text: /*
   * Pro Pinball Series Soundbank (44c, 22c, 11c, 5c) demuxer.
   *
   * Copyright (C) 2020 Zane van Iperen (zane@zanevaniperen.com)
   *
   * 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 "avformat.h"
  #include "internal.h"
  #include "libavutil/intreadwrite.h"
  #include "libavutil/avassert.h"
  #include "libavutil/internal.h"
  
  #define PP_BNK_MAX_READ_SIZE    4096
  #define PP_BNK_FILE_HEADER_SIZE 20
  #define PP_BNK_TRACK_SIZE       20
  
  typedef struct PPBnkHeader {
      uint32_t        bank_id;        /*< Bank ID, useless for our purposes. */
      uint32_t        sample_rate;    /*< Sample rate of the contained tracks. */
      uint32_t        always1;        /*< Unknown, always seems to be 1. */
      uint32_t        track_count;    /*< Number of tracks in the file. */
      uint32_t        flags;          /*< Flags. */
  } PPBnkHeader;
  
  typedef struct PPBnkTrack {
      uint32_t        id;             /*< Track ID. Usually track[i].id == track[i-1].id + 1, but not always */
      uint32_t        size;           /*< Size of the data in bytes. */
      uint32_t        sample_rate;    /*< Sample rate. */
      uint32_t        always1_1;      /*< Unknown, always seems to be 1. */
      uint32_t        always1_2;      /*< Unknown, always seems to be 1. */
  } PPBnkTrack;
  
  typedef struct PPBnkCtxTrack {
      int64_t         data_offset;
      uint32_t        data_size;
      uint32_t        bytes_read;
  } PPBnkCtxTrack;
  
  typedef struct PPBnkCtx {
      int             track_count;
      PPBnkCtxTrack   *tracks;
      uint32_t        current_track;
  } PPBnkCtx;
  
  enum {
      PP_BNK_FLAG_PERSIST = (1 << 0), /*< This is a large file, keep in memory. */
      PP_BNK_FLAG_MUSIC   = (1 << 1), /*< This is music. */
      PP_BNK_FLAG_MASK    = (PP_BNK_FLAG_PERSIST | PP_BNK_FLAG_MUSIC)
  };
  
  static void pp_bnk_parse_header(PPBnkHeader *hdr, const uint8_t *buf)
  {
      hdr->bank_id        = AV_RL32(buf +  0);
      hdr->sample_rate    = AV_RL32(buf +  4);
      hdr->always1        = AV_RL32(buf +  8);
      hdr->track_count    = AV_RL32(buf + 12);
      hdr->flags          = AV_RL32(buf + 16);
  }
  
  static void pp_bnk_parse_track(PPBnkTrack *trk, const uint8_t *buf)
  {
      trk->id             = AV_RL32(buf +  0);
      trk->size           = AV_RL32(buf +  4);
      trk->sample_rate    = AV_RL32(buf +  8);
      trk->always1_1      = AV_RL32(buf + 12);
      trk->always1_2      = AV_RL32(buf + 16);
  }
  
  static int pp_bnk_probe(const AVProbeData *p)
  {
      uint32_t sample_rate = AV_RL32(p->buf +  4);
      uint32_t track_count = AV_RL32(p->buf + 12);
      uint32_t flags       = AV_RL32(p->buf + 16);
  
      if (track_count == 0 || track_count > INT_MAX)
          return 0;
  
      if ((sample_rate !=  5512) && (sample_rate != 11025) &&
          (sample_rate != 22050) && (sample_rate != 44100))
          return 0;
  
      /* Check the first track header. */
      if (AV_RL32(p->buf + 28) != sample_rate)
          return 0;
  
      if ((flags & ~PP_BNK_FLAG_MASK) != 0)
          return 0;
  
      return AVPROBE_SCORE_MAX / 4 + 1;
  }
  
  static int pp_bnk_read_header(AVFormatContext *s)
  {
      int64_t ret;
      AVStream *st;
      AVCodecParameters *par;
      PPBnkCtx *ctx = s->priv_data;
      uint8_t buf[FFMAX(PP_BNK_FILE_HEADER_SIZE, PP_BNK_TRACK_SIZE)];
      PPBnkHeader hdr;
  
      if ((ret = avio_read(s->pb, buf, PP_BNK_FILE_HEADER_SIZE)) < 0)
          return ret;
      else if (ret != PP_BNK_FILE_HEADER_SIZE)
          return AVERROR(EIO);
  
      pp_bnk_parse_header(&hdr, buf);
  
      if (hdr.track_count == 0 || hdr.track_count > INT_MAX)
          return AVERROR_INVALIDDATA;
  
      if (hdr.sample_rate == 0 || hdr.sample_rate > INT_MAX)
          return AVERROR_INVALIDDATA;
  
      if (hdr.always1 != 1) {
          avpriv_request_sample(s, "Non-one header value");
          return AVERROR_PATCHWELCOME;
      }
  
      ctx->track_count = hdr.track_count;
  
      if (!(ctx->tracks = av_malloc_array(hdr.track_count, sizeof(PPBnkCtxTrack))))
          return AVERROR(ENOMEM);
  
