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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>I would like to try to implement a kind of reverse playback from gst-rtsp server, starting first with matroska files with mpeg4 video (for which reverse playback from file source already works fine).<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I’m using a slightly modified version of test-mkv.exe as rtsp server to stream that kind of files (the pipeline is:<o:p></o:p></p><p class=MsoNormal>filesrc ! matroskademux ! queue ! mpeg4vparse (needed?) ! rtpmp4vpay).<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Rtsp-server has already been modified to handle negative rates and perform a seek in reverse direction, so that server-side filesrc element starts reading file chunks in reverse order. The client receives some packets but it seems to me they are discarded since buffering level stays to 0.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Now some questions on which is the best way to proceed (not necessarily a “standard” way, but possibly the less complicated one):<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>What shall be the play response from server to a negative scale request (e.g. -1.0 with range 10-0)? Shall the server notify the actual negative rate and range in use, so that the client pipeline is aware of that, or shall reply with e.g. 1.0 speed and 0-10 range as if the playback was in forward order?<o:p></o:p></p><p class=MsoListParagraph>In the first case, it should mean the client pipeline has to finish some frame / timestamp reordering , while in the second case i guess the server has completed all the job and the client pipeline processes frames just as they were in normal play order.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>In both cases, which are the pipeline elements that shall be modified in order to implement this feature? I guess that, since the client is able to reverse play from file, most elements are OK (filesrc, matroskademux, decodebin, videosink). Maybe there is something to do in rtp pay/depay elements, can you give me an idea?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks in advance,<o:p></o:p></p><p class=MsoNormal>Daniela<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoListParagraph style='margin-left:0in'><o:p> </o:p></p></div></body></html>