[FFmpeg-cvslog] r9684 - trunk/libavcodec/ac3dec.c
jbr
subversion
Sun Jul 15 15:53:43 CEST 2007
Author: jbr
Date: Sun Jul 15 15:53:42 2007
New Revision: 9684
Log:
use shared ac3 bit allocation function
Modified:
trunk/libavcodec/ac3dec.c
Modified: trunk/libavcodec/ac3dec.c
==============================================================================
--- trunk/libavcodec/ac3dec.c (original)
+++ trunk/libavcodec/ac3dec.c Sun Jul 15 15:53:42 2007
@@ -161,6 +161,7 @@ typedef struct {
int cplstrtmant; //coupling start mantissa
int cplendmant; //coupling end mantissa
int endmant[5]; //channel end mantissas
+ AC3BitAllocParameters bit_alloc_params; ///< bit allocation parameters
uint8_t dcplexps[256]; //decoded coupling exponents
uint8_t dexps[5][256]; //decoded fbw channel exponents
@@ -549,211 +550,39 @@ static int decode_exponents(GetBitContex
return 0;
}
-/*********** HELPER FUNCTIONS FOR BIT ALLOCATION ***********/
-static inline int logadd(int a, int b)
-{
- int c = a - b;
- int address;
-
- address = FFMIN((FFABS(c) >> 1), 255);
-
- if (c >= 0)
- return (a + ff_ac3_latab[address]);
- else
- return (b + ff_ac3_latab[address]);
-}
-
-static inline int calc_lowcomp(int a, int b0, int b1, int bin)
-{
- if (bin < 7) {
- if ((b0 + 256) == b1)
- a = 384;
- else if (b0 > b1)
- a = FFMAX(0, (a - 64));
- }
- else if (bin < 20) {
- if ((b0 + 256) == b1)
- a = 320;
- else if (b0 > b1)
- a = FFMAX(0, (a - 64));
- }
- else
- a = FFMAX(0, (a - 128));
-
- return a;
-}
-/*********** END HELPER FUNCTIONS FOR BIT ALLOCATION ***********/
-
/* Performs bit allocation.
* This function performs bit allocation for the requested chanenl.
*/
static void do_bit_allocation(AC3DecodeContext *ctx, int chnl)
{
- int16_t psd[256], bndpsd[50], excite[50], mask[50], delta;
- int sdecay, fdecay, sgain, dbknee, floor;
- int lowcomp = 0, fgain = 0, snroffset = 0, fastleak = 0, slowleak = 0, do_delta = 0;
- int start = 0, end = 0, bin = 0, i = 0, j = 0, k = 0, lastbin = 0, bndstrt = 0;
- int bndend = 0, begin = 0, deltnseg = 0, band = 0, seg = 0, address = 0;
- int fscod = ctx->fscod;
- uint8_t *deltoffst = 0, *deltlen = 0, *deltba = 0;
- uint8_t *exps = 0, *bap = 0;
-
- /* initialization */
- sdecay = ff_sdecaytab[ctx->sdcycod];
- fdecay = ff_fdecaytab[ctx->fdcycod];
- sgain = ff_sgaintab[ctx->sgaincod];
- dbknee = ff_dbkneetab[ctx->dbpbcod];
- floor = ff_floortab[ctx->floorcod];
+ int fgain, snroffset;
if (chnl == 5) {
- start = ctx->cplstrtmant;
- end = ctx->cplendmant;
fgain = ff_fgaintab[ctx->cplfgaincod];
snroffset = (((ctx->csnroffst - 15) << 4) + ctx->cplfsnroffst) << 2;
- fastleak = (ctx->cplfleak << 8) + 768;
- slowleak = (ctx->cplsleak << 8) + 768;
- exps = ctx->dcplexps;
- bap = ctx->cplbap;
- if (ctx->cpldeltbae == DBA_NEW || ctx->deltbae == DBA_REUSE) {
- do_delta = 1;
- deltnseg = ctx->cpldeltnseg;
- deltoffst = ctx->cpldeltoffst;
- deltlen = ctx->cpldeltlen;
- deltba = ctx->cpldeltba;
- }
+ ac3_parametric_bit_allocation(&ctx->bit_alloc_params, ctx->cplbap,
+ ctx->dcplexps, ctx->cplstrtmant,
+ ctx->cplendmant, snroffset, fgain, 0,
+ ctx->cpldeltbae, ctx->cpldeltnseg,
+ ctx->cpldeltoffst, ctx->cpldeltlen,
+ ctx->cpldeltba);
}
else if (chnl == 6) {
- start = 0;
- end = 7;
- lowcomp = 0;
- fastleak = 0;
- slowleak = 0;
fgain = ff_fgaintab[ctx->lfefgaincod];
snroffset = (((ctx->csnroffst - 15) << 4) + ctx->lfefsnroffst) << 2;
- exps = ctx->dlfeexps;
- bap = ctx->lfebap;
+ ac3_parametric_bit_allocation(&ctx->bit_alloc_params, ctx->lfebap,
+ ctx->dlfeexps, 0, 7, snroffset, fgain, 1,
+ DBA_NONE, 0, NULL, NULL, NULL);
}
else {
- start = 0;
- end = ctx->endmant[chnl];
- lowcomp = 0;
- fastleak = 0;
- slowleak = 0;
fgain = ff_fgaintab[ctx->fgaincod[chnl]];
snroffset = (((ctx->csnroffst - 15) << 4) + ctx->fsnroffst[chnl]) << 2;
- exps = ctx->dexps[chnl];
- bap = ctx->bap[chnl];
- if (ctx->deltbae[chnl] == DBA_NEW || ctx->deltbae[chnl] == DBA_REUSE) {
