Hi. Another point that I forgot to mention:
When I have the negative sleep values, I also get the following errors in VLC: " late picture skipped (572329543999) ... dropping early frame " I believe that these messages are due to the incorrect timing, and because the frames arriving late, the vlc doesn't show them hence causing the visual artifacts. Fixing the timing would prevent any frame delays, and prevent the visual artifacts from happening. ---------- Forwarded message ---------- From: Stas Oskin <[EