text: /*
   * WMA compatible encoder
   * Copyright (c) 2007 Michael Niedermayer
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include "libavutil/attributes.h"
  #include "libavutil/ffmath.h"
  
  #include "avcodec.h"
  #include "encode.h"
  #include "internal.h"
  #include "wma.h"
  #include "libavutil/avassert.h"
  
  
  static av_cold int encode_init(AVCodecContext *avctx)
  {
      WMACodecContext *s = avctx->priv_data;
      int i, flags1, flags2, block_align;
      uint8_t *extradata;
      int ret;
  
      s->avctx = avctx;
  
      if (avctx->channels > MAX_CHANNELS) {
          av_log(avctx, AV_LOG_ERROR,
                 "too many channels: got %i, need %i or fewer\n",
                 avctx->channels, MAX_CHANNELS);
          return AVERROR(EINVAL);
      }
  
      if (avctx->sample_rate > 48000) {
          av_log(avctx, AV_LOG_ERROR, "sample rate is too high: %d > 48kHz\n",
                 avctx->sample_rate);
          return AVERROR(EINVAL);
      }
  
      if (avctx->bit_rate < 24 * 1000) {
          av_log(avctx, AV_LOG_ERROR,
                 "bitrate too low: got %"PRId64", need 24000 or higher\n",
                 avctx->bit_rate);
          return AVERROR(EINVAL);
      }
  
      /* extract flag info */
      flags1 = 0;
      flags2 = 1;
      if (avctx->codec->id == AV_CODEC_ID_WMAV1) {
          extradata             = av_malloc(4);
          if (!extradata)
              return AVERROR(ENOMEM);
          avctx->extradata_size = 4;
          AV_WL16(extradata, flags1);
          AV_WL16(extradata + 2, flags2);
      } else if (avctx->codec->id == AV_CODEC_ID_WMAV2) {
          extradata             = av_mallocz(10);
          if (!extradata)
              return AVERROR(ENOMEM);
          avctx->extradata_size = 10;
          AV_WL32(extradata, flags1);
          AV_WL16(extradata + 4, flags2);
      } else {
          av_assert0(0);
      }
      avctx->extradata          = extradata;
      s->use_exp_vlc            = flags2 & 0x0001;
      s->use_bit_reservoir      = flags2 & 0x0002;
      s->use_variable_block_len = flags2 & 0x0004;
      if (avctx->channels == 2)
          s->ms_stereo = 1;
  
      if ((ret = ff_wma_init(avctx, flags2)) < 0)
          return ret;
  
      /* init MDCT */
      for (i = 0; i < s->nb_block_sizes; i++) {
          ret = ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 0, 1.0);
          if (ret < 0)
              return ret;
      }
  
      block_align        = avctx->bit_rate * (int64_t) s->frame_len /
                           (avctx->sample_rate * 8);
      block_align        = FFMIN(block_align, MAX_CODED_SUPERFRAME_SIZE);
      avctx->block_align = block_align;
      avctx->frame_size = avctx->initial_padding = s->frame_len;
  
      return 0;
  }
  
  static int apply_window_and_mdct(AVCodecContext *avctx, const AVFrame *frame)
  {
      WMACodecContext *s = avctx->priv_data;
      float **audio      = (float **) frame->extended_data;
      int len            = frame->nb_samples;
      int window_index   = s->frame_len_bits - s->block_len_bits;
      FFTContext *mdct   = &s->mdct_ctx[window_index];
      int ch;
      const float *win   = s->windows[window_index];
      int window_len     = 1 << s->block_len_bits;
      float n            = 2.0 * 32768.0 / window_len;
  
