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libavformat/rl2.c

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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     ByteIOContext *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     int data_size;
00084     unsigned short encoding_method;
00085     unsigned short sound_rate;
00086     unsigned short rate;
00087     unsigned short channels;
00088     unsigned short def_sound_size;
00089     unsigned int signature;
00090     unsigned int pts_den = 11025; /* video only case */
00091     unsigned int pts_num = 1103;
00092     unsigned int* chunk_offset = NULL;
00093     int* chunk_size = NULL;
00094     int* audio_size = NULL;
00095     int i;
00096     int ret = 0;
00097 
00098     url_fskip(pb,4);          /* skip FORM tag */
00099     back_size = get_le32(pb); 
00100     signature = get_be32(pb);
00101     data_size = get_be32(pb);
00102     frame_count = get_le32(pb);
00103 
00104     /* disallow back_sizes and frame_counts that may lead to overflows later */
00105     if(back_size > INT_MAX/2  || frame_count > INT_MAX / sizeof(uint32_t))
00106         return AVERROR_INVALIDDATA;
00107 
00108     encoding_method = get_le16(pb);
00109     sound_rate = get_le16(pb);
00110     rate = get_le16(pb);
00111     channels = get_le16(pb);
00112     def_sound_size = get_le16(pb);
00113 
00115     st = av_new_stream(s, 0);
00116     if(!st)
00117          return AVERROR(ENOMEM);
00118 
00119     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00120     st->codec->codec_id = CODEC_ID_RL2;
00121     st->codec->codec_tag = 0;  /* no fourcc */
00122     st->codec->width = 320;
00123     st->codec->height = 200;
00124 
00126     st->codec->extradata_size = EXTRADATA1_SIZE;
00127 
00128     if(signature == RLV3_TAG && back_size > 0)
00129         st->codec->extradata_size += back_size;
00130 
00131     st->codec->extradata = av_mallocz(st->codec->extradata_size +
00132                                           FF_INPUT_BUFFER_PADDING_SIZE);
00133     if(!st->codec->extradata)
00134         return AVERROR(ENOMEM);
00135 
00136     if(get_buffer(pb,st->codec->extradata,st->codec->extradata_size) !=
00137                       st->codec->extradata_size)
00138         return AVERROR(EIO);
00139 
00141     if(sound_rate){
00142         pts_num = def_sound_size;
00143         pts_den = rate;
00144 
00145         st = av_new_stream(s, 0);
00146         if (!st)
00147             return AVERROR(ENOMEM);
00148         st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00149         st->codec->codec_id = CODEC_ID_PCM_U8;
00150         st->codec->codec_tag = 1;
00151         st->codec->channels = channels;
00152         st->codec->bits_per_coded_sample = 8;
00153         st->codec->sample_rate = rate;
00154         st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
00155             st->codec->bits_per_coded_sample;
00156         st->codec->block_align = st->codec->channels *
00157             st->codec->bits_per_coded_sample / 8;
00158         av_set_pts_info(st,32,1,rate);
00159     }
00160 
00161     av_set_pts_info(s->streams[0], 32, pts_num, pts_den);
00162 
00163     chunk_size =   av_malloc(frame_count * sizeof(uint32_t));
00164     audio_size =   av_malloc(frame_count * sizeof(uint32_t));
00165     chunk_offset = av_malloc(frame_count * sizeof(uint32_t));
00166 
00167     if(!chunk_size || !audio_size || !chunk_offset){
00168         av_free(chunk_size);
00169         av_free(audio_size);
00170         av_free(chunk_offset);
00171         return AVERROR(ENOMEM);
00172     }
00173 
00175     for(i=0; i < frame_count;i++)
00176         chunk_size[i] = get_le32(pb);
00177     for(i=0; i < frame_count;i++)
00178         chunk_offset[i] = get_le32(pb);
00179     for(i=0; i < frame_count;i++)
00180         audio_size[i] = get_le32(pb) & 0xFFFF;
00181 
00183     for(i=0;i<frame_count;i++){
00184         if(chunk_size[i] < 0 || audio_size[i] > chunk_size[i]){
00185             ret = AVERROR_INVALIDDATA;
00186             break;
00187         }
00188 
00189         if(sound_rate && audio_size[i]){
00190             av_add_index_entry(s->streams[1], chunk_offset[i],
00191                 audio_frame_counter,audio_size[i], 0, AVINDEX_KEYFRAME);
00192             audio_frame_counter += audio_size[i] / channels;
00193         }
00194         av_add_index_entry(s->streams[0], chunk_offset[i] + audio_size[i],
00195             video_frame_counter,chunk_size[i]-audio_size[i],0,AVINDEX_KEYFRAME);
00196         ++video_frame_counter;
00197     }
00198 
00199 
00200     av_free(chunk_size);
00201     av_free(audio_size);
00202     av_free(chunk_offset);
00203 
00204     return ret;
00205 }
00206 
00213 static int rl2_read_packet(AVFormatContext *s,
00214                             AVPacket *pkt)
00215 {
00216     Rl2DemuxContext *rl2 = s->priv_data;
00217     ByteIOContext *pb = s->pb;
00218     AVIndexEntry *sample = NULL;
00219     int i;
00220     int ret = 0;
00221     int stream_id = -1;
00222     int64_t pos = INT64_MAX;
00223 
00225     for(i=0; i<s->nb_streams; i++){
00226         if(rl2->index_pos[i] < s->streams[i]->nb_index_entries
00227               && s->streams[i]->index_entries[ rl2->index_pos[i] ].pos < pos){
00228             sample = &s->streams[i]->index_entries[ rl2->index_pos[i] ];
00229             pos= sample->pos;
00230             stream_id= i;
00231         }
00232     }
00233 
00234     if(stream_id == -1)
00235         return AVERROR(EIO);
00236 
00237     ++rl2->index_pos[stream_id];
00238 
00240     url_fseek(pb, sample->pos, SEEK_SET);
00241 
00243     ret = av_get_packet(pb, pkt, sample->size);
00244     if(ret != sample->size){
00245         av_free_packet(pkt);
00246         return AVERROR(EIO);
00247     }
00248 
00249     pkt->stream_index = stream_id;
00250     pkt->pts = sample->timestamp;
00251 
00252     return ret;
00253 }
00254 
00263 static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
00264 {
00265     AVStream *st = s->streams[stream_index];
00266     Rl2DemuxContext *rl2 = s->priv_data;
00267     int i;
00268     int index = av_index_search_timestamp(st, timestamp, flags);
00269     if(index < 0)
00270         return -1;
00271 
00272     rl2->index_pos[stream_index] = index;
00273     timestamp = st->index_entries[index].timestamp;
00274 
00275     for(i=0; i < s->nb_streams; i++){
00276         AVStream *st2 = s->streams[i];
00277         index = av_index_search_timestamp(st2,
00278                     av_rescale_q(timestamp, st->time_base, st2->time_base),
00279                     flags | AVSEEK_FLAG_BACKWARD);
00280 
00281         if(index < 0)
00282             index = 0;
00283 
00284         rl2->index_pos[i] = index;
00285     }
00286 
00287     return 0;
00288 }
00289 
00290 AVInputFormat rl2_demuxer = {
00291     "rl2",
00292     NULL_IF_CONFIG_SMALL("RL2 format"),
00293     sizeof(Rl2DemuxContext),
00294     rl2_probe,
00295     rl2_read_header,
00296     rl2_read_packet,
00297     NULL,
00298     rl2_read_seek,
00299 };
00300 

Generated on Fri Sep 16 2011 17:17:42 for FFmpeg by  doxygen 1.7.1