bits(gbc, 2 - (ch == s->lfe_ch));
+ if(s->exp_strategy[blk][ch] != EXP_REUSE)
bit_alloc_stages[ch] = 3;
}
/* channel bandwidth */
- for (ch = 1; ch <= nfchans; ch++) {
- ctx->startmant[ch] = 0;
- if (ctx->expstr[ch] != EXP_REUSE) {
- int prev = ctx->endmant[ch];
- if (ctx->chincpl[ch])
- ctx->endmant[ch] = ctx->startmant[CPL_CH];
+ for (ch = 1; ch <= fbw_channels; ch++) {
+ s->start_freq[ch] = 0;
+ if (s->exp_strategy[blk][ch] != EXP_REUSE) {
+ int group_size;
+ int prev = s->end_freq[ch];
+ if (s->channel_in_cpl[ch])
+ s->end_freq[ch] = s->start_freq[CPL_CH];
else {
- int chbwcod = get_bits(gb, 6);
- if (chbwcod > 60) {
- av_log(ctx->avctx, AV_LOG_ERROR, "chbwcod = %d > 60", chbwcod);
+ int bandwidth_code = get_bits(gbc, 6);
+ if (bandwidth_code > 60) {
+ av_log(s->avctx, AV_LOG_ERROR, "bandwidth code = %d > 60\n", bandwidth_code);
return -1;
}
- ctx->endmant[ch] = chbwcod * 3 + 73;
+ s->end_freq[ch] = bandwidth_code * 3 + 73;
}
- if(blk > 0 && ctx->endmant[ch] != prev)
+ group_size = 3 << (s->exp_strategy[blk][ch] - 1);
+ s->num_exp_groups[ch] = (s->end_freq[ch]+group_size-4) / group_size;
+ if(blk > 0 && s->end_freq[ch] != prev)
memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
}
}
- ctx->startmant[ctx->lfe_ch] = 0;
- ctx->endmant[ctx->lfe_ch] = 7;
+ if (cpl_in_use && s->exp_strategy[blk][CPL_CH] != EXP_REUSE) {
+ s->num_exp_groups[CPL_CH] = (s->end_freq[CPL_CH] - s->start_freq[CPL_CH]) /
+ (3 << (s->exp_strategy[blk][CPL_CH] - 1));
+ }
/* decode exponents for each channel */
- for (ch = !ctx->cplinu; ch <= ctx->nchans; ch++) {
- if (ctx->expstr[ch] != EXP_REUSE) {
- int grpsize, ngrps;
- grpsize = 3 << (ctx->expstr[ch] - 1);
- if(ch == CPL_CH)
- ngrps = (ctx->endmant[ch] - ctx->startmant[ch]) / grpsize;
- else if(ch == ctx->lfe_ch)
- ngrps = 2;
- else
- ngrps = (ctx->endmant[ch] + grpsize - 4) / grpsize;
- ctx->dexps[ch][0] = get_bits(gb, 4) << !ch;
- decode_exponents(gb, ctx->expstr[ch], ngrps, ctx->dexps[ch][0],
- &ctx->dexps[ch][ctx->startmant[ch]+!!ch]);
- if(ch != CPL_CH && ch != ctx->lfe_ch)
- skip_bits(gb, 2); /* skip gainrng */
+ for (ch = !cpl_in_use; ch <= s->channels; ch++) {
+ if (s->exp_strategy[blk][ch] != EXP_REUSE) {
+ s->dexps[ch][0] = get_bits(gbc, 4) << !ch;
+ if (decode_exponents(gbc, s->exp_strategy[blk][ch],
+ s->num_exp_groups[ch], s->dexps[ch][0],
+ &s->dexps[ch][s->start_freq[ch]+!!ch])) {
+ av_log(s->avctx, AV_LOG_ERROR, "exponent out-of-range\n");
+ return -1;
+ }
+ if(ch != CPL_CH && ch != s->lfe_ch)
+ skip_bits(gbc, 2); /* skip gainrng */
}
}
/* bit allocation information */
- if (get_bits1(gb)) {