- do_delta = 1;
- deltnseg = ctx->deltnseg[chnl];
- deltoffst = ctx->deltoffst[chnl];
- deltlen = ctx->deltlen[chnl];
- deltba = ctx->deltba[chnl];
- }
- }
-
- for (bin = start; bin < end; bin++) /* exponent mapping into psd */
- psd[bin] = psdtab[exps[bin]];
-
- /* psd integration */
- j = start;
- k = masktab[start];
- do {
- lastbin = FFMIN((bndtab[k] + ff_ac3_bndsz[k]), end);
- bndpsd[k] = psd[j];
- j++;
- for (i = j; i < lastbin; i++) {
- bndpsd[k] = logadd(bndpsd[k], psd[j]);
- j++;
- }
- k++;
- } while (end > lastbin);
-
- /* compute the excite function */
- bndstrt = masktab[start];
- bndend = masktab[end - 1] + 1;
- if (bndstrt == 0) {
- lowcomp = calc_lowcomp(lowcomp, bndpsd[0], bndpsd[1], 0);
- excite[0] = bndpsd[0] - fgain - lowcomp;
- lowcomp = calc_lowcomp(lowcomp, bndpsd[1], bndpsd[2], 1);
- excite[1] = bndpsd[1] - fgain - lowcomp;
- begin = 7;
- for (bin = 2; bin < 7; bin++) {
- if ((bndend != 7) || (bin != 6))
- lowcomp = calc_lowcomp(lowcomp, bndpsd[bin], bndpsd[bin + 1], bin);
- fastleak = bndpsd[bin] - fgain;
- slowleak = bndpsd[bin] - sgain;
- excite[bin] = fastleak - lowcomp;
- if ((bndend != 7) || (bin != 6))
- if (bndpsd[bin] <= bndpsd[bin + 1]) {
- begin = bin + 1;
- break;
- }
- }
- for (bin = begin; bin < FFMIN(bndend, 22); bin++) {
- if ((bndend != 7) || (bin != 6))
- lowcomp = calc_lowcomp(lowcomp, bndpsd[bin], bndpsd[bin + 1], bin);
- fastleak -= fdecay;
- fastleak = FFMAX(fastleak, (bndpsd[bin] - fgain));
- slowleak -= sdecay;
- slowleak = FFMAX(slowleak, (bndpsd[bin] - sgain));
- excite[bin] = FFMAX((fastleak - lowcomp), slowleak);
- }
- begin = 22;
- }
- else {
- begin = bndstrt;
- }
- for (bin = begin; bin < bndend; bin++) {
- fastleak -= fdecay;
- fastleak = FFMAX(fastleak, (bndpsd[bin] - fgain));
- slowleak -= sdecay;
- slowleak = FFMAX(slowleak, (bndpsd[bin] - sgain));
- excite[bin] = FFMAX(fastleak, slowleak);
- }
-
- /* compute the masking curve */
- for (bin = bndstrt; bin < bndend; bin++) {
- if (bndpsd[bin] < dbknee)
- excite[bin] += ((dbknee - bndpsd[bin]) >> 2);
- mask[bin] = FFMAX(excite[bin], ff_ac3_hth[bin][fscod]);
- }
-
- /* apply the delta bit allocation */
- if (do_delta) {
- band = 0;
- for (seg = 0; seg < deltnseg + 1; seg++) {
- band += deltoffst[seg];
- if (deltba[seg] >= 4)
- delta = (deltba[seg] - 3) << 7;
- else
- delta = (deltba[seg] - 4) << 7;
- for (k = 0; k < deltlen[seg]; k++) {
- mask[band] += delta;
- band++;
- }
- }
+ ac3_parametric_bit_allocation(&ctx->bit_alloc_params, ctx->bap[chnl],
+ ctx->dexps[chnl], 0, ctx->endmant[chnl],
+ snroffset, fgain, 0, ctx->deltbae[chnl],
+ ctx->deltnseg[chnl], ctx->deltoffst[chnl],
+ ctx->deltlen[chnl], ctx->deltba[chnl]);
}
-
- /*compute the bit allocation */
- i = start;
- j = masktab[start];
- do {
- lastbin = FFMIN((bndtab[j] + ff_ac3_bndsz[j]), end);
- mask[j] -= snroffset;
- mask[j] -= floor;
- if (mask[j] < 0)
- mask[j] = 0;
- mask[j] &= 0x1fe0;
- mask[j] += floor;
- for (k = i; k < lastbin; k++) {
- address = (psd[i] - mask[j]) >> 5;
- address = FFMIN(63, (FFMAX(0, address)));
- bap[i] = ff_ac3_baptab[address];
- i++;
- }
- j++;
- } while (end > lastbin);
}
/* Check if snroffsets are zero. */
@@ -1856,6 +1685,17 @@ static int ac3_parse_audio_block(AC3Deco
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;
+ ctx->bit_alloc_params.sdecay = ff_sdecaytab[ctx->sdcycod];
+ ctx->bit_alloc_params.fdecay = ff_fdecaytab[ctx->fdcycod];
+ ctx->bit_alloc_params.sgain = ff_sgaintab[ctx->sgaincod];
+ ctx->bit_alloc_params.dbknee = ff_dbkneetab[ctx->dbpbcod];
+ ctx->bit_alloc_params.floor = ff_floortab[ctx->floorcod];
+ ctx->bit_alloc_params.cplfleak = ctx->cplfleak;
+ ctx->bit_alloc_params.cplsleak = ctx->cplsleak;
+
if (ctx->chincpl && (bit_alloc_flags & 64))
do_bit_allocation(ctx, 5);
for (i = 0; i < nfchans; i++)
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