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Decode XBR extension in first asset

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Reviewed-by: Benjamin Larsson <benjamin@southpole.se>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
pull/30/merge
Nick Brereton 13 years ago committed by Michael Niedermayer
parent f14f3bae6b
commit 8036a69e6b
1 changed files with 181 additions and 2 deletions
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  1. 183
      libavcodec/dca.c

183
libavcodec/dca.c
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@ -51,12 +51,14 @@
//#define TRACE
#define DCA_PRIM_CHANNELS_MAX (7)
#define DCA_SUBBANDS (32)
#define DCA_SUBBANDS (64)
#define DCA_ABITS_MAX (32) /* Should be 28 */
#define DCA_SUBSUBFRAMES_MAX (4)
#define DCA_SUBFRAMES_MAX (16)
#define DCA_BLOCKS_MAX (16)
#define DCA_LFE_MAX (3)
#define DCA_CHSETS_MAX (4)
#define DCA_CHSET_CHANS_MAX (8)
enum DCAMode {
DCA_MONO = 0,
@ -1564,6 +1566,166 @@ static int dca_exss_parse_asset_header(DCAContext *s)
return 0;
}
static int dca_xbr_parse_frame(DCAContext *s)
{
int scale_table_high[DCA_CHSET_CHANS_MAX][DCA_SUBBANDS][2];
int active_bands[DCA_CHSETS_MAX][DCA_CHSET_CHANS_MAX];
int abits_high[DCA_CHSET_CHANS_MAX][DCA_SUBBANDS];
int anctemp[DCA_CHSET_CHANS_MAX];
int chset_fsize[DCA_CHSETS_MAX];
int n_xbr_ch[DCA_CHSETS_MAX];
int hdr_size, num_chsets, xbr_tmode, hdr_pos;
int i, j, k, l, chset, chan_base;
av_log(s->avctx, AV_LOG_DEBUG, "DTS-XBR: decoding XBR extension\n");
/* get bit position of sync header */
hdr_pos = get_bits_count(&s->gb) - 32;
hdr_size = get_bits(&s->gb, 6) + 1;
num_chsets = get_bits(&s->gb, 2) + 1;
for(i = 0; i < num_chsets; i++)
chset_fsize[i] = get_bits(&s->gb, 14) + 1;
xbr_tmode = get_bits1(&s->gb);
for(i = 0; i < num_chsets; i++) {
n_xbr_ch[i] = get_bits(&s->gb, 3) + 1;
k = get_bits(&s->gb, 2) + 5;
for(j = 0; j < n_xbr_ch[i]; j++)
active_bands[i][j] = get_bits(&s->gb, k) + 1;
}
/* 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);
/* loop over the channel data sets */
/* only decode as many channels as we've decoded base data for */
for(chset = 0, chan_base = 0;
chset < num_chsets && chan_base + n_xbr_ch[chset] <= s->prim_channels;
chan_base += n_xbr_ch[chset++]) {
int start_posn = get_bits_count(&s->gb);
int subsubframe = 0;
int subframe = 0;
/* loop over subframes */
for (k = 0; k < (s->sample_blocks / 8); k++) {
/* parse header if we're on first subsubframe of a block */
if(subsubframe == 0) {
/* Parse subframe header */
for(i = 0; i < n_xbr_ch[chset]; i++) {
anctemp[i] = get_bits(&s->gb, 2) + 2;
}
for(i = 0; i < n_xbr_ch[chset]; i++) {
get_array(&s->gb, abits_high[i], active_bands[chset][i], anctemp[i]);
}
for(i = 0; i < n_xbr_ch[chset]; i++) {
anctemp[i] = get_bits(&s->gb, 3);
if(anctemp[i] < 1) {
av_log(s->avctx, AV_LOG_ERROR, "DTS-XBR: SYNC ERROR\n");
return AVERROR_INVALIDDATA;
}
}
/* generate scale factors */
for(i = 0; i < n_xbr_ch[chset]; i++) {
const uint32_t *scale_table;
int nbits;
if (s->scalefactor_huffman[chan_base+i] == 6) {
scale_table = scale_factor_quant7;
} else {
scale_table = scale_factor_quant6;
}
