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<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif">Hi, Does the h264 source contain b-frames? It could be a time-stamping issue between DTS and PTS if b frames are involved<o:p></o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">Von:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> gstreamer-devel [mailto:gstreamer-devel-bounces@lists.freedesktop.org]
<b>Im Auftrag von </b>Joel Keller<br>
<b>Gesendet:</b> Mittwoch, 10. Januar 2018 20:28<br>
<b>An:</b> gstreamer-devel@lists.freedesktop.org<br>
<b>Betreff:</b> RTP video stream corruption<o:p></o:p></span></p>
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<p class="MsoNormal">Hello,<o:p></o:p></p>
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<p class="MsoNormal">I have a pipeline that looks like this:<o:p></o:p></p>
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<p class="MsoNormal">rtspsrc ! rtph264depay ! h264parse ! omxh264dec ! videoconvert ! video/x-raw,format=RGBA ! appsink <o:p></o:p></p>
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<p class="MsoNormal">which I use to receive a 4k video stream from a camera on the LAN (or to test - a stream from localhost). Occasionally, I see that the video stream gets 'corrupted' - moving objects get smeared & then sometimes jump back/forth in time
momentarily. It looks like perhaps some I-frame information gets dropped & the h264 decoder just does the best it can until the next I-frame. This would be okay for something like a video-conferencing solution, but my application takes decoded frames & does
object recognition & temporal tracking, and the smearing & jumping really messes with this downstream processing - it would be much better to have no frames at all than these 'corrupt' ones.<o:p></o:p></p>
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<p class="MsoNormal">I have tried all the properties & knobs that I know of w.r.t rtspsrc ( udp-buffer-size, latency, drop-on-latency, buffer-mode, retransmissions), and have tried adding queues in the pipeline, etc.. No matter what I do, this occasionally
happens when there is any other significant usage of cpu (for example a multi-job compilation). I do know that I have enough CPU time 'on-average' to keep up with the stream rate, so it seems like with correct buffering in the right places, I shouldn't have
to drop any information.<o:p></o:p></p>
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<p class="MsoNormal">I have three questions:<o:p></o:p></p>
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<p class="MsoNormal">1) Is there some way to configure my gstreamer pipeline so that I don't drop this information (I suspect it is the rtsp jitterbuffer dropping, but I'm not sure), and therefore don't have any problem.<o:p></o:p></p>
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<p class="MsoNormal">2) If I can't eliminate this via #1, can I somehow configure different information to be dropped (essentially p-frames, but not i-frames).<o:p></o:p></p>
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<p class="MsoNormal">3) If not #1 or #2, is there a way I can detect downstream from the video-decoder that the frame is 'corrupt' - I think the decoder should know when something is missing from the h264 stream, right?<o:p></o:p></p>
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<p class="MsoNormal">Thanks in advance to anyone who can help shed some light on this issue.<o:p></o:p></p>
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<p class="MsoNormal">-Joel<o:p></o:p></p>
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