      for (ch = 0; ch < avctx->channels; ch++) {
          memcpy(s->output, s->frame_out[ch], window_len * sizeof(*s->output));
          s->fdsp->vector_fmul_scalar(s->frame_out[ch], audio[ch], n, len);
          s->fdsp->vector_fmul_reverse(&s->output[window_len], s->frame_out[ch],
                                      win, len);
          s->fdsp->vector_fmul(s->frame_out[ch], s->frame_out[ch], win, len);
          mdct->mdct_calc(mdct, s->coefs[ch], s->output);
          if (!isfinite(s->coefs[ch][0])) {
              av_log(avctx, AV_LOG_ERROR, "Input contains NaN/+-Inf\n");
              return AVERROR(EINVAL);
          }
      }
  
      return 0;
  }
  
  // FIXME use for decoding too
  static void init_exp(WMACodecContext *s, int ch, const int *exp_param)
  {
      int n;
      const uint16_t *ptr;
      float v, *q, max_scale, *q_end;
  
      ptr       = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
      q         = s->exponents[ch];
      q_end     = q + s->block_len;
      max_scale = 0;
      while (q < q_end) {
          /* XXX: use a table */
          v         = ff_exp10(*exp_param++ *(1.0 / 16.0));
          max_scale = FFMAX(max_scale, v);
          n         = *ptr++;
          do {
              *q++ = v;
          } while (--n);
      }
      s->max_exponent[ch] = max_scale;
  }
  
  static void encode_exp_vlc(WMACodecContext *s, int ch, const int *exp_param)
  {
      int last_exp;
      const uint16_t *ptr;
      float *q, *q_end;
  
      ptr   = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
      q     = s->exponents[ch];
      q_end = q + s->block_len;
      if (s->version == 1) {
          last_exp = *exp_param++;
          av_assert0(last_exp - 10 >= 0 && last_exp - 10 < 32);
          put_bits(&s->pb, 5, last_exp - 10);
          q += *ptr++;
      } else
          last_exp = 36;
      while (q < q_end) {
          int exp  = *exp_param++;
          int code = exp - last_exp + 60;
          av_assert1(code >= 0 && code < 120);
          put_bits(&s->pb, ff_aac_scalefactor_bits[code],
                   ff_aac_scalefactor_code[code]);
          /* XXX: use a table */
          q       += *ptr++;
          last_exp = exp;
      }
  }
  
  static int encode_block(WMACodecContext *s, float (*src_coefs)[BLOCK_MAX_SIZE],
                          int total_gain)
  {
      int v, bsize, ch, coef_nb_bits, parse_exponents;
      float mdct_norm;
      int nb_coefs[MAX_CHANNELS];
      static const int fixed_exp[25] = {
          20, 20, 20, 20, 20,
          20, 20, 20, 20, 20,
          20, 20, 20, 20, 20,
          20, 20, 20, 20, 20,
          20, 20, 20, 20, 20
      };
  
      // FIXME remove duplication relative to decoder
      if (s->use_variable_block_len) {
          av_assert0(0); // FIXME not implemented
      } else {
          /* fixed block len */
          s->next_block_len_bits = s->frame_len_bits;
          s->prev_block_len_bits = s->frame_len_bits;
          s->block_len_bits      = s->frame_len_bits;
      }
  
      s->block_len = 1 << s->block_len_bits;
  //     av_assert0((s->block_pos + s->block_len) <= s->frame_len);
      bsize = s->frame_len_bits - s->block_len_bits;
  
      // FIXME factor
      v = s->coefs_end[bsize] - s->coefs_start;
      for (ch = 0; ch < s->avctx->channels; ch++)
          nb_coefs[ch] = v;
      {
          int n4 = s->block_len / 2;
          mdct_norm = 1.0 / (float) n4;
          if (s->version == 1)
              mdct_norm *= sqrt(n4);
      }
  
      if (s->avctx->channels == 2)
          put_bits(&s->pb, 1, !!s->ms_stereo);
  
      for (ch = 0; ch < s->avctx->channels; ch++) {
          // FIXME only set channel_coded when needed, instead of always
          s->channel_coded[ch] = 1;
          if (s->channel_coded[ch])
              init_exp(s, ch, fixed_exp);
      }
  
