text: /*
   * copyright (c) 2006 Oded Shimon <ods15@ods15.dyndns.org>
   *
   * 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
   */
  
  /**
   * @file
   * Native Vorbis encoder.
   * @author Oded Shimon <ods15@ods15.dyndns.org>
   */
  
  #include <float.h>
  #include "avcodec.h"
  #include "dsputil.h"
  #include "internal.h"
  #include "fft.h"
  #include "vorbis.h"
  #include "vorbis_enc_data.h"
  
  #define BITSTREAM_WRITER_LE
  #include "put_bits.h"
  
  #undef NDEBUG
  #include <assert.h>
  
  typedef struct {
      int nentries;
      uint8_t *lens;
      uint32_t *codewords;
      int ndimensions;
      float min;
      float delta;
      int seq_p;
      int lookup;
      int *quantlist;
      float *dimensions;
      float *pow2;
  } vorbis_enc_codebook;
  
  typedef struct {
      int dim;
      int subclass;
      int masterbook;
      int *books;
  } vorbis_enc_floor_class;
  
  typedef struct {
      int partitions;
      int *partition_to_class;
      int nclasses;
      vorbis_enc_floor_class *classes;
      int multiplier;
      int rangebits;
      int values;
      vorbis_floor1_entry *list;
  } vorbis_enc_floor;
  
  typedef struct {
      int type;
      int begin;
      int end;
      int partition_size;
      int classifications;
      int classbook;
      int8_t (*books)[8];
      float (*maxes)[2];
  } vorbis_enc_residue;
  
  typedef struct {
      int submaps;
      int *mux;
      int *floor;
      int *residue;
      int coupling_steps;
      int *magnitude;
      int *angle;
  } vorbis_enc_mapping;
  
  typedef struct {
      int blockflag;
      int mapping;
  } vorbis_enc_mode;
  
  typedef struct {
      int channels;
      int sample_rate;
      int log2_blocksize[2];
      FFTContext mdct[2];
      const float *win[2];
      int have_saved;
      float *saved;
      float *samples;
      float *floor;  // also used for tmp values for mdct
      float *coeffs; // also used for residue after floor
      float quality;
  
      int ncodebooks;
      vorbis_enc_codebook *codebooks;
  
      int nfloors;
      vorbis_enc_floor *floors;
  
      int nresidues;
      vorbis_enc_residue *residues;
  
      int nmappings;
      vorbis_enc_mapping *mappings;
  
      int nmodes;
      vorbis_enc_mode *modes;
  
      int64_t next_pts;
  } vorbis_enc_context;
  
  #define MAX_CHANNELS     2
  #define MAX_CODEBOOK_DIM 8
  
  #define MAX_FLOOR_CLASS_DIM  4
  #define NUM_FLOOR_PARTITIONS 8
  #define MAX_FLOOR_VALUES     (MAX_FLOOR_CLASS_DIM*NUM_FLOOR_PARTITIONS+2)
  
  #define RESIDUE_SIZE           1600
  #define RESIDUE_PART_SIZE      32
  #define NUM_RESIDUE_PARTITIONS (RESIDUE_SIZE/RESIDUE_PART_SIZE)
  
  static inline int put_codeword(PutBitContext *pb, vorbis_enc_codebook *cb,
                                 int entry)
  {
      assert(entry >= 0);
      assert(entry < cb->nentries);
      assert(cb->lens[entry]);
      if (pb->size_in_bits - put_bits_count(pb) < cb->lens[entry])
          return AVERROR(EINVAL);
      put_bits(pb, cb->lens[entry], cb->codewords[entry]);
      return 0;
  }
  
  static int cb_lookup_vals(int lookup, int dimensions, int entries)
  {
      if (lookup == 1)
          return ff_vorbis_nth_root(entries, dimensions);
      else if (lookup == 2)
          return dimensions *entries;
      return 0;
  }
  
  static int ready_codebook(vorbis_enc_codebook *cb)
  {
      int i;
  
      ff_vorbis_len2vlc(cb->lens, cb->codewords, cb->nentries);
  
      if (!cb->lookup) {
          cb->pow2 = cb->dimensions = NULL;
      } else {
          int vals = cb_lookup_vals(cb->lookup, cb->ndimensions, cb->nentries);
          cb->dimensions = av_malloc(sizeof(float) * cb->nentries * cb->ndimensions);
          cb->pow2 = av_mallocz(sizeof(float) * cb->nentries);
          if (!cb->dimensions || !cb->pow2)
              return AVERROR(ENOMEM);
          for (i = 0; i < cb->nentries; i++) {
              float last = 0;
              int j;
              int div = 1;
              for (j = 0; j < cb->ndimensions; j++) {
                  int off;
                  if (cb->lookup == 1)
                      off = (i / div) % vals; // lookup type 1
                  else
                      off = i * cb->ndimensions + j; // lookup type 2
  
                  cb->dimensions[i * cb->ndimensions + j] = last + cb->min + cb->quantlist[off] * cb->delta;
                  if (cb->seq_p)
                      last = cb->dimensions[i * cb->ndimensions + j];
                  cb->pow2[i] += cb->dimensions[i * cb->ndimensions + j] * cb->dimensions[i * cb->ndimensions + j];
                  div *= vals;
              }
              cb->pow2[i] /= 2.;
          }
      }
      return 0;
  }
  
