• Main Page
  • Related Pages
  • Modules
  • Data Structures
  • Files
  • Examples
  • File List
  • Globals

libavformat/rl2.c

Go to the documentation of this file.
00001 /*
00002  * RL2 Format Demuxer
00003  * Copyright (c) 2008 Sascha Sommer (saschasommer@freenet.de)
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 
00036 #include "libavutil/intreadwrite.h"
00037 #include "avformat.h"
00038 
00039 #define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr, palette
00040 
00041 #define FORM_TAG MKBETAG('F', 'O', 'R', 'M')
00042 #define RLV2_TAG MKBETAG('R', 'L', 'V', '2')
00043 #define RLV3_TAG MKBETAG('R', 'L', 'V', '3')
00044 
00045 typedef struct Rl2DemuxContext {
00046     unsigned int index_pos[2];   
00047 } Rl2DemuxContext;
00048 
00049 
00055 static int rl2_probe(AVProbeData *p)
00056 {
00057 
00058     if(AV_RB32(&p->buf[0]) != FORM_TAG)
00059         return 0;
00060 
00061     if(AV_RB32(&p->buf[8]) != RLV2_TAG &&
00062         AV_RB32(&p->buf[8]) != RLV3_TAG)
00063         return 0;
00064 
00065     return AVPROBE_SCORE_MAX;
00066 }
00067 
00074 static av_cold int rl2_read_header(AVFormatContext *s,
00075                             AVFormatParameters *ap)
00076 {
00077     AVIOContext *pb = s->pb;
00078     AVStream *st;
00079     unsigned int frame_count;
00080     unsigned int audio_frame_counter = 0;
00081     unsigned int video_frame_counter = 0;
00082     unsigned int back_size;
00083     unsigned short sound_rate;
00084     unsigned short rate;
00085     unsigned short channels;
00086     unsigned short def_sound_size;
00087     unsigned int signature;
00088     unsigned int pts_den = 11025; /* video only case */
00089     unsigned int pts_num = 1103;
00090     unsigned int* chunk_offset = NULL;
00091     int* chunk_size = NULL;
00092     int* audio_size = NULL;
00093     int i;
00094     int ret = 0;
00095 
00096     avio_skip(pb,4);          /* skip FORM tag */
00097     back_size = avio_rl32(pb); 
00098     signature = avio_rb32(pb);
00099     avio_skip(pb, 4);         /* data size */
00100     frame_count = avio_rl32(pb);
00101 
00102     /* disallow back_sizes and frame_counts that may lead to overflows later */
00103     if(back_size > INT_MAX/2  || frame_count > INT_MAX / sizeof(uint32_t))
00104         return AVERROR_INVALIDDATA;
00105 
00106     avio_skip(pb, 2);         /* encoding mentod */
00107     sound_rate = avio_rl16(pb);
00108     rate = avio_rl16(pb);
00109     channels = avio_rl16(pb);
00110     def_sound_size = avio_rl16(pb);
00111 
00113     st = av_new_stream(s, 0);
00114     if(!st)
00115          return AVERROR(ENOMEM);
00116 
00117     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00118     st->codec->codec_id = CODEC_ID_RL2;
00119     st->codec->codec_tag = 0;  /* no fourcc */
00120     st->codec->width = 320;
00121     st->codec->height = 200;
00122 
00124     st->codec->extradata_size = EXTRADATA1_SIZE;
00125 
00126     if(signature == RLV3_TAG && back_size > 0)
00127         st->codec->extradata_size += back_size;
00128 
00129     st->codec->extradata = av_mallocz(st->codec->extradata_size +
00130                                           FF_INPUT_BUFFER_PADDING_SIZE);
00131     if(!st->codec->extradata)
00132         return AVERROR(ENOMEM);
00133 
00134     if(avio_read(pb,st->codec->extradata,st->codec->extradata_size) !=
00135                       st->codec->extradata_size)
00136         return AVERROR(EIO);
00137 
00139     if(sound_rate){
00140         pts_num = def_sound_size;
00141         pts_den = rate;
00142 
00143         st = av_new_stream(s, 0);
00144         if (!st)
00145             return AVERROR(ENOMEM);
00146         st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00147         st->codec->codec_id = CODEC_ID_PCM_U8;
00148         st->codec->codec_tag = 1;
00149         st->codec->channels = channels;
00150         st->codec->bits_per_coded_sample = 8;
00151         st->codec->sample_rate = rate;
00152         st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
00153             st->codec->bits_per_coded_sample;
00154         st->codec->block_align = st->codec->channels *
