static int parse_descriptor(struct exss_asset *asset)
{
struct exss_parser *exss = asset->parser;
int i, j, ret, descr_pos = exss->bits.index;
// Size of audio asset descriptor in bytes
int descr_size = bits_get(&exss->bits, 9) + 1;
// Audio asset identifier
asset->asset_index = bits_get(&exss->bits, 3);
//
// Per stream static metadata
//
if (exss->static_fields_present) {
// Asset type descriptor presence
if (bits_get1(&exss->bits))
// Asset type descriptor
bits_skip(&exss->bits, 4);
// Language descriptor presence
if (bits_get1(&exss->bits))
// Language descriptor
bits_skip(&exss->bits, 24);
// Additional textual information presence
if (bits_get1(&exss->bits)) {
// Byte size of additional text info
int text_size = bits_get(&exss->bits, 10) + 1;
// Additional textual information string
bits_skip(&exss->bits, text_size * 8);
}
// PCM bit resolution
asset->pcm_bit_res = bits_get(&exss->bits, 5) + 1;
// Maximum sample rate
asset->max_sample_rate = exss_sample_rates[bits_get(&exss->bits, 4)];
// Total number of channels
asset->nchannels_total = bits_get(&exss->bits, 8) + 1;
// One to one map channel to speakers
asset->one_to_one_map_ch_to_spkr = bits_get1(&exss->bits);
if (asset->one_to_one_map_ch_to_spkr) {
// Embedded stereo flag
if (asset->nchannels_total > 2)
asset->embedded_stereo = bits_get1(&exss->bits);
// Embedded 6 channels flag
if (asset->nchannels_total > 6)
asset->embedded_6ch = bits_get1(&exss->bits);
// Speaker mask enabled flag
asset->spkr_mask_enabled = bits_get1(&exss->bits);
int spkr_mask_nbits = 0;
if (asset->spkr_mask_enabled) {
// Number of bits for speaker activity mask
spkr_mask_nbits = (bits_get(&exss->bits, 2) + 1) << 2;
// Loudspeaker activity mask
asset->spkr_mask = bits_get(&exss->bits, spkr_mask_nbits);
}
// Number of speaker remapping sets
int spkr_remap_nsets = bits_get(&exss->bits, 3);
if (spkr_remap_nsets && !spkr_mask_nbits) {
exss_err("Speaker mask disabled yet there are remapping sets");
return -DCADEC_EBADDATA;
}
// Standard loudspeaker layout mask
int nspeakers[8];
for (i = 0; i < spkr_remap_nsets; i++)
nspeakers[i] = count_chs_for_mask(bits_get(&exss->bits, spkr_mask_nbits));
for (i = 0; i < spkr_remap_nsets; i++) {
// Number of channels to be decoded for speaker remapping
int nch_for_remaps = bits_get(&exss->bits, 5) + 1;
for (j = 0; j < nspeakers[i]; j++) {
// Decoded channels to output speaker mapping mask
int remap_ch_mask = bits_get(&exss->bits, nch_for_remaps);
// Loudspeaker remapping codes
int ncodes = dca_popcount(remap_ch_mask);
bits_skip(&exss->bits, ncodes * 5);
}
}
} else {
asset->embedded_stereo = false;
asset->embedded_6ch = false;
asset->spkr_mask_enabled = false;
asset->spkr_mask = 0;
// Representation type
asset->representation_type = bits_get(&exss->bits, 3);
}
}
//
// DRC, DNC and mixing metadata
//
// Dynamic range coefficient presence flag
bool drc_present = bits_get1(&exss->bits);
// Code for dynamic range coefficient
if (drc_present)
bits_skip(&exss->bits, 8);
// Dialog normalization presence flag
if (bits_get1(&exss->bits))
// Dialog normalization code
bits_skip(&exss->bits, 5);
// DRC for stereo downmix
if (drc_present && asset->embedded_stereo)
bits_skip(&exss->bits, 8);
// Mixing metadata presence flag
