text: /*
   * Monkey's Audio APE demuxer
   * Copyright (c) 2007 Benjamin Zores <ben@geexbox.org>
   *  based upon libdemac from Dave Chapman.
   *
   * 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 <stdio.h>
  
  #include "libavutil/intreadwrite.h"
  #include "avformat.h"
  #include "internal.h"
  #include "apetag.h"
  
  /* The earliest and latest file formats supported by this library */
  #define APE_MIN_VERSION 3800
  #define APE_MAX_VERSION 3990
  
  #define MAC_FORMAT_FLAG_8_BIT                 1 // is 8-bit [OBSOLETE]
  #define MAC_FORMAT_FLAG_CRC                   2 // uses the new CRC32 error detection [OBSOLETE]
  #define MAC_FORMAT_FLAG_HAS_PEAK_LEVEL        4 // uint32 nPeakLevel after the header [OBSOLETE]
  #define MAC_FORMAT_FLAG_24_BIT                8 // is 24-bit [OBSOLETE]
  #define MAC_FORMAT_FLAG_HAS_SEEK_ELEMENTS    16 // has the number of seek elements after the peak level
  #define MAC_FORMAT_FLAG_CREATE_WAV_HEADER    32 // create the wave header on decompression (not stored)
  
  #define APE_EXTRADATA_SIZE 6
  
  typedef struct APEFrame {
      int64_t pos;
      int nblocks;
      int size;
      int skip;
      int64_t pts;
  } APEFrame;
  
  typedef struct APEContext {
      /* Derived fields */
      uint32_t junklength;
      uint32_t firstframe;
      uint32_t totalsamples;
      int currentframe;
      APEFrame *frames;
  
      /* Info from Descriptor Block */
      char magic[4];
      int16_t fileversion;
      int16_t padding1;
      uint32_t descriptorlength;
      uint32_t headerlength;
      uint32_t seektablelength;
      uint32_t wavheaderlength;
      uint32_t audiodatalength;
      uint32_t audiodatalength_high;
      uint32_t wavtaillength;
      uint8_t md5[16];
  
      /* Info from Header Block */
      uint16_t compressiontype;
      uint16_t formatflags;
      uint32_t blocksperframe;
      uint32_t finalframeblocks;
      uint32_t totalframes;
      uint16_t bps;
      uint16_t channels;
      uint32_t samplerate;
  
      /* Seektable */
      uint32_t *seektable;
      uint8_t  *bittable;
  } APEContext;
  
  static int ape_probe(AVProbeData * p)
  {
      int version = AV_RL16(p->buf+4);
      if (AV_RL32(p->buf) != MKTAG('M', 'A', 'C', ' '))
          return 0;
  
      if (version < APE_MIN_VERSION || version > APE_MAX_VERSION)
          return AVPROBE_SCORE_MAX/4;
  
      return AVPROBE_SCORE_MAX;
  }
  
  static void ape_dumpinfo(AVFormatContext * s, APEContext * ape_ctx)
  {
  #ifdef DEBUG
      int i;
  
      av_log(s, AV_LOG_DEBUG, "Descriptor Block:\n\n");
      av_log(s, AV_LOG_DEBUG, "magic                = \"%c%c%c%c\"\n", ape_ctx->magic[0], ape_ctx->magic[1], ape_ctx->magic[2], ape_ctx->magic[3]);
      av_log(s, AV_LOG_DEBUG, "fileversion          = %"PRId16"\n", ape_ctx->fileversion);
      av_log(s, AV_LOG_DEBUG, "descriptorlength     = %"PRIu32"\n", ape_ctx->descriptorlength);
      av_log(s, AV_LOG_DEBUG, "headerlength         = %"PRIu32"\n", ape_ctx->headerlength);
      av_log(s, AV_LOG_DEBUG, "seektablelength      = %"PRIu32"\n", ape_ctx->seektablelength);
      av_log(s, AV_LOG_DEBUG, "wavheaderlength      = %"PRIu32"\n", ape_ctx->wavheaderlength);
      av_log(s, AV_LOG_DEBUG, "audiodatalength      = %"PRIu32"\n", ape_ctx->audiodatalength);
      av_log(s, AV_LOG_DEBUG, "audiodatalength_high = %"PRIu32"\n", ape_ctx->audiodatalength_high);
      av_log(s, AV_LOG_DEBUG, "wavtaillength        = %"PRIu32"\n", ape_ctx->wavtaillength);
      av_log(s, AV_LOG_DEBUG, "md5                  = ");
      for (i = 0; i < 16; i++)
           av_log(s, AV_LOG_DEBUG, "%02x", ape_ctx->md5[i]);
      av_log(s, AV_LOG_DEBUG, "\n");
  
