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authorJustin Ruggles <justin.ruggles@gmail.com>2007-08-04 00:04:17 +0000
committerJustin Ruggles <justin.ruggles@gmail.com>2007-08-04 00:04:17 +0000
commit285bf28c67f4414b94c358b1fe032a56d14fd432 (patch)
tree2f67a9c9d47199533027aa8bd28664d3af75e480 /libavcodec
parentd7dc7ad05cbedb397574d87ebb17f10d1c1e8e59 (diff)
merge decoding of coupling channel coefficients and regular channel coefficients
Originally committed as revision 9883 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec')
-rw-r--r--libavcodec/ac3dec.c87
1 files changed, 13 insertions, 74 deletions
diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c
index d44d8f0c17..fa95f6ccdd 100644
--- a/libavcodec/ac3dec.c
+++ b/libavcodec/ac3dec.c
@@ -456,101 +456,40 @@ typedef struct { /* grouped mantissas for 3-level 5-leve and 11-level quantizati
int l11ptr;
} mant_groups;
-/* Get the transform coefficients for coupling channel and uncouple channels.
- * The coupling transform coefficients starts at the the cplstrtmant, which is
- * equal to endmant[ch] for fbw channels. Hence we can uncouple channels before
- * getting transform coefficients for the channel.
- */
-static int get_transform_coeffs_cpling(AC3DecodeContext *ctx, mant_groups *m)
-{
- GetBitContext *gb = &ctx->gb;
- int start, gcode, tbap;
- float cplcoeff;
- uint8_t *exps = ctx->dcplexps;
- uint8_t *bap = ctx->cplbap;
- start = ctx->cplstrtmant;
-
- while (start < ctx->cplendmant) {
- tbap = bap[start];
- switch(tbap) {
- case 0:
- cplcoeff = (av_random(&ctx->dith_state) & 0xFFFF);
- break;
- case 1:
- if (m->l3ptr > 2) {
- gcode = get_bits(gb, 5);
- m->l3_quantizers[0] = l3_quantizers_1[gcode];
- m->l3_quantizers[1] = l3_quantizers_2[gcode];
- m->l3_quantizers[2] = l3_quantizers_3[gcode];
- m->l3ptr = 0;
- }
- cplcoeff = m->l3_quantizers[m->l3ptr++];
- break;
-
- case 2:
- if (m->l5ptr > 2) {
- gcode = get_bits(gb, 7);
- m->l5_quantizers[0] = l5_quantizers_1[gcode];
- m->l5_quantizers[1] = l5_quantizers_2[gcode];
- m->l5_quantizers[2] = l5_quantizers_3[gcode];
- m->l5ptr = 0;
- }
- cplcoeff = m->l5_quantizers[m->l5ptr++];
- break;
-
- case 3:
- cplcoeff = l7_quantizers[get_bits(gb, 3)];
- break;
-
- case 4:
- if (m->l11ptr > 1) {
- gcode = get_bits(gb, 7);
- m->l11_quantizers[0] = l11_quantizers_1[gcode];
- m->l11_quantizers[1] = l11_quantizers_2[gcode];
- m->l11ptr = 0;
- }
- cplcoeff = m->l11_quantizers[m->l11ptr++];
- break;
-
- case 5:
- cplcoeff = l15_quantizers[get_bits(gb, 4)];
- break;
-
- default:
- cplcoeff = get_sbits(gb, qntztab[tbap]) << (16 - qntztab[tbap]);
- }
- ctx->transform_coeffs_cpl[start] = cplcoeff * scale_factors[exps[start]];
- start++;
- }
-
- return 0;
-}
-
/* Get the transform coefficients for particular channel */
static int get_transform_coeffs_ch(AC3DecodeContext *ctx, int ch_index, mant_groups *m)
{
GetBitContext *gb = &ctx->gb;
- int i, gcode, tbap, dithflag, end;
+ int i, gcode, tbap, dithflag, start, end;
uint8_t *exps;
uint8_t *bap;
float *coeffs;
- if (ch_index != -1) { /* fbw channels */
+ if (ch_index >= 0) { /* fbw channels */
dithflag = ctx->dithflag[ch_index];
exps = ctx->dexps[ch_index];
bap = ctx->bap[ch_index];
coeffs = ctx->transform_coeffs[ch_index + 1];
+ start = 0;
end = ctx->endmant[ch_index];
} else if (ch_index == -1) {
dithflag = 0;
exps = ctx->dlfeexps;
bap = ctx->lfebap;
coeffs = ctx->transform_coeffs[0];
+ start = 0;
end = 7;
+ } else {
+ dithflag = 0;
+ exps = ctx->dcplexps;
+ bap = ctx->cplbap;
+ coeffs = ctx->transform_coeffs_cpl;
+ start = ctx->cplstrtmant;
+ end = ctx->cplendmant;
}
- for (i = 0; i < end; i++) {
+ for (i = start; i < end; i++) {
tbap = bap[i];
switch (tbap) {
case 0:
@@ -632,7 +571,7 @@ static int get_transform_coeffs(AC3DecodeContext * ctx)
/* tranform coefficients for coupling channels */
if (ctx->chincpl[i]) {
if (!got_cplchan) {
- if (get_transform_coeffs_cpling(ctx, &m)) {
+ if (get_transform_coeffs_ch(ctx, -2, &m)) {
av_log(NULL, AV_LOG_ERROR, "error in decoupling channels\n");
return -1;
}