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avcodec/ac3_parser: handle more header bits in ff_ac3_parse_header()

Browse Source 
Based on a patch by nyanmisaka.

Signed-off-by: James Almer <jamrial@gmail.com>
This commit is contained in:
James Almer
2025-06-05 16:36:26 -03:00
parent efbcd31206
commit 117343c0ba
7 changed files with 282 additions and 221 deletions
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219
libavcodec/ac3_parser.c
View File

@ -73,6 +73,217 @@ int ff_ac3_find_syncword(const uint8_t *buf, int buf_size)
return i;
}
/**
* Parse the 'sync info' and 'bit stream info' from the AC-3 bitstream.
* GetBitContext within AC3DecodeContext must point to
* the start of the synchronized AC-3 bitstream.
*/
static int ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
{
/* read the rest of the bsi. read twice for dual mono mode. */
for (int i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
hdr->dialog_normalization[i] = -get_bits(gbc, 5);
hdr->compression_exists[i] = get_bits1(gbc);
if (hdr->compression_exists[i])
hdr->heavy_dynamic_range[i] = get_bits(gbc, 8);
if (get_bits1(gbc))
skip_bits(gbc, 8); //skip language code
if (get_bits1(gbc))
skip_bits(gbc, 7); //skip audio production information
}
skip_bits(gbc, 2); //skip copyright bit and original bitstream bit
/* skip the timecodes or parse the Alternate Bit Stream Syntax */
if (hdr->bitstream_id != 6) {
if (get_bits1(gbc))
skip_bits(gbc, 14); //skip timecode1
if (get_bits1(gbc))
skip_bits(gbc, 14); //skip timecode2
} else {
if (get_bits1(gbc)) {
hdr->preferred_downmix = get_bits(gbc, 2);
hdr->center_mix_level_ltrt = get_bits(gbc, 3);
hdr->surround_mix_level_ltrt = av_clip(get_bits(gbc, 3), 3, 7);
hdr->center_mix_level = get_bits(gbc, 3);
hdr->surround_mix_level = av_clip(get_bits(gbc, 3), 3, 7);
}
if (get_bits1(gbc)) {
hdr->dolby_surround_ex_mode = get_bits(gbc, 2);
hdr->dolby_headphone_mode = get_bits(gbc, 2);
skip_bits(gbc, 10); // skip adconvtyp (1), xbsi2 (8), encinfo (1)
}
}
/* skip additional bitstream info */
if (get_bits1(gbc)) {
int i = get_bits(gbc, 6);
do {
skip_bits(gbc, 8);
} while (i--);
}
return 0;
}
static int eac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
{
if (hdr->frame_type == EAC3_FRAME_TYPE_RESERVED)
return AC3_PARSE_ERROR_FRAME_TYPE;
if (hdr->substreamid)
return AC3_PARSE_ERROR_FRAME_TYPE;
skip_bits(gbc, 5); // skip bitstream id
/* volume control params */
for (int i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
hdr->dialog_normalization[i] = -get_bits(gbc, 5);
hdr->compression_exists[i] = get_bits1(gbc);
if (hdr->compression_exists[i])
hdr->heavy_dynamic_range[i] = get_bits(gbc, 8);
}
/* dependent stream channel map */
if (hdr->frame_type == EAC3_FRAME_TYPE_DEPENDENT) {
hdr->channel_map_present = get_bits1(gbc);
if (hdr->channel_map_present) {
int64_t channel_layout = 0;
int channel_map = get_bits(gbc, 16);
for (int i = 0; i < 16; i++)
if (channel_map & (1 << (EAC3_MAX_CHANNELS - i - 1)))
channel_layout |= ff_eac3_custom_channel_map_locations[i][1];
if (av_popcount64(channel_layout) > EAC3_MAX_CHANNELS) {
return AC3_PARSE_ERROR_CHANNEL_MAP;
}
hdr->channel_map = channel_map;
}
}
/* mixing metadata */
if (get_bits1(gbc)) {
/* center and surround mix levels */
if (hdr->channel_mode > AC3_CHMODE_STEREO) {
hdr->preferred_downmix = get_bits(gbc, 2);
if (hdr->channel_mode & 1) {
/* if three front channels exist */
hdr->center_mix_level_ltrt = get_bits(gbc, 3);
hdr->center_mix_level = get_bits(gbc, 3);
}
if (hdr->channel_mode & 4) {
/* if a surround channel exists */
hdr->surround_mix_level_ltrt = av_clip(get_bits(gbc, 3), 3, 7);
hdr->surround_mix_level = av_clip(get_bits(gbc, 3), 3, 7);
}
}
/* lfe mix level */
if (hdr->lfe_on && (hdr->lfe_mix_level_exists = get_bits1(gbc))) {
