aacenc: Trellis over scalefactors using an estimated codebook rather than every codebook.

The minimal codebook to encode the band without clipping is used (as is done in the TLS).

Originally committed as revision 23318 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/aaccoder.c

@@ -568,18 +568,13 @@ static void search_for_quantizers_anmr(AVCodecContext *avctx, AACEncContext *s,
                 minscale = av_clip(minscale - q0, 0, TRELLIS_STATES - 1);
                 maxscale = av_clip(maxscale - q0, 0, TRELLIS_STATES);
                 for (q = minscale; q < maxscale; q++) {
-                    float dists[12], dist;
-                    memset(dists, 0, sizeof(dists));
+                    float dist = 0;
+                    int cb = find_min_book(sce->sf_idx[w*16+g], sce->ics.group_len[w], sce->ics.swb_sizes[g], s->scoefs+start);
                     for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
                         FFPsyBand *band = &s->psy.psy_bands[s->cur_channel*PSY_MAX_BANDS+(w+w2)*16+g];
-                        int cb;
-                        for (cb = 0; cb <= ESC_BT; cb++)
-                            dists[cb] += quantize_band_cost(s, coefs + w2*128, s->scoefs + start + w2*128, sce->ics.swb_sizes[g],
+                        dist += quantize_band_cost(s, coefs + w2*128, s->scoefs + start + w2*128, sce->ics.swb_sizes[g],
                                                             q + q0, cb, lambda / band->threshold, INFINITY, NULL);
                     }
-                    dist = dists[0];
-                    for (i = 1; i <= ESC_BT; i++)
-                        dist = FFMIN(dist, dists[i]);
                     minrd = FFMIN(minrd, dist);
 
                     for (i = 0; i < q1 - q0; i++) {