use shared ac3 bit allocation function
Originally committed as revision 9684 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Justin Ruggles
parent
8749180c3b
commit
623b79435d
@ -161,6 +161,7 @@ typedef struct {
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int cplstrtmant; //coupling start mantissa
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int cplendmant; //coupling end mantissa
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int endmant[5]; //channel end mantissas
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AC3BitAllocParameters bit_alloc_params; ///< bit allocation parameters
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uint8_t dcplexps[256]; //decoded coupling exponents
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uint8_t dexps[5][256]; //decoded fbw channel exponents
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@ -549,211 +550,39 @@ static int decode_exponents(GetBitContext *gb, int expstr, int ngrps, uint8_t ab
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return 0;
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}
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/*********** HELPER FUNCTIONS FOR BIT ALLOCATION ***********/
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static inline int logadd(int a, int b)
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{
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int c = a - b;
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int address;
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address = FFMIN((FFABS(c) >> 1), 255);
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if (c >= 0)
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return (a + ff_ac3_latab[address]);
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else
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return (b + ff_ac3_latab[address]);
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}
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static inline int calc_lowcomp(int a, int b0, int b1, int bin)
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{
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if (bin < 7) {
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if ((b0 + 256) == b1)
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a = 384;
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else if (b0 > b1)
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a = FFMAX(0, (a - 64));
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}
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else if (bin < 20) {
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if ((b0 + 256) == b1)
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a = 320;
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else if (b0 > b1)
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a = FFMAX(0, (a - 64));
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}
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else
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a = FFMAX(0, (a - 128));
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return a;
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}
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/*********** END HELPER FUNCTIONS FOR BIT ALLOCATION ***********/
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/* Performs bit allocation.
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* This function performs bit allocation for the requested chanenl.
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*/
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static void do_bit_allocation(AC3DecodeContext *ctx, int chnl)
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{
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int16_t psd[256], bndpsd[50], excite[50], mask[50], delta;
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int sdecay, fdecay, sgain, dbknee, floor;
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int lowcomp = 0, fgain = 0, snroffset = 0, fastleak = 0, slowleak = 0, do_delta = 0;
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int start = 0, end = 0, bin = 0, i = 0, j = 0, k = 0, lastbin = 0, bndstrt = 0;
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int bndend = 0, begin = 0, deltnseg = 0, band = 0, seg = 0, address = 0;
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int fscod = ctx->fscod;
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uint8_t *deltoffst = 0, *deltlen = 0, *deltba = 0;
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uint8_t *exps = 0, *bap = 0;
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/* initialization */
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sdecay = ff_sdecaytab[ctx->sdcycod];
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fdecay = ff_fdecaytab[ctx->fdcycod];
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sgain = ff_sgaintab[ctx->sgaincod];
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dbknee = ff_dbkneetab[ctx->dbpbcod];
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floor = ff_floortab[ctx->floorcod];
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int fgain, snroffset;
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if (chnl == 5) {
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start = ctx->cplstrtmant;
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end = ctx->cplendmant;
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fgain = ff_fgaintab[ctx->cplfgaincod];
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snroffset = (((ctx->csnroffst - 15) << 4) + ctx->cplfsnroffst) << 2;
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fastleak = (ctx->cplfleak << 8) + 768;
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slowleak = (ctx->cplsleak << 8) + 768;
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exps = ctx->dcplexps;
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bap = ctx->cplbap;
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if (ctx->cpldeltbae == DBA_NEW || ctx->deltbae == DBA_REUSE) {
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do_delta = 1;
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deltnseg = ctx->cpldeltnseg;
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deltoffst = ctx->cpldeltoffst;
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deltlen = ctx->cpldeltlen;
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deltba = ctx->cpldeltba;
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}
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ac3_parametric_bit_allocation(&ctx->bit_alloc_params, ctx->cplbap,
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ctx->dcplexps, ctx->cplstrtmant,
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ctx->cplendmant, snroffset, fgain, 0,
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ctx->cpldeltbae, ctx->cpldeltnseg,
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ctx->cpldeltoffst, ctx->cpldeltlen,
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ctx->cpldeltba);
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}
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else if (chnl == 6) {
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start = 0;
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end = 7;
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lowcomp = 0;
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fastleak = 0;
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slowleak = 0;
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fgain = ff_fgaintab[ctx->lfefgaincod];
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snroffset = (((ctx->csnroffst - 15) << 4) + ctx->lfefsnroffst) << 2;
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exps = ctx->dlfeexps;
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bap = ctx->lfebap;
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ac3_parametric_bit_allocation(&ctx->bit_alloc_params, ctx->lfebap,
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ctx->dlfeexps, 0, 7, snroffset, fgain, 1,
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DBA_NONE, 0, NULL, NULL, NULL);
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}
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else {
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start = 0;
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end = ctx->endmant[chnl];
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lowcomp = 0;
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fastleak = 0;
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slowleak = 0;
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fgain = ff_fgaintab[ctx->fgaincod[chnl]];
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snroffset = (((ctx->csnroffst - 15) << 4) + ctx->fsnroffst[chnl]) << 2;
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exps = ctx->dexps[chnl];
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bap = ctx->bap[chnl];
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if (ctx->deltbae[chnl] == DBA_NEW || ctx->deltbae[chnl] == DBA_REUSE) {
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do_delta = 1;
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deltnseg = ctx->deltnseg[chnl];
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deltoffst = ctx->deltoffst[chnl];
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deltlen = ctx->deltlen[chnl];
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deltba = ctx->deltba[chnl];
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}
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ac3_parametric_bit_allocation(&ctx->bit_alloc_params, ctx->bap[chnl],
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ctx->dexps[chnl], 0, ctx->endmant[chnl],