hdr->lfe_mix_level = get_bits(gbc, 5);
}
/* info for mixing with other streams and substreams */
if (hdr->frame_type == EAC3_FRAME_TYPE_INDEPENDENT) {
for (int i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
// TODO: apply program scale factor
if (get_bits1(gbc)) {
skip_bits(gbc, 6); // skip program scale factor
}
}
if (get_bits1(gbc)) {
skip_bits(gbc, 6); // skip external program scale factor
}
/* skip mixing parameter data */
switch(get_bits(gbc, 2)) {
case 1: skip_bits(gbc, 5); break;
case 2: skip_bits(gbc, 12); break;
case 3: {
int mix_data_size = (get_bits(gbc, 5) + 2) << 3;
skip_bits_long(gbc, mix_data_size);
break;
}
}
/* skip pan information for mono or dual mono source */
if (hdr->channel_mode < AC3_CHMODE_STEREO) {
for (int i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
if (get_bits1(gbc)) {
/* note: this is not in the ATSC A/52B specification
reference: ETSI TS 102 366 V1.1.1
section: E.1.3.1.25 */
skip_bits(gbc, 8); // skip pan mean direction index
skip_bits(gbc, 6); // skip reserved paninfo bits
}
}
}
/* skip mixing configuration information */
if (get_bits1(gbc)) {
for (int i = 0; i < hdr->num_blocks; i++) {
if (hdr->num_blocks == 1 || get_bits1(gbc)) {
skip_bits(gbc, 5);
}
}
}
}
}
/* informational metadata */
if (get_bits1(gbc)) {
hdr->bitstream_mode = get_bits(gbc, 3);
skip_bits(gbc, 2); // skip copyright bit and original bitstream bit
if (hdr->channel_mode == AC3_CHMODE_STEREO) {
hdr->dolby_surround_mode = get_bits(gbc, 2);
hdr->dolby_headphone_mode = get_bits(gbc, 2);
}
if (hdr->channel_mode >= AC3_CHMODE_2F2R) {
hdr->dolby_surround_ex_mode = get_bits(gbc, 2);
}
for (int i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
if (get_bits1(gbc)) {
skip_bits(gbc, 8); // skip mix level, room type, and A/D converter type
}
}
if (hdr->sr_code != EAC3_SR_CODE_REDUCED) {
skip_bits1(gbc); // skip source sample rate code
}
}
/* converter synchronization flag
If frames are less than six blocks, this bit should be turned on
once every 6 blocks to indicate the start of a frame set.
reference: RFC 4598, Section 2.1.3 Frame Sets */
if (hdr->frame_type == EAC3_FRAME_TYPE_INDEPENDENT && hdr->num_blocks != 6) {
skip_bits1(gbc); // skip converter synchronization flag
}
/* original frame size code if this stream was converted from AC-3 */
if (hdr->frame_type == EAC3_FRAME_TYPE_AC3_CONVERT &&
(hdr->num_blocks == 6 || get_bits1(gbc))) {
skip_bits(gbc, 6); // skip frame size code
}
/* additional bitstream info */
if (get_bits1(gbc)) {
int addbsil = get_bits(gbc, 6);
for (int i = 0; i < addbsil + 1; i++) {
if (i == 0) {
/* In this 8 bit chunk, the LSB is equal to flag_ec3_extension_type_a
which can be used to detect Atmos presence */
skip_bits(gbc, 7);
hdr->eac3_extension_type_a = get_bits1(gbc);
if (hdr->eac3_extension_type_a) {
hdr->complexity_index_type_a = get_bits(gbc, 8);
i++;
}
} else {
skip_bits(gbc, 8); // skip additional bit stream info
}
}
}
return 0;
}
int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
{
int frame_size_code;
@ -133,6 +344,10 @@ int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
hdr->frame_size = ff_ac3_frame_size_tab[frame_size_code][hdr->sr_code] * 2;
hdr->frame_type = EAC3_FRAME_TYPE_AC3_CONVERT; //EAC3_FRAME_TYPE_INDEPENDENT;
hdr->substreamid = 0;
int ret = ac3_parse_header(gbc, hdr);
if (ret < 0)
return ret;
} else {
/* Enhanced AC-3 */
hdr->crc1 = 0;
@ -165,6 +380,10 @@ int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
hdr->bit_rate = 8LL * hdr->frame_size * hdr->sample_rate /
(hdr->num_blocks * 256);
hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on;
int ret = eac3_parse_header(gbc, hdr);
if (ret < 0)
return ret;
}
hdr->channel_layout = ff_ac3_channel_layout_tab[hdr->channel_mode];
if (hdr->lfe_on)