      for (ch = 0; ch < s->avctx->channels; ch++) {
          if (s->channel_coded[ch]) {
              WMACoef *coefs1;
              float *coefs, *exponents, mult;
              int i, n;
  
              coefs1    = s->coefs1[ch];
              exponents = s->exponents[ch];
              mult      = ff_exp10(total_gain * 0.05) / s->max_exponent[ch];
              mult     *= mdct_norm;
              coefs     = src_coefs[ch];
              if (s->use_noise_coding && 0) {
                  av_assert0(0); // FIXME not implemented
              } else {
                  coefs += s->coefs_start;
                  n      = nb_coefs[ch];
                  for (i = 0; i < n; i++) {
                      double t = *coefs++ / (exponents[i] * mult);
                      if (t < -32768 || t > 32767)
                          return -1;
  
                      coefs1[i] = lrint(t);
                  }
              }
          }
      }
  
      v = 0;
      for (ch = 0; ch < s->avctx->channels; ch++) {
          int a = s->channel_coded[ch];
          put_bits(&s->pb, 1, a);
          v |= a;
      }
  
      if (!v)
          return 1;
  
      for (v = total_gain - 1; v >= 127; v -= 127)
          put_bits(&s->pb, 7, 127);
      put_bits(&s->pb, 7, v);
  
      coef_nb_bits = ff_wma_total_gain_to_bits(total_gain);
  
      if (s->use_noise_coding) {
          for (ch = 0; ch < s->avctx->channels; ch++) {
              if (s->channel_coded[ch]) {
                  int i, n;
                  n = s->exponent_high_sizes[bsize];
                  for (i = 0; i < n; i++) {
                      put_bits(&s->pb, 1, s->high_band_coded[ch][i] = 0);
                      if (0)
                          nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
                  }
              }
          }
      }
  
      parse_exponents = 1;
      if (s->block_len_bits != s->frame_len_bits)
          put_bits(&s->pb, 1, parse_exponents);
  
      if (parse_exponents) {
          for (ch = 0; ch < s->avctx->channels; ch++) {
              if (s->channel_coded[ch]) {
                  if (s->use_exp_vlc) {
                      encode_exp_vlc(s, ch, fixed_exp);
                  } else {
                      av_assert0(0); // FIXME not implemented
  //                    encode_exp_lsp(s, ch);
                  }
              }
          }
      } else
          av_assert0(0); // FIXME not implemented
  
      for (ch = 0; ch < s->avctx->channels; ch++) {
          if (s->channel_coded[ch]) {
              int run, tindex;
              WMACoef *ptr, *eptr;
              tindex = (ch == 1 && s->ms_stereo);
              ptr    = &s->coefs1[ch][0];
              eptr   = ptr + nb_coefs[ch];
  
              run = 0;
              for (; ptr < eptr; ptr++) {
                  if (*ptr) {
                      int level     = *ptr;
                      int abs_level = FFABS(level);
                      int code      = 0;
                      if (abs_level <= s->coef_vlcs[tindex]->max_level)
                          if (run < s->coef_vlcs[tindex]->levels[abs_level - 1])
                              code = run + s->int_table[tindex][abs_level - 1];
  
                      av_assert2(code < s->coef_vlcs[tindex]->n);
                      put_bits(&s->pb, s->coef_vlcs[tindex]->huffbits[code],
                               s->coef_vlcs[tindex]->huffcodes[code]);
  
                      if (code == 0) {
                          if (1 << coef_nb_bits <= abs_level)
                              return -1;
  
