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Parse & decode DTS XXCH frames 

Reviewed-by: Benjamin Larsson <benjamin@southpole.se>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
tags/n1.0
Nick Brereton Michael Niedermayer 13 years ago
parent
8d9fd58113
commit
16f6c16ac0
1 changed files with 101 additions and 7 deletions
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  1. +101
    -7
      libavcodec/dca.c

+ 101
- 7
libavcodec/dca.c View File

@@ -376,6 +376,10 @@ typedef struct {
int xch_present; ///< XCh extension present and valid
int xch_base_channel; ///< index of first (only) channel containing XCH data

/* XXCH extension information */
int xxch_spk_layout;
int xxch_nbits_spk_mask;

/* ExSS header parser */
int static_fields; ///< static fields present
int mix_metadata; ///< mixing metadata present
@@ -462,16 +466,44 @@ static inline void get_array(GetBitContext *gb, int *dst, int len, int bits)
*dst++ = get_bits(gb, bits);
}

static int dca_parse_audio_coding_header(DCAContext *s, int base_channel)
static int dca_parse_audio_coding_header(DCAContext *s, int base_channel,
int xxch)
{
int i, j;
static const float adj_table[4] = { 1.0, 1.1250, 1.2500, 1.4375 };
static const int bitlen[11] = { 0, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3 };
static const int thr[11] = { 0, 1, 3, 3, 3, 3, 7, 7, 7, 7, 7 };
int hdr_pos = 0, hdr_size = 0;
int mask[8];

/* xxch has arbitrary sized audio coding headers */
if (xxch) {
hdr_pos = get_bits_count(&s->gb);
hdr_size = get_bits(&s->gb, 7) + 1;
}

s->total_channels = get_bits(&s->gb, 3) + 1 + base_channel;
s->prim_channels = s->total_channels;

/* obtain speaker layout mask & mixdown coefficients if applicable */
if (xxch) {
s->xxch_spk_layout |= get_bits(&s->gb, s->xxch_nbits_spk_mask - 6);
if (get_bits1(&s->gb)) {
get_bits1(&s->gb);
skip_bits(&s->gb, 6);
for (i = base_channel; i < s->prim_channels; i++) {
mask[i] = get_bits(&s->gb, s->xxch_nbits_spk_mask);
}
for (j = base_channel; j < s->prim_channels; j++) {
for (i = 0; i < s->xxch_nbits_spk_mask; i++) {
if (mask[j] & (1 << i)) {
int coeff = get_bits(&s->gb, 7);
}
}
}
}
}

if (s->prim_channels > DCA_PRIM_CHANNELS_MAX)
s->prim_channels = DCA_PRIM_CHANNELS_MAX;

@@ -508,9 +540,16 @@ static int dca_parse_audio_coding_header(DCAContext *s, int base_channel)
if (s->quant_index_huffman[i][j] < thr[j])
s->scalefactor_adj[i][j] = adj_table[get_bits(&s->gb, 2)];

if (s->crc_present) {
/* Audio header CRC check */
get_bits(&s->gb, 16);
if (!xxch) {
if (s->crc_present) {
/* Audio header CRC check */
get_bits(&s->gb, 16);
}
} else {
/* Skip to the end of the header, also ignore CRC if present */
i = get_bits_count(&s->gb);
if (hdr_pos + 8 * hdr_size > i)
skip_bits_long(&s->gb, hdr_pos + 8 * hdr_size - i);
}

s->current_subframe = 0;
@@ -639,7 +678,7 @@ static int dca_parse_frame_header(DCAContext *s)
/* Primary audio coding header */
s->subframes = get_bits(&s->gb, 4) + 1;

return dca_parse_audio_coding_header(s, 0);
return dca_parse_audio_coding_header(s, 0, 0);
}


@@ -1727,6 +1766,58 @@ static int dca_xbr_parse_frame(DCAContext *s)
return 0;
}

/* parse initial header for XXCH and dump details */
static int dca_xxch_decode_frame(DCAContext *s)
{
int hdr_size, chhdr_crc, spkmsk_bits, num_chsets, core_spk, hdr_pos;
int i, chset, base_channel, chstart, fsize[8];

/* assume header word has already been parsed */
hdr_pos = get_bits_count(&s->gb) - 32;
hdr_size = get_bits(&s->gb, 6) + 1;
chhdr_crc = get_bits1(&s->gb);
spkmsk_bits = get_bits(&s->gb, 5) + 1;
num_chsets = get_bits(&s->gb, 2) + 1;

for (i = 0; i < num_chsets; i++)
fsize[i] = get_bits(&s->gb, 14) + 1;

core_spk = get_bits(&s->gb, spkmsk_bits);

s->xxch_spk_layout = core_spk;
s->xxch_nbits_spk_mask = spkmsk_bits;

/* skip to the end of the header */
i = get_bits_count(&s->gb);
if (hdr_pos + hdr_size * 8 > i)
skip_bits_long(&s->gb, hdr_pos + hdr_size * 8 - i);

for (chset = 0; chset < num_chsets; chset++) {
chstart = get_bits_count(&s->gb);
base_channel = s->prim_channels;

/* XXCH and Core headers differ, see 6.4.2 "XXCH Channel Set Header" vs.
5.3.2 "Primary Audio Coding Header", DTS Spec 1.3.1 */
dca_parse_audio_coding_header(s, base_channel, 1);

/* decode channel data */
for (i = 0; i < (s->sample_blocks / 8); i++) {
if (dca_decode_block(s, base_channel, i)) {
av_log(s->avctx, AV_LOG_ERROR,
"Error decoding DTS-XXCH extension\n");
continue;
}
}

/* skip to end of this section */
i = get_bits_count(&s->gb);
if (chstart + fsize[chset] * 8 > i)
skip_bits_long(&s->gb, chstart + fsize[chset] * 8 - i);
}

return 0;
}

/**
* Parse extension substream header (HD)
*/
@@ -1823,6 +1914,8 @@ static void dca_exss_parse_header(DCAContext *s)

if(mkr == 0x655e315e)
dca_xbr_parse_frame(s);
else
av_log(s->avctx, AV_LOG_DEBUG, "DTS-MA: unknown marker = 0x%08x\n", mkr);
}
}

@@ -1885,7 +1978,7 @@ static int dca_decode_frame(AVCodecContext *avctx, void *data,

/* only scan for extensions if ext_descr was unknown or indicated a
* supported XCh extension */
if (s->core_ext_mask < 0 || s->core_ext_mask & DCA_EXT_XCH) {
if (s->core_ext_mask < 0 || s->core_ext_mask & (DCA_EXT_XCH | DCA_EXT_XXCH)) {

/* if ext_descr was unknown, clear s->core_ext_mask so that the
* extensions scan can fill it up */
@@ -1923,7 +2016,7 @@ static int dca_decode_frame(AVCodecContext *avctx, void *data,
}

/* much like core primary audio coding header */
dca_parse_audio_coding_header(s, s->xch_base_channel);
dca_parse_audio_coding_header(s, s->xch_base_channel, 0);

for (i = 0; i < (s->sample_blocks / 8); i++)
if ((ret = dca_decode_block(s, s->xch_base_channel, i))) {
@@ -1939,6 +2032,7 @@ static int dca_decode_frame(AVCodecContext *avctx, void *data,
/* usually found either in core or HD part in DTS-HD HRA streams,
* but not in DTS-ES which contains XCh extensions instead */
s->core_ext_mask |= DCA_EXT_XXCH;
dca_xxch_decode_frame(s);
break;

case 0x1d95f262: {


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