      av_log(s, AV_LOG_DEBUG, "\nHeader Block:\n\n");
  
      av_log(s, AV_LOG_DEBUG, "compressiontype      = %"PRIu16"\n", ape_ctx->compressiontype);
      av_log(s, AV_LOG_DEBUG, "formatflags          = %"PRIu16"\n", ape_ctx->formatflags);
      av_log(s, AV_LOG_DEBUG, "blocksperframe       = %"PRIu32"\n", ape_ctx->blocksperframe);
      av_log(s, AV_LOG_DEBUG, "finalframeblocks     = %"PRIu32"\n", ape_ctx->finalframeblocks);
      av_log(s, AV_LOG_DEBUG, "totalframes          = %"PRIu32"\n", ape_ctx->totalframes);
      av_log(s, AV_LOG_DEBUG, "bps                  = %"PRIu16"\n", ape_ctx->bps);
      av_log(s, AV_LOG_DEBUG, "channels             = %"PRIu16"\n", ape_ctx->channels);
      av_log(s, AV_LOG_DEBUG, "samplerate           = %"PRIu32"\n", ape_ctx->samplerate);
  
      av_log(s, AV_LOG_DEBUG, "\nSeektable\n\n");
      if ((ape_ctx->seektablelength / sizeof(uint32_t)) != ape_ctx->totalframes) {
          av_log(s, AV_LOG_DEBUG, "No seektable\n");
      } else {
          for (i = 0; i < ape_ctx->seektablelength / sizeof(uint32_t); i++) {
              if (i < ape_ctx->totalframes - 1) {
                  av_log(s, AV_LOG_DEBUG, "%8d   %"PRIu32" (%"PRIu32" bytes)",
                         i, ape_ctx->seektable[i],
                         ape_ctx->seektable[i + 1] - ape_ctx->seektable[i]);
                  if (ape_ctx->bittable)
                      av_log(s, AV_LOG_DEBUG, " + %2d bits\n",
                             ape_ctx->bittable[i]);
                  av_log(s, AV_LOG_DEBUG, "\n");
              } else {
                  av_log(s, AV_LOG_DEBUG, "%8d   %"PRIu32"\n", i, ape_ctx->seektable[i]);
              }
          }
      }
  
      av_log(s, AV_LOG_DEBUG, "\nFrames\n\n");
      for (i = 0; i < ape_ctx->totalframes; i++)
          av_log(s, AV_LOG_DEBUG, "%8d   %8"PRId64" %8d (%d samples)\n", i,
                 ape_ctx->frames[i].pos, ape_ctx->frames[i].size,
                 ape_ctx->frames[i].nblocks);
  
      av_log(s, AV_LOG_DEBUG, "\nCalculated information:\n\n");
      av_log(s, AV_LOG_DEBUG, "junklength           = %"PRIu32"\n", ape_ctx->junklength);
      av_log(s, AV_LOG_DEBUG, "firstframe           = %"PRIu32"\n", ape_ctx->firstframe);
      av_log(s, AV_LOG_DEBUG, "totalsamples         = %"PRIu32"\n", ape_ctx->totalsamples);
  #endif
  }
  
  static int ape_read_header(AVFormatContext * s)
  {
      AVIOContext *pb = s->pb;
      APEContext *ape = s->priv_data;
      AVStream *st;
      uint32_t tag;
      int i;
      int total_blocks, final_size = 0;
      int64_t pts, file_size;
  