                          put_bits(&s->pb, coef_nb_bits, abs_level);
                          put_bits(&s->pb, s->frame_len_bits, run);
                      }
                      // FIXME the sign is flipped somewhere
                      put_bits(&s->pb, 1, level < 0);
                      run = 0;
                  } else
                      run++;
              }
              if (run)
                  put_bits(&s->pb, s->coef_vlcs[tindex]->huffbits[1],
                           s->coef_vlcs[tindex]->huffcodes[1]);
          }
          if (s->version == 1 && s->avctx->channels >= 2)
              align_put_bits(&s->pb);
      }
      return 0;
  }
  
  static int encode_frame(WMACodecContext *s, float (*src_coefs)[BLOCK_MAX_SIZE],
                          uint8_t *buf, int buf_size, int total_gain)
  {
      init_put_bits(&s->pb, buf, buf_size);
  
      if (s->use_bit_reservoir)
          av_assert0(0); // FIXME not implemented
      else if (encode_block(s, src_coefs, total_gain) < 0)
          return INT_MAX;
  
      align_put_bits(&s->pb);
  
      return put_bits_count(&s->pb) / 8 - s->avctx->block_align;
  }
  
  static int encode_superframe(AVCodecContext *avctx, AVPacket *avpkt,
                               const AVFrame *frame, int *got_packet_ptr)
  {
      WMACodecContext *s = avctx->priv_data;
      int i, total_gain, ret, error;
  
      s->block_len_bits = s->frame_len_bits; // required by non variable block len
      s->block_len      = 1 << s->block_len_bits;
  
      ret = apply_window_and_mdct(avctx, frame);
  
      if (ret < 0)
          return ret;
  
      if (s->ms_stereo) {
          float a, b;
          int i;
  
          for (i = 0; i < s->block_len; i++) {
              a              = s->coefs[0][i] * 0.5;
              b              = s->coefs[1][i] * 0.5;
              s->coefs[0][i] = a + b;
              s->coefs[1][i] = a - b;
          }
      }
  
      if ((ret = ff_alloc_packet(avctx, avpkt, 2 * MAX_CODED_SUPERFRAME_SIZE)) < 0)
          return ret;
  
      total_gain = 128;
      for (i = 64; i; i >>= 1) {
          error = encode_frame(s, s->coefs, avpkt->data, avpkt->size,
                                   total_gain - i);
          if (error <= 0)
              total_gain -= i;
      }
  
      while(total_gain <= 128 && error > 0)
          error = encode_frame(s, s->coefs, avpkt->data, avpkt->size, total_gain++);
      if (error > 0) {
          av_log(avctx, AV_LOG_ERROR, "Invalid input data or requested bitrate too low, cannot encode\n");
          avpkt->size = 0;
          return AVERROR(EINVAL);
      }
      av_assert0((put_bits_count(&s->pb) & 7) == 0);
      i = avctx->block_align - put_bytes_count(&s->pb, 0);
      av_assert0(i>=0);
      while(i--)
          put_bits(&s->pb, 8, 'N');
  
      flush_put_bits(&s->pb);
      av_assert0(put_bits_ptr(&s->pb) - s->pb.buf == avctx->block_align);
  
      if (frame->pts != AV_NOPTS_VALUE)
          avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->initial_padding);
  
      avpkt->size     = avctx->block_align;
      *got_packet_ptr = 1;
      return 0;
  }
  
  #if CONFIG_WMAV1_ENCODER
  const AVCodec ff_wmav1_encoder = {
      .name           = "wmav1",
      .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Audio 1"),
      .type           = AVMEDIA_TYPE_AUDIO,
      .id             = AV_CODEC_ID_WMAV1,
      .priv_data_size = sizeof(WMACodecContext),
      .init           = encode_init,
      .encode2        = encode_superframe,
      .close          = ff_wma_end,
      .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
                                                        AV_SAMPLE_FMT_NONE },
      .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
  };
  #endif
  #if CONFIG_WMAV2_ENCODER
  const AVCodec ff_wmav2_encoder = {
      .name           = "wmav2",
      .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Audio 2"),
      .type           = AVMEDIA_TYPE_AUDIO,
      .id             = AV_CODEC_ID_WMAV2,
      .priv_data_size = sizeof(WMACodecContext),
      .init           = encode_init,
      .encode2        = encode_superframe,
      .close          = ff_wma_end,
      .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
                                                        AV_SAMPLE_FMT_NONE },
      .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
  };
  #endif
  