- ctx->bit_alloc_params.sdecay = ff_sdecaytab[get_bits(gb, 2)] >> ctx->bit_alloc_params.halfratecod;
- ctx->bit_alloc_params.fdecay = ff_fdecaytab[get_bits(gb, 2)] >> ctx->bit_alloc_params.halfratecod;
- ctx->bit_alloc_params.sgain = ff_sgaintab[get_bits(gb, 2)];
- ctx->bit_alloc_params.dbknee = ff_dbkneetab[get_bits(gb, 2)];
- ctx->bit_alloc_params.floor = ff_floortab[get_bits(gb, 3)];
- for(ch=!ctx->cplinu; ch<=ctx->nchans; ch++) {
- bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
+ if (s->bit_allocation_syntax) {
+ if (get_bits1(gbc)) {
+ s->bit_alloc_params.slow_decay = ff_ac3_slow_decay_tab[get_bits(gbc, 2)] >> s->bit_alloc_params.sr_shift;
+ s->bit_alloc_params.fast_decay = ff_ac3_fast_decay_tab[get_bits(gbc, 2)] >> s->bit_alloc_params.sr_shift;
+ s->bit_alloc_params.slow_gain = ff_ac3_slow_gain_tab[get_bits(gbc, 2)];
+ s->bit_alloc_params.db_per_bit = ff_ac3_db_per_bit_tab[get_bits(gbc, 2)];
+ s->bit_alloc_params.floor = ff_ac3_floor_tab[get_bits(gbc, 3)];
+ for(ch=!cpl_in_use; ch<=s->channels; ch++)
+ bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
+ } else if (!blk) {
+ av_log(s->avctx, AV_LOG_ERROR, "new bit allocation info must be present in block 0\n");
+ return -1;
}
}
/* signal-to-noise ratio offsets and fast gains (signal-to-mask ratios) */
- if (get_bits1(gb)) {
- int csnr;
- csnr = (get_bits(gb, 6) - 15) << 4;
- for (ch = !ctx->cplinu; ch <= ctx->nchans; ch++) { /* snr offset and fast gain */
- ctx->snroffst[ch] = (csnr + get_bits(gb, 4)) << 2;
- ctx->fgain[ch] = ff_fgaintab[get_bits(gb, 3)];
+ if(!s->eac3 || !blk){
+ if(s->snr_offset_strategy && get_bits1(gbc)) {
+ int snr = 0;
+ int csnr;
+ csnr = (get_bits(gbc, 6) - 15) << 4;
+ for (i = ch = !cpl_in_use; ch <= s->channels; ch++) {
+ /* snr offset */
+ if (ch == i || s->snr_offset_strategy == 2)
+ snr = (csnr + get_bits(gbc, 4)) << 2;
+ /* run at least last bit allocation stage if snr offset changes */
+ if(blk && s->snr_offset[ch] != snr) {
+ bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 1);
+ }
+ s->snr_offset[ch] = snr;
+
+ /* fast gain (normal AC-3 only) */
+ if (!s->eac3) {
+ int prev = s->fast_gain[ch];
+ s->fast_gain[ch] = ff_ac3_fast_gain_tab[get_bits(gbc, 3)];
+ /* run last 2 bit allocation stages if fast gain changes */
+ if(blk && prev != s->fast_gain[ch])
+ bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
+ }
+ }
+ } else if (!s->eac3 && !blk) {
+ av_log(s->avctx, AV_LOG_ERROR, "new snr offsets must be present in block 0\n");
+ return -1;
}
- memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
+ }
+
+ /* fast gain (E-AC-3 only) */