19
libavcodec/ac3_parser_internal.h
View File

@ -46,6 +46,7 @@ typedef struct AC3HeaderInfo {
int substreamid; ///< substream identification
int center_mix_level; ///< Center mix level index
int surround_mix_level; ///< Surround mix level index
uint8_t channel_map_present;
uint16_t channel_map;
int num_blocks; ///< number of audio blocks
int dolby_surround_mode;
@ -62,6 +63,23 @@ typedef struct AC3HeaderInfo {
uint64_t channel_layout;
int8_t ac3_bit_rate_code;
/** @} */
/** @name enhanced eac3 extension coded elements
* @{
*/
int8_t dialog_normalization[2];
uint8_t compression_exists[2];
uint8_t heavy_dynamic_range[2];
uint8_t center_mix_level_ltrt; ///< Center mix level index
uint8_t surround_mix_level_ltrt; ///< Surround mix level index
uint8_t dolby_headphone_mode;
uint8_t dolby_surround_ex_mode;
uint8_t lfe_mix_level_exists;
uint8_t lfe_mix_level;
uint8_t preferred_downmix;
uint8_t eac3_extension_type_a;
uint8_t complexity_index_type_a;
/** @} */
} AC3HeaderInfo;
typedef enum {
@ -71,6 +89,7 @@ typedef enum {
AC3_PARSE_ERROR_FRAME_SIZE = -0x4030c0a,
AC3_PARSE_ERROR_FRAME_TYPE = -0x5030c0a,
AC3_PARSE_ERROR_CRC = -0x6030c0a,
AC3_PARSE_ERROR_CHANNEL_MAP = -0x7030c0a,
} AC3ParseError;
/**

