func: static int aac_encode_frame(AVCodecContext *avctx,
  
                              uint8_t *frame, int buf_size, void *data)
  
  {
  
      AACEncContext *s = avctx->priv_data;
  
      int16_t *samples = s->samples, *samples2, *la;
  
      ChannelElement *cpe;
  
      int i, j, chans, tag, start_ch;
  
      const uint8_t *chan_map = aac_chan_configs[avctx->channels-1];
  
      int chan_el_counter[4];
  
      FFPsyWindowInfo windows[AAC_MAX_CHANNELS];
  
  
  
      if (s->last_frame)
  
          return 0;
  
      if (data) {
  
          if (!s->psypp) {
  
              memcpy(s->samples + 1024 * avctx->channels, data,
  
                     1024 * avctx->channels * sizeof(s->samples[0]));
  
          } else {
  
              start_ch = 0;
  
              samples2 = s->samples + 1024 * avctx->channels;
  
              for (i = 0; i < chan_map[0]; i++) {
  
                  tag = chan_map[i+1];
  
                  chans = tag == TYPE_CPE ? 2 : 1;
  
                  ff_psy_preprocess(s->psypp, (uint16_t*)data + start_ch,
  
                                    samples2 + start_ch, start_ch, chans);
  
                  start_ch += chans;
  
              }
  
          }
  
      }
  
      if (!avctx->frame_number) {
  
          memcpy(s->samples, s->samples + 1024 * avctx->channels,
  
                 1024 * avctx->channels * sizeof(s->samples[0]));
  
          return 0;
  
      }
  
  
  
      start_ch = 0;
  
      for (i = 0; i < chan_map[0]; i++) {
  
          FFPsyWindowInfo* wi = windows + start_ch;
  
          tag      = chan_map[i+1];
  
          chans    = tag == TYPE_CPE ? 2 : 1;
  
          cpe      = &s->cpe[i];
  
          for (j = 0; j < chans; j++) {
  
              IndividualChannelStream *ics = &cpe->ch[j].ics;
  
              int k;
  
              int cur_channel = start_ch + j;
  
              samples2 = samples + cur_channel;
  
              la       = samples2 + (448+64) * avctx->channels;
  
              if (!data)
  
                  la = NULL;
  
              if (tag == TYPE_LFE) {
  
                  wi[j].window_type[0] = ONLY_LONG_SEQUENCE;
  
                  wi[j].window_shape   = 0;
  
                  wi[j].num_windows    = 1;
  
                  wi[j].grouping[0]    = 1;
  
              } else {
  
                  wi[j] = ff_psy_suggest_window(&s->psy, samples2, la, cur_channel,
  
                                                ics->window_sequence[0]);
  
              }
  
              ics->window_sequence[1] = ics->window_sequence[0];
  
              ics->window_sequence[0] = wi[j].window_type[0];
  
              ics->use_kb_window[1]   = ics->use_kb_window[0];
  
              ics->use_kb_window[0]   = wi[j].window_shape;
  
              ics->num_windows        = wi[j].num_windows;
  
              ics->swb_sizes          = s->psy.bands    [ics->num_windows == 8];
  
              ics->num_swb            = tag == TYPE_LFE ? 12 : s->psy.num_bands[ics->num_windows == 8];
  
              for (k = 0; k < ics->num_windows; k++)
  
                  ics->group_len[k] = wi[j].grouping[k];
  
  
  
              apply_window_and_mdct(avctx, s, &cpe->ch[j], samples2);
  
          }
  
          start_ch += chans;
  
      }
  
      do {
  
          int frame_bits;
  
          init_put_bits(&s->pb, frame, buf_size*8);
  
          if ((avctx->frame_number & 0xFF)==1 && !(avctx->flags & CODEC_FLAG_BITEXACT))
  
              put_bitstream_info(avctx, s, LIBAVCODEC_IDENT);
  
          start_ch = 0;
  
          memset(chan_el_counter, 0, sizeof(chan_el_counter));
  
          for (i = 0; i < chan_map[0]; i++) {
  
              FFPsyWindowInfo* wi = windows + start_ch;
  
              tag      = chan_map[i+1];
  
              chans    = tag == TYPE_CPE ? 2 : 1;
  
              cpe      = &s->cpe[i];
  
              put_bits(&s->pb, 3, tag);
  
              put_bits(&s->pb, 4, chan_el_counter[tag]++);
  
              for (j = 0; j < chans; j++) {
  
                  s->cur_channel = start_ch + j;
  
                  ff_psy_set_band_info(&s->psy, s->cur_channel, cpe->ch[j].coeffs, &wi[j]);
  
                  s->coder->search_for_quantizers(avctx, s, &cpe->ch[j], s->lambda);
  
              }
  
              cpe->common_window = 0;
  
              if (chans > 1
  
                  && wi[0].window_type[0] == wi[1].window_type[0]
  
                  && wi[0].window_shape   == wi[1].window_shape) {
  
  
  
                  cpe->common_window = 1;
  
                  for (j = 0; j < wi[0].num_windows; j++) {
  
                      if (wi[0].grouping[j] != wi[1].grouping[j]) {
  
                          cpe->common_window = 0;
  
                          break;
  
                      }
  
                  }
  
              }
  
              s->cur_channel = start_ch;
  
              if (cpe->common_window && s->coder->search_for_ms)
  
                  s->coder->search_for_ms(s, cpe, s->lambda);
  
              adjust_frame_information(s, cpe, chans);
  
              if (chans == 2) {
  
                  put_bits(&s->pb, 1, cpe->common_window);
  
                  if (cpe->common_window) {
  
                      put_ics_info(s, &cpe->ch[0].ics);
  
                      encode_ms_info(&s->pb, cpe);
  
                  }
  
              }
  
              for (j = 0; j < chans; j++) {
  
                  s->cur_channel = start_ch + j;
  
                  encode_individual_channel(avctx, s, &cpe->ch[j], cpe->common_window);
  
              }
  
              start_ch += chans;
  
          }
  
  
  
          frame_bits = put_bits_count(&s->pb);
  
          if (frame_bits <= 6144 * avctx->channels - 3) {
  
              s->psy.bitres.bits = frame_bits / avctx->channels;
  
              break;
  
          }
  
  
  
          s->lambda *= avctx->bit_rate * 1024.0f / avctx->sample_rate / frame_bits;
  
  
  
      } while (1);
  
  
  
      put_bits(&s->pb, 3, TYPE_END);
  
      flush_put_bits(&s->pb);
  
      avctx->frame_bits = put_bits_count(&s->pb);
  
  
  
      // rate control stuff
  
      if (!(avctx->flags & CODEC_FLAG_QSCALE)) {
  
          float ratio = avctx->bit_rate * 1024.0f / avctx->sample_rate / avctx->frame_bits;
  
          s->lambda *= ratio;
  
          s->lambda = FFMIN(s->lambda, 65536.f);
  
      }
  
  
  
      if (!data)
  
          s->last_frame = 1;
  
      memcpy(s->samples, s->samples + 1024 * avctx->channels,
  
             1024 * avctx->channels * sizeof(s->samples[0]));
  
      return put_bits_count(&s->pb)>>3;
  
  }
  