+ if (s->fast_gain_syntax && get_bits1(gbc)) {
+ for (ch = !cpl_in_use; ch <= s->channels; ch++) {
+ int prev = s->fast_gain[ch];
+ s->fast_gain[ch] = ff_ac3_fast_gain_tab[get_bits(gbc, 3)];
+ /* run last 2 bit allocation stages if fast gain changes */
+ if(blk && prev != s->fast_gain[ch])
+ bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
+ }
+ } else if (s->eac3 && !blk) {
+ for (ch = !cpl_in_use; ch <= s->channels; ch++)
+ s->fast_gain[ch] = ff_ac3_fast_gain_tab[4];
+ }
+
+ /* E-AC-3 to AC-3 converter SNR offset */
+ if (s->frame_type == EAC3_FRAME_TYPE_INDEPENDENT && get_bits1(gbc)) {
+ skip_bits(gbc, 10); // skip converter snr offset
}
/* coupling leak information */
- if (ctx->cplinu && get_bits1(gb)) {
- ctx->bit_alloc_params.cplfleak = get_bits(gb, 3);
- ctx->bit_alloc_params.cplsleak = get_bits(gb, 3);
- bit_alloc_stages[CPL_CH] = FFMAX(bit_alloc_stages[CPL_CH], 2);
+ if (cpl_in_use) {
+ if (s->first_cpl_leak || get_bits1(gbc)) {
+ int fl = get_bits(gbc, 3);
+ int sl = get_bits(gbc, 3);
+ /* run last 2 bit allocation stages for coupling channel if
+ coupling leak changes */
+ if(blk && (fl != s->bit_alloc_params.cpl_fast_leak ||
+ sl != s->bit_alloc_params.cpl_slow_leak)) {
+ bit_alloc_stages[CPL_CH] = FFMAX(bit_alloc_stages[CPL_CH], 2);
+ }
+ s->bit_alloc_params.cpl_fast_leak = fl;
+ s->bit_alloc_params.cpl_slow_leak = sl;
+ } else if (!s->eac3 && !blk) {
+ av_log(s->avctx, AV_LOG_ERROR, "new coupling leak info must be present in block 0\n");
+ return -1;
+ }
+ s->first_cpl_leak = 0;
}
/* delta bit allocation information */
- if (get_bits1(gb)) {
+ if (s->dba_syntax && get_bits1(gbc)) {
/* delta bit allocation exists (strategy) */
- for (ch = !ctx->cplinu; ch <= nfchans; ch++) {
- ctx->deltbae[ch] = get_bits(gb, 2);
- if (ctx->deltbae[ch] == DBA_RESERVED) {
- av_log(ctx->avctx, AV_LOG_ERROR, "delta bit allocation strategy reserved\n");
+ for (ch = !cpl_in_use; ch <= fbw_channels; ch++) {
+ s->dba_mode[ch] = get_bits(gbc, 2);
+ if (s->dba_mode[ch] == DBA_RESERVED) {
+ av_log(s->avctx, AV_LOG_ERROR, "delta bit allocation strategy reserved\n");
return -1;
}
bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
}
/* channel delta offset, len and bit allocation */
- for (ch = !ctx->cplinu; ch <= nfchans; ch++) {
- if (ctx->deltbae[ch] == DBA_NEW) {
- ctx->deltnseg[ch] = get_bits(gb, 3);
- for (seg = 0; seg <= ctx->deltnseg[ch]; seg++) {
- ctx->deltoffst[ch][seg] = get_bits(gb, 5);
- ctx->deltlen[ch][seg] = get_bits(gb, 4);
- ctx->deltba[ch][seg] = get_bits(gb, 3);
+ for (ch = !cpl_in_use; ch <= fbw_channels; ch++) {
+ if (s->dba_mode[ch] == DBA_NEW) {