if (exss->mix_metadata_enabled && bits_get1(&exss->bits)) {
// External mixing flag
bits_skip1(&exss->bits);
// Post mixing / replacement gain adjustment
bits_skip(&exss->bits, 6);
// DRC prior to mixing
if (bits_get(&exss->bits, 2) == 3)
// Custom code for mixing DRC
bits_skip(&exss->bits, 8);
else
// Limit for mixing DRC
bits_skip(&exss->bits, 3);
// Scaling type for channels of main audio
// Scaling parameters of main audio
if (bits_get1(&exss->bits))
for (i = 0; i < exss->nmixoutconfigs; i++)
bits_skip(&exss->bits, 6 * exss->nmixoutchs[i]);
else
bits_skip(&exss->bits, 6 * exss->nmixoutconfigs);
int nchannels_dmix = asset->nchannels_total;
if (asset->embedded_6ch)
nchannels_dmix += 6;
if (asset->embedded_stereo)
nchannels_dmix += 2;
for (i = 0; i < exss->nmixoutconfigs; i++) {
for (j = 0; j < nchannels_dmix; j++) {
if (!exss->nmixoutchs[i]) {
exss_err("Invalid speaker layout mask for mixing configuration");
return -DCADEC_EBADDATA;
}
// Mix output mask
int mix_map_mask = bits_get(&exss->bits, exss->nmixoutchs[i]);
// Mixing coefficients
int nmixcoefs = dca_popcount(mix_map_mask);
bits_skip(&exss->bits, 6 * nmixcoefs);
}
}
}
//
// Decoder navigation data
//
// Coding mode for the asset
asset->coding_mode = bits_get(&exss->bits, 2);
// Coding components used in asset
switch (asset->coding_mode) {
case 0: // Coding mode that may contain multiple coding components
asset->extension_mask = bits_get(&exss->bits, 12);
if (asset->extension_mask & EXSS_CORE) {
// Size of core component in extension substream
asset->core_size = bits_get(&exss->bits, 14) + 1;
// Core sync word present flag
if (bits_get1(&exss->bits))
// Core sync distance
bits_skip(&exss->bits, 2);
}
if (asset->extension_mask & EXSS_XBR)
// Size of XBR extension in extension substream
asset->xbr_size = bits_get(&exss->bits, 14) + 1;
if (asset->extension_mask & EXSS_XXCH)
// Size of XXCH extension in extension substream
asset->xxch_size = bits_get(&exss->bits, 14) + 1;
if (asset->extension_mask & EXSS_X96)
// Size of X96 extension in extension substream
asset->x96_size = bits_get(&exss->bits, 12) + 1;
if (asset->extension_mask & EXSS_LBR)
parse_lbr_parameters(asset);
if (asset->extension_mask & EXSS_XLL)
parse_xll_parameters(asset);
if (asset->extension_mask & EXSS_RSV1)
bits_skip(&exss->bits, 16);
if (asset->extension_mask & EXSS_RSV2)
bits_skip(&exss->bits, 16);
break;
case 1: // Loss-less coding mode without CBR component
asset->extension_mask = EXSS_XLL;
parse_xll_parameters(asset);
break;
case 2: // Low bit rate mode
asset->extension_mask = EXSS_LBR;
parse_lbr_parameters(asset);
break;
case 3: // Auxiliary coding mode
asset->extension_mask = 0;
// Size of auxiliary coded data
bits_skip(&exss->bits, 14);
// Auxiliary codec identification
bits_skip(&exss->bits, 8);
// Aux sync word present flag
if (bits_get1(&exss->bits))
// Aux sync distance
bits_skip(&exss->bits, 3);
break;
}
if (asset->extension_mask & EXSS_XLL)
// DTS-HD stream ID
asset->hd_stream_id = bits_get(&exss->bits, 3);
// One to one mixing flag
// Per channel main audio scaling flag
// Main audio scaling codes
// Decode asset in secondary decoder flag
// Revision 2 DRC metadata
// Reserved
// Zero pad
if ((ret = bits_seek(&exss->bits, descr_pos + descr_size * 8)) < 0)
