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 Libav.
00006  *
00007  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00035 #include "libavutil/intreadwrite.h"
00036 #include "libavutil/mathematics.h"
00037 #include "avformat.h"
00038 #include "internal.h"
00039 
00040 #define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr, palette
00041 
00042 #define FORM_TAG MKBETAG('F', 'O', 'R', 'M')
00043 #define RLV2_TAG MKBETAG('R', 'L', 'V', '2')
00044 #define RLV3_TAG MKBETAG('R', 'L', 'V', '3')
00045 
00046 typedef struct Rl2DemuxContext {
00047     unsigned int index_pos[2];   
00048 } Rl2DemuxContext;
00049 
00050 
00056 static int rl2_probe(AVProbeData *p)
00057 {
00058 
00059     if(AV_RB32(&p->buf[0]) != FORM_TAG)
00060         return 0;
00061 
00062     if(AV_RB32(&p->buf[8]) != RLV2_TAG &&
00063         AV_RB32(&p->buf[8]) != RLV3_TAG)
00064         return 0;
00065 
00066     return AVPROBE_SCORE_MAX;
00067 }
00068 
00075 static av_cold int rl2_read_header(AVFormatContext *s,
00076                             AVFormatParameters *ap)
00077 {
00078     AVIOContext *pb = s->pb;
00079     AVStream *st;
00080     unsigned int frame_count;
00081     unsigned int audio_frame_counter = 0;
00082     unsigned int video_frame_counter = 0;
00083     unsigned int back_size;
00084     unsigned short sound_rate;
00085     unsigned short rate;
00086     unsigned short channels;
00087     unsigned short def_sound_size;
00088     unsigned int signature;
00089     unsigned int pts_den = 11025; /* video only case */
00090     unsigned int pts_num = 1103;
00091     unsigned int* chunk_offset = NULL;
00092     int* chunk_size = NULL;
00093     int* audio_size = NULL;
00094     int i;
00095     int ret = 0;
00096 
00097     avio_skip(pb,4);          /* skip FORM tag */
00098     back_size = avio_rl32(pb); 
00099     signature = avio_rb32(pb);
00100     avio_skip(pb, 4);         /* data size */
00101     frame_count = avio_rl32(pb);
00102 
00103     /* disallow back_sizes and frame_counts that may lead to overflows later */
00104     if(back_size > INT_MAX/2  || frame_count > INT_MAX / sizeof(uint32_t))
00105         return AVERROR_INVALIDDATA;
00106 
00107     avio_skip(pb, 2);         /* encoding mentod */
00108     sound_rate = avio_rl16(pb);
00109     rate = avio_rl16(pb);
00110     channels = avio_rl16(pb);
00111     def_sound_size = avio_rl16(pb);
00112     if (!channels || channels > 42) {
00113         av_log(s, AV_LOG_ERROR, "Invalid number of channels: %d\n", channels);
00114         return AVERROR_INVALIDDATA;
00115     }
00116 
00118     st = avformat_new_stream(s, NULL);
00119     if(!st)
00120          return AVERROR(ENOMEM);
00121 
00122     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00123     st->codec->codec_id = CODEC_ID_RL2;
00124     st->codec->codec_tag = 0;  /* no fourcc */
00125     st->codec->width = 320;
00126     st->codec->height = 200;
00127 
00129     st->codec->extradata_size = EXTRADATA1_SIZE;
00130 
00131     if(signature == RLV3_TAG && back_size > 0)
00132         st->codec->extradata_size += back_size;
00133 
00134     st->codec->extradata = av_mallocz(st->codec->extradata_size +
00135                                           FF_INPUT_BUFFER_PADDING_SIZE);
00136     if(!st->codec->extradata)
00137         return AVERROR(ENOMEM);
00138 
00139     if(avio_read(pb,st->codec->extradata,st->codec->extradata_size) !=
00140                       st->codec->extradata_size)
00141         return AVERROR(EIO);
00142 
00144     if(sound_rate){
00145         pts_num = def_sound_size;
00146         pts_den = rate;
00147 
00148         st = avformat_new_stream(s, NULL);
00149         if (!st)
00150             return AVERROR(ENOMEM);
00151         st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00152         st->codec->codec_id = CODEC_ID_PCM_U8;
00153         st->codec->codec_tag = 1;
00154         st->codec->channels = channels;
00155         st->codec->bits_per_coded_sample = 8;
00156         st->codec->sample_rate = rate;
00157         st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
00158             st->codec->bits_per_coded_sample;
00159         st->codec->block_align = st->codec->channels *