+ s->dba_nsegs[ch] = get_bits(gbc, 3);
+ for (seg = 0; seg <= s->dba_nsegs[ch]; seg++) {
+ s->dba_offsets[ch][seg] = get_bits(gbc, 5);
+ s->dba_lengths[ch][seg] = get_bits(gbc, 4);
+ s->dba_values[ch][seg] = get_bits(gbc, 3);
}
+ /* run last 2 bit allocation stages if new dba values */
+ bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
}
}
} else if(blk == 0) {
- for(ch=0; ch<=ctx->nchans; ch++) {
- ctx->deltbae[ch] = DBA_NONE;
+ for(ch=0; ch<=s->channels; ch++) {
+ s->dba_mode[ch] = DBA_NONE;
}
}
/* Bit allocation */
- for(ch=!ctx->cplinu; ch<=ctx->nchans; ch++) {
+ for(ch=!cpl_in_use; ch<=s->channels; ch++) {
if(bit_alloc_stages[ch] > 2) {
/* Exponent mapping into PSD and PSD integration */
- ff_ac3_bit_alloc_calc_psd(ctx->dexps[ch],
- ctx->startmant[ch], ctx->endmant[ch],
- ctx->psd[ch], ctx->bndpsd[ch]);
+ ff_ac3_bit_alloc_calc_psd(s->dexps[ch],
+ s->start_freq[ch], s->end_freq[ch],
+ s->psd[ch], s->band_psd[ch]);
}
if(bit_alloc_stages[ch] > 1) {
/* Compute excitation function, Compute masking curve, and
Apply delta bit allocation */
- ff_ac3_bit_alloc_calc_mask(&ctx->bit_alloc_params, ctx->bndpsd[ch],
- ctx->startmant[ch], ctx->endmant[ch],
- ctx->fgain[ch], (ch == ctx->lfe_ch),
- ctx->deltbae[ch], ctx->deltnseg[ch],
- ctx->deltoffst[ch], ctx->deltlen[ch],
- ctx->deltba[ch], ctx->mask[ch]);
+ if (ff_ac3_bit_alloc_calc_mask(&s->bit_alloc_params, s->band_psd[ch],
+ s->start_freq[ch], s->end_freq[ch],
+ s->fast_gain[ch], (ch == s->lfe_ch),
+ s->dba_mode[ch], s->dba_nsegs[ch],
+ s->dba_offsets[ch], s->dba_lengths[ch],
+ s->dba_values[ch], s->mask[ch])) {
+ av_log(s->avctx, AV_LOG_ERROR, "error in bit allocation\n");
+ return -1;
+ }
}
if(bit_alloc_stages[ch] > 0) {
/* Compute bit allocation */
- ff_ac3_bit_alloc_calc_bap(ctx->mask[ch], ctx->psd[ch],
- ctx->startmant[ch], ctx->endmant[ch],
- ctx->snroffst[ch],
- ctx->bit_alloc_params.floor,
- ctx->bap[ch]);
+ const uint8_t *bap_tab = s->channel_uses_aht[ch] ?
+ ff_eac3_hebap_tab : ff_ac3_bap_tab;
+ ff_ac3_bit_alloc_calc_bap(s->mask[ch], s->psd[ch],
+ s->start_freq[ch], s->end_freq[ch],
+ s->snr_offset[ch],
+ s->bit_alloc_params.floor,
+ bap_tab, s->bap[ch]);
}
}
/* unused dummy data */
- if (get_bits1(gb)) {
- int skipl = get_bits(gb, 9);
+ if (s->skip_syntax && get_bits1(gbc)) {
+ int skipl = get_bits(gbc, 9);
while(skipl--)
- skip_bits(gb, 8);
+ skip_bits(gbc, 8);
}
/* unpack the transform coefficients
this also uncouples channels if coupling is in use. */
- if (get_transform_coeffs(ctx)) {
- av_log(ctx->avctx, AV_LOG_ERROR, "Error in routine get_transform_coeffs\n");
- return -1;
- }
