/*
  * Brute Force & Ignorance (BFI) demuxer
  * Copyright (c) 2008 Sisir Koppaka
  *
  * 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

  * @brief Brute Force & Ignorance (.bfi) file demuxer
  * @author Sisir Koppaka ( sisir.koppaka at gmail dot com )

  * @see http://wiki.multimedia.cx/index.php?title=BFI

  */
 

 #include "libavutil/channel_layout.h"

 #include "libavutil/intreadwrite.h"

 #include "avformat.h"

 #include "internal.h"

 
 typedef struct BFIContext {
     int nframes;
     int audio_frame;
     int video_frame;
     int video_size;
     int avflag;
 } BFIContext;
 
 static int bfi_probe(AVProbeData * p)
 {
     /* Check file header */
     if (AV_RL32(p->buf) == MKTAG('B', 'F', '&', 'I'))
         return AVPROBE_SCORE_MAX;
     else
         return 0;
 }
 

 static int bfi_read_header(AVFormatContext * s)

 {
     BFIContext *bfi = s->priv_data;

     AVIOContext *pb = s->pb;

     AVStream *vstream;
     AVStream *astream;
     int fps, chunk_header;
 
     /* Initialize the video codec... */

     vstream = avformat_new_stream(s, NULL);

     if (!vstream)
         return AVERROR(ENOMEM);
 
     /* Initialize the audio codec... */

     astream = avformat_new_stream(s, NULL);

     if (!astream)
         return AVERROR(ENOMEM);
 
     /* Set the total number of frames. */

     avio_skip(pb, 8);

     chunk_header           = avio_rl32(pb);
     bfi->nframes           = avio_rl32(pb);
     avio_rl32(pb);
     avio_rl32(pb);
     avio_rl32(pb);
     fps                    = avio_rl32(pb);

     avio_skip(pb, 12);

     vstream->codec->width  = avio_rl32(pb);
     vstream->codec->height = avio_rl32(pb);

 
     /*Load the palette to extradata */

     avio_skip(pb, 8);

     vstream->codec->extradata      = av_malloc(768);

     if (!vstream->codec->extradata)
         return AVERROR(ENOMEM);

     vstream->codec->extradata_size = 768;

     avio_read(pb, vstream->codec->extradata,

                vstream->codec->extradata_size);
 

     astream->codec->sample_rate = avio_rl32(pb);

 
     /* Set up the video codec... */

     avpriv_set_pts_info(vstream, 32, 1, fps);

     vstream->codec->codec_type = AVMEDIA_TYPE_VIDEO;

     vstream->codec->codec_id   = AV_CODEC_ID_BFI;

     vstream->codec->pix_fmt    = AV_PIX_FMT_PAL8;

     vstream->nb_frames         =
     vstream->duration          = bfi->nframes;

 
     /* Set up the audio codec now... */

     astream->codec->codec_type      = AVMEDIA_TYPE_AUDIO;

     astream->codec->codec_id        = AV_CODEC_ID_PCM_U8;

     astream->codec->channels        = 1;

     astream->codec->channel_layout  = AV_CH_LAYOUT_MONO;

     astream->codec->bits_per_coded_sample = 8;

     astream->codec->bit_rate        =

         astream->codec->sample_rate * astream->codec->bits_per_coded_sample;

     avio_seek(pb, chunk_header - 3, SEEK_SET);

     avpriv_set_pts_info(astream, 64, 1, astream->codec->sample_rate);

     return 0;
 }
 
 
 static int bfi_read_packet(AVFormatContext * s, AVPacket * pkt)
 {
     BFIContext *bfi = s->priv_data;

     AVIOContext *pb = s->pb;

     int ret, audio_offset, video_offset, chunk_size, audio_size = 0;
     if (bfi->nframes == 0 || url_feof(pb)) {

         return AVERROR_EOF;

     }
 
     /* If all previous chunks were completely read, then find a new one... */
     if (!bfi->avflag) {
         uint32_t state = 0;
         while(state != MKTAG('S','A','V','I')){
             if (url_feof(pb))
                 return AVERROR(EIO);

             state = 256*state + avio_r8(pb);

         }
         /* Now that the chunk's location is confirmed, we proceed... */

         chunk_size      = avio_rl32(pb);
         avio_rl32(pb);
         audio_offset    = avio_rl32(pb);
         avio_rl32(pb);
         video_offset    = avio_rl32(pb);

         audio_size      = video_offset - audio_offset;
         bfi->video_size = chunk_size - video_offset;

         if (audio_size < 0 || bfi->video_size < 0) {
             av_log(s, AV_LOG_ERROR, "Invalid audio/video offsets or chunk size\n");
             return AVERROR_INVALIDDATA;
         }

 
         //Tossing an audio packet at the audio decoder.
         ret = av_get_packet(pb, pkt, audio_size);
         if (ret < 0)
             return ret;
 
         pkt->pts          = bfi->audio_frame;
         bfi->audio_frame += ret;

     } else if (bfi->video_size > 0) {

 
         //Tossing a video packet at the video decoder.
         ret = av_get_packet(pb, pkt, bfi->video_size);
         if (ret < 0)
             return ret;
 
         pkt->pts          = bfi->video_frame;
         bfi->video_frame += ret / bfi->video_size;
 
         /* One less frame to read. A cursory decrement. */
         bfi->nframes--;

     } else {
         /* Empty video packet */
         ret = AVERROR(EAGAIN);

     }
 
     bfi->avflag       = !bfi->avflag;
     pkt->stream_index = bfi->avflag;
     return ret;
 }
 

 AVInputFormat ff_bfi_demuxer = {

     .name           = "bfi",
     .long_name      = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
     .priv_data_size = sizeof(BFIContext),
     .read_probe     = bfi_probe,
     .read_header    = bfi_read_header,
     .read_packet    = bfi_read_packet,

 };