libavformat/jvdec.c
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00001 /*
00002  * Bitmap Brothers JV demuxer
00003  * Copyright (c) 2005, 2011 Peter Ross <pross@xvid.org>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00028 #include "libavutil/intreadwrite.h"
00029 #include "avformat.h"
00030 #include "internal.h"
00031 
00032 #define JV_PREAMBLE_SIZE 5
00033 
00034 typedef struct {
00035     int audio_size;    
00036     int video_size;    
00037     int palette_size;  
00038     int video_type;    
00039 } JVFrame;
00040 
00041 typedef struct {
00042     JVFrame *frames;
00043     enum {
00044         JV_AUDIO = 0,
00045         JV_VIDEO,
00046         JV_PADDING
00047     } state;
00048     int64_t pts;
00049 } JVDemuxContext;
00050 
00051 #define MAGIC " Compression by John M Phillips Copyright (C) 1995 The Bitmap Brothers Ltd."
00052 
00053 static int read_probe(AVProbeData *pd)
00054 {
00055     if (pd->buf[0] == 'J' && pd->buf[1] == 'V' &&
00056         !memcmp(pd->buf + 4, MAGIC, FFMIN(strlen(MAGIC), pd->buf_size - 4)))
00057         return AVPROBE_SCORE_MAX;
00058     return 0;
00059 }
00060 
00061 static int read_header(AVFormatContext *s,
00062                        AVFormatParameters *ap)
00063 {
00064     JVDemuxContext *jv = s->priv_data;
00065     AVIOContext *pb = s->pb;
00066     AVStream *vst, *ast;
00067     int64_t audio_pts = 0;
00068     int64_t offset;
00069     int i;
00070 
00071     avio_skip(pb, 80);
00072 
00073     ast = avformat_new_stream(s, NULL);
00074     vst = avformat_new_stream(s, NULL);
00075     if (!ast || !vst)
00076         return AVERROR(ENOMEM);
00077 
00078     vst->codec->codec_type  = AVMEDIA_TYPE_VIDEO;
00079     vst->codec->codec_id    = CODEC_ID_JV;
00080     vst->codec->codec_tag   = 0; /* no fourcc */
00081     vst->codec->width       = avio_rl16(pb);
00082     vst->codec->height      = avio_rl16(pb);
00083     vst->nb_frames          =
00084     ast->nb_index_entries   = avio_rl16(pb);
00085     avpriv_set_pts_info(vst, 64, avio_rl16(pb), 1000);
00086 
00087     avio_skip(pb, 4);
00088 
00089     ast->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
00090     ast->codec->codec_id    = CODEC_ID_PCM_U8;
00091     ast->codec->codec_tag   = 0; /* no fourcc */
00092     ast->codec->sample_rate = avio_rl16(pb);
00093     ast->codec->channels    = 1;
00094     avpriv_set_pts_info(ast, 64, 1, ast->codec->sample_rate);
00095 
00096     avio_skip(pb, 10);
00097 
00098     ast->index_entries = av_malloc(ast->nb_index_entries * sizeof(*ast->index_entries));
00099     if (!ast->index_entries)
00100         return AVERROR(ENOMEM);
00101 
00102     jv->frames = av_malloc(ast->nb_index_entries * sizeof(JVFrame));
00103     if (!jv->frames)
00104         return AVERROR(ENOMEM);
00105 
00106     offset = 0x68 + ast->nb_index_entries * 16;
00107     for(i = 0; i < ast->nb_index_entries; i++) {
00108         AVIndexEntry *e   = ast->index_entries + i;
00109         JVFrame      *jvf = jv->frames + i;
00110 
00111         /* total frame size including audio, video, palette data and padding */
00112         e->size         = avio_rl32(pb);
00113         e->timestamp    = i;
00114         e->pos          = offset;
00115         offset         += e->size;
00116 
00117         jvf->audio_size = avio_rl32(pb);
00118         jvf->video_size = avio_rl32(pb);
00119         jvf->palette_size = avio_r8(pb) ? 768 : 0;
00120         jvf->video_size = FFMIN(FFMAX(jvf->video_size, 0),
00121                                 INT_MAX - JV_PREAMBLE_SIZE - jvf->palette_size);
00122         if (avio_r8(pb))
00123              av_log(s, AV_LOG_WARNING, "unsupported audio codec\n");