+ decode_transform_coeffs(s, blk);
+
+ /* TODO: generate enhanced coupling coordinates and uncouple */
+
+ /* TODO: apply spectral extension */
/* recover coefficients if rematrixing is in use */
- if(ctx->acmod == AC3_ACMOD_STEREO)
- do_rematrixing(ctx);
-
- /* apply scaling to coefficients (headroom, dialnorm, dynrng) */
- for(ch=1; ch<=ctx->nchans; ch++) {
- float gain = 2.0f * ctx->mul_bias;
- if(ctx->acmod == AC3_ACMOD_DUALMONO) {
- gain *= ctx->dialnorm[ch-1] * ctx->dynrng[ch-1];
+ if(s->channel_mode == AC3_CHMODE_STEREO)
+ do_rematrixing(s);
+
+ /* apply scaling to coefficients (headroom, dynrng) */
+ for(ch=1; ch<=s->channels; ch++) {
+ float gain = s->mul_bias / 4194304.0f;
+ if(s->channel_mode == AC3_CHMODE_DUALMONO) {
+ gain *= s->dynamic_range[2-ch];
} else {
- gain *= ctx->dialnorm[0] * ctx->dynrng[0];
- }
- for(i=0; i<ctx->endmant[ch]; i++) {
- ctx->transform_coeffs[ch][i] *= gain;
+ gain *= s->dynamic_range[0];
}
+ s->dsp.int32_to_float_fmul_scalar(s->transform_coeffs[ch], s->fixed_coeffs[ch], gain, 256);
}
- do_imdct(ctx);
+ /* downmix and MDCT. order depends on whether block switching is used for
+ any channel in this block. this is because coefficients for the long
+ and short transforms cannot be mixed. */
+ downmix_output = s->channels != s->out_channels &&
+ !((s->output_mode & AC3_OUTPUT_LFEON) &&
+ s->fbw_channels == s->out_channels);
+ if(different_transforms) {
+ /* the delay samples have already been downmixed, so we upmix the delay
+ samples in order to reconstruct all channels before downmixing. */
+ if(s->downmixed) {
+ s->downmixed = 0;
+ ac3_upmix_delay(s);
+ }
- /* downmix output if needed */
- if(ctx->nchans != ctx->out_channels && !((ctx->output_mode & AC3_OUTPUT_LFEON) &&
- ctx->nfchans == ctx->out_channels)) {
- ac3_downmix(ctx->output, ctx->nfchans, ctx->output_mode,
- ctx->downmix_coeffs);
- }
+ do_imdct(s, s->channels);
+
+ if(downmix_output) {
+ s->dsp.ac3_downmix(s->output, s->downmix_coeffs, s->out_channels, s->fbw_channels, 256);
+ }
+ } else {
+ if(downmix_output) {
+ s->dsp.ac3_downmix(s->transform_coeffs+1, s->downmix_coeffs, s->out_channels, s->fbw_channels, 256);
+ }
- /* convert float to 16-bit integer */
- for(ch=0; ch<ctx->out_channels; ch++) {
- for(i=0; i<256; i++) {
- ctx->output[ch][i] += ctx->add_bias;
+ if(downmix_output && !s->downmixed) {
+ s->downmixed = 1;
+ s->dsp.ac3_downmix(s->delay, s->downmix_coeffs, s->out_channels, s->fbw_channels, 128);
}
- ctx->dsp.float_to_int16(ctx->int_output[ch], ctx->output[ch], 256);
+
+ do_imdct(s, s->out_channels);
}
return 0;
/**
* Decode a single AC-3 frame.
