#include "ac3_parser.h"
#include "bitstream.h"
#include "dsputil.h"
+#include "ac3dec.h"
+#include "ac3dec_data.h"
/** Maximum possible frame size when the specification limit is ignored */
#define AC3_MAX_FRAME_SIZE 21695
-/**
- * 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 };
-
/** table for grouping exponents */
static uint8_t exp_ungroup_tab[128][3];
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 center_levels[4] = { 4, 5, 6, 5 };
+
+/**
+ * Table for surround mix levels
+ * reference: Section 5.4.2.5 surmixlev
+ */
+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 num_blocks; ///< number of audio blocks
- int channel_mode; ///< channel mode (acmod)
- int block_switch[AC3_MAX_CHANNELS]; ///< block switch flags
- int dither_flag[AC3_MAX_CHANNELS]; ///< dither flags
- int dither_all; ///< true if all channels are dithered
- int cpl_in_use; ///< coupling in use
- int channel_in_cpl[AC3_MAX_CHANNELS]; ///< channel in coupling
- int phase_flags_in_use; ///< phase flags in use
- int phase_flags[18]; ///< phase flags
- int cpl_band_struct[18]; ///< coupling band structure
- int num_rematrixing_bands; ///< number of rematrixing bands
- int rematrixing_flags[4]; ///< rematrixing flags
- int exp_strategy[AC3_MAX_CHANNELS]; ///< exponent strategies
- int snr_offset[AC3_MAX_CHANNELS]; ///< signal-to-noise ratio offsets
- int fast_gain[AC3_MAX_CHANNELS]; ///< fast gain values (signal-to-mask ratio)
- int dba_mode[AC3_MAX_CHANNELS]; ///< delta bit allocation mode
- int dba_nsegs[AC3_MAX_CHANNELS]; ///< number of delta segments
- uint8_t dba_offsets[AC3_MAX_CHANNELS][8]; ///< delta segment offsets
- uint8_t dba_lengths[AC3_MAX_CHANNELS][8]; ///< delta segment lengths
- uint8_t dba_values[AC3_MAX_CHANNELS][8]; ///< delta values for each segment
-
- int sample_rate; ///< sample frequency, in Hz
- int bit_rate; ///< stream bit rate, in bits-per-second
- int frame_type; ///< frame type (strmtyp)
- int substreamid; ///< substream identification
- int frame_size; ///< current frame size, in bytes
-
- int channels; ///< number of total channels
- int fbw_channels; ///< number of full-bandwidth channels
- int lfe_on; ///< lfe channel in use
- int lfe_ch; ///< index of LFE channel
- int output_mode; ///< output channel configuration
- int out_channels; ///< number of output channels
-
- int center_mix_level; ///< Center mix level index
- int surround_mix_level; ///< Surround mix level index
- float downmix_coeffs[AC3_MAX_CHANNELS][2]; ///< stereo downmix coefficients
- float downmix_coeff_adjust[2]; ///< adjustment needed for each output channel when downmixing
- float dynamic_range[2]; ///< dynamic range
- int cpl_coords[AC3_MAX_CHANNELS][18]; ///< coupling coordinates
- int num_cpl_bands; ///< number of coupling bands
- int num_cpl_subbands; ///< number of coupling sub bands
- int start_freq[AC3_MAX_CHANNELS]; ///< start frequency bin
- int end_freq[AC3_MAX_CHANNELS]; ///< end frequency bin
- AC3BitAllocParameters bit_alloc_params; ///< bit allocation parameters
-
- int num_exp_groups[AC3_MAX_CHANNELS]; ///< Number of exponent groups
- 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 band_psd[AC3_MAX_CHANNELS][50]; ///< interpolated exponents
- int16_t mask[AC3_MAX_CHANNELS][50]; ///< masking curve values
-
- int fixed_coeffs[AC3_MAX_CHANNELS][256]; ///> fixed-point transform coefficients
- DECLARE_ALIGNED_16(float, transform_coeffs[AC3_MAX_CHANNELS][256]); ///< transform coefficients
- int downmixed; ///< indicates if coeffs are currently downmixed
-
- /* 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][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][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 gbc; ///< bitstream reader
- AVRandomState dith_state; ///< for dither generation
- AVCodecContext *avctx; ///< parent context
- uint8_t *input_buffer; ///< temp buffer to prevent overread
-} AC3DecodeContext;
-
/**
* Symmetrical Dequantization
* reference: Section 7.3.3 Expansion of Mantissas for Symmetrical Quantization
* start of the synchronized ac3 bitstream.
