[FFmpeg-cvslog] Parse & decode DTS XXCH frames
Nick Brereton
git at videolan.org
Thu Jun 28 22:26:42 CEST 2012
ffmpeg | branch: master | Nick Brereton <nick at nbrereton.net> | Wed Jun 20 20:52:46 2012 +0100| [16f6c16ac04bb61f468719d6469064a32d65424c] | committer: Michael Niedermayer
Parse & decode DTS XXCH frames
Reviewed-by: Benjamin Larsson <benjamin at southpole.se>
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=16f6c16ac04bb61f468719d6469064a32d65424c
---
libavcodec/dca.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 101 insertions(+), 7 deletions(-)
diff --git a/libavcodec/dca.c b/libavcodec/dca.c
index 76b258b..3cd161c 100644
--- a/libavcodec/dca.c
+++ b/libavcodec/dca.c
@@ -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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