00155             st->codec->bits_per_coded_sample / 8;
00156         av_set_pts_info(st,32,1,rate);
00157     }
00158 
00159     av_set_pts_info(s->streams[0], 32, pts_num, pts_den);
00160 
00161     chunk_size =   av_malloc(frame_count * sizeof(uint32_t));
00162     audio_size =   av_malloc(frame_count * sizeof(uint32_t));
00163     chunk_offset = av_malloc(frame_count * sizeof(uint32_t));
00164 
00165     if(!chunk_size || !audio_size || !chunk_offset){
00166         av_free(chunk_size);
00167         av_free(audio_size);
00168         av_free(chunk_offset);
00169         return AVERROR(ENOMEM);
00170     }
00171 
00173     for(i=0; i < frame_count;i++)
00174         chunk_size[i] = avio_rl32(pb);
00175     for(i=0; i < frame_count;i++)
00176         chunk_offset[i] = avio_rl32(pb);
00177     for(i=0; i < frame_count;i++)
00178         audio_size[i] = avio_rl32(pb) & 0xFFFF;
00179 
00181     for(i=0;i<frame_count;i++){
00182         if(chunk_size[i] < 0 || audio_size[i] > chunk_size[i]){
00183             ret = AVERROR_INVALIDDATA;
00184             break;
00185         }
00186 
00187         if(sound_rate && audio_size[i]){
00188             av_add_index_entry(s->streams[1], chunk_offset[i],
00189                 audio_frame_counter,audio_size[i], 0, AVINDEX_KEYFRAME);
00190             audio_frame_counter += audio_size[i] / channels;
00191         }
00192         av_add_index_entry(s->streams[0], chunk_offset[i] + audio_size[i],
00193             video_frame_counter,chunk_size[i]-audio_size[i],0,AVINDEX_KEYFRAME);
00194         ++video_frame_counter;
00195     }
00196 
00197 
00198     av_free(chunk_size);
00199     av_free(audio_size);
00200     av_free(chunk_offset);
00201 
00202     return ret;
00203 }
00204 
00211 static int rl2_read_packet(AVFormatContext *s,
00212                             AVPacket *pkt)
00213 {
00214     Rl2DemuxContext *rl2 = s->priv_data;
00215     AVIOContext *pb = s->pb;
00216     AVIndexEntry *sample = NULL;
00217     int i;
00218     int ret = 0;
00219     int stream_id = -1;
00220     int64_t pos = INT64_MAX;
00221 
00223     for(i=0; i<s->nb_streams; i++){
00224         if(rl2->index_pos[i] < s->streams[i]->nb_index_entries
00225               && s->streams[i]->index_entries[ rl2->index_pos[i] ].pos < pos){
00226             sample = &s->streams[i]->index_entries[ rl2->index_pos[i] ];
00227             pos= sample->pos;
00228             stream_id= i;
00229         }
00230     }
00231 
00232     if(stream_id == -1)
00233         return AVERROR(EIO);
00234 
00235     ++rl2->index_pos[stream_id];
00236 
00238     avio_seek(pb, sample->pos, SEEK_SET);
00239 
00241     ret = av_get_packet(pb, pkt, sample->size);
00242     if(ret != sample->size){
00243         av_free_packet(pkt);
00244         return AVERROR(EIO);
00245     }
00246 
00247     pkt->stream_index = stream_id;
00248     pkt->pts = sample->timestamp;
00249 
00250     return ret;
00251 }
00252 
00261 static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
00262 {
00263     AVStream *st = s->streams[stream_index];
00264     Rl2DemuxContext *rl2 = s->priv_data;
00265     int i;
00266     int index = av_index_search_timestamp(st, timestamp, flags);
00267     if(index < 0)
00268         return -1;
00269 
00270     rl2->index_pos[stream_index] = index;
00271     timestamp = st->index_entries[index].timestamp;
00272 
00273     for(i=0; i < s->nb_streams; i++){
00274         AVStream *st2 = s->streams[i];
00275         index = av_index_search_timestamp(st2,
00276                     av_rescale_q(timestamp, st->time_base, st2->time_base),
00277                     flags | AVSEEK_FLAG_BACKWARD);
00278 
00279         if(index < 0)
00280             index = 0;
00281 
00282         rl2->index_pos[i] = index;
00283     }
00284 
00285     return 0;
00286 }
00287 
00288 AVInputFormat ff_rl2_demuxer = {
00289     "rl2",
00290     NULL_IF_CONFIG_SMALL("RL2 format"),
00291     sizeof(Rl2DemuxContext),
00292     rl2_probe,
00293     rl2_read_header,
00294     rl2_read_packet,
00295     NULL,
00296     rl2_read_seek,
00297 };
00298 

Generated on Wed Apr 11 2012 07:31:34 for FFmpeg by  doxygen 1.7.1