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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Hi Everyone,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I’ve an IP Camera which gives RTSP stream on <b>rtsp://192.168.1.90/MediaInput/Mpeg4. </b>I want to archive the video and audio of this stream using libavcodec. I’ve the following code sample. This code creates a video file. But, time_base.den/time_base.num value(which is frame rate?) comes out to be 30000. I tried to set the value of time_base.num to 1000 to get frame rate as 30. I get one hour duration video for 100 frames. <o:p></o:p></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Courier New";color:blue'>int</span><span style='font-size:12.0pt;font-family:"Courier New"'> main(<span style='color:blue'>int</span> argc, <span style='color:blue'>char</span>** argv) {</span><o:p></o:p></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> AVFormatContext* context = avformat_alloc_context();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:blue'>int</span> video_stream_index;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:blue'>int</span> audio_stream_index;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> av_register_all();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> avcodec_register_all();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> avformat_network_init();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:green'>//open rtsp<o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> avformat_open_input(&context, <span style='color:#A31515'>"rtsp://192.168.1.90/MediaInput/Mpeg4"</span>,NULL,NULL);<o:p></o:p></span></p><p class=MsoNormal style='text-indent:.5in;text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'>avformat_find_stream_info(context,NULL);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:green'>//search video stream<o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:blue'>for</span>(<span style='color:blue'>int</span> i =0;i<context->nb_streams;i++)<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:blue'>if</span>(context->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> { <o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> video_stream_index = i;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:blue'>else</span> <span style='color:blue'>if</span>(context->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO)<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> { <o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> audio_stream_index = i;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> AVPacket packet;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> av_init_packet(&packet);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:green'>//open output file<o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> AVOutputFormat* fmt = av_guess_format(NULL,<span style='color:#A31515'>"test2.avi"</span>,NULL);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> AVFormatContext* oc = avformat_alloc_context();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> oc->oformat = fmt;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> avio_open2(&oc->pb, <span style='color:#A31515'>"test.avi"</span>, AVIO_FLAG_WRITE,NULL,NULL);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> AVStream* stream=NULL;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:blue'>int</span> cnt = 0;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> AVCodec *videoCodec;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> AVCodecContext *videoCodecCtx;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:green'>// Get a pointer to the codec context for the video stream<o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> videoCodecCtx=context->streams[video_stream_index]->codec;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:green'>// Find the decoder for the video stream<o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> videoCodec=avcodec_find_decoder(videoCodecCtx->codec_id);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:green'>// Open codec<o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> avcodec_open(videoCodecCtx, videoCodec);<span style='color:green'><o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New";color:green'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:blue'>if</span>(videoCodec->capabilities & CODEC_CAP_TRUNCATED)<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> videoCodecCtx->flags |= CODEC_FLAG_TRUNCATED; <span style='color:green'>/* we do not send complete frames */<o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New";color:green'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:blue'>if</span> ((videoCodecCtx->time_base.den / videoCodecCtx->time_base.num) > 1000 && videoCodecCtx->time_base.num == 1)<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> videoCodecCtx->time_base.num = 1000;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> av_read_play(context);<span style='color:green'>//play RTSP<o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:blue'>while</span>(av_read_frame(context,&packet)>=0 && cnt <100){<span style='color:green'>//read 100 frames<o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:blue'>if</span>(packet.stream_index == video_stream_index){<span style='color:green'>//packet is video <o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:blue'>if</span>(stream == NULL){<span style='color:green'>//create stream in file<o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> stream = avformat_new_stream(oc,context->streams[video_stream_index]->codec->codec);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> avcodec_copy_context(stream->codec,context->streams[video_stream_index]->codec);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> stream->sample_aspect_ratio = context->streams[video_stream_index]->codec->sample_aspect_ratio;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> avformat_write_header(oc,NULL);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> packet.stream_index = stream->id;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> av_write_frame(oc,&packet);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> cnt++; <o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:blue'>else</span> <span style='color:blue'>if</span>(packet.stream_index == audio_stream_index)<span style='color:green'>//packet is audio<o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:green'>//std::cout<<"Audio packet"<<std::endl;<o:p></o:p></span></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> cnt++;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> av_free_packet(&packet);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> av_init_packet(&packet);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> av_read_pause(context);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> av_write_trailer(oc);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> avio_close(oc->pb);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'> avformat_free_context(oc);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:12.0pt;font-family:"Courier New"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Courier New"'> <span style='color:blue'>return</span> (EXIT_SUCCESS);</span><o:p></o:p></p><p class=MsoNormal>}<o:p></o:p></p><p class=MsoNormal>Thanks<o:p></o:p></p><p class=MsoNormal>Naresh<o:p></o:p></p><p class=MsoNormal>Ph. 8884199804<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>