exss_err("Read past end of asset descriptor");
return ret;
}
static int parse_descriptor(DCAExssParser *s, DCAExssAsset *asset)
{
int i, j, drc_present, descr_size, descr_pos = get_bits_count(&s->gb);
// Size of audio asset descriptor in bytes
descr_size = get_bits(&s->gb, 9) + 1;
// Audio asset identifier
asset->asset_index = get_bits(&s->gb, 3);
//
// Per stream static metadata
//
if (s->static_fields_present) {
// Asset type descriptor presence
if (get_bits1(&s->gb))
// Asset type descriptor
skip_bits(&s->gb, 4);
// Language descriptor presence
if (get_bits1(&s->gb))
// Language descriptor
skip_bits(&s->gb, 24);
// Additional textual information presence
if (get_bits1(&s->gb)) {
// Byte size of additional text info
int text_size = get_bits(&s->gb, 10) + 1;
// Sanity check available size
if (get_bits_left(&s->gb) < text_size * 8)
return AVERROR_INVALIDDATA;
// Additional textual information string
skip_bits_long(&s->gb, text_size * 8);
}
// PCM bit resolution
asset->pcm_bit_res = get_bits(&s->gb, 5) + 1;
// Maximum sample rate
asset->max_sample_rate = ff_dca_sampling_freqs[get_bits(&s->gb, 4)];
// Total number of channels
asset->nchannels_total = get_bits(&s->gb, 8) + 1;
// One to one map channel to speakers
if (asset->one_to_one_map_ch_to_spkr = get_bits1(&s->gb)) {
int spkr_mask_nbits = 0;
int spkr_remap_nsets;
int nspeakers[8];
// Embedded stereo flag
asset->embedded_stereo = asset->nchannels_total > 2 && get_bits1(&s->gb);
// Embedded 6 channels flag
asset->embedded_6ch = asset->nchannels_total > 6 && get_bits1(&s->gb);
// Speaker mask enabled flag
if (asset->spkr_mask_enabled = get_bits1(&s->gb)) {
// Number of bits for speaker activity mask
spkr_mask_nbits = (get_bits(&s->gb, 2) + 1) << 2;
// Loudspeaker activity mask
asset->spkr_mask = get_bits(&s->gb, spkr_mask_nbits);
}
// Number of speaker remapping sets
if ((spkr_remap_nsets = get_bits(&s->gb, 3)) && !spkr_mask_nbits) {
av_log(s->avctx, AV_LOG_ERROR, "Speaker mask disabled yet there are remapping sets\n");
return AVERROR_INVALIDDATA;
}
// Standard loudspeaker layout mask
for (i = 0; i < spkr_remap_nsets; i++)
nspeakers[i] = ff_dca_count_chs_for_mask(get_bits(&s->gb, spkr_mask_nbits));
for (i = 0; i < spkr_remap_nsets; i++) {
// Number of channels to be decoded for speaker remapping
int nch_for_remaps = get_bits(&s->gb, 5) + 1;
for (j = 0; j < nspeakers[i]; j++) {
// Decoded channels to output speaker mapping mask
int remap_ch_mask = get_bits_long(&s->gb, nch_for_remaps);
// Loudspeaker remapping codes
skip_bits_long(&s->gb, av_popcount(remap_ch_mask) * 5);
}
}
} else {
asset->embedded_stereo = 0;
asset->embedded_6ch = 0;
asset->spkr_mask_enabled = 0;
asset->spkr_mask = 0;
// Representation type
asset->representation_type = get_bits(&s->gb, 3);
}
}
//
// DRC, DNC and mixing metadata
//
// Dynamic range coefficient presence flag
drc_present = get_bits1(&s->gb);
// Code for dynamic range coefficient
if (drc_present)
skip_bits(&s->gb, 8);
// Dialog normalization presence flag
if (get_bits1(&s->gb))
// Dialog normalization code
skip_bits(&s->gb, 5);
// DRC for stereo downmix
if (drc_present && asset->embedded_stereo)
skip_bits(&s->gb, 8);
// Mixing metadata presence flag
if (s->mix_metadata_enabled && get_bits1(&s->gb)) {