  static int ready_residue(vorbis_enc_residue *rc, vorbis_enc_context *venc)
  {
      int i;
      assert(rc->type == 2);
      rc->maxes = av_mallocz(sizeof(float[2]) * rc->classifications);
      if (!rc->maxes)
          return AVERROR(ENOMEM);
      for (i = 0; i < rc->classifications; i++) {
          int j;
          vorbis_enc_codebook * cb;
          for (j = 0; j < 8; j++)
              if (rc->books[i][j] != -1)
                  break;
          if (j == 8) // zero
              continue;
          cb = &venc->codebooks[rc->books[i][j]];
          assert(cb->ndimensions >= 2);
          assert(cb->lookup);
  
          for (j = 0; j < cb->nentries; j++) {
              float a;
              if (!cb->lens[j])
                  continue;
              a = fabs(cb->dimensions[j * cb->ndimensions]);
              if (a > rc->maxes[i][0])
                  rc->maxes[i][0] = a;
              a = fabs(cb->dimensions[j * cb->ndimensions + 1]);
              if (a > rc->maxes[i][1])
                  rc->maxes[i][1] = a;
          }
      }
      // small bias
      for (i = 0; i < rc->classifications; i++) {
          rc->maxes[i][0] += 0.8;
          rc->maxes[i][1] += 0.8;
      }
      return 0;
  }
  
  static int create_vorbis_context(vorbis_enc_context *venc,
                                   AVCodecContext *avccontext)
  {
      vorbis_enc_floor   *fc;
      vorbis_enc_residue *rc;
      vorbis_enc_mapping *mc;
      int i, book, ret;
  
      venc->channels    = avccontext->channels;
      venc->sample_rate = avccontext->sample_rate;
      venc->log2_blocksize[0] = venc->log2_blocksize[1] = 11;
  
      venc->ncodebooks = FF_ARRAY_ELEMS(cvectors);
      venc->codebooks  = av_malloc(sizeof(vorbis_enc_codebook) * venc->ncodebooks);
      if (!venc->codebooks)
          return AVERROR(ENOMEM);
  
      // codebook 0..14 - floor1 book, values 0..255
      // codebook 15 residue masterbook
      // codebook 16..29 residue
      for (book = 0; book < venc->ncodebooks; book++) {
          vorbis_enc_codebook *cb = &venc->codebooks[book];
          int vals;
          cb->ndimensions = cvectors[book].dim;
          cb->nentries    = cvectors[book].real_len;
          cb->min         = cvectors[book].min;
          cb->delta       = cvectors[book].delta;
          cb->lookup      = cvectors[book].lookup;
          cb->seq_p       = 0;
  
          cb->lens      = av_malloc(sizeof(uint8_t)  * cb->nentries);
          cb->codewords = av_malloc(sizeof(uint32_t) * cb->nentries);
          if (!cb->lens || !cb->codewords)
              return AVERROR(ENOMEM);
          memcpy(cb->lens, cvectors[book].clens, cvectors[book].len);
          memset(cb->lens + cvectors[book].len, 0, cb->nentries - cvectors[book].len);
  
          if (cb->lookup) {
              vals = cb_lookup_vals(cb->lookup, cb->ndimensions, cb->nentries);
              cb->quantlist = av_malloc(sizeof(int) * vals);
              if (!cb->quantlist)
                  return AVERROR(ENOMEM);
              for (i = 0; i < vals; i++)
                  cb->quantlist[i] = cvectors[book].quant[i];
          } else {
              cb->quantlist = NULL;
          }
          if ((ret = ready_codebook(cb)) < 0)
              return ret;
      }
  
      venc->nfloors = 1;
      venc->floors  = av_malloc(sizeof(vorbis_enc_floor) * venc->nfloors);
      if (!venc->floors)
          return AVERROR(ENOMEM);
  
      // just 1 floor
      fc = &venc->floors[0];
      fc->partitions         = NUM_FLOOR_PARTITIONS;
      fc->partition_to_class = av_malloc(sizeof(int) * fc->partitions);
      if (!fc->partition_to_class)
          return AVERROR(ENOMEM);
      fc->nclasses           = 0;
      for (i = 0; i < fc->partitions; i++) {
          static const int a[] = {0, 1, 2, 2, 3, 3, 4, 4};
          fc->partition_to_class[i] = a[i];
          fc->nclasses = FFMAX(fc->nclasses, fc->partition_to_class[i]);
      }
      fc->nclasses++;
      fc->classes = av_malloc(sizeof(vorbis_enc_floor_class) * fc->nclasses);
      if (!fc->classes)
          return AVERROR(ENOMEM);
      for (i = 0; i < fc->nclasses; i++) {
          vorbis_enc_floor_class * c = &fc->classes[i];
          int j, books;
          c->dim        = floor_classes[i].dim;
          c->subclass   = floor_classes[i].subclass;
          c->masterbook = floor_classes[i].masterbook;
          books         = (1 << c->subclass);
          c->books      = av_malloc(sizeof(int) * books);
          if (!c->books)
              return AVERROR(ENOMEM);
          for (j = 0; j < books; j++)
              c->books[j] = floor_classes[i].nbooks[j];
      }
      fc->multiplier = 2;
      fc->rangebits  = venc->log2_blocksize[0] - 1;
  
      fc->values = 2;
      for (i = 0; i < fc->partitions; i++)
          fc->values += fc->classes[fc->partition_to_class[i]].dim;
  
      fc->list = av_malloc(sizeof(vorbis_floor1_entry) * fc->values);
      if (!fc->list)
          return AVERROR(ENOMEM);
      fc->list[0].x = 0;
      fc->list[1].x = 1 << fc->rangebits;
      for (i = 2; i < fc->values; i++) {
          static const int a[] = {
               93, 23,372,  6, 46,186,750, 14, 33, 65,
              130,260,556,  3, 10, 18, 28, 39, 55, 79,
              111,158,220,312,464,650,850
          };
          fc->list[i].x = a[i - 2];
      }
      ff_vorbis_ready_floor1_list(fc->list, fc->values);
  
      venc->nresidues = 1;
      venc->residues  = av_malloc(sizeof(vorbis_enc_residue) * venc->nresidues);
      if (!venc->residues)
          return AVERROR(ENOMEM);
  
