/*
  * BRSTM demuxer
  * Copyright (c) 2012 Paul B Mahol
  *
  * 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/intreadwrite.h"
 #include "libavcodec/bytestream.h"
 #include "avformat.h"
 #include "internal.h"
 
 typedef struct BRSTMDemuxContext {
     uint32_t    block_size;
     uint32_t    block_count;
     uint32_t    current_block;
     uint32_t    samples_per_block;
     uint32_t    last_block_used_bytes;
     uint8_t     *table;
     uint8_t     *adpc;
 } BRSTMDemuxContext;
 
 static int probe(AVProbeData *p)
 {
     if (AV_RL32(p->buf) == MKTAG('R','S','T','M') &&
         (AV_RL16(p->buf + 4) == 0xFFFE ||
          AV_RL16(p->buf + 4) == 0xFEFF))
         return AVPROBE_SCORE_MAX / 3 * 2;
     return 0;
 }
 
 static int read_close(AVFormatContext *s)
 {
     BRSTMDemuxContext *b = s->priv_data;
 
     av_freep(&b->table);
     av_freep(&b->adpc);
 
     return 0;
 }
 
 static int read_header(AVFormatContext *s)
 {
     BRSTMDemuxContext *b = s->priv_data;
     int bom, major, minor, codec, chunk;
     int64_t pos, h1offset, toffset;
     uint32_t size, start, asize;
     AVStream *st;
     int ret = AVERROR_EOF;
 
     st = avformat_new_stream(s, NULL);
     if (!st)
         return AVERROR(ENOMEM);
     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
 
     avio_skip(s->pb, 4);
 
     bom = avio_rb16(s->pb);
     if (bom != 0xFEFF && bom != 0xFFFE) {
         av_log(s, AV_LOG_ERROR, "invalid byte order: %X\n", bom);
         return AVERROR_INVALIDDATA;
     }
     if (bom == 0xFFFE) {

         avpriv_request_sample(s, "little endian byte order");

         return AVERROR_PATCHWELCOME;
     }
 
     major = avio_r8(s->pb);
     minor = avio_r8(s->pb);
     avio_skip(s->pb, 4); // size of file
     size = avio_rb16(s->pb);
     if (size < 14)
         return AVERROR_INVALIDDATA;
 
     avio_skip(s->pb, size - 14);
     pos = avio_tell(s->pb);
     if (avio_rl32(s->pb) != MKTAG('H','E','A','D'))
         return AVERROR_INVALIDDATA;
     size = avio_rb32(s->pb);
     if (size < 256)
         return AVERROR_INVALIDDATA;
     avio_skip(s->pb, 4); // unknown
     h1offset = avio_rb32(s->pb);
     if (h1offset > size)
         return AVERROR_INVALIDDATA;
     avio_skip(s->pb, 12);
     toffset = avio_rb32(s->pb) + 16LL;
     if (toffset > size)
         return AVERROR_INVALIDDATA;
 
     avio_skip(s->pb, pos + h1offset + 8 - avio_tell(s->pb));
     codec = avio_r8(s->pb);
 
     switch (codec) {
     case 0: codec = AV_CODEC_ID_PCM_S8_PLANAR;    break;
     case 1: codec = AV_CODEC_ID_PCM_S16BE_PLANAR; break;
     case 2: codec = AV_CODEC_ID_ADPCM_THP;        break;
     default:

         avpriv_request_sample(s, "codec %d", codec);

         return AVERROR_PATCHWELCOME;
     }
 
     avio_skip(s->pb, 1); // loop flag
     st->codec->codec_id = codec;
     st->codec->channels = avio_r8(s->pb);
     if (!st->codec->channels)
         return AVERROR_INVALIDDATA;
 
     avio_skip(s->pb, 1); // padding
     st->codec->sample_rate = avio_rb16(s->pb);
     if (!st->codec->sample_rate)
         return AVERROR_INVALIDDATA;
 
     avio_skip(s->pb, 2); // padding
     avio_skip(s->pb, 4); // loop start sample
     st->start_time = 0;
     st->duration = avio_rb32(s->pb);
     avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
 
     start = avio_rb32(s->pb);
     b->current_block = 0;
     b->block_count = avio_rb32(s->pb);
     if (b->block_count > UINT16_MAX) {
         av_log(s, AV_LOG_WARNING, "too many blocks: %u\n", b->block_count);
         return AVERROR_INVALIDDATA;
     }
 
     b->block_size = avio_rb32(s->pb);
     if (b->block_size > UINT16_MAX / st->codec->channels)
         return AVERROR_INVALIDDATA;
     b->block_size *= st->codec->channels;
 
     b->samples_per_block = avio_rb32(s->pb);
     b->last_block_used_bytes = avio_rb32(s->pb);
     if (b->last_block_used_bytes > UINT16_MAX / st->codec->channels)
         return AVERROR_INVALIDDATA;
     b->last_block_used_bytes *= st->codec->channels;
 