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snroffset, fgain, 0, ctx->deltbae[chnl],
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ctx->deltnseg[chnl], ctx->deltoffst[chnl],
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ctx->deltlen[chnl], ctx->deltba[chnl]);
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}
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for (bin = start; bin < end; bin++) /* exponent mapping into psd */
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psd[bin] = psdtab[exps[bin]];
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/* psd integration */
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j = start;
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k = masktab[start];
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do {
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lastbin = FFMIN((bndtab[k] + ff_ac3_bndsz[k]), end);
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bndpsd[k] = psd[j];
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j++;
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for (i = j; i < lastbin; i++) {
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bndpsd[k] = logadd(bndpsd[k], psd[j]);
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j++;
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}
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k++;
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} while (end > lastbin);
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/* compute the excite function */
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bndstrt = masktab[start];
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bndend = masktab[end - 1] + 1;
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if (bndstrt == 0) {
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lowcomp = calc_lowcomp(lowcomp, bndpsd[0], bndpsd[1], 0);
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excite[0] = bndpsd[0] - fgain - lowcomp;
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lowcomp = calc_lowcomp(lowcomp, bndpsd[1], bndpsd[2], 1);
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excite[1] = bndpsd[1] - fgain - lowcomp;
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begin = 7;
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for (bin = 2; bin < 7; bin++) {
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if ((bndend != 7) || (bin != 6))
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lowcomp = calc_lowcomp(lowcomp, bndpsd[bin], bndpsd[bin + 1], bin);
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fastleak = bndpsd[bin] - fgain;
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slowleak = bndpsd[bin] - sgain;
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excite[bin] = fastleak - lowcomp;
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if ((bndend != 7) || (bin != 6))
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if (bndpsd[bin] <= bndpsd[bin + 1]) {
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begin = bin + 1;
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break;
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}
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}
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for (bin = begin; bin < FFMIN(bndend, 22); bin++) {
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if ((bndend != 7) || (bin != 6))
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lowcomp = calc_lowcomp(lowcomp, bndpsd[bin], bndpsd[bin + 1], bin);
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fastleak -= fdecay;
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fastleak = FFMAX(fastleak, (bndpsd[bin] - fgain));
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slowleak -= sdecay;
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slowleak = FFMAX(slowleak, (bndpsd[bin] - sgain));
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excite[bin] = FFMAX((fastleak - lowcomp), slowleak);
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}
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begin = 22;
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}
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else {
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begin = bndstrt;
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}
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for (bin = begin; bin < bndend; bin++) {
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fastleak -= fdecay;
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fastleak = FFMAX(fastleak, (bndpsd[bin] - fgain));
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slowleak -= sdecay;
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slowleak = FFMAX(slowleak, (bndpsd[bin] - sgain));
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excite[bin] = FFMAX(fastleak, slowleak);
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}
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/* compute the masking curve */
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for (bin = bndstrt; bin < bndend; bin++) {
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if (bndpsd[bin] < dbknee)
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excite[bin] += ((dbknee - bndpsd[bin]) >> 2);
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mask[bin] = FFMAX(excite[bin], ff_ac3_hth[bin][fscod]);
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}
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/* apply the delta bit allocation */
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if (do_delta) {
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band = 0;
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for (seg = 0; seg < deltnseg + 1; seg++) {
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band += deltoffst[seg];
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if (deltba[seg] >= 4)
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delta = (deltba[seg] - 3) << 7;
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else
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delta = (deltba[seg] - 4) << 7;
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for (k = 0; k < deltlen[seg]; k++) {
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mask[band] += delta;
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band++;
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}
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}
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}
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/*compute the bit allocation */
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i = start;
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j = masktab[start];
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do {
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lastbin = FFMIN((bndtab[j] + ff_ac3_bndsz[j]), end);
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mask[j] -= snroffset;
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mask[j] -= floor;
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if (mask[j] < 0)
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mask[j] = 0;
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mask[j] &= 0x1fe0;
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mask[j] += floor;
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for (k = i; k < lastbin; k++) {
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address = (psd[i] - mask[j]) >> 5;
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address = FFMIN(63, (FFMAX(0, address)));
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bap[i] = ff_ac3_baptab[address];
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i++;
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}
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j++;
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} while (end > lastbin);
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}
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/* Check if snroffsets are zero. */
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@ -1856,6 +1685,17 @@ static int ac3_parse_audio_block(AC3DecodeContext * ctx)
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for (i = 0; i < nfchans; i++)
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memset(ctx->bap[i], 0, sizeof(ctx->bap[i]));
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} else {
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/* set bit allocation parameters */
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ctx->bit_alloc_params.fscod = ctx->fscod;
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ctx->bit_alloc_params.halfratecod = 0;
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ctx->bit_alloc_params.sdecay = ff_sdecaytab[ctx->sdcycod];
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ctx->bit_alloc_params.fdecay = ff_fdecaytab[ctx->fdcycod];
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ctx->bit_alloc_params.sgain = ff_sgaintab[ctx->sgaincod];
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ctx->bit_alloc_params.dbknee = ff_dbkneetab[ctx->dbpbcod];
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ctx->bit_alloc_params.floor = ff_floortab[ctx->floorcod];
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ctx->bit_alloc_params.cplfleak = ctx->cplfleak;
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ctx->bit_alloc_params.cplsleak = ctx->cplsleak;
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if (ctx->chincpl && (bit_alloc_flags & 64))
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do_bit_allocation(ctx, 5);
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for (i = 0; i < nfchans; i++)
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