      // single residue
      rc = &venc->residues[0];
      rc->type            = 2;
      rc->begin           = 0;
      rc->end             = 1600;
      rc->partition_size  = 32;
      rc->classifications = 10;
      rc->classbook       = 15;
      rc->books           = av_malloc(sizeof(*rc->books) * rc->classifications);
      if (!rc->books)
          return AVERROR(ENOMEM);
      {
          static const int8_t a[10][8] = {
              { -1, -1, -1, -1, -1, -1, -1, -1, },
              { -1, -1, 16, -1, -1, -1, -1, -1, },
              { -1, -1, 17, -1, -1, -1, -1, -1, },
              { -1, -1, 18, -1, -1, -1, -1, -1, },
              { -1, -1, 19, -1, -1, -1, -1, -1, },
              { -1, -1, 20, -1, -1, -1, -1, -1, },
              { -1, -1, 21, -1, -1, -1, -1, -1, },
              { 22, 23, -1, -1, -1, -1, -1, -1, },
              { 24, 25, -1, -1, -1, -1, -1, -1, },
              { 26, 27, 28, -1, -1, -1, -1, -1, },
          };
          memcpy(rc->books, a, sizeof a);
      }
      if ((ret = ready_residue(rc, venc)) < 0)
          return ret;
  
      venc->nmappings = 1;
      venc->mappings  = av_malloc(sizeof(vorbis_enc_mapping) * venc->nmappings);
      if (!venc->mappings)
          return AVERROR(ENOMEM);
  
      // single mapping
      mc = &venc->mappings[0];
      mc->submaps = 1;
      mc->mux     = av_malloc(sizeof(int) * venc->channels);
      if (!mc->mux)
          return AVERROR(ENOMEM);
      for (i = 0; i < venc->channels; i++)
          mc->mux[i] = 0;
      mc->floor   = av_malloc(sizeof(int) * mc->submaps);
      mc->residue = av_malloc(sizeof(int) * mc->submaps);
      if (!mc->floor || !mc->residue)
          return AVERROR(ENOMEM);
      for (i = 0; i < mc->submaps; i++) {
          mc->floor[i]   = 0;
          mc->residue[i] = 0;
      }
      mc->coupling_steps = venc->channels == 2 ? 1 : 0;
      mc->magnitude      = av_malloc(sizeof(int) * mc->coupling_steps);
      mc->angle          = av_malloc(sizeof(int) * mc->coupling_steps);
      if (!mc->magnitude || !mc->angle)
          return AVERROR(ENOMEM);
      if (mc->coupling_steps) {
          mc->magnitude[0] = 0;
          mc->angle[0]     = 1;
      }
  
      venc->nmodes = 1;
      venc->modes  = av_malloc(sizeof(vorbis_enc_mode) * venc->nmodes);
      if (!venc->modes)
          return AVERROR(ENOMEM);
  
      // single mode
      venc->modes[0].blockflag = 0;
      venc->modes[0].mapping   = 0;
  
      venc->have_saved = 0;
      venc->saved      = av_malloc(sizeof(float) * venc->channels * (1 << venc->log2_blocksize[1]) / 2);
      venc->samples    = av_malloc(sizeof(float) * venc->channels * (1 << venc->log2_blocksize[1]));
      venc->floor      = av_malloc(sizeof(float) * venc->channels * (1 << venc->log2_blocksize[1]) / 2);
      venc->coeffs     = av_malloc(sizeof(float) * venc->channels * (1 << venc->log2_blocksize[1]) / 2);
      if (!venc->saved || !venc->samples || !venc->floor || !venc->coeffs)
          return AVERROR(ENOMEM);
  
      venc->win[0] = ff_vorbis_vwin[venc->log2_blocksize[0] - 6];
      venc->win[1] = ff_vorbis_vwin[venc->log2_blocksize[1] - 6];
  
      if ((ret = ff_mdct_init(&venc->mdct[0], venc->log2_blocksize[0], 0, 1.0)) < 0)
          return ret;
      if ((ret = ff_mdct_init(&venc->mdct[1], venc->log2_blocksize[1], 0, 1.0)) < 0)
          return ret;
  
      return 0;
  }
  
  static void put_float(PutBitContext *pb, float f)
  {
      int exp, mant;
      uint32_t res = 0;
      mant = (int)ldexp(frexp(f, &exp), 20);
      exp += 788 - 20;
      if (mant < 0) {
          res |= (1U << 31);
          mant = -mant;
      }
      res |= mant | (exp << 21);
      put_bits32(pb, res);
  }
  
  static void put_codebook_header(PutBitContext *pb, vorbis_enc_codebook *cb)
  {
      int i;
      int ordered = 0;
  
      put_bits(pb, 24, 0x564342); //magic
      put_bits(pb, 16, cb->ndimensions);
      put_bits(pb, 24, cb->nentries);
  
      for (i = 1; i < cb->nentries; i++)
          if (cb->lens[i] < cb->lens[i-1])
              break;
      if (i == cb->nentries)
          ordered = 1;
  