      /* Skip any leading junk such as id3v2 tags */
      ape->junklength = avio_tell(pb);
  
      tag = avio_rl32(pb);
      if (tag != MKTAG('M', 'A', 'C', ' '))
          return AVERROR_INVALIDDATA;
  
      ape->fileversion = avio_rl16(pb);
  
      if (ape->fileversion < APE_MIN_VERSION || ape->fileversion > APE_MAX_VERSION) {
          av_log(s, AV_LOG_ERROR, "Unsupported file version - %d.%02d\n",
                 ape->fileversion / 1000, (ape->fileversion % 1000) / 10);
          return AVERROR_PATCHWELCOME;
      }
  
      if (ape->fileversion >= 3980) {
          ape->padding1             = avio_rl16(pb);
          ape->descriptorlength     = avio_rl32(pb);
          ape->headerlength         = avio_rl32(pb);
          ape->seektablelength      = avio_rl32(pb);
          ape->wavheaderlength      = avio_rl32(pb);
          ape->audiodatalength      = avio_rl32(pb);
          ape->audiodatalength_high = avio_rl32(pb);
          ape->wavtaillength        = avio_rl32(pb);
          avio_read(pb, ape->md5, 16);
  
          /* Skip any unknown bytes at the end of the descriptor.
             This is for future compatibility */
          if (ape->descriptorlength > 52)
              avio_skip(pb, ape->descriptorlength - 52);
  
          /* Read header data */
          ape->compressiontype      = avio_rl16(pb);
          ape->formatflags          = avio_rl16(pb);
          ape->blocksperframe       = avio_rl32(pb);
          ape->finalframeblocks     = avio_rl32(pb);
          ape->totalframes          = avio_rl32(pb);
          ape->bps                  = avio_rl16(pb);
          ape->channels             = avio_rl16(pb);
          ape->samplerate           = avio_rl32(pb);
      } else {
          ape->descriptorlength = 0;
          ape->headerlength = 32;
  
          ape->compressiontype      = avio_rl16(pb);
          ape->formatflags          = avio_rl16(pb);
          ape->channels             = avio_rl16(pb);
          ape->samplerate           = avio_rl32(pb);
          ape->wavheaderlength      = avio_rl32(pb);
          ape->wavtaillength        = avio_rl32(pb);
          ape->totalframes          = avio_rl32(pb);
          ape->finalframeblocks     = avio_rl32(pb);
  
          if (ape->formatflags & MAC_FORMAT_FLAG_HAS_PEAK_LEVEL) {
              avio_skip(pb, 4); /* Skip the peak level */
              ape->headerlength += 4;
          }
  
          if (ape->formatflags & MAC_FORMAT_FLAG_HAS_SEEK_ELEMENTS) {
              ape->seektablelength = avio_rl32(pb);
              ape->headerlength += 4;
              ape->seektablelength *= sizeof(int32_t);
          } else
              ape->seektablelength = ape->totalframes * sizeof(int32_t);
  
          if (ape->formatflags & MAC_FORMAT_FLAG_8_BIT)
              ape->bps = 8;
          else if (ape->formatflags & MAC_FORMAT_FLAG_24_BIT)
              ape->bps = 24;
          else
              ape->bps = 16;
  
          if (ape->fileversion >= 3950)
              ape->blocksperframe = 73728 * 4;
          else if (ape->fileversion >= 3900 || (ape->fileversion >= 3800  && ape->compressiontype >= 4000))
              ape->blocksperframe = 73728;
          else
              ape->blocksperframe = 9216;
  
          /* Skip any stored wav header */
          if (!(ape->formatflags & MAC_FORMAT_FLAG_CREATE_WAV_HEADER))
              avio_skip(pb, ape->wavheaderlength);
      }
  