      /* Parse and validate each track. */
      for (int i = 0; i < hdr.track_count; i++) {
          PPBnkTrack e;
          PPBnkCtxTrack *trk = ctx->tracks + i;
  
          ret = avio_read(s->pb, buf, PP_BNK_TRACK_SIZE);
          if (ret < 0 && ret != AVERROR_EOF)
              goto fail;
  
          /* Short byte-count or EOF, we have a truncated file. */
          if (ret != PP_BNK_TRACK_SIZE) {
              av_log(s, AV_LOG_WARNING, "File truncated at %d/%u track(s)\n",
                     i, hdr.track_count);
              ctx->track_count = i;
              break;
          }
  
          pp_bnk_parse_track(&e, buf);
  
          /* The individual sample rates of all tracks must match that of the file header. */
          if (e.sample_rate != hdr.sample_rate) {
              ret = AVERROR_INVALIDDATA;
              goto fail;
          }
  
          if (e.always1_1 != 1 || e.always1_2 != 1) {
              avpriv_request_sample(s, "Non-one track header values");
              ret = AVERROR_PATCHWELCOME;
              goto fail;
          }
  
          trk->data_offset = avio_tell(s->pb);
          trk->data_size   = e.size;
          trk->bytes_read  = 0;
  
          /*
           * Skip over the data to the next stream header.
           * Sometimes avio_skip() doesn't detect EOF. If it doesn't, either:
           *   - the avio_read() above will, or
           *   - pp_bnk_read_packet() will read a truncated last track.
           */
          if ((ret = avio_skip(s->pb, e.size)) == AVERROR_EOF) {
              ctx->track_count = i + 1;
              av_log(s, AV_LOG_WARNING,
                     "Track %d has truncated data, assuming track count == %d\n",
                     i, ctx->track_count);
              break;
          } else if (ret < 0) {
              goto fail;
          }
      }
  
      /* File is only a header. */
      if (ctx->track_count == 0) {
          ret = AVERROR_INVALIDDATA;
          goto fail;
      }
  
      /* Build the streams. */
      for (int i = 0; i < ctx->track_count; i++) {
          if (!(st = avformat_new_stream(s, NULL))) {
              ret = AVERROR(ENOMEM);
              goto fail;
          }
  
          par                         = st->codecpar;
          par->codec_type             = AVMEDIA_TYPE_AUDIO;
          par->codec_id               = AV_CODEC_ID_ADPCM_IMA_CUNNING;
          par->format                 = AV_SAMPLE_FMT_S16;
          par->channel_layout         = AV_CH_LAYOUT_MONO;
          par->channels               = 1;
          par->sample_rate            = hdr.sample_rate;
          par->bits_per_coded_sample  = 4;
          par->bits_per_raw_sample    = 16;
          par->block_align            = 1;
          par->bit_rate               = par->sample_rate * par->bits_per_coded_sample;
  
          avpriv_set_pts_info(st, 64, 1, par->sample_rate);
          st->start_time              = 0;
          st->duration                = ctx->tracks[i].data_size * 2;
      }
  
      return 0;
  
  fail:
      av_freep(&ctx->tracks);
      return ret;
  }
  
  static int pp_bnk_read_packet(AVFormatContext *s, AVPacket *pkt)
  {
      PPBnkCtx *ctx = s->priv_data;
  
      /*
       * Read a packet from each track, round-robin style.
       * This method is nasty, but needed to avoid "Too many packets buffered" errors.
       */
      for (int i = 0; i < ctx->track_count; i++, ctx->current_track++)
      {
          int64_t ret;
          int size;
          PPBnkCtxTrack *trk;
  
          ctx->current_track %= ctx->track_count;
  
          trk = ctx->tracks + ctx->current_track;
  
          if (trk->bytes_read == trk->data_size)
              continue;
  
          if ((ret = avio_seek(s->pb, trk->data_offset + trk->bytes_read, SEEK_SET)) < 0)
              return ret;
          else if (ret != trk->data_offset + trk->bytes_read)
              return AVERROR(EIO);
  
          size = FFMIN(trk->data_size - trk->bytes_read, PP_BNK_MAX_READ_SIZE);
  
          if ((ret = av_get_packet(s->pb, pkt, size)) == AVERROR_EOF) {
              /* If we've hit EOF, don't attempt this track again. */
              trk->data_size = trk->bytes_read;
              continue;
          } else if (ret < 0) {
              return ret;
          }
  
          trk->bytes_read    += ret;
          pkt->flags         &= ~AV_PKT_FLAG_CORRUPT;
          pkt->stream_index   = ctx->current_track++;
          pkt->duration       = ret * 2;
          return 0;
      }
  
      /* If we reach here, we're done. */
      return AVERROR_EOF;
  }
  
  static int pp_bnk_read_close(AVFormatContext *s)
  {
      PPBnkCtx *ctx = s->priv_data;
  
      av_freep(&ctx->tracks);
  
      return 0;
  }
  
  AVInputFormat ff_pp_bnk_demuxer = {
      .name           = "pp_bnk",
      .long_name      = NULL_IF_CONFIG_SMALL("Pro Pinball Series Soundbank"),
      .priv_data_size = sizeof(PPBnkCtx),
      .read_probe     = pp_bnk_probe,
      .read_header    = pp_bnk_read_header,
      .read_packet    = pp_bnk_read_packet,
      .read_close     = pp_bnk_read_close
  };
  