*/
-static int ac3_decode_frame(AVCodecContext * avctx, void *data, int *data_size, uint8_t *buf, int buf_size)
+static int ac3_decode_frame(AVCodecContext * avctx, void *data, int *data_size,
+ AVPacket *avpkt)
{
- AC3DecodeContext *ctx = (AC3DecodeContext *)avctx->priv_data;
+ const uint8_t *buf = avpkt->data;
+ int buf_size = avpkt->size;
+ AC3DecodeContext *s = avctx->priv_data;
int16_t *out_samples = (int16_t *)data;
- int i, blk, ch, err;
+ int blk, ch, err;
+ const uint8_t *channel_map;
+ const float *output[AC3_MAX_CHANNELS];
/* initialize the GetBitContext with the start of valid AC-3 Frame */
- init_get_bits(&ctx->gb, buf, buf_size * 8);
+ if (s->input_buffer) {
+ /* copy input buffer to decoder context to avoid reading past the end
+ of the buffer, which can be caused by a damaged input stream. */
+ memcpy(s->input_buffer, buf, FFMIN(buf_size, AC3_FRAME_BUFFER_SIZE));
+ init_get_bits(&s->gbc, s->input_buffer, buf_size * 8);
+ } else {
+ init_get_bits(&s->gbc, buf, buf_size * 8);
+ }
/* parse the syncinfo */
- err = ac3_parse_header(ctx);
- if(err) {
+ *data_size = 0;
+ err = parse_frame_header(s);
+
+ /* check that reported frame size fits in input buffer */
+ if(s->frame_size > buf_size) {
+ av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");
+ err = AAC_AC3_PARSE_ERROR_FRAME_SIZE;
+ }
+
+ /* check for crc mismatch */
+ if(err != AAC_AC3_PARSE_ERROR_FRAME_SIZE && avctx->error_recognition >= FF_ER_CAREFUL) {
+ if(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, &buf[2], s->frame_size-2)) {
+ av_log(avctx, AV_LOG_ERROR, "frame CRC mismatch\n");
+ err = AAC_AC3_PARSE_ERROR_CRC;
+ }
+ }
+
+ if(err && err != AAC_AC3_PARSE_ERROR_CRC) {
switch(err) {
- case AC3_PARSE_ERROR_SYNC:
+ case AAC_AC3_PARSE_ERROR_SYNC:
av_log(avctx, AV_LOG_ERROR, "frame sync error\n");
- break;
- case AC3_PARSE_ERROR_BSID:
+ return -1;
+ case AAC_AC3_PARSE_ERROR_BSID:
av_log(avctx, AV_LOG_ERROR, "invalid bitstream id\n");
break;
- case AC3_PARSE_ERROR_SAMPLE_RATE:
+ case AAC_AC3_PARSE_ERROR_SAMPLE_RATE:
av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");
break;
- case AC3_PARSE_ERROR_FRAME_SIZE:
+ case AAC_AC3_PARSE_ERROR_FRAME_SIZE:
av_log(avctx, AV_LOG_ERROR, "invalid frame size\n");
break;
+ case AAC_AC3_PARSE_ERROR_FRAME_TYPE:
+ /* skip frame if CRC is ok. otherwise use error concealment. */
+ /* TODO: add support for substreams and dependent frames */
+ if(s->frame_type == EAC3_FRAME_TYPE_DEPENDENT || s->substreamid) {
+ av_log(avctx, AV_LOG_ERROR, "unsupported frame type : skipping frame\n");
+ return s->frame_size;
+ } else {
+ av_log(avctx, AV_LOG_ERROR, "invalid frame type\n");
+ }
+ break;
default:
av_log(avctx, AV_LOG_ERROR, "invalid header\n");
break;
}
- return -1;
}
- avctx->sample_rate = ctx->sampling_rate;
- avctx->bit_rate = ctx->bit_rate;
+ /* if frame is ok, set audio parameters */
+ if (!err) {
+ avctx->sample_rate = s->sample_rate;
+ avctx->bit_rate = s->bit_rate;
+
+ /* channel config */
+ s->out_channels = s->channels;
+ s->output_mode = s->channel_mode;
+ if(s->lfe_on)
+ s->output_mode |= AC3_OUTPUT_LFEON;
+ if (avctx->request_channels > 0 && avctx->request_channels <= 2 &&
+ avctx->request_channels < s->channels) {
+ s->out_channels = avctx->request_channels;
+ s->output_mode = avctx->request_channels == 1 ? AC3_CHMODE_MONO : AC3_CHMODE_STEREO;