      if(!ape->totalframes){
          av_log(s, AV_LOG_ERROR, "No frames in the file!\n");
          return AVERROR(EINVAL);
      }
      if(ape->totalframes > UINT_MAX / sizeof(APEFrame)){
          av_log(s, AV_LOG_ERROR, "Too many frames: %"PRIu32"\n",
                 ape->totalframes);
          return AVERROR_INVALIDDATA;
      }
      if (ape->seektablelength / sizeof(*ape->seektable) < ape->totalframes) {
          av_log(s, AV_LOG_ERROR,
                 "Number of seek entries is less than number of frames: %"SIZE_SPECIFIER" vs. %"PRIu32"\n",
                 ape->seektablelength / sizeof(*ape->seektable), ape->totalframes);
          return AVERROR_INVALIDDATA;
      }
      ape->frames       = av_malloc_array(ape->totalframes, sizeof(APEFrame));
      if(!ape->frames)
          return AVERROR(ENOMEM);
      ape->firstframe   = ape->junklength + ape->descriptorlength + ape->headerlength + ape->seektablelength + ape->wavheaderlength;
      if (ape->fileversion < 3810)
          ape->firstframe += ape->totalframes;
      ape->currentframe = 0;
  
  
      ape->totalsamples = ape->finalframeblocks;
      if (ape->totalframes > 1)
          ape->totalsamples += ape->blocksperframe * (ape->totalframes - 1);
  
      if (ape->seektablelength > 0) {
          ape->seektable = av_mallocz(ape->seektablelength);
          if (!ape->seektable)
              return AVERROR(ENOMEM);
          for (i = 0; i < ape->seektablelength / sizeof(uint32_t) && !pb->eof_reached; i++)
              ape->seektable[i] = avio_rl32(pb);
          if (ape->fileversion < 3810) {
              ape->bittable = av_mallocz(ape->totalframes);
              if (!ape->bittable)
                  return AVERROR(ENOMEM);
              for (i = 0; i < ape->totalframes && !pb->eof_reached; i++)
                  ape->bittable[i] = avio_r8(pb);
          }
          if (pb->eof_reached)
              av_log(s, AV_LOG_WARNING, "File truncated\n");
      }
  
      ape->frames[0].pos     = ape->firstframe;
      ape->frames[0].nblocks = ape->blocksperframe;
      ape->frames[0].skip    = 0;
      for (i = 1; i < ape->totalframes; i++) {
          ape->frames[i].pos      = ape->seektable[i] + ape->junklength;
          ape->frames[i].nblocks  = ape->blocksperframe;
          ape->frames[i - 1].size = ape->frames[i].pos - ape->frames[i - 1].pos;
          ape->frames[i].skip     = (ape->frames[i].pos - ape->frames[0].pos) & 3;
      }
      ape->frames[ape->totalframes - 1].nblocks = ape->finalframeblocks;
      /* calculate final packet size from total file size, if available */
      file_size = avio_size(pb);
      if (file_size > 0) {
          final_size = file_size - ape->frames[ape->totalframes - 1].pos -
                       ape->wavtaillength;
          final_size -= final_size & 3;
      }
      if (file_size <= 0 || final_size <= 0)
          final_size = ape->finalframeblocks * 8;
      ape->frames[ape->totalframes - 1].size = final_size;
  
      for (i = 0; i < ape->totalframes; i++) {
          if(ape->frames[i].skip){
              ape->frames[i].pos  -= ape->frames[i].skip;
              ape->frames[i].size += ape->frames[i].skip;
          }
          ape->frames[i].size = (ape->frames[i].size + 3) & ~3;
      }
      if (ape->fileversion < 3810) {
          for (i = 0; i < ape->totalframes; i++) {
              if (i < ape->totalframes - 1 && ape->bittable[i + 1])
                  ape->frames[i].size += 4;
              ape->frames[i].skip <<= 3;
              ape->frames[i].skip  += ape->bittable[i];
          }
      }
  
      ape_dumpinfo(s, ape);
  
      av_log(s, AV_LOG_VERBOSE, "Decoding file - v%d.%02d, compression level %"PRIu16"\n",
             ape->fileversion / 1000, (ape->fileversion % 1000) / 10,
             ape->compressiontype);
  