00124         jvf->video_type = avio_r8(pb);
00125         avio_skip(pb, 1);
00126 
00127         e->timestamp = jvf->audio_size ? audio_pts : AV_NOPTS_VALUE;
00128         audio_pts += jvf->audio_size;
00129 
00130         e->flags = jvf->video_type != 1 ? AVINDEX_KEYFRAME : 0;
00131     }
00132 
00133     jv->state = JV_AUDIO;
00134     return 0;
00135 }
00136 
00137 static int read_packet(AVFormatContext *s, AVPacket *pkt)
00138 {
00139     JVDemuxContext *jv = s->priv_data;
00140     AVIOContext *pb = s->pb;
00141     AVStream *ast = s->streams[0];
00142 
00143     while (!url_feof(s->pb) && jv->pts < ast->nb_index_entries) {
00144         const AVIndexEntry *e   = ast->index_entries + jv->pts;
00145         const JVFrame      *jvf = jv->frames + jv->pts;
00146 
00147         switch(jv->state) {
00148         case JV_AUDIO:
00149             jv->state++;
00150             if (jvf->audio_size ) {
00151                 if (av_get_packet(s->pb, pkt, jvf->audio_size) < 0)
00152                     return AVERROR(ENOMEM);
00153                 pkt->stream_index = 0;
00154                 pkt->pts          = e->timestamp;
00155                 pkt->flags       |= AV_PKT_FLAG_KEY;
00156                 return 0;
00157             }
00158         case JV_VIDEO:
00159             jv->state++;
00160             if (jvf->video_size || jvf->palette_size) {
00161                 int size = jvf->video_size + jvf->palette_size;
00162                 if (av_new_packet(pkt, size + JV_PREAMBLE_SIZE))
00163                     return AVERROR(ENOMEM);
00164 
00165                 AV_WL32(pkt->data, jvf->video_size);
00166                 pkt->data[4]      = jvf->video_type;
00167                 if (avio_read(pb, pkt->data + JV_PREAMBLE_SIZE, size) < 0)
00168                     return AVERROR(EIO);
00169 
00170                 pkt->size         = size + JV_PREAMBLE_SIZE;
00171                 pkt->stream_index = 1;
00172                 pkt->pts          = jv->pts;
00173                 if (jvf->video_type != 1)
00174                     pkt->flags |= AV_PKT_FLAG_KEY;
00175                 return 0;
00176             }
00177         case JV_PADDING:
00178             avio_skip(pb, FFMAX(e->size - jvf->audio_size - jvf->video_size
00179                                         - jvf->palette_size, 0));
00180             jv->state = JV_AUDIO;
00181             jv->pts++;
00182         }
00183     }
00184 
00185     return AVERROR(EIO);
00186 }
00187 
00188 static int read_seek(AVFormatContext *s, int stream_index,
00189                      int64_t ts, int flags)
00190 {
00191     JVDemuxContext *jv = s->priv_data;
00192     AVStream *ast = s->streams[0];
00193     int i;
00194 
00195     if (flags & (AVSEEK_FLAG_BYTE|AVSEEK_FLAG_FRAME))
00196         return AVERROR(ENOSYS);
00197 
00198     switch(stream_index) {
00199     case 0:
00200         i = av_index_search_timestamp(ast, ts, flags);
00201         break;
00202     case 1:
00203         i = ts;
00204         break;
00205     default:
00206         return 0;
00207     }
00208 
00209     if (i < 0 || i >= ast->nb_index_entries)
00210         return 0;
00211     if (avio_seek(s->pb, ast->index_entries[i].pos, SEEK_SET) < 0)
00212         return -1;
00213 
00214     jv->state = JV_AUDIO;
00215     jv->pts   = i;
00216     return 0;
00217 }
00218 
00219 AVInputFormat ff_jv_demuxer = {
00220     .name           = "jv",
00221     .long_name      = NULL_IF_CONFIG_SMALL("Bitmap Brothers JV"),
00222     .priv_data_size = sizeof(JVDemuxContext),
00223     .read_probe     = read_probe,
00224     .read_header    = read_header,
00225     .read_packet    = read_packet,
00226     .read_seek      = read_seek,
00227 };