int nchannels_dmix;
// External mixing flag
skip_bits1(&s->gb);
// Post mixing / replacement gain adjustment
skip_bits(&s->gb, 6);
// DRC prior to mixing
if (get_bits(&s->gb, 2) == 3)
// Custom code for mixing DRC
skip_bits(&s->gb, 8);
else
// Limit for mixing DRC
skip_bits(&s->gb, 3);
// Scaling type for channels of main audio
// Scaling parameters of main audio
if (get_bits1(&s->gb))
for (i = 0; i < s->nmixoutconfigs; i++)
skip_bits_long(&s->gb, 6 * s->nmixoutchs[i]);
else
skip_bits_long(&s->gb, 6 * s->nmixoutconfigs);
nchannels_dmix = asset->nchannels_total;
if (asset->embedded_6ch)
nchannels_dmix += 6;
if (asset->embedded_stereo)
nchannels_dmix += 2;
for (i = 0; i < s->nmixoutconfigs; i++) {
if (!s->nmixoutchs[i]) {
av_log(s->avctx, AV_LOG_ERROR, "Invalid speaker layout mask for mixing configuration\n");
return AVERROR_INVALIDDATA;
}
for (j = 0; j < nchannels_dmix; j++) {
// Mix output mask
int mix_map_mask = get_bits(&s->gb, s->nmixoutchs[i]);
// Mixing coefficients
skip_bits_long(&s->gb, av_popcount(mix_map_mask) * 6);
}
}
}
//
// Decoder navigation data
//
// Coding mode for the asset
asset->coding_mode = get_bits(&s->gb, 2);
// Coding components used in asset
switch (asset->coding_mode) {
case 0: // Coding mode that may contain multiple coding components
asset->extension_mask = get_bits(&s->gb, 12);
if (asset->extension_mask & DCA_EXSS_CORE) {
// Size of core component in extension substream
asset->core_size = get_bits(&s->gb, 14) + 1;
// Core sync word present flag
if (get_bits1(&s->gb))
// Core sync distance
skip_bits(&s->gb, 2);
}
if (asset->extension_mask & DCA_EXSS_XBR)
// Size of XBR extension in extension substream
asset->xbr_size = get_bits(&s->gb, 14) + 1;
if (asset->extension_mask & DCA_EXSS_XXCH)
// Size of XXCH extension in extension substream
asset->xxch_size = get_bits(&s->gb, 14) + 1;
if (asset->extension_mask & DCA_EXSS_X96)
// Size of X96 extension in extension substream
asset->x96_size = get_bits(&s->gb, 12) + 1;
if (asset->extension_mask & DCA_EXSS_LBR)
parse_lbr_parameters(s, asset);
if (asset->extension_mask & DCA_EXSS_XLL)
parse_xll_parameters(s, asset);
if (asset->extension_mask & DCA_EXSS_RSV1)
skip_bits(&s->gb, 16);
if (asset->extension_mask & DCA_EXSS_RSV2)
skip_bits(&s->gb, 16);
break;
case 1: // Loss-less coding mode without CBR component
asset->extension_mask = DCA_EXSS_XLL;
parse_xll_parameters(s, asset);
break;
case 2: // Low bit rate mode
asset->extension_mask = DCA_EXSS_LBR;
parse_lbr_parameters(s, asset);
break;
case 3: // Auxiliary coding mode
asset->extension_mask = 0;
// Size of auxiliary coded data
skip_bits(&s->gb, 14);
// Auxiliary codec identification
skip_bits(&s->gb, 8);
// Aux sync word present flag
if (get_bits1(&s->gb))
// Aux sync distance
skip_bits(&s->gb, 3);
break;
}
if (asset->extension_mask & DCA_EXSS_XLL)
// DTS-HD stream ID
asset->hd_stream_id = get_bits(&s->gb, 3);
// One to one mixing flag
// Per channel main audio scaling flag
// Main audio scaling codes
// Decode asset in secondary decoder flag
// Revision 2 DRC metadata
// Reserved
// Zero pad
if (ff_dca_seek_bits(&s->gb, descr_pos + descr_size * 8)) {
av_log(s->avctx, AV_LOG_ERROR, "Read past end of EXSS asset descriptor\n");
return AVERROR_INVALIDDATA;
}
return 0;
}
