libavformat/bfi.c

   1 /*
   2  * Brute Force & Ignorance (BFI) demuxer
   3  * Copyright (c) 2008 Sisir Koppaka
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file
  24  * @brief Brute Force & Ignorance (.bfi) file demuxer
  25  * @author Sisir Koppaka ( sisir.koppaka at gmail dot com )
  26  * @see http://wiki.multimedia.cx/index.php?title=BFI
  27  */
  28
  29 #include "libavutil/channel_layout.h"
  30 #include "libavutil/intreadwrite.h"
  31 #include "avformat.h"
  32 #include "demux.h"
  33 #include "internal.h"
  34
  35 typedef struct BFIContext {
  36     int nframes;
  37     int audio_frame;
  38     int video_frame;
  39     int video_size;
  40     int avflag;
  41 } BFIContext;
  42
  43 static int bfi_probe(const AVProbeData * p)
  44 {
  45     /* Check file header */
  46     if (AV_RL32(p->buf) == MKTAG('B', 'F', '&', 'I'))
  47         return AVPROBE_SCORE_MAX;
  48     else
  49         return 0;
  50 }
  51
  52 static int bfi_read_header(AVFormatContext * s)
  53 {
  54     BFIContext *bfi = s->priv_data;
  55     AVIOContext *pb = s->pb;
  56     AVStream *vstream;
  57     AVStream *astream;
  58     int ret, fps, chunk_header;
  59
  60     /* Initialize the video codec... */
  61     vstream = avformat_new_stream(s, NULL);
  62     if (!vstream)
  63         return AVERROR(ENOMEM);
  64
  65     /* Initialize the audio codec... */
  66     astream = avformat_new_stream(s, NULL);
  67     if (!astream)
  68         return AVERROR(ENOMEM);
  69
  70     /* Set the total number of frames. */
  71     avio_skip(pb, 8);
  72     chunk_header           = avio_rl32(pb);
  73     if (chunk_header < 3)
  74         return AVERROR_INVALIDDATA;
  75
  76     bfi->nframes           = avio_rl32(pb);
  77     if (bfi->nframes < 0)
  78         return AVERROR_INVALIDDATA;
  79     avio_rl32(pb);
  80     avio_rl32(pb);
  81     avio_rl32(pb);
  82     fps                    = avio_rl32(pb);
  83     avio_skip(pb, 12);
  84     vstream->codecpar->width  = avio_rl32(pb);
  85     vstream->codecpar->height = avio_rl32(pb);
  86
  87     /*Load the palette to extradata */
  88     avio_skip(pb, 8);
  89     ret = ff_get_extradata(s, vstream->codecpar, pb, 768);
  90     if (ret < 0)
  91         return ret;
  92
  93     astream->codecpar->sample_rate = avio_rl32(pb);
  94     if (astream->codecpar->sample_rate <= 0) {
  95         av_log(s, AV_LOG_ERROR, "Invalid sample rate %d\n", astream->codecpar->sample_rate);
  96         return AVERROR_INVALIDDATA;
  97     }
  98
  99     /* Set up the video codec... */
 100     avpriv_set_pts_info(vstream, 32, 1, fps);
 101     vstream->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
 102     vstream->codecpar->codec_id   = AV_CODEC_ID_BFI;
 103     vstream->codecpar->format     = AV_PIX_FMT_PAL8;
 104     vstream->nb_frames            =
 105     vstream->duration             = bfi->nframes;
 106
 107     /* Set up the audio codec now... */
 108     astream->codecpar->codec_type      = AVMEDIA_TYPE_AUDIO;
 109     astream->codecpar->codec_id        = AV_CODEC_ID_PCM_U8;
 110     astream->codecpar->ch_layout       = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
 111     astream->codecpar->bits_per_coded_sample = 8;
 112     astream->codecpar->bit_rate        =
 113         (int64_t)astream->codecpar->sample_rate * astream->codecpar->bits_per_coded_sample;
 114     avio_seek(pb, chunk_header - 3, SEEK_SET);
 115     avpriv_set_pts_info(astream, 64, 1, astream->codecpar->sample_rate);
 116     return 0;
 117 }
 118
 119
 120 static int bfi_read_packet(AVFormatContext * s, AVPacket * pkt)
 121 {
 122     BFIContext *bfi = s->priv_data;
 123     AVIOContext *pb = s->pb;
 124     int ret, audio_offset, video_offset, chunk_size, audio_size = 0;
 125     if (bfi->nframes == 0 || avio_feof(pb)) {
 126         return AVERROR_EOF;
 127     }
 128
 129     /* If all previous chunks were completely read, then find a new one... */
 130     if (!bfi->avflag) {
 131         uint32_t state = 0;
 132         while(state != MKTAG('S','A','V','I')){
 133             if (avio_feof(pb))
 134                 return AVERROR_INVALIDDATA;
 135             state = 256*state + avio_r8(pb);
 136         }
 137         /* Now that the chunk's location is confirmed, we proceed... */
 138         chunk_size      = avio_rl32(pb);
 139         avio_rl32(pb);
 140         audio_offset    = avio_rl32(pb);
 141         avio_rl32(pb);
 142         video_offset    = avio_rl32(pb);
 143         if (audio_offset < 0 || video_offset < audio_offset || chunk_size < video_offset) {
 144             av_log(s, AV_LOG_ERROR, "Invalid audio/video offsets or chunk size\n");
 145             return AVERROR_INVALIDDATA;
 146         }
 147         audio_size      = video_offset - audio_offset;
 148         bfi->video_size = chunk_size - video_offset;
 149
 150         //Tossing an audio packet at the audio decoder.
 151         ret = av_get_packet(pb, pkt, audio_size);
 152         if (ret < 0)
 153             return ret;
 154
 155         pkt->pts          = bfi->audio_frame;
 156         bfi->audio_frame += ret;
 157     } else if (bfi->video_size > 0) {
 158
 159         //Tossing a video packet at the video decoder.
 160         ret = av_get_packet(pb, pkt, bfi->video_size);
 161         if (ret < 0)
 162             return ret;
 163
 164         pkt->pts          = bfi->video_frame;
 165         bfi->video_frame += ret / bfi->video_size;
 166
 167         /* One less frame to read. A cursory decrement. */
 168         bfi->nframes--;
 169     } else {
 170         /* Empty video packet */
 171         ret = AVERROR(EAGAIN);
 172     }
 173
 174     bfi->avflag       = !bfi->avflag;
 175     pkt->stream_index = bfi->avflag;
 176     return ret;
 177 }
 178
 179 const FFInputFormat ff_bfi_demuxer = {
 180     .p.name         = "bfi",
 181     .p.long_name    = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
 182     .priv_data_size = sizeof(BFIContext),
 183     .read_probe     = bfi_probe,
 184     .read_header    = bfi_read_header,
 185     .read_packet    = bfi_read_packet,
 186 };