nbits = anctemp[i];
for(j = 0; j < active_bands[chset][i]; j++) {
if(abits_high[i][j] > 0) {
scale_table_high[i][j][0] =
scale_table[get_bits(&s->gb, nbits)];
if(xbr_tmode && s->transition_mode[i][j]) {
scale_table_high[i][j][1] =
scale_table[get_bits(&s->gb, nbits)];
}
}
}
}
}
/* decode audio array for this block */
for(i = 0; i < n_xbr_ch[chset]; i++) {
for(j = 0; j < active_bands[chset][i]; j++) {
const int xbr_abits = abits_high[i][j];
const float quant_step_size = lossless_quant_d[xbr_abits];
const int sfi = xbr_tmode && s->transition_mode[i][j] && subsubframe >= s->transition_mode[i][j];
const float rscale = quant_step_size * scale_table_high[i][j][sfi];
float *subband_samples = s->subband_samples[k][chan_base+i][j];
int block[8];
if(xbr_abits <= 0)
continue;
if(xbr_abits > 7) {
get_array(&s->gb, block, 8, xbr_abits - 3);
} else {
int block_code1, block_code2, size, levels, err;
size = abits_sizes[xbr_abits - 1];
levels = abits_levels[xbr_abits - 1];
block_code1 = get_bits(&s->gb, size);
block_code2 = get_bits(&s->gb, size);
err = decode_blockcodes(block_code1, block_code2,
levels, block);
if (err) {
av_log(s->avctx, AV_LOG_ERROR,
"ERROR: DTS-XBR: block code look-up failed\n");
return AVERROR_INVALIDDATA;
}
}
/* scale & sum into subband */
for(l = 0; l < 8; l++)
subband_samples[l] += (float)block[l] * rscale;
}
}
/* check DSYNC marker */
if(s->aspf || subsubframe == s->subsubframes[subframe] - 1) {
if(get_bits(&s->gb, 16) != 0xffff) {
av_log(s->avctx, AV_LOG_ERROR, "DTS-XBR: Didn't get subframe DSYNC\n");
return AVERROR_INVALIDDATA;
}
}
/* advance sub-sub-frame index */
if(++subsubframe >= s->subsubframes[subframe]) {
subsubframe = 0;
subframe++;
}
}
/* skip to next channel set */
i = get_bits_count(&s->gb);
if(start_posn + chset_fsize[chset] * 8 != i) {
j = start_posn + chset_fsize[chset] * 8 - i;
if(j < 0 || j >= 8)
av_log(s->avctx, AV_LOG_ERROR, "DTS-XBR: end of channel set,"
" skipping further than expected (%d bits)\n", j);
skip_bits_long(&s->gb, j);
}
}
return 0;
}
/**
* Parse extension substream header (HD)
*/
@ -1575,15 +1737,20 @@ static void dca_exss_parse_header(DCAContext *s)
int num_assets = 1;
int active_ss_mask[8];
int i, j;
int start_posn;
int hdrsize;
uint32_t mkr;
if (get_bits_left(&s->gb) < 52)
return;
start_posn = get_bits_count(&s->gb) - 32;
skip_bits(&s->gb, 8); // user data
ss_index = get_bits(&s->gb, 2);
blownup = get_bits1(&s->gb);
skip_bits(&s->gb, 8 + 4 * blownup); // header_size
hdrsize = get_bits(&s->gb, 8 + 4 * blownup) + 1; // header_size
skip_bits(&s->gb, 16 + 4 * blownup); // hd_size
s->static_fields = get_bits1(&s->gb);
@ -1644,6 +1811,18 @@ static void dca_exss_parse_header(DCAContext *s)
/* not parsed further, we were only interested in the extensions mask
* from the asset header */
if(num_assets > 0) {
j = get_bits_count(&s->gb);
if(start_posn + hdrsize * 8 > j)
skip_bits_long(&s->gb, start_posn + hdrsize * 8 - j);
/* check first asset for XBR -- should also check extension mask! */
mkr = get_bits_long(&s->gb, 32);
if(mkr == 0x655e315e)
dca_xbr_parse_frame(s);
}
}
/**

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