+ s->channel_layout = ff_ac3_channel_layout_tab[s->output_mode];
+ }
+ avctx->channels = s->out_channels;
+ avctx->channel_layout = s->channel_layout;
- /* check that reported frame size fits in input buffer */
- if(ctx->frame_size > buf_size) {
- av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");
- return -1;
+ /* set downmixing coefficients if needed */
+ if(s->channels != s->out_channels && !((s->output_mode & AC3_OUTPUT_LFEON) &&
+ s->fbw_channels == s->out_channels)) {
+ set_downmix_coeffs(s);
+ }
+ } else if (!s->out_channels) {
+ s->out_channels = avctx->channels;
+ if(s->out_channels < s->channels)
+ s->output_mode = s->out_channels == 1 ? AC3_CHMODE_MONO : AC3_CHMODE_STEREO;
}
- /* channel config */
- ctx->out_channels = ctx->nchans;
- if (avctx->channels == 0) {
- avctx->channels = ctx->out_channels;
- } else if(ctx->out_channels < avctx->channels) {
- av_log(avctx, AV_LOG_ERROR, "Cannot upmix AC3 from %d to %d channels.\n",
- ctx->out_channels, avctx->channels);
- return -1;
- }
- if(avctx->channels == 2) {
- ctx->output_mode = AC3_ACMOD_STEREO;
- } else if(avctx->channels == 1) {
- ctx->output_mode = AC3_ACMOD_MONO;
- } else if(avctx->channels != ctx->out_channels) {
- av_log(avctx, AV_LOG_ERROR, "Cannot downmix AC3 from %d to %d channels.\n",
- ctx->out_channels, avctx->channels);
- return -1;
- }
- ctx->out_channels = avctx->channels;
-
- /* parse the audio blocks */
- for (blk = 0; blk < NB_BLOCKS; blk++) {
- if (ac3_parse_audio_block(ctx, blk)) {
- av_log(avctx, AV_LOG_ERROR, "error parsing the audio block\n");
- *data_size = 0;
- return ctx->frame_size;
+ /* decode the audio blocks */
+ channel_map = ff_ac3_dec_channel_map[s->output_mode & ~AC3_OUTPUT_LFEON][s->lfe_on];
+ for (ch = 0; ch < s->out_channels; ch++)
+ output[ch] = s->output[channel_map[ch]];
+ for (blk = 0; blk < s->num_blocks; blk++) {
+ if (!err && decode_audio_block(s, blk)) {
+ av_log(avctx, AV_LOG_ERROR, "error decoding the audio block\n");
+ err = 1;
}
- for (i = 0; i < 256; i++)
- for (ch = 0; ch < ctx->out_channels; ch++)
- *(out_samples++) = ctx->int_output[ch][i];
+ s->dsp.float_to_int16_interleave(out_samples, output, 256, s->out_channels);
+ out_samples += 256 * s->out_channels;
}
- *data_size = NB_BLOCKS * 256 * avctx->channels * sizeof (int16_t);
- return ctx->frame_size;
+ *data_size = s->num_blocks * 256 * avctx->channels * sizeof (int16_t);
+ return s->frame_size;
}
/**
* Uninitialize the AC-3 decoder.
*/
-static int ac3_decode_end(AVCodecContext *avctx)
+static av_cold int ac3_decode_end(AVCodecContext *avctx)
{
- AC3DecodeContext *ctx = (AC3DecodeContext *)avctx->priv_data;
- ff_mdct_end(&ctx->imdct_512);
- ff_mdct_end(&ctx->imdct_256);
+ AC3DecodeContext *s = avctx->priv_data;
+ ff_mdct_end(&s->imdct_512);
+ ff_mdct_end(&s->imdct_256);
+
+ av_freep(&s->input_buffer);
return 0;
}
.init = ac3_decode_init,
.close = ac3_decode_end,
.decode = ac3_decode_frame,
+ .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
+};
+
+#if CONFIG_EAC3_DECODER
+AVCodec eac3_decoder = {
+ .name = "eac3",
+ .type = CODEC_TYPE_AUDIO,
+ .id = CODEC_ID_EAC3,
+ .priv_data_size = sizeof (AC3DecodeContext),
+ .init = ac3_decode_init,
+ .close = ac3_decode_end,
+ .decode = ac3_decode_frame,
+ .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52B (AC-3, E-AC-3)"),
};
+#endif