     avio_skip(s->pb, 4); // last block samples
     avio_skip(s->pb, 4); // last block size
 
     if (codec == AV_CODEC_ID_ADPCM_THP) {
         int ch;
 
         avio_skip(s->pb, pos + toffset - avio_tell(s->pb));
         toffset = avio_rb32(s->pb) + 16LL;
         if (toffset > size)
             return AVERROR_INVALIDDATA;
 
         avio_skip(s->pb, pos + toffset - avio_tell(s->pb));
         b->table = av_mallocz(32 * st->codec->channels);
         if (!b->table)
             return AVERROR(ENOMEM);
 
         for (ch = 0; ch < st->codec->channels; ch++) {
             if (avio_read(s->pb, b->table + ch * 32, 32) != 32) {
                 ret = AVERROR_INVALIDDATA;
                 goto fail;
             }
             avio_skip(s->pb, 24);
         }
     }
 
     if (size < (avio_tell(s->pb) - pos)) {
         ret = AVERROR_INVALIDDATA;
         goto fail;
     }
     avio_skip(s->pb, size - (avio_tell(s->pb) - pos));
 

     while (!avio_feof(s->pb)) {

         chunk = avio_rl32(s->pb);
         size  = avio_rb32(s->pb);
         if (size < 8) {
             ret = AVERROR_INVALIDDATA;
             goto fail;
         }
         size -= 8;
         switch (chunk) {
         case MKTAG('A','D','P','C'):
             if (codec != AV_CODEC_ID_ADPCM_THP)
                 goto skip;
 
             asize = b->block_count * st->codec->channels * 4;
             if (size < asize) {
                 ret = AVERROR_INVALIDDATA;
                 goto fail;
             }
             if (b->adpc) {

                 av_log(s, AV_LOG_WARNING, "skipping additional ADPC chunk\n");

                 goto skip;
             } else {
                 b->adpc = av_mallocz(asize);
                 if (!b->adpc) {
                     ret = AVERROR(ENOMEM);
                     goto fail;
                 }
                 avio_read(s->pb, b->adpc, asize);
                 avio_skip(s->pb, size - asize);
             }
             break;
         case MKTAG('D','A','T','A'):
             if ((start < avio_tell(s->pb)) ||
                 (!b->adpc && codec == AV_CODEC_ID_ADPCM_THP)) {
                 ret = AVERROR_INVALIDDATA;
                 goto fail;
             }
             avio_skip(s->pb, start - avio_tell(s->pb));

             if (major != 1 || minor)
                 avpriv_request_sample(s, "Version %d.%d", major, minor);

             return 0;
         default:
             av_log(s, AV_LOG_WARNING, "skipping unknown chunk: %X\n", chunk);
 skip:
             avio_skip(s->pb, size);
         }
     }
 
 fail:
     read_close(s);
 
     return ret;
 }
 
 static int read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     AVCodecContext *codec = s->streams[0]->codec;
     BRSTMDemuxContext *b = s->priv_data;
     uint32_t samples, size;
     int ret;
 

     if (avio_feof(s->pb))

         return AVERROR_EOF;
     b->current_block++;
     if (b->current_block == b->block_count) {
         size    = b->last_block_used_bytes;

         samples = size / (8 * codec->channels) * 14;

     } else if (b->current_block < b->block_count) {
         size    = b->block_size;
         samples = b->samples_per_block;
     } else {
         return AVERROR_EOF;
     }
 
     if (codec->codec_id == AV_CODEC_ID_ADPCM_THP) {
         uint8_t *dst;
 
         if (av_new_packet(pkt, 8 + (32 + 4) * codec->channels + size) < 0)
             return AVERROR(ENOMEM);
         dst = pkt->data;
         bytestream_put_be32(&dst, size);
         bytestream_put_be32(&dst, samples);
         bytestream_put_buffer(&dst, b->table, 32 * codec->channels);
         bytestream_put_buffer(&dst, b->adpc + 4 * codec->channels *
                                     (b->current_block - 1), 4 * codec->channels);
 
         ret = avio_read(s->pb, dst, size);

         if (ret != size)

             av_free_packet(pkt);
         pkt->duration = samples;
     } else {
         ret = av_get_packet(s->pb, pkt, size);
     }
 
     pkt->stream_index = 0;
 

     if (ret != size)
         ret = AVERROR(EIO);
 

     return ret;
 }
 
 AVInputFormat ff_brstm_demuxer = {
     .name           = "brstm",
     .long_name      = NULL_IF_CONFIG_SMALL("BRSTM (Binary Revolution Stream)"),
     .priv_data_size = sizeof(BRSTMDemuxContext),
     .read_probe     = probe,
     .read_header    = read_header,
     .read_packet    = read_packet,
     .read_close     = read_close,
     .extensions     = "brstm",
 };