      put_bits(pb, 1, ordered);
      if (ordered) {
          int len = cb->lens[0];
          put_bits(pb, 5, len - 1);
          i = 0;
          while (i < cb->nentries) {
              int j;
              for (j = 0; j+i < cb->nentries; j++)
                  if (cb->lens[j+i] != len)
                      break;
              put_bits(pb, ilog(cb->nentries - i), j);
              i += j;
              len++;
          }
      } else {
          int sparse = 0;
          for (i = 0; i < cb->nentries; i++)
              if (!cb->lens[i])
                  break;
          if (i != cb->nentries)
              sparse = 1;
          put_bits(pb, 1, sparse);
  
          for (i = 0; i < cb->nentries; i++) {
              if (sparse)
                  put_bits(pb, 1, !!cb->lens[i]);
              if (cb->lens[i])
                  put_bits(pb, 5, cb->lens[i] - 1);
          }
      }
  
      put_bits(pb, 4, cb->lookup);
      if (cb->lookup) {
          int tmp  = cb_lookup_vals(cb->lookup, cb->ndimensions, cb->nentries);
          int bits = ilog(cb->quantlist[0]);
  
          for (i = 1; i < tmp; i++)
              bits = FFMAX(bits, ilog(cb->quantlist[i]));
  
          put_float(pb, cb->min);
          put_float(pb, cb->delta);
  
          put_bits(pb, 4, bits - 1);
          put_bits(pb, 1, cb->seq_p);
  
          for (i = 0; i < tmp; i++)
              put_bits(pb, bits, cb->quantlist[i]);
      }
  }
  
  static void put_floor_header(PutBitContext *pb, vorbis_enc_floor *fc)
  {
      int i;
  
      put_bits(pb, 16, 1); // type, only floor1 is supported
  
      put_bits(pb, 5, fc->partitions);
  
      for (i = 0; i < fc->partitions; i++)
          put_bits(pb, 4, fc->partition_to_class[i]);
  
      for (i = 0; i < fc->nclasses; i++) {
          int j, books;
  
          put_bits(pb, 3, fc->classes[i].dim - 1);
          put_bits(pb, 2, fc->classes[i].subclass);
  
          if (fc->classes[i].subclass)
              put_bits(pb, 8, fc->classes[i].masterbook);
  
          books = (1 << fc->classes[i].subclass);
  
          for (j = 0; j < books; j++)
              put_bits(pb, 8, fc->classes[i].books[j] + 1);
      }
  
      put_bits(pb, 2, fc->multiplier - 1);
      put_bits(pb, 4, fc->rangebits);
  
      for (i = 2; i < fc->values; i++)
          put_bits(pb, fc->rangebits, fc->list[i].x);
  }
  
  static void put_residue_header(PutBitContext *pb, vorbis_enc_residue *rc)
  {
      int i;
  
      put_bits(pb, 16, rc->type);
  
      put_bits(pb, 24, rc->begin);
      put_bits(pb, 24, rc->end);
      put_bits(pb, 24, rc->partition_size - 1);
      put_bits(pb, 6, rc->classifications - 1);
      put_bits(pb, 8, rc->classbook);
  
      for (i = 0; i < rc->classifications; i++) {
          int j, tmp = 0;
          for (j = 0; j < 8; j++)
              tmp |= (rc->books[i][j] != -1) << j;
  
          put_bits(pb, 3, tmp & 7);
          put_bits(pb, 1, tmp > 7);
  
          if (tmp > 7)
              put_bits(pb, 5, tmp >> 3);
      }
  
      for (i = 0; i < rc->classifications; i++) {
          int j;
          for (j = 0; j < 8; j++)
              if (rc->books[i][j] != -1)
                  put_bits(pb, 8, rc->books[i][j]);
      }
  }
  
  static int put_main_header(vorbis_enc_context *venc, uint8_t **out)
  {
      int i;
      PutBitContext pb;
      uint8_t buffer[50000] = {0}, *p = buffer;
      int buffer_len = sizeof buffer;
      int len, hlens[3];
  
      // identification header
      init_put_bits(&pb, p, buffer_len);
      put_bits(&pb, 8, 1); //magic
      for (i = 0; "vorbis"[i]; i++)
          put_bits(&pb, 8, "vorbis"[i]);
      put_bits32(&pb, 0); // version
      put_bits(&pb,  8, venc->channels);
      put_bits32(&pb, venc->sample_rate);
      put_bits32(&pb, 0); // bitrate
      put_bits32(&pb, 0); // bitrate
      put_bits32(&pb, 0); // bitrate
      put_bits(&pb,  4, venc->log2_blocksize[0]);
      put_bits(&pb,  4, venc->log2_blocksize[1]);
      put_bits(&pb,  1, 1); // framing
  
      flush_put_bits(&pb);
      hlens[0] = put_bits_count(&pb) >> 3;
      buffer_len -= hlens[0];
      p += hlens[0];
  
      // comment header
      init_put_bits(&pb, p, buffer_len);
      put_bits(&pb, 8, 3); //magic
      for (i = 0; "vorbis"[i]; i++)
          put_bits(&pb, 8, "vorbis"[i]);
      put_bits32(&pb, 0); // vendor length TODO
      put_bits32(&pb, 0); // amount of comments
      put_bits(&pb,  1, 1); // framing
  
      flush_put_bits(&pb);
      hlens[1] = put_bits_count(&pb) >> 3;
      buffer_len -= hlens[1];
      p += hlens[1];
  
