+static void codebook_trellis_rate(AACEncContext *s, SingleChannelElement *sce,
+ int win, int group_len, const float lambda)
+{
+ BandCodingPath path[120][12];
+ int w, swb, cb, start, size;
+ int i, j;
+ const int max_sfb = sce->ics.max_sfb;
+ const int run_bits = sce->ics.num_windows == 1 ? 5 : 3;
+ const int run_esc = (1 << run_bits) - 1;
+ int idx, ppos, count;
+ int stackrun[120], stackcb[120], stack_len;
+ float next_minbits = INFINITY;
+ int next_mincb = 0;
+
+ abs_pow34_v(s->scoefs, sce->coeffs, 1024);
+ start = win*128;
+ for (cb = 0; cb < 12; cb++) {
+ path[0][cb].cost = run_bits+4;
+ path[0][cb].prev_idx = -1;
+ path[0][cb].run = 0;
+ }
+ for (swb = 0; swb < max_sfb; swb++) {
+ size = sce->ics.swb_sizes[swb];
+ if (sce->zeroes[win*16 + swb]) {
+ float cost_stay_here = path[swb][0].cost;
+ float cost_get_here = next_minbits + run_bits + 4;
+ if ( run_value_bits[sce->ics.num_windows == 8][path[swb][0].run]
+ != run_value_bits[sce->ics.num_windows == 8][path[swb][0].run+1])
+ cost_stay_here += run_bits;
+ if (cost_get_here < cost_stay_here) {
+ path[swb+1][0].prev_idx = next_mincb;
+ path[swb+1][0].cost = cost_get_here;
+ path[swb+1][0].run = 1;
+ } else {
+ path[swb+1][0].prev_idx = 0;
+ path[swb+1][0].cost = cost_stay_here;
+ path[swb+1][0].run = path[swb][0].run + 1;
+ }
+ next_minbits = path[swb+1][0].cost;
+ next_mincb = 0;
+ for (cb = 1; cb < 12; cb++) {
+ path[swb+1][cb].cost = 61450;
+ path[swb+1][cb].prev_idx = -1;
+ path[swb+1][cb].run = 0;
+ }
+ } else {
+ float minbits = next_minbits;
+ int mincb = next_mincb;
+ int startcb = sce->band_type[win*16+swb];
+ next_minbits = INFINITY;
+ next_mincb = 0;
+ for (cb = 0; cb < startcb; cb++) {
+ path[swb+1][cb].cost = 61450;
+ path[swb+1][cb].prev_idx = -1;
+ path[swb+1][cb].run = 0;
+ }
+ for (cb = startcb; cb < 12; cb++) {
+ float cost_stay_here, cost_get_here;
+ float bits = 0.0f;
+ for (w = 0; w < group_len; w++) {
+ bits += quantize_band_cost(s, sce->coeffs + start + w*128,
+ s->scoefs + start + w*128, size,
+ sce->sf_idx[(win+w)*16+swb], cb,
+ 0, INFINITY, NULL);
+ }
+ cost_stay_here = path[swb][cb].cost + bits;
+ cost_get_here = minbits + bits + run_bits + 4;
+ if ( run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run]
+ != run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run+1])
+ cost_stay_here += run_bits;
+ if (cost_get_here < cost_stay_here) {
+ path[swb+1][cb].prev_idx = mincb;
+ path[swb+1][cb].cost = cost_get_here;
+ path[swb+1][cb].run = 1;
+ } else {
+ path[swb+1][cb].prev_idx = cb;
+ path[swb+1][cb].cost = cost_stay_here;
+ path[swb+1][cb].run = path[swb][cb].run + 1;
+ }
+ if (path[swb+1][cb].cost < next_minbits) {
+ next_minbits = path[swb+1][cb].cost;
+ next_mincb = cb;
+ }
+ }
+ }
+ start += sce->ics.swb_sizes[swb];
+ }
+
+ //convert resulting path from backward-linked list
+ stack_len = 0;
+ idx = 0;
+ for (cb = 1; cb < 12; cb++)
+ if (path[max_sfb][cb].cost < path[max_sfb][idx].cost)
+ idx = cb;
+ ppos = max_sfb;
+ while (ppos > 0) {
+ assert(idx >= 0);
+ cb = idx;
+ stackrun[stack_len] = path[ppos][cb].run;
+ stackcb [stack_len] = cb;
+ idx = path[ppos-path[ppos][cb].run+1][cb].prev_idx;
+ ppos -= path[ppos][cb].run;
+ stack_len++;
+ }
+ //perform actual band info encoding
+ start = 0;
+ for (i = stack_len - 1; i >= 0; i--) {
+ put_bits(&s->pb, 4, stackcb[i]);
+ count = stackrun[i];
+ memset(sce->zeroes + win*16 + start, !stackcb[i], count);
+ //XXX: memset when band_type is also uint8_t
+ for (j = 0; j < count; j++) {
+ sce->band_type[win*16 + start] = stackcb[i];
+ start++;
+ }
+ while (count >= run_esc) {
+ put_bits(&s->pb, run_bits, run_esc);
+ count -= run_esc;
+ }
+ put_bits(&s->pb, run_bits, count);
+ }
+}
+
+/** Return the minimum scalefactor where the quantized coef does not clip. */
+static av_always_inline uint8_t coef2minsf(float coef) {
+ return av_clip_uint8(log2f(coef)*4 - 69 + SCALE_ONE_POS - SCALE_DIV_512);
+}
+
+/** Return the maximum scalefactor where the quantized coef is not zero. */
+static av_always_inline uint8_t coef2maxsf(float coef) {
+ return av_clip_uint8(log2f(coef)*4 + 6 + SCALE_ONE_POS - SCALE_DIV_512);
+}
+