00160             st->codec->bits_per_coded_sample / 8;
00161         avpriv_set_pts_info(st,32,1,rate);
00162     }
00163 
00164     avpriv_set_pts_info(s->streams[0], 32, pts_num, pts_den);
00165 
00166     chunk_size =   av_malloc(frame_count * sizeof(uint32_t));
00167     audio_size =   av_malloc(frame_count * sizeof(uint32_t));
00168     chunk_offset = av_malloc(frame_count * sizeof(uint32_t));
00169 
00170     if(!chunk_size || !audio_size || !chunk_offset){
00171         av_free(chunk_size);
00172         av_free(audio_size);
00173         av_free(chunk_offset);
00174         return AVERROR(ENOMEM);
00175     }
00176 
00178     for(i=0; i < frame_count;i++)
00179         chunk_size[i] = avio_rl32(pb);
00180     for(i=0; i < frame_count;i++)
00181         chunk_offset[i] = avio_rl32(pb);
00182     for(i=0; i < frame_count;i++)
00183         audio_size[i] = avio_rl32(pb) & 0xFFFF;
00184 
00186     for(i=0;i<frame_count;i++){
00187         if(chunk_size[i] < 0 || audio_size[i] > chunk_size[i]){
00188             ret = AVERROR_INVALIDDATA;
00189             break;
00190         }
00191 
00192         if(sound_rate && audio_size[i]){
00193             av_add_index_entry(s->streams[1], chunk_offset[i],
00194                 audio_frame_counter,audio_size[i], 0, AVINDEX_KEYFRAME);
00195             audio_frame_counter += audio_size[i] / channels;
00196         }
00197         av_add_index_entry(s->streams[0], chunk_offset[i] + audio_size[i],
00198             video_frame_counter,chunk_size[i]-audio_size[i],0,AVINDEX_KEYFRAME);
00199         ++video_frame_counter;
00200     }
00201 
00202 
00203     av_free(chunk_size);
00204     av_free(audio_size);
00205     av_free(chunk_offset);
00206 
00207     return ret;
00208 }
00209 
00216 static int rl2_read_packet(AVFormatContext *s,
00217                             AVPacket *pkt)
00218 {
00219     Rl2DemuxContext *rl2 = s->priv_data;
00220     AVIOContext *pb = s->pb;
00221     AVIndexEntry *sample = NULL;
00222     int i;
00223     int ret = 0;
00224     int stream_id = -1;
00225     int64_t pos = INT64_MAX;
00226 
00228     for(i=0; i<s->nb_streams; i++){
00229         if(rl2->index_pos[i] < s->streams[i]->nb_index_entries
00230               && s->streams[i]->index_entries[ rl2->index_pos[i] ].pos < pos){
00231             sample = &s->streams[i]->index_entries[ rl2->index_pos[i] ];
00232             pos= sample->pos;
00233             stream_id= i;
00234         }
00235     }
00236 
00237     if(stream_id == -1)
00238         return AVERROR(EIO);
00239 
00240     ++rl2->index_pos[stream_id];
00241 
00243     avio_seek(pb, sample->pos, SEEK_SET);
00244 
00246     ret = av_get_packet(pb, pkt, sample->size);
00247     if(ret != sample->size){
00248         av_free_packet(pkt);
00249         return AVERROR(EIO);
00250     }
00251 
00252     pkt->stream_index = stream_id;
00253     pkt->pts = sample->timestamp;
00254 
00255     return ret;
00256 }
00257 
00266 static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
00267 {
00268     AVStream *st = s->streams[stream_index];
00269     Rl2DemuxContext *rl2 = s->priv_data;
00270     int i;
00271     int index = av_index_search_timestamp(st, timestamp, flags);
00272     if(index < 0)
00273         return -1;
00274 
00275     rl2->index_pos[stream_index] = index;
00276     timestamp = st->index_entries[index].timestamp;
00277 
00278     for(i=0; i < s->nb_streams; i++){
00279         AVStream *st2 = s->streams[i];
00280         index = av_index_search_timestamp(st2,
00281                     av_rescale_q(timestamp, st->time_base, st2->time_base),
00282                     flags | AVSEEK_FLAG_BACKWARD);
00283 
00284         if(index < 0)
00285             index = 0;
00286 
00287         rl2->index_pos[i] = index;
00288     }
00289 
00290     return 0;
00291 }
00292 
00293 AVInputFormat ff_rl2_demuxer = {
00294     .name           = "rl2",
00295     .long_name      = NULL_IF_CONFIG_SMALL("RL2 format"),
00296     .priv_data_size = sizeof(Rl2DemuxContext),
00297     .read_probe     = rl2_probe,
00298     .read_header    = rl2_read_header,
00299     .read_packet    = rl2_read_packet,
00300     .read_seek      = rl2_read_seek,
00301 };
00302