      // setup header
      init_put_bits(&pb, p, buffer_len);
      put_bits(&pb, 8, 5); //magic
      for (i = 0; "vorbis"[i]; i++)
          put_bits(&pb, 8, "vorbis"[i]);
  
      // codebooks
      put_bits(&pb, 8, venc->ncodebooks - 1);
      for (i = 0; i < venc->ncodebooks; i++)
          put_codebook_header(&pb, &venc->codebooks[i]);
  
      // time domain, reserved, zero
      put_bits(&pb,  6, 0);
      put_bits(&pb, 16, 0);
  
      // floors
      put_bits(&pb, 6, venc->nfloors - 1);
      for (i = 0; i < venc->nfloors; i++)
          put_floor_header(&pb, &venc->floors[i]);
  
      // residues
      put_bits(&pb, 6, venc->nresidues - 1);
      for (i = 0; i < venc->nresidues; i++)
          put_residue_header(&pb, &venc->residues[i]);
  
      // mappings
      put_bits(&pb, 6, venc->nmappings - 1);
      for (i = 0; i < venc->nmappings; i++) {
          vorbis_enc_mapping *mc = &venc->mappings[i];
          int j;
          put_bits(&pb, 16, 0); // mapping type
  
          put_bits(&pb, 1, mc->submaps > 1);
          if (mc->submaps > 1)
              put_bits(&pb, 4, mc->submaps - 1);
  
          put_bits(&pb, 1, !!mc->coupling_steps);
          if (mc->coupling_steps) {
              put_bits(&pb, 8, mc->coupling_steps - 1);
              for (j = 0; j < mc->coupling_steps; j++) {
                  put_bits(&pb, ilog(venc->channels - 1), mc->magnitude[j]);
                  put_bits(&pb, ilog(venc->channels - 1), mc->angle[j]);
              }
          }
  
          put_bits(&pb, 2, 0); // reserved
  
          if (mc->submaps > 1)
              for (j = 0; j < venc->channels; j++)
                  put_bits(&pb, 4, mc->mux[j]);
  
          for (j = 0; j < mc->submaps; j++) {
              put_bits(&pb, 8, 0); // reserved time configuration
              put_bits(&pb, 8, mc->floor[j]);
              put_bits(&pb, 8, mc->residue[j]);
          }
      }
  
      // modes
      put_bits(&pb, 6, venc->nmodes - 1);
      for (i = 0; i < venc->nmodes; i++) {
          put_bits(&pb, 1, venc->modes[i].blockflag);
          put_bits(&pb, 16, 0); // reserved window type
          put_bits(&pb, 16, 0); // reserved transform type
          put_bits(&pb, 8, venc->modes[i].mapping);
      }
  
      put_bits(&pb, 1, 1); // framing
  
      flush_put_bits(&pb);
      hlens[2] = put_bits_count(&pb) >> 3;
  
      len = hlens[0] + hlens[1] + hlens[2];
      p = *out = av_mallocz(64 + len + len/255);
      if (!p)
          return AVERROR(ENOMEM);
  
      *p++ = 2;
      p += av_xiphlacing(p, hlens[0]);
      p += av_xiphlacing(p, hlens[1]);
      buffer_len = 0;
      for (i = 0; i < 3; i++) {
          memcpy(p, buffer + buffer_len, hlens[i]);
          p += hlens[i];
          buffer_len += hlens[i];
      }
  
      return p - *out;
  }
  
  static float get_floor_average(vorbis_enc_floor * fc, float *coeffs, int i)
  {
      int begin = fc->list[fc->list[FFMAX(i-1, 0)].sort].x;
      int end   = fc->list[fc->list[FFMIN(i+1, fc->values - 1)].sort].x;
      int j;
      float average = 0;
  
      for (j = begin; j < end; j++)
          average += fabs(coeffs[j]);
      return average / (end - begin);
  }
  
  static void floor_fit(vorbis_enc_context *venc, vorbis_enc_floor *fc,
                        float *coeffs, uint16_t *posts, int samples)
  {
      int range = 255 / fc->multiplier + 1;
      int i;
      float tot_average = 0.;
      float averages[MAX_FLOOR_VALUES];
      for (i = 0; i < fc->values; i++) {
          averages[i] = get_floor_average(fc, coeffs, i);
          tot_average += averages[i];
      }
      tot_average /= fc->values;
      tot_average /= venc->quality;
  
      for (i = 0; i < fc->values; i++) {
          int position  = fc->list[fc->list[i].sort].x;
          float average = averages[i];
          int j;
  
          average = sqrt(tot_average * average) * pow(1.25f, position*0.005f); // MAGIC!
          for (j = 0; j < range - 1; j++)
              if (ff_vorbis_floor1_inverse_db_table[j * fc->multiplier] > average)
                  break;
          posts[fc->list[i].sort] = j;
      }
  }
  
  static int render_point(int x0, int y0, int x1, int y1, int x)
  {
      return y0 +  (x - x0) * (y1 - y0) / (x1 - x0);
  }
  
  static int floor_encode(vorbis_enc_context *venc, vorbis_enc_floor *fc,
                          PutBitContext *pb, uint16_t *posts,
                          float *floor, int samples)
  {
      int range = 255 / fc->multiplier + 1;
      int coded[MAX_FLOOR_VALUES]; // first 2 values are unused
      int i, counter;
  
      if (pb->size_in_bits - put_bits_count(pb) < 1 + 2 * ilog(range - 1))
          return AVERROR(EINVAL);
      put_bits(pb, 1, 1); // non zero
      put_bits(pb, ilog(range - 1), posts[0]);
      put_bits(pb, ilog(range - 1), posts[1]);
      coded[0] = coded[1] = 1;
  
