virtualenv/FFmpeg
1
0
Fork 0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-23 12:43:46 +02:00
Code Issues Releases Activity

remove portions of bit allocation which are no longer needed since they are shared with the encoder

Browse Source 
Originally committed as revision 9747 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Justin Ruggles 2007-07-19 00:50:31 +00:00
parent d24ce947ca
commit 0ce668015f
1 changed files with 1 additions and 44 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
libavcodec/ac3dec.c
View File

@ -39,9 +39,6 @@
#include "dsputil.h"
#include "random.h"
static uint8_t bndtab[51];
static uint8_t masktab[253];
static const int nfchans_tbl[8] = { 2, 1, 2, 3, 3, 4, 4, 5 };
/* table for exponent to scale_factor mapping
@ -49,8 +46,6 @@ static const int nfchans_tbl[8] = { 2, 1, 2, 3, 3, 4, 4, 5 };
*/
static float scale_factors[25];
static int16_t psdtab[25];
static int8_t exp_1[128];
static int8_t exp_2[128];
static int8_t exp_3[128];
@ -272,22 +267,7 @@ static void generate_quantizers_table_3(int16_t quantizers[], int level, int len
*/
static void ac3_tables_init(void)
{
int i, j, k, l, v;
/* compute bndtab and masktab from bandsz */
k = 0;
l = 0;
for(i=0;i<50;i++) {
bndtab[i] = l;
v = ff_ac3_bndsz[i];
for(j=0;j<v;j++) masktab[k++]=i;
l += v;
}
masktab[253] = masktab[254] = masktab[255] = 0;
bndtab[50] = 0;
/* PSD Table For Mapping Exponents To PSD. */
for (i = 0; i < 25; i++)
psdtab[i] = 3072 - (i << 7);
int i, j, v;
/* Exponent Decoding Tables */
for (i = 0; i < 5; i++) {
@ -583,22 +563,6 @@ static void do_bit_allocation(AC3DecodeContext *ctx, int chnl)
}
}
/* Check if snroffsets are zero. */
static int is_snr_offsets_zero(AC3DecodeContext *ctx)
{
int i;
if ((ctx->csnroffst) || (ctx->cplinu && ctx->cplfsnroffst) ||
(ctx->lfeon && ctx->lfefsnroffst))
return 0;
for (i = 0; i < ctx->nfchans; i++)
if (ctx->fsnroffst[i])
return 0;
return 1;
}
typedef struct { /* grouped mantissas for 3-level 5-leve and 11-level quantization */
int16_t l3_quantizers[3];
int16_t l5_quantizers[3];
@ -1674,12 +1638,6 @@ static int ac3_parse_audio_block(AC3DecodeContext * ctx)
}
if (bit_alloc_flags) {
if (is_snr_offsets_zero(ctx)) {
memset(ctx->cplbap, 0, sizeof (ctx->cplbap));
memset(ctx->lfebap, 0, sizeof (ctx->lfebap));
for (i = 0; i < nfchans; i++)
memset(ctx->bap[i], 0, sizeof(ctx->bap[i]));
} else {
/* set bit allocation parameters */
ctx->bit_alloc_params.fscod = ctx->fscod;
ctx->bit_alloc_params.halfratecod = 0;
@ -1698,7 +1656,6 @@ static int ac3_parse_audio_block(AC3DecodeContext * ctx)
do_bit_allocation(ctx, i);
if (ctx->lfeon && (bit_alloc_flags & 32))
do_bit_allocation(ctx, 6);
}
}
if (get_bits1(gb)) { /* unused dummy data */