text: /*
   * TTA demuxer
   * Copyright (c) 2006 Alex Beregszaszi
   *
   * 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 "libavcodec/get_bits.h"
  #include "avformat.h"
  #include "id3v2.h"
  #include "id3v1.h"
  
  typedef struct {
      int totalframes, currentframe;
  } TTAContext;
  
  static int tta_probe(AVProbeData *p)
  {
      const uint8_t *d = p->buf;
  
      if (ff_id3v2_match(d))
          d += ff_id3v2_tag_len(d);
  
      if (d - p->buf >= p->buf_size)
          return 0;
  
      if (d[0] == 'T' && d[1] == 'T' && d[2] == 'A' && d[3] == '1')
          return 80;
      return 0;
  }
  
  static int tta_read_header(AVFormatContext *s, AVFormatParameters *ap)
  {
      TTAContext *c = s->priv_data;
      AVStream *st;
      int i, channels, bps, samplerate, datalen, framelen;
      uint64_t framepos, start_offset;
  
      ff_id3v2_read(s);
      if (!av_metadata_get(s->metadata, "", NULL, AV_METADATA_IGNORE_SUFFIX))
          ff_id3v1_read(s);
  
      start_offset = url_ftell(s->pb);
      if (get_le32(s->pb) != AV_RL32("TTA1"))
          return -1; // not tta file
  
      url_fskip(s->pb, 2); // FIXME: flags
      channels = get_le16(s->pb);
      bps = get_le16(s->pb);
      samplerate = get_le32(s->pb);
      if(samplerate <= 0 || samplerate > 1000000){
          av_log(s, AV_LOG_ERROR, "nonsense samplerate\n");
          return -1;
      }
  
      datalen = get_le32(s->pb);
      if(datalen < 0){
          av_log(s, AV_LOG_ERROR, "nonsense datalen\n");
          return -1;
      }
  
      url_fskip(s->pb, 4); // header crc
  
      framelen = samplerate*256/245;
      c->totalframes = datalen / framelen + ((datalen % framelen) ? 1 : 0);
      c->currentframe = 0;
  
      if(c->totalframes >= UINT_MAX/sizeof(uint32_t)){
          av_log(s, AV_LOG_ERROR, "totalframes too large\n");
          return -1;
      }
  
      st = av_new_stream(s, 0);
      if (!st)
          return AVERROR(ENOMEM);
  
      av_set_pts_info(st, 64, 1, samplerate);
      st->start_time = 0;
      st->duration = datalen;
  
      framepos = url_ftell(s->pb) + 4*c->totalframes + 4;
  
      for (i = 0; i < c->totalframes; i++) {
          uint32_t size = get_le32(s->pb);
          av_add_index_entry(st, framepos, i*framelen, size, 0, AVINDEX_KEYFRAME);
          framepos += size;
      }
      url_fskip(s->pb, 4); // seektable crc
  
      st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
      st->codec->codec_id = CODEC_ID_TTA;
      st->codec->channels = channels;
      st->codec->sample_rate = samplerate;
      st->codec->bits_per_coded_sample = bps;
  
      st->codec->extradata_size = url_ftell(s->pb) - start_offset;
      if(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE <= (unsigned)st->codec->extradata_size){
          //this check is redundant as get_buffer should fail
          av_log(s, AV_LOG_ERROR, "extradata_size too large\n");
          return -1;
      }
      st->codec->extradata = av_mallocz(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE);
      url_fseek(s->pb, start_offset, SEEK_SET);
      get_buffer(s->pb, st->codec->extradata, st->codec->extradata_size);
  
      return 0;
  }
  
  static int tta_read_packet(AVFormatContext *s, AVPacket *pkt)
  {
      TTAContext *c = s->priv_data;
      AVStream *st = s->streams[0];
      int size, ret;
  
      // FIXME!
      if (c->currentframe > c->totalframes)
          return -1;
  
      size = st->index_entries[c->currentframe].size;
  
      ret = av_get_packet(s->pb, pkt, size);
      pkt->dts = st->index_entries[c->currentframe++].timestamp;
      return ret;
  }
  
  static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
  {
      TTAContext *c = s->priv_data;
      AVStream *st = s->streams[stream_index];
      int index = av_index_search_timestamp(st, timestamp, flags);
      if (index < 0)
          return -1;
  
      c->currentframe = index;
      url_fseek(s->pb, st->index_entries[index].pos, SEEK_SET);
  
      return 0;
  }
  
  AVInputFormat tta_demuxer = {
      "tta",
      NULL_IF_CONFIG_SMALL("True Audio"),
      sizeof(TTAContext),
      tta_probe,
      tta_read_header,
      tta_read_packet,
      NULL,
      tta_read_seek,
      .extensions = "tta",
  };
  