      for (i = 2; i < fc->values; i++) {
          int predicted = render_point(fc->list[fc->list[i].low].x,
                                       posts[fc->list[i].low],
                                       fc->list[fc->list[i].high].x,
                                       posts[fc->list[i].high],
                                       fc->list[i].x);
          int highroom = range - predicted;
          int lowroom = predicted;
          int room = FFMIN(highroom, lowroom);
          if (predicted == posts[i]) {
              coded[i] = 0; // must be used later as flag!
              continue;
          } else {
              if (!coded[fc->list[i].low ])
                  coded[fc->list[i].low ] = -1;
              if (!coded[fc->list[i].high])
                  coded[fc->list[i].high] = -1;
          }
          if (posts[i] > predicted) {
              if (posts[i] - predicted > room)
                  coded[i] = posts[i] - predicted + lowroom;
              else
                  coded[i] = (posts[i] - predicted) << 1;
          } else {
              if (predicted - posts[i] > room)
                  coded[i] = predicted - posts[i] + highroom - 1;
              else
                  coded[i] = ((predicted - posts[i]) << 1) - 1;
          }
      }
  
      counter = 2;
      for (i = 0; i < fc->partitions; i++) {
          vorbis_enc_floor_class * c = &fc->classes[fc->partition_to_class[i]];
          int k, cval = 0, csub = 1<<c->subclass;
          if (c->subclass) {
              vorbis_enc_codebook * book = &venc->codebooks[c->masterbook];
              int cshift = 0;
              for (k = 0; k < c->dim; k++) {
                  int l;
                  for (l = 0; l < csub; l++) {
                      int maxval = 1;
                      if (c->books[l] != -1)
                          maxval = venc->codebooks[c->books[l]].nentries;
                      // coded could be -1, but this still works, cause that is 0
                      if (coded[counter + k] < maxval)
                          break;
                  }
                  assert(l != csub);
                  cval   |= l << cshift;
                  cshift += c->subclass;
              }
              if (put_codeword(pb, book, cval))
                  return AVERROR(EINVAL);
          }
          for (k = 0; k < c->dim; k++) {
              int book  = c->books[cval & (csub-1)];
              int entry = coded[counter++];
              cval >>= c->subclass;
              if (book == -1)
                  continue;
              if (entry == -1)
                  entry = 0;
              if (put_codeword(pb, &venc->codebooks[book], entry))
                  return AVERROR(EINVAL);
          }
      }
  
      ff_vorbis_floor1_render_list(fc->list, fc->values, posts, coded,
                                   fc->multiplier, floor, samples);
  
      return 0;
  }
  
  static float *put_vector(vorbis_enc_codebook *book, PutBitContext *pb,
                           float *num)
  {
      int i, entry = -1;
      float distance = FLT_MAX;
      assert(book->dimensions);
      for (i = 0; i < book->nentries; i++) {
          float * vec = book->dimensions + i * book->ndimensions, d = book->pow2[i];
          int j;
          if (!book->lens[i])
              continue;
          for (j = 0; j < book->ndimensions; j++)
              d -= vec[j] * num[j];
          if (distance > d) {
              entry    = i;
              distance = d;
          }
      }
      if (put_codeword(pb, book, entry))
          return NULL;
      return &book->dimensions[entry * book->ndimensions];
  }
  
  static int residue_encode(vorbis_enc_context *venc, vorbis_enc_residue *rc,
                            PutBitContext *pb, float *coeffs, int samples,
                            int real_ch)
  {
      int pass, i, j, p, k;
      int psize      = rc->partition_size;
      int partitions = (rc->end - rc->begin) / psize;
      int channels   = (rc->type == 2) ? 1 : real_ch;
      int classes[MAX_CHANNELS][NUM_RESIDUE_PARTITIONS];
      int classwords = venc->codebooks[rc->classbook].ndimensions;
  
      assert(rc->type == 2);
      assert(real_ch == 2);
      for (p = 0; p < partitions; p++) {
          float max1 = 0., max2 = 0.;
          int s = rc->begin + p * psize;
          for (k = s; k < s + psize; k += 2) {
              max1 = FFMAX(max1, fabs(coeffs[          k / real_ch]));
              max2 = FFMAX(max2, fabs(coeffs[samples + k / real_ch]));
          }
  
          for (i = 0; i < rc->classifications - 1; i++)
              if (max1 < rc->maxes[i][0] && max2 < rc->maxes[i][1])
                  break;
          classes[0][p] = i;
      }
  
      for (pass = 0; pass < 8; pass++) {
          p = 0;
          while (p < partitions) {
              if (pass == 0)
                  for (j = 0; j < channels; j++) {
                      vorbis_enc_codebook * book = &venc->codebooks[rc->classbook];
                      int entry = 0;
                      for (i = 0; i < classwords; i++) {
                          entry *= rc->classifications;
                          entry += classes[j][p + i];
                      }
                      if (put_codeword(pb, book, entry))
                          return AVERROR(EINVAL);
                  }
              for (i = 0; i < classwords && p < partitions; i++, p++) {
                  for (j = 0; j < channels; j++) {
                      int nbook = rc->books[classes[j][p]][pass];
                      vorbis_enc_codebook * book = &venc->codebooks[nbook];
                      float *buf = coeffs + samples*j + rc->begin + p*psize;
                      if (nbook == -1)
                          continue;
  
