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 libavformat/bfi.c 24 * @brief Brute Force & Ignorance (.bfi) file demuxer 25 * @author Sisir Koppaka ( sisir.koppaka at gmail dot com ) 26 * @sa http://wiki.multimedia.cx/index.php?title=BFI 27 */ 28 29#include "libavutil/intreadwrite.h" 30#include "avformat.h" 31 32typedef struct BFIContext { 33 int nframes; 34 int audio_frame; 35 int video_frame; 36 int video_size; 37 int avflag; 38} BFIContext; 39 40static int bfi_probe(AVProbeData * p) 41{ 42 /* Check file header */ 43 if (AV_RL32(p->buf) == MKTAG('B', 'F', '&', 'I')) 44 return AVPROBE_SCORE_MAX; 45 else 46 return 0; 47} 48 49static int bfi_read_header(AVFormatContext * s, AVFormatParameters * ap) 50{ 51 BFIContext *bfi = s->priv_data; 52 ByteIOContext *pb = s->pb; 53 AVStream *vstream; 54 AVStream *astream; 55 int fps, chunk_header; 56 57 /* Initialize the video codec... */ 58 vstream = av_new_stream(s, 0); 59 if (!vstream) 60 return AVERROR(ENOMEM); 61 62 /* Initialize the audio codec... */ 63 astream = av_new_stream(s, 0); 64 if (!astream) 65 return AVERROR(ENOMEM); 66 67 /* Set the total number of frames. */ 68 url_fskip(pb, 8); 69 chunk_header = get_le32(pb); 70 bfi->nframes = get_le32(pb); 71 get_le32(pb); 72 get_le32(pb); 73 get_le32(pb); 74 fps = get_le32(pb); 75 url_fskip(pb, 12); 76 vstream->codec->width = get_le32(pb); 77 vstream->codec->height = get_le32(pb); 78 79 /*Load the palette to extradata */ 80 url_fskip(pb, 8); 81 vstream->codec->extradata = av_malloc(768); 82 vstream->codec->extradata_size = 768; 83 get_buffer(pb, vstream->codec->extradata, 84 vstream->codec->extradata_size); 85 86 astream->codec->sample_rate = get_le32(pb); 87 88 /* Set up the video codec... */ 89 av_set_pts_info(vstream, 32, 1, fps); 90 vstream->codec->codec_type = CODEC_TYPE_VIDEO; 91 vstream->codec->codec_id = CODEC_ID_BFI; 92 vstream->codec->pix_fmt = PIX_FMT_PAL8; 93 94 /* Set up the audio codec now... */ 95 astream->codec->codec_type = CODEC_TYPE_AUDIO; 96 astream->codec->codec_id = CODEC_ID_PCM_U8; 97 astream->codec->channels = 1; 98 astream->codec->bits_per_coded_sample = 8; 99 astream->codec->bit_rate = 100 astream->codec->sample_rate * astream->codec->bits_per_coded_sample; 101 url_fseek(pb, chunk_header - 3, SEEK_SET); 102 av_set_pts_info(astream, 64, 1, astream->codec->sample_rate); 103 return 0; 104} 105 106 107static int bfi_read_packet(AVFormatContext * s, AVPacket * pkt) 108{ 109 BFIContext *bfi = s->priv_data; 110 ByteIOContext *pb = s->pb; 111 int ret, audio_offset, video_offset, chunk_size, audio_size = 0; 112 if (bfi->nframes == 0 || url_feof(pb)) { 113 return AVERROR(EIO); 114 } 115 116 /* If all previous chunks were completely read, then find a new one... */ 117 if (!bfi->avflag) { 118 uint32_t state = 0; 119 while(state != MKTAG('S','A','V','I')){ 120 if (url_feof(pb)) 121 return AVERROR(EIO); 122 state = 256*state + get_byte(pb); 123 } 124 /* Now that the chunk's location is confirmed, we proceed... */ 125 chunk_size = get_le32(pb); 126 get_le32(pb); 127 audio_offset = get_le32(pb); 128 get_le32(pb); 129 video_offset = get_le32(pb); 130 audio_size = video_offset - audio_offset; 131 bfi->video_size = chunk_size - video_offset; 132 133 //Tossing an audio packet at the audio decoder. 134 ret = av_get_packet(pb, pkt, audio_size); 135 if (ret < 0) 136 return ret; 137 138 pkt->pts = bfi->audio_frame; 139 bfi->audio_frame += ret; 140 } 141 142 else { 143 144 //Tossing a video packet at the video decoder. 145 ret = av_get_packet(pb, pkt, bfi->video_size); 146 if (ret < 0) 147 return ret; 148 149 pkt->pts = bfi->video_frame; 150 bfi->video_frame += ret / bfi->video_size; 151 152 /* One less frame to read. A cursory decrement. */ 153 bfi->nframes--; 154 } 155 156 bfi->avflag = !bfi->avflag; 157 pkt->stream_index = bfi->avflag; 158 return ret; 159} 160 161AVInputFormat bfi_demuxer = { 162 "bfi", 163 NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"), 164 sizeof(BFIContext), 165 bfi_probe, 166 bfi_read_header, 167 bfi_read_packet, 168}; 169