      /* now we are ready: build format streams */
      st = avformat_new_stream(s, NULL);
      if (!st)
          return AVERROR(ENOMEM);
  
      total_blocks = (ape->totalframes == 0) ? 0 : ((ape->totalframes - 1) * ape->blocksperframe) + ape->finalframeblocks;
  
      st->codecpar->codec_type      = AVMEDIA_TYPE_AUDIO;
      st->codecpar->codec_id        = AV_CODEC_ID_APE;
      st->codecpar->codec_tag       = MKTAG('A', 'P', 'E', ' ');
      st->codecpar->channels        = ape->channels;
      st->codecpar->sample_rate     = ape->samplerate;
      st->codecpar->bits_per_coded_sample = ape->bps;
  
      st->nb_frames = ape->totalframes;
      st->start_time = 0;
      st->duration  = total_blocks;
      avpriv_set_pts_info(st, 64, 1, ape->samplerate);
  
      if (ff_alloc_extradata(st->codecpar, APE_EXTRADATA_SIZE))
          return AVERROR(ENOMEM);
      AV_WL16(st->codecpar->extradata + 0, ape->fileversion);
      AV_WL16(st->codecpar->extradata + 2, ape->compressiontype);
      AV_WL16(st->codecpar->extradata + 4, ape->formatflags);
  
      pts = 0;
      for (i = 0; i < ape->totalframes; i++) {
          ape->frames[i].pts = pts;
          av_add_index_entry(st, ape->frames[i].pos, ape->frames[i].pts, 0, 0, AVINDEX_KEYFRAME);
          pts += ape->blocksperframe;
      }
  
      /* try to read APE tags */
      if (pb->seekable) {
          ff_ape_parse_tag(s);
          avio_seek(pb, 0, SEEK_SET);
      }
  
      return 0;
  }
  
  static int ape_read_packet(AVFormatContext * s, AVPacket * pkt)
  {
      int ret;
      int nblocks;
      APEContext *ape = s->priv_data;
      uint32_t extra_size = 8;
  
      if (avio_feof(s->pb))
          return AVERROR_EOF;
      if (ape->currentframe >= ape->totalframes)
          return AVERROR_EOF;
  
      if (avio_seek(s->pb, ape->frames[ape->currentframe].pos, SEEK_SET) < 0)
          return AVERROR(EIO);
  
      /* Calculate how many blocks there are in this frame */
      if (ape->currentframe == (ape->totalframes - 1))
          nblocks = ape->finalframeblocks;
      else
          nblocks = ape->blocksperframe;
  
      if (ape->frames[ape->currentframe].size <= 0 ||
          ape->frames[ape->currentframe].size > INT_MAX - extra_size) {
          av_log(s, AV_LOG_ERROR, "invalid packet size: %d\n",
                 ape->frames[ape->currentframe].size);
          ape->currentframe++;
          return AVERROR(EIO);
      }
  
      if (av_new_packet(pkt,  ape->frames[ape->currentframe].size + extra_size) < 0)
          return AVERROR(ENOMEM);
  
      AV_WL32(pkt->data    , nblocks);
      AV_WL32(pkt->data + 4, ape->frames[ape->currentframe].skip);
      ret = avio_read(s->pb, pkt->data + extra_size, ape->frames[ape->currentframe].size);
      if (ret < 0) {
          av_packet_unref(pkt);
          return ret;
      }
  
      pkt->pts = ape->frames[ape->currentframe].pts;
      pkt->stream_index = 0;
  
      /* note: we need to modify the packet size here to handle the last
         packet */
      pkt->size = ret + extra_size;
  
      ape->currentframe++;
  
      return 0;
  }
  
  static int ape_read_close(AVFormatContext * s)
  {
      APEContext *ape = s->priv_data;
  
      av_freep(&ape->frames);
      av_freep(&ape->seektable);
      av_freep(&ape->bittable);
      return 0;
  }
  
  static int ape_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
  {
      AVStream *st = s->streams[stream_index];
      APEContext *ape = s->priv_data;
      int index = av_index_search_timestamp(st, timestamp, flags);
  
      if (index < 0)
          return -1;
  
      if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
          return -1;
      ape->currentframe = index;
      return 0;
  }
  
  AVInputFormat ff_ape_demuxer = {
      .name           = "ape",
      .long_name      = NULL_IF_CONFIG_SMALL("Monkey's Audio"),
      .priv_data_size = sizeof(APEContext),
      .read_probe     = ape_probe,
      .read_header    = ape_read_header,
      .read_packet    = ape_read_packet,
      .read_close     = ape_read_close,
      .read_seek      = ape_read_seek,
      .extensions     = "ape,apl,mac",
  };
  