88
libavcodec/ac3dec.c
View File

@ -156,72 +156,6 @@ static av_cold void ac3_decode_flush(AVCodecContext *avctx)
av_lfg_init(&s->dith_state, 0);
}
/**
* Parse the 'sync info' and 'bit stream info' from the AC-3 bitstream.
* GetBitContext within AC3DecodeContext must point to
* the start of the synchronized AC-3 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 {
s->dialog_normalization[(!s->channel_mode)-i] = -get_bits(gbc, 5);
if (s->dialog_normalization[(!s->channel_mode)-i] == 0) {
s->dialog_normalization[(!s->channel_mode)-i] = -31;
}
if (s->target_level != 0) {
s->level_gain[(!s->channel_mode)-i] = powf(2.0f,
(float)(s->target_level -
s->dialog_normalization[(!s->channel_mode)-i])/6.0f);
}
if (s->compression_exists[(!s->channel_mode)-i] = get_bits1(gbc)) {
s->heavy_dynamic_range[(!s->channel_mode)-i] =
AC3_HEAVY_RANGE(get_bits(gbc, 8));
}
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 parse the Alternate Bit Stream Syntax */
if (s->bitstream_id != 6) {
if (get_bits1(gbc))
skip_bits(gbc, 14); //skip timecode1
if (get_bits1(gbc))
skip_bits(gbc, 14); //skip timecode2
} else {
if (get_bits1(gbc)) {
s->preferred_downmix = get_bits(gbc, 2);
s->center_mix_level_ltrt = get_bits(gbc, 3);
s->surround_mix_level_ltrt = av_clip(get_bits(gbc, 3), 3, 7);
s->center_mix_level = get_bits(gbc, 3);
s->surround_mix_level = av_clip(get_bits(gbc, 3), 3, 7);
}
if (get_bits1(gbc)) {
s->dolby_surround_ex_mode = get_bits(gbc, 2);
s->dolby_headphone_mode = get_bits(gbc, 2);
skip_bits(gbc, 10); // skip adconvtyp (1), xbsi2 (8), encinfo (1)
}
}
/* 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 AC-3 or E-AC-3 frame header
*/
@ -281,10 +215,25 @@ static int parse_frame_header(AC3DecodeContext *s)
s->dba_syntax = 1;
s->skip_syntax = 1;
memset(s->channel_uses_aht, 0, sizeof(s->channel_uses_aht));
return ac3_parse_header(s);
/* volume control params */
for (int i = 0; i < (s->channel_mode ? 1 : 2); i++) {
s->dialog_normalization[i] = hdr.dialog_normalization[i];
if (s->dialog_normalization[i] == 0) {
s->dialog_normalization[i] = -31;
}
if (s->target_level != 0) {
s->level_gain[i] = powf(2.0f,
(float)(s->target_level - s->dialog_normalization[i])/6.0f);
}
s->compression_exists[i] = hdr.compression_exists[i];
if (s->compression_exists[i]) {
s->heavy_dynamic_range[i] = AC3_HEAVY_RANGE(hdr.heavy_dynamic_range[i]);
}
}
return 0;
} else if (CONFIG_EAC3_DECODER) {
s->eac3 = 1;
return ff_eac3_parse_header(s);
return ff_eac3_parse_header(s, &hdr);
} else {
av_log(s->avctx, AV_LOG_ERROR, "E-AC-3 support not compiled in\n");
return AVERROR(ENOSYS);
@ -1469,6 +1418,9 @@ dependent_frame:
av_log(avctx, AV_LOG_ERROR, "invalid frame type\n");
}
break;
case AC3_PARSE_ERROR_CHANNEL_MAP:
av_log(avctx, AV_LOG_ERROR, "invalid channel map\n");
return AVERROR_INVALIDDATA;
case AC3_PARSE_ERROR_CRC:
break;
default: // Normal AVERROR do not try to recover.

4
libavcodec/ac3dec.h
View File

@ -260,11 +260,13 @@ typedef struct AC3DecodeContext {
///@}
} AC3DecodeContext;
struct AC3HeaderInfo;
/**
* Parse the E-AC-3 frame header.
* This parses both the bit stream info and audio frame header.
*/
static int ff_eac3_parse_header(AC3DecodeContext *s);
static int ff_eac3_parse_header(AC3DecodeContext *s, const struct AC3HeaderInfo *hdr);
/**
* Decode mantissas in a single channel for the entire frame.

2
libavcodec/ac3defs.h
View File

@ -34,6 +34,8 @@
#define AC3_CRITICAL_BANDS 50
#define AC3_MAX_CPL_BANDS 18
#define EAC3_SR_CODE_REDUCED 3
/* pre-defined gain values */
#define LEVEL_PLUS_3DB M_SQRT2
#define LEVEL_PLUS_1POINT5DB 1.1892071150027209

