static int dca_parse_params(const uint8_t *buf, int buf_size, int *duration,
int *sample_rate)
{
GetBitContext gb;
uint8_t hdr[12 + FF_INPUT_BUFFER_PADDING_SIZE] = { 0 };
int ret, sample_blocks, sr_code;
if (buf_size < 12)
return AVERROR_INVALIDDATA;
if ((ret = ff_dca_convert_bitstream(buf, 12, hdr, 12)) < 0)
return ret;
init_get_bits(&gb, hdr, 96);
skip_bits_long(&gb, 39);
sample_blocks = get_bits(&gb, 7) + 1;
if (sample_blocks < 8)
return AVERROR_INVALIDDATA;
*duration = 256 * (sample_blocks / 8);
skip_bits(&gb, 20);
sr_code = get_bits(&gb, 4);
*sample_rate = avpriv_dca_sample_rates[sr_code];
if (*sample_rate == 0)
return AVERROR_INVALIDDATA;
return 0;
}
int parse_dts_header(DTSParserContext *pContext, DTSHeader *pHeader, uint8_t *pBuffer, unsigned uSize)
{
if(!pContext) return -1;
if(!pHeader) return -1;
unsigned ExtDescriptor = 0, ExtCoding = 0;
uint8_t dts_buffer[32 + FF_INPUT_BUFFER_PADDING_SIZE] = {0};
int ret = ff_dca_convert_bitstream(pBuffer, uSize, dts_buffer, 32);
bool is16be = (AV_RB32(pBuffer) == DCA_MARKER_RAW_BE);
/* Parse Core Header */
if (ret >= 0) {
pHeader->HasCore = 1;
GetBitContext *gb = pContext->gb;
init_get_bits(gb, dts_buffer, 32 << 3);
skip_bits_long(gb, 32); /* Sync code */
skip_bits1(gb); /* Frame type */
pHeader->SamplesPerBlock = get_bits(gb, 5) + 1; /* Samples deficit */
pHeader->CRCPresent = get_bits1(gb); /* CRC present */
pHeader->Blocks = get_bits(gb, 7) + 1; /* Number of Blocks */
pHeader->FrameSize = get_bits(gb, 14) + 1; /* Primary (core) Frame Size */
pHeader->ChannelLayout = get_bits(gb, 6); /* Channel configuration */
unsigned sample_index = get_bits(gb, 4); /* Sample frequency index */
pHeader->SampleRate = avpriv_dca_sample_rates[sample_index];
unsigned bitrate_index = get_bits(gb, 5); /* Bitrate index */
pHeader->Bitrate = dca_bit_rates[bitrate_index];
skip_bits1(gb); /* Down mix */
skip_bits1(gb); /* Dynamic range */
skip_bits1(gb); /* Time stamp */
skip_bits1(gb); /* Auxiliary data */
skip_bits1(gb); /* HDCD */
ExtDescriptor = get_bits(gb, 3); /* External descriptor */
ExtCoding = get_bits1(gb); /* Extended coding */
skip_bits1(gb); /* ASPF */
pHeader->LFE = get_bits(gb, 2); /* LFE */
skip_bits1(gb); /* Predictor History */
if(pHeader->CRCPresent)
skip_bits(gb, 16); /* CRC */
skip_bits1(gb); /* Multirate Interpolator */
skip_bits(gb, 4); /* Encoder Software Revision */
skip_bits(gb, 2); /* Copy history */
pHeader->ES = get_bits1(gb); /* ES */
skip_bits(gb, 2); /* PCMR (source PCM resolution) */
skip_bits1(gb); /* SUMF (Front Sum/Difference Flag) */
skip_bits1(gb); /* SUMS (Surround Sum/Difference Flag) */
skip_bits(gb, 4); /* Dialog Normalization Parameter or Unspecified (dependent on encoder version) */
// Check some basic validity
if (uSize < pHeader->FrameSize)
return -1;
} else {
pHeader->HasCore = 0;
}
if (pHeader->HasCore && !is16be)
return 0;
// DTS-HD parsing
const uint8_t *pHD = nullptr;
if (pHeader->HasCore) { // If we have a core, only search after the normal buffer
if (uSize > (pHeader->FrameSize + 4)) { // at least 4 bytes extra, could probably insert a minimal size of a HD header, but so what
pHD = find_marker32_position(pBuffer + pHeader->FrameSize, uSize - pHeader->FrameSize, DCA_HD_MARKER);
}
} else {
pHD = find_marker32_position(pBuffer, uSize, DCA_HD_MARKER);
}
if (pHD) {
pHeader->IsHD = 1;
size_t remaining = uSize - (pHD - pBuffer);
parse_dts_hd_header(pContext, pHeader, pHD, (unsigned)remaining);
const uint8_t *pXChHD = find_marker32_position(pHD, remaining, DCA_XCH_MARKER);
if (pXChHD) {
size_t remaining = uSize - (pXChHD - pBuffer);
parse_dts_xch_hd_header(pContext, pHeader, pXChHD, (unsigned)remaining);
}
const uint8_t *pXXChHD = find_marker32_position(pHD, remaining, DCA_XXCH_MARKER);
if (pXXChHD) {
size_t remaining = uSize - (pXXChHD - pBuffer);
parse_dts_xxch_hd_header(pContext, pHeader, pXXChHD, (unsigned)remaining);
}
}
// Handle DTS extensions
if (ExtCoding) {
size_t coreSize = pHD ? (pHD - pBuffer) : uSize;
if (ExtDescriptor == 0 || ExtDescriptor == 3) {
const uint8_t *pXCh = find_marker32_position(pBuffer, coreSize, DCA_XCH_MARKER);
if (pXCh) {
size_t remaining = coreSize - (pXCh - pBuffer);
parse_dts_xch_header(pContext, pHeader, pXCh, (unsigned)remaining);
}
}
if (ExtDescriptor == 6) {
const uint8_t *pXXCh = find_marker32_position(pBuffer, coreSize, DCA_XXCH_MARKER);
if (pXXCh) {
size_t remaining = coreSize - (pXXCh - pBuffer);
parse_dts_xxch_header(pContext, pHeader, pXXCh, (unsigned)remaining);
}
}
}
return 0;
}