                      assert(rc->type == 0 || rc->type == 2);
                      assert(!(psize % book->ndimensions));
  
                      if (rc->type == 0) {
                          for (k = 0; k < psize; k += book->ndimensions) {
                              int l;
                              float *a = put_vector(book, pb, &buf[k]);
                              if (!a)
                                  return AVERROR(EINVAL);
                              for (l = 0; l < book->ndimensions; l++)
                                  buf[k + l] -= a[l];
                          }
                      } else {
                          int s = rc->begin + p * psize, a1, b1;
                          a1 = (s % real_ch) * samples;
                          b1 =  s / real_ch;
                          s  = real_ch * samples;
                          for (k = 0; k < psize; k += book->ndimensions) {
                              int dim, a2 = a1, b2 = b1;
                              float vec[MAX_CODEBOOK_DIM], *pv = vec;
                              for (dim = book->ndimensions; dim--; ) {
                                  *pv++ = coeffs[a2 + b2];
                                  if ((a2 += samples) == s) {
                                      a2 = 0;
                                      b2++;
                                  }
                              }
                              pv = put_vector(book, pb, vec);
                              if (!pv)
                                  return AVERROR(EINVAL);
                              for (dim = book->ndimensions; dim--; ) {
                                  coeffs[a1 + b1] -= *pv++;
                                  if ((a1 += samples) == s) {
                                      a1 = 0;
                                      b1++;
                                  }
                              }
                          }
                      }
                  }
              }
          }
      }
      return 0;
  }
  
  static int apply_window_and_mdct(vorbis_enc_context *venc, const signed short *audio,
                                   int samples)
  {
      int i, j, channel;
      const float * win = venc->win[0];
      int window_len = 1 << (venc->log2_blocksize[0] - 1);
      float n = (float)(1 << venc->log2_blocksize[0]) / 4.;
      // FIXME use dsp
  
      if (!venc->have_saved && !samples)
          return 0;
  
      if (venc->have_saved) {
          for (channel = 0; channel < venc->channels; channel++)
              memcpy(venc->samples + channel * window_len * 2,
                     venc->saved + channel * window_len, sizeof(float) * window_len);
      } else {
          for (channel = 0; channel < venc->channels; channel++)
              memset(venc->samples + channel * window_len * 2, 0,
                     sizeof(float) * window_len);
      }
  
      if (samples) {
          for (channel = 0; channel < venc->channels; channel++) {
              float * offset = venc->samples + channel*window_len*2 + window_len;
              j = channel;
              for (i = 0; i < samples; i++, j += venc->channels)
                  offset[i] = audio[j] / 32768. / n * win[window_len - i - 1];
          }
      } else {
          for (channel = 0; channel < venc->channels; channel++)
              memset(venc->samples + channel * window_len * 2 + window_len,
                     0, sizeof(float) * window_len);
      }
  
      for (channel = 0; channel < venc->channels; channel++)
          venc->mdct[0].mdct_calc(&venc->mdct[0], venc->coeffs + channel * window_len,
                       venc->samples + channel * window_len * 2);
  
      if (samples) {
          for (channel = 0; channel < venc->channels; channel++) {
              float *offset = venc->saved + channel * window_len;
              j = channel;
              for (i = 0; i < samples; i++, j += venc->channels)
                  offset[i] = audio[j] / 32768. / n * win[i];
          }
          venc->have_saved = 1;
      } else {
          venc->have_saved = 0;
      }
      return 1;
  }
  
  static int vorbis_encode_frame(AVCodecContext *avccontext, AVPacket *avpkt,
                                 const AVFrame *frame, int *got_packet_ptr)
  {
      vorbis_enc_context *venc = avccontext->priv_data;
      const int16_t *audio = frame ? (const int16_t *)frame->data[0] : NULL;
      int samples = frame ? frame->nb_samples : 0;
      vorbis_enc_mode *mode;
      vorbis_enc_mapping *mapping;
      PutBitContext pb;
      int i, ret;
  
      if (!apply_window_and_mdct(venc, audio, samples))
          return 0;
      samples = 1 << (venc->log2_blocksize[0] - 1);
  
      if ((ret = ff_alloc_packet2(avccontext, avpkt, 8192)))
          return ret;
  
      init_put_bits(&pb, avpkt->data, avpkt->size);
  
      if (pb.size_in_bits - put_bits_count(&pb) < 1 + ilog(venc->nmodes - 1)) {
          av_log(avccontext, AV_LOG_ERROR, "output buffer is too small\n");
          return AVERROR(EINVAL);
      }
  
      put_bits(&pb, 1, 0); // magic bit
  
      put_bits(&pb, ilog(venc->nmodes - 1), 0); // 0 bits, the mode
  
      mode    = &venc->modes[0];
      mapping = &venc->mappings[mode->mapping];
      if (mode->blockflag) {
          put_bits(&pb, 1, 0);
          put_bits(&pb, 1, 0);
      }
  
      for (i = 0; i < venc->channels; i++) {
          vorbis_enc_floor *fc = &venc->floors[mapping->floor[mapping->mux[i]]];
          uint16_t posts[MAX_FLOOR_VALUES];
          floor_fit(venc, fc, &venc->coeffs[i * samples], posts, samples);
          if (floor_encode(venc, fc, &pb, posts, &venc->floor[i * samples], samples)) {
              av_log(avccontext, AV_LOG_ERROR, "output buffer is too small\n");
              return AVERROR(EINVAL);
          }
      }
  
      for (i = 0; i < venc->channels * samples; i++)
          venc->coeffs[i] /= venc->floor[i];
  