*/
static int ac3_parse_header(AC3DecodeContext *s)
+{
+ GetBitContext *gbc = &s->gbc;
+ int i;
+
+ /* read the rest of the bsi. read twice for dual mono mode. */
+ i = !(s->channel_mode);
+ do {
+ 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(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(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(gbc)) {
+ i = get_bits(gbc, 6);
+ do {
+ skip_bits(gbc, 8);
+ } while(i--);
+ }
+
+ return 0;
+}
+
+/**
+ * Common function to parse AC3 or E-AC3 frame header
+ */
+static int parse_frame_header(AC3DecodeContext *s)
{
AC3HeaderInfo hdr;
GetBitContext *gbc = &s->gbc;
- int err, i;
+ int err;
err = ff_ac3_parse_header(gbc, &hdr);
if(err)
s->channel_in_cpl[s->lfe_ch] = 0;
}
- /* read the rest of the bsi. read twice for dual mono mode. */
- i = !(s->channel_mode);
- do {
- 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(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(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(gbc)) {
- i = get_bits(gbc, 6);
- do {
- skip_bits(gbc, 8);
- } while(i--);
- }
-
- return 0;
+ return ac3_parse_header(s);
}
/**
static void set_downmix_coeffs(AC3DecodeContext *s)
{
int i;
- float cmix = gain_levels[s->center_mix_level];
- float smix = gain_levels[s->surround_mix_level];
+ float cmix = gain_levels[center_levels[s->center_mix_level]];
+ float smix = gain_levels[surround_levels[s->surround_mix_level]];
for(i=0; i<s->fbw_channels; i++) {
s->downmix_coeffs[i][0] = gain_levels[ac3_default_coeffs[s->channel_mode][i][0]];
tbap = bap[i];
switch (tbap) {
case 0:
- coeffs[i] = (av_random(&s->dith_state) & 0x7FFFFF) - 4194304;
+ coeffs[i] = (av_random(&s->dith_state) & 0x7FFFFF) - 0x400000;
break;
case 1:
for(bnd=0; bnd<s->num_rematrixing_bands; bnd++) {
if(s->rematrixing_flags[bnd]) {
- bndend = FFMIN(end, rematrix_band_tab[bnd+1]);
- for(i=rematrix_band_tab[bnd]; i<bndend; i++) {
+ bndend = FFMIN(end, ff_ac3_rematrix_band_tab[bnd+1]);
+ for(i=ff_ac3_rematrix_band_tab[bnd]; i<bndend; i++) {
tmp0 = s->fixed_coeffs[1][i];
tmp1 = s->fixed_coeffs[2][i];
s->fixed_coeffs[1][i] = tmp0 + tmp1;
int i, bnd, seg, ch;
int different_transforms;
int downmix_output;
+ int cpl_in_use;
GetBitContext *gbc = &s->gbc;
uint8_t bit_alloc_stages[AC3_MAX_CHANNELS];
/* coupling strategy */
if (get_bits1(gbc)) {
memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
- s->cpl_in_use = get_bits1(gbc);
- if (s->cpl_in_use) {
+ s->cpl_in_use[blk] = get_bits1(gbc);
+ if (s->cpl_in_use[blk]) {
/* coupling in use */
int cpl_begin_freq, cpl_end_freq;
} else 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 (s->cpl_in_use) {
+ if (cpl_in_use) {
int cpl_coords_exist = 0;
for (ch = 1; ch <= fbw_channels; ch++) {
if (channel_mode == AC3_CHMODE_STEREO) {
if (get_bits1(gbc)) {
s->num_rematrixing_bands = 4;
- if(s->cpl_in_use && s->start_freq[CPL_CH] <= 61)
+ 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);
}
/* exponent strategies for each channel */
- s->exp_strategy[CPL_CH] = EXP_REUSE;
- s->exp_strategy[s->lfe_ch] = EXP_REUSE;
- for (ch = !s->cpl_in_use; ch <= s->channels; ch++) {