154
libavcodec/eac3dec.c
View File

@ -53,8 +53,6 @@ typedef enum {
EAC3_GAQ_124
} EAC3GaqMode;
#define EAC3_SR_CODE_REDUCED 3
static void ff_eac3_apply_spectral_extension(AC3DecodeContext *s)
{
int bin, bnd, ch, i;
@ -287,7 +285,7 @@ static void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch)
}
}
static int ff_eac3_parse_header(AC3DecodeContext *s)
static int ff_eac3_parse_header(AC3DecodeContext *s, const AC3HeaderInfo *hdr)
{
int i, blk, ch;
int ac3_exponent_strategy, parse_aht_info, parse_spx_atten_data;
@ -323,11 +321,10 @@ static int ff_eac3_parse_header(AC3DecodeContext *s)
avpriv_request_sample(s->avctx, "Reduced sampling rate");
return AVERROR_PATCHWELCOME;
}
skip_bits(gbc, 5); // skip bitstream id
/* volume control params */
for (i = 0; i < (s->channel_mode ? 1 : 2); i++) {
s->dialog_normalization[i] = -get_bits(gbc, 5);
s->dialog_normalization[i] = hdr->dialog_normalization[i];
if (s->dialog_normalization[i] == 0) {
s->dialog_normalization[i] = -31;
}
@ -335,147 +332,30 @@ static int ff_eac3_parse_header(AC3DecodeContext *s)
s->level_gain[i] = powf(2.0f,
(float)(s->target_level - s->dialog_normalization[i])/6.0f);
}
s->compression_exists[i] = get_bits1(gbc);
if (s->compression_exists[i]) {
s->heavy_dynamic_range[i] = AC3_HEAVY_RANGE(get_bits(gbc, 8));
if (hdr->compression_exists[i]) {
s->heavy_dynamic_range[i] = AC3_HEAVY_RANGE(hdr->heavy_dynamic_range[i]);
}
}
/* dependent stream channel map */
if (s->frame_type == EAC3_FRAME_TYPE_DEPENDENT) {
if (get_bits1(gbc)) {
int64_t channel_layout = 0;
int channel_map = get_bits(gbc, 16);
av_log(s->avctx, AV_LOG_DEBUG, "channel_map: %0X\n", channel_map);
for (i = 0; i < 16; i++)
if (channel_map & (1 << (EAC3_MAX_CHANNELS - i - 1)))
channel_layout |= ff_eac3_custom_channel_map_locations[i][1];
if (av_popcount64(channel_layout) > EAC3_MAX_CHANNELS) {
return AVERROR_INVALIDDATA;
}
s->channel_map = channel_map;
}
}
s->channel_map = hdr->channel_map;
/* mixing metadata */
if (get_bits1(gbc)) {
/* center and surround mix levels */
if (s->channel_mode > AC3_CHMODE_STEREO) {
s->preferred_downmix = get_bits(gbc, 2);
if (s->channel_mode & 1) {
/* if three front channels exist */
s->center_mix_level_ltrt = get_bits(gbc, 3);
s->center_mix_level = get_bits(gbc, 3);
}
if (s->channel_mode & 4) {
/* if a surround channel exists */
s->surround_mix_level_ltrt = av_clip(get_bits(gbc, 3), 3, 7);
s->surround_mix_level = av_clip(get_bits(gbc, 3), 3, 7);
}
}
/* lfe mix level */
if (s->lfe_on && (s->lfe_mix_level_exists = get_bits1(gbc))) {
s->lfe_mix_level = get_bits(gbc, 5);
}
/* info for mixing with other streams and substreams */
if (s->frame_type == EAC3_FRAME_TYPE_INDEPENDENT) {
for (i = 0; i < (s->channel_mode ? 1 : 2); i++) {
// TODO: apply program scale factor
if (get_bits1(gbc)) {
skip_bits(gbc, 6); // skip program scale factor
}
}
if (get_bits1(gbc)) {
skip_bits(gbc, 6); // skip external program scale factor
}
/* skip mixing parameter data */
switch(get_bits(gbc, 2)) {
case 1: skip_bits(gbc, 5); break;
case 2: skip_bits(gbc, 12); break;
case 3: {
int mix_data_size = (get_bits(gbc, 5) + 2) << 3;
skip_bits_long(gbc, mix_data_size);
break;
}
}
/* skip pan information for mono or dual mono source */
if (s->channel_mode < AC3_CHMODE_STEREO) {
for (i = 0; i < (s->channel_mode ? 1 : 2); i++) {
if (get_bits1(gbc)) {
/* note: this is not in the ATSC A/52B specification
reference: ETSI TS 102 366 V1.1.1
section: E.1.3.1.25 */
skip_bits(gbc, 8); // skip pan mean direction index
skip_bits(gbc, 6); // skip reserved paninfo bits
}
}
}
/* skip mixing configuration information */
if (get_bits1(gbc)) {
for (blk = 0; blk < s->num_blocks; blk++) {
if (s->num_blocks == 1 || get_bits1(gbc)) {
skip_bits(gbc, 5);
}
}
}
}
}
s->preferred_downmix = hdr->preferred_downmix;
s->center_mix_level_ltrt = hdr->center_mix_level_ltrt;
s->center_mix_level = hdr->center_mix_level;
s->surround_mix_level_ltrt = hdr->surround_mix_level_ltrt;
s->surround_mix_level = hdr->surround_mix_level;
s->lfe_mix_level_exists = hdr->lfe_mix_level_exists;
s->lfe_mix_level = hdr->lfe_mix_level;
s->dolby_surround_mode = hdr->dolby_surround_mode;
s->dolby_headphone_mode = hdr->dolby_headphone_mode;
s->dolby_surround_ex_mode = hdr->dolby_surround_ex_mode;
/* informational metadata */
if (get_bits1(gbc)) {
s->bitstream_mode = get_bits(gbc, 3);
skip_bits(gbc, 2); // skip copyright bit and original bitstream bit
if (s->channel_mode == AC3_CHMODE_STEREO) {
s->dolby_surround_mode = get_bits(gbc, 2);
s->dolby_headphone_mode = get_bits(gbc, 2);
}
if (s->channel_mode >= AC3_CHMODE_2F2R) {
s->dolby_surround_ex_mode = get_bits(gbc, 2);
}
for (i = 0; i < (s->channel_mode ? 1 : 2); i++) {
if (get_bits1(gbc)) {
skip_bits(gbc, 8); // skip mix level, room type, and A/D converter type
}
}
if (s->bit_alloc_params.sr_code != EAC3_SR_CODE_REDUCED) {
skip_bits1(gbc); // skip source sample rate code
}
}
/* converter synchronization flag
If frames are less than six blocks, this bit should be turned on
once every 6 blocks to indicate the start of a frame set.
reference: RFC 4598, Section 2.1.3 Frame Sets */
if (s->frame_type == EAC3_FRAME_TYPE_INDEPENDENT && s->num_blocks != 6) {
skip_bits1(gbc); // skip converter synchronization flag
}
/* original frame size code if this stream was converted from AC-3 */
if (s->frame_type == EAC3_FRAME_TYPE_AC3_CONVERT &&
(s->num_blocks == 6 || get_bits1(gbc))) {
skip_bits(gbc, 6); // skip frame size code
}
s->bitstream_mode = hdr->bitstream_mode;
/* additional bitstream info */
if (get_bits1(gbc)) {
int addbsil = get_bits(gbc, 6);
for (i = 0; i < addbsil + 1; i++) {
if (i == 0) {
/* In this 8 bit chunk, the LSB is equal to flag_ec3_extension_type_a
which can be used to detect Atmos presence */
skip_bits(gbc, 7);
if (get_bits1(gbc)) {
s->eac3_extension_type_a = 1;
}
} else {
skip_bits(gbc, 8); // skip additional bit stream info
}
}
}
s->eac3_extension_type_a = hdr->eac3_extension_type_a;
/* audio frame syntax flags, strategy data, and per-frame data */