      for (i = 0; i < mapping->coupling_steps; i++) {
          float *mag = venc->coeffs + mapping->magnitude[i] * samples;
          float *ang = venc->coeffs + mapping->angle[i]     * samples;
          int j;
          for (j = 0; j < samples; j++) {
              float a = ang[j];
              ang[j] -= mag[j];
              if (mag[j] > 0)
                  ang[j] = -ang[j];
              if (ang[j] < 0)
                  mag[j] = a;
          }
      }
  
      if (residue_encode(venc, &venc->residues[mapping->residue[mapping->mux[0]]],
                         &pb, venc->coeffs, samples, venc->channels)) {
          av_log(avccontext, AV_LOG_ERROR, "output buffer is too small\n");
          return AVERROR(EINVAL);
      }
  
      flush_put_bits(&pb);
      avpkt->size = put_bits_count(&pb) >> 3;
  
      avpkt->duration = ff_samples_to_time_base(avccontext, avccontext->frame_size);
      if (frame)
          if (frame->pts != AV_NOPTS_VALUE)
              avpkt->pts = ff_samples_to_time_base(avccontext, frame->pts);
      else
          avpkt->pts = venc->next_pts;
      if (avpkt->pts != AV_NOPTS_VALUE)
          venc->next_pts = avpkt->pts + avpkt->duration;
  
      *got_packet_ptr = 1;
      return 0;
  }
  
  
  static av_cold int vorbis_encode_close(AVCodecContext *avccontext)
  {
      vorbis_enc_context *venc = avccontext->priv_data;
      int i;
  
      if (venc->codebooks)
          for (i = 0; i < venc->ncodebooks; i++) {
              av_freep(&venc->codebooks[i].lens);
              av_freep(&venc->codebooks[i].codewords);
              av_freep(&venc->codebooks[i].quantlist);
              av_freep(&venc->codebooks[i].dimensions);
              av_freep(&venc->codebooks[i].pow2);
          }
      av_freep(&venc->codebooks);
  
      if (venc->floors)
          for (i = 0; i < venc->nfloors; i++) {
              int j;
              if (venc->floors[i].classes)
                  for (j = 0; j < venc->floors[i].nclasses; j++)
                      av_freep(&venc->floors[i].classes[j].books);
              av_freep(&venc->floors[i].classes);
              av_freep(&venc->floors[i].partition_to_class);
              av_freep(&venc->floors[i].list);
          }
      av_freep(&venc->floors);
  
      if (venc->residues)
          for (i = 0; i < venc->nresidues; i++) {
              av_freep(&venc->residues[i].books);
              av_freep(&venc->residues[i].maxes);
          }
      av_freep(&venc->residues);
  
      if (venc->mappings)
          for (i = 0; i < venc->nmappings; i++) {
              av_freep(&venc->mappings[i].mux);
              av_freep(&venc->mappings[i].floor);
              av_freep(&venc->mappings[i].residue);
              av_freep(&venc->mappings[i].magnitude);
              av_freep(&venc->mappings[i].angle);
          }
      av_freep(&venc->mappings);
  
      av_freep(&venc->modes);
  
      av_freep(&venc->saved);
      av_freep(&venc->samples);
      av_freep(&venc->floor);
      av_freep(&venc->coeffs);
  
      ff_mdct_end(&venc->mdct[0]);
      ff_mdct_end(&venc->mdct[1]);
  
  #if FF_API_OLD_ENCODE_AUDIO
      av_freep(&avccontext->coded_frame);
  #endif
      av_freep(&avccontext->extradata);
  
      return 0 ;
  }
  
  static av_cold int vorbis_encode_init(AVCodecContext *avccontext)
  {
      vorbis_enc_context *venc = avccontext->priv_data;
      int ret;
  
      if (avccontext->channels != 2) {
          av_log(avccontext, AV_LOG_ERROR, "Current FFmpeg Vorbis encoder only supports 2 channels.\n");
          return -1;
      }
  
      if ((ret = create_vorbis_context(venc, avccontext)) < 0)
          goto error;
  
      if (avccontext->flags & CODEC_FLAG_QSCALE)
          venc->quality = avccontext->global_quality / (float)FF_QP2LAMBDA / 10.;
      else
          venc->quality = 8;
      venc->quality *= venc->quality;
  
      if ((ret = put_main_header(venc, (uint8_t**)&avccontext->extradata)) < 0)
          goto error;
      avccontext->extradata_size = ret;
  
      avccontext->frame_size = 1 << (venc->log2_blocksize[0] - 1);
  
  #if FF_API_OLD_ENCODE_AUDIO
      avccontext->coded_frame = avcodec_alloc_frame();
      if (!avccontext->coded_frame) {
          ret = AVERROR(ENOMEM);
          goto error;
      }
  #endif
  
      return 0;
  error:
      vorbis_encode_close(avccontext);
      return ret;
  }
  
  AVCodec ff_vorbis_encoder = {
      .name           = "vorbis",
      .type           = AVMEDIA_TYPE_AUDIO,
      .id             = CODEC_ID_VORBIS,
      .priv_data_size = sizeof(vorbis_enc_context),
      .init           = vorbis_encode_init,
      .encode2        = vorbis_encode_frame,
      .close          = vorbis_encode_close,
      .capabilities   = CODEC_CAP_DELAY | CODEC_CAP_EXPERIMENTAL,
      .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
                                                       AV_SAMPLE_FMT_NONE },
      .long_name      = NULL_IF_CONFIG_SMALL("Vorbis"),
  };
  