diff options
| -rw-r--r-- | src/libdts/TODO | 8 | ||||
| -rw-r--r-- | src/libdts/xine_decoder.c | 39 |
2 files changed, 38 insertions, 9 deletions
diff --git a/src/libdts/TODO b/src/libdts/TODO new file mode 100644 index 000000000..f9ad94240 --- /dev/null +++ b/src/libdts/TODO @@ -0,0 +1,8 @@ +Todo list for software dts core (48Khz PCM, not 96Khz PCM) decode. +1) Enter all the huffman tables. +2) Get InverseQ to parse the input stream via the huffman tables. +3) We don't have the "Prediction Coefficients VQ" for ADPCM, so we might never get software decode working. Any help here would be very welcome!!! +4) Move over the sync detection and packet joining code from liba52 and modify it to recognise dts. +5) Get all the parsing code to compile and work correctly. Requires (1) and (2) first. +6) Work out what the LookUp function needs to do. + diff --git a/src/libdts/xine_decoder.c b/src/libdts/xine_decoder.c index 49aea5f80..b42bb67fe 100644 --- a/src/libdts/xine_decoder.c +++ b/src/libdts/xine_decoder.c @@ -17,7 +17,7 @@ * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA * - * $Id: xine_decoder.c,v 1.42 2003/05/25 15:45:06 jcdutton Exp $ + * $Id: xine_decoder.c,v 1.43 2003/05/27 14:31:24 jcdutton Exp $ * * 04-09-2001 DTS passtrough (C) Joachim Koenig * 09-12-2001 DTS passthrough inprovements (C) James Courtier-Dutton @@ -255,6 +255,11 @@ static void dts_parse_data (dts_decoder_t *this, buf_element_t *buf) { float scale_factor_adjustment_index[8][10]; uint16_t audio_header_crc_check_word; + int32_t nVQIndex; + int32_t nQSelect; + int8_t subsubframe_count; + int8_t partial_subsubframe_sample_count; + int8_t prediction_mode[8][33]; uint32_t channel_extension_sync_word; @@ -461,7 +466,6 @@ static void dts_parse_data (dts_decoder_t *this, buf_element_t *buf) { audio_header_crc_check_word = getbits(&state, 16); } -#if 0 /* FIXME: ALL CODE BELOW HERE does not compile yet. */ @@ -473,12 +477,13 @@ static void dts_parse_data (dts_decoder_t *this, buf_element_t *buf) { /* Partial Subsubframe Sample Count V PSC 3 bit */ partial_subsubframe_sample_count = getbits(&state, 3); /* Prediction Mode V PMODE 1 bit per subband */ - for (ch=0; ch<number_of_primary_audio_channels; ch++) - for (n=0; n<subband_activity_count[ch]; n++) + for (ch=0; ch<number_of_primary_audio_channels; ch++) { + for (n=0; n<subband_activity_count[ch]; n++) { prediction_mode[ch][n] = getbits(&state, 1); + } + } /* Prediction Coefficients VQ Address V PVQ 12 bits per occurrence */ - int32_t nVQIndex; for (ch=0; ch<number_of_primary_audio_channels; ch++) { for (n=0; n<subband_activity_count[ch]; n++) { if ( prediction_mode[ch][n]>0 ) { /* Transmitted only when ADPCM active */ @@ -486,15 +491,15 @@ static void dts_parse_data (dts_decoder_t *this, buf_element_t *buf) { nVQIndex = getbits(&state,12); /* Look up the VQ table for prediction coefficients. */ /* FIXME: How to implement LookUp? */ - ADPCMCoeffVQ.LookUp(nVQIndex, PVQ[ch][n]); /* 4 coefficients FIXME: Need to work out what this does. */ + /* FIXME: We don't have the ADPCMCoeff table. */ + /* ADPCMCoeffVQ.LookUp(nVQIndex, PVQ[ch][n]);*/ /* 4 coefficients FIXME: Need to work out what this does. */ } } } /* Bit Allocation Index V ABITS variable bits */ - /* FIXME: No getbits here */ - int32_t nQSelect; + /* FIXME: No getbits here InverseQ does the getbits */ for (ch=0; ch<number_of_primary_audio_channels; ch++) { /* Bit Allocation Quantizer Select tells which codebook was used */ nQSelect = bit_allocation_quantizer_select[ch]; @@ -502,10 +507,16 @@ static void dts_parse_data (dts_decoder_t *this, buf_element_t *buf) { for (n=0; n<high_frequency_VQ_start_subband[ch]; n++) { /* Not for VQ encoded subbands. */ /* FIXME: What is Inverse Quantization(InverseQ) ? */ - QABITS.ppQ[nQSelect]->InverseQ(InputFrame, bit_allocation_index[ch][n]); + /* This basically selects a huffman table number nQSelect, */ + /* and uses it to read a variable amount of bits and does a huffman search to find the value. */ + /* FIXME: Need to implement InverseQ, so we can uncomment this line */ + /*QABITS.ppQ[nQSelect]->InverseQ(&state, bit_allocation_index[ch][n]); */ } } +#if 0 +/* FIXME: ALL CODE BELOW HERE does not compile yet. */ + /* Transition Mode V TMODE variable bits */ /* Always assume no transition unless told */ @@ -761,6 +772,7 @@ static void dts_parse_data (dts_decoder_t *this, buf_element_t *buf) { } /* * Extract bits from the bit stream + * This retrieves 8 AUDIO values */ switch ( nQType ) { case 0: /* No bits allocated */ @@ -782,6 +794,15 @@ static void dts_parse_data (dts_decoder_t *this, buf_element_t *buf) { } break; case 3: /* Block code */ + /* Block code is just 1 value with 4 samples derived from it. + * with each sample a digit from the number (using a base derived from nABITS via a table) + * E.g. nABITS = 10, base = 5 (Base value taken from table.) + * 1st sample = (value % 5) - (int(5/2); (Values between -2 and +2 ) + * 2st sample = ((value / 5) % 5) - (int(5/2); + * 3rd sample = ((value / 25) % 5) - (int(5/2); + * 4th sample = ((value / 125) % 5) - (int(5/2); + * + */ pCBQ = &pCBlockQ[nABITS-1]; /* Select block code book */ m = 0; for (nBlock=0; nBlock<2; nBlock++) { |