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</o:shapelayout></xml><![endif]--></head><body lang=RU link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt'>Hi Vahid:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt'>perhaps you need to take into account pStream-></span><span lang=EN-US style='font-size:10.0pt;font-family:Consolas'>codec.time_base and </span><span lang=EN-US style='font-size:10.0pt'>pStream-></span><span lang=EN-US style='font-size:10.0pt;font-family:Consolas'>codec.ticks_per_frame. I believe that </span><span lang=EN-US style='font-size:10.0pt'>pStream->time_base matches to frame rate for interleaved video streams, whereas pStream-></span><span lang=EN-US style='font-size:10.0pt;font-family:Consolas'>codec.time_base matches to field rate. E.g. for 25fps interleaved stream you will get </span><span lang=EN-US style='font-size:10.0pt'>time_base=1/25 but </span><span lang=EN-US style='font-size:10.0pt;font-family:Consolas'>codec.time_base=1/50 and codec.ticks_per_frame==2.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:Consolas'>Sincerely,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:Consolas'>LM<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas;color:green'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> libav-user-bounces@ffmpeg.org [mailto:libav-user-bounces@ffmpeg.org] <b>On Behalf Of </b>Vahid Kowsari<br><b>Sent:</b> Monday, July 08, 2013 3:02 AM<br><b>To:</b> libav-user@ffmpeg.org<br><b>Subject:</b> [Libav-user] Getting frame duration when decoding<o:p></o:p></span></p></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Hi All,<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I am decoding some MPEG-2 and H264 streams from file and have a problem getting the correct duration of a frame. Some files are MPEG2 transport streams while other are wrapped in mp4 or MOV container.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I use the following section of code <o:p></o:p></p></div><div><p class=MsoNormal> pFrame is the input AVFrame after decoding<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><div><p class=MsoNormal> AVStream *pStream = pCtx->pFormatCtx->streams[pCtx->activeVideoStream];<o:p></o:p></p></div><div><p class=MsoNormal> double time_base = av_q2d(pStream->time_base);<o:p></o:p></p></div><div><p class=MsoNormal> double duration = time_base * av_frame_get_pkt_duration(pFrame);<o:p></o:p></p></div><div><p class=MsoNormal> duration += duration * (pFrame->repeat_pict / 2);<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>My problem is that for alot of streams this works while for others streams the duration needs to be multipled by 2 for the timing to work correctly...even though repeat_pic is 0. I checked interlace flag but in the files that I had the problem, they are both interlaced.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>What timebase is the correct timebase to use? The codec timebase or the stream timebase?<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>How do I correctly get the duration of a frame regardless of the type of file and the encoding parameters that were used?<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Thanks much for your help!<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div></div></div></div></body></html>