- s->exp_strategy[ch] = get_bits(gbc, 2 - (ch == s->lfe_ch));
- if(s->exp_strategy[ch] != EXP_REUSE)
+ s->exp_strategy[blk][CPL_CH] = EXP_REUSE;
+ s->exp_strategy[blk][s->lfe_ch] = EXP_REUSE;
+ for (ch = !cpl_in_use; ch <= s->channels; ch++) {
+ 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 <= fbw_channels; ch++) {
s->start_freq[ch] = 0;
- if (s->exp_strategy[ch] != EXP_REUSE) {
+ 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] = bandwidth_code * 3 + 73;
}
- group_size = 3 << (s->exp_strategy[ch] - 1);
+ 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);
}
}
- if (s->cpl_in_use && s->exp_strategy[CPL_CH] != EXP_REUSE) {
+ 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[CPL_CH] - 1));
+ (3 << (s->exp_strategy[blk][CPL_CH] - 1));
}
/* decode exponents for each channel */
- for (ch = !s->cpl_in_use; ch <= s->channels; ch++) {
- if (s->exp_strategy[ch] != EXP_REUSE) {
+ 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;
- decode_exponents(gbc, s->exp_strategy[ch],
+ 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]);
if(ch != CPL_CH && ch != s->lfe_ch)
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=!s->cpl_in_use; ch<=s->channels; ch++)
+ 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");
if (get_bits1(gbc)) {
int csnr;
csnr = (get_bits(gbc, 6) - 15) << 4;
- for (ch = !s->cpl_in_use; ch <= s->channels; ch++) { /* snr offset and fast gain */
+ for (ch = !cpl_in_use; ch <= s->channels; ch++) { /* snr offset and fast gain */
s->snr_offset[ch] = (csnr + get_bits(gbc, 4)) << 2;
s->fast_gain[ch] = ff_ac3_fast_gain_tab[get_bits(gbc, 3)];
}
}
/* coupling leak information */
- if (s->cpl_in_use) {
+ if (cpl_in_use) {
if (get_bits1(gbc)) {
s->bit_alloc_params.cpl_fast_leak = get_bits(gbc, 3);
s->bit_alloc_params.cpl_slow_leak = get_bits(gbc, 3);
/* delta bit allocation information */
if (get_bits1(gbc)) {
/* delta bit allocation exists (strategy) */
- for (ch = !s->cpl_in_use; ch <= fbw_channels; ch++) {
+ 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");
bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
}
/* channel delta offset, len and bit allocation */
- for (ch = !s->cpl_in_use; ch <= fbw_channels; ch++) {
+ 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++) {
}
/* Bit allocation */
- for(ch=!s->cpl_in_use; ch<=s->channels; 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(s->dexps[ch],
s->start_freq[ch], s->end_freq[ch],
s->snr_offset[ch],
s->bit_alloc_params.floor,
- s->bap[ch]);
+ ff_ac3_bap_tab, s->bap[ch]);
}
}
/* parse the syncinfo */
*data_size = 0;
- err = ac3_parse_header(s);
+ 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, "unsupported frame type : skipping frame\n");
return s->frame_size;
} else {
- av_log(avctx, AV_LOG_ERROR, "invalid frame type\n");
+ av_log(avctx, AV_LOG_ERROR, "invalid frame type\n");
}
break;
default:
.init = ac3_decode_init,
.close = ac3_decode_end,
.decode = ac3_decode_frame,
- .long_name = "ATSC A/52 / AC-3",
+ .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52 / AC-3"),
};
projects / ffmpeg / blobdiff