17
libavformat/movenc.c
View File

@ -532,8 +532,6 @@ static int handle_eac3(MOVMuxContext *mov, AVPacket *pkt, MOVTrack *track)
int parent = hdr->substreamid;
while (cumul_size != pkt->size) {
GetBitContext gbc;
int i;
ret = avpriv_ac3_parse_header(&hdr, pkt->data + cumul_size, pkt->size - cumul_size);
if (ret < 0)
goto end;
@ -544,20 +542,9 @@ static int handle_eac3(MOVMuxContext *mov, AVPacket *pkt, MOVTrack *track)
info->substream[parent].num_dep_sub++;
ret /= 8;
/* header is parsed up to lfeon, but custom channel map may be needed */
init_get_bits8(&gbc, pkt->data + cumul_size + ret, pkt->size - cumul_size - ret);
/* skip bsid */
skip_bits(&gbc, 5);
/* skip volume control params */
for (i = 0; i < (hdr->channel_mode ? 1 : 2); i++) {
skip_bits(&gbc, 5); // skip dialog normalization
if (get_bits1(&gbc)) {
skip_bits(&gbc, 8); // skip compression gain word
}
}
/* get the dependent stream channel map, if exists */
if (get_bits1(&gbc))
info->substream[parent].chan_loc |= (get_bits(&gbc, 16) >> 5) & 0x1f;
if (hdr->channel_map_present)
info->substream[parent].chan_loc |= (hdr->channel_map >> 5) & 0x1f;
else
info->substream[parent].chan_loc |= hdr->channel_mode;
cumul_size += hdr->frame_size;