use shared ac3 bit allocation function

Originally committed as revision 9684 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 27 insertions, 187 deletions

diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c
index 62c7616376..5028385568 100644
--- a/libavcodec/ac3dec.c
+++ b/libavcodec/ac3dec.c
@@ -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(GetBitContext *gb, int expstr, int ngrps, uint8_t ab
     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);
+        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 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++;
-            }
-        }
-    }
-
-    /*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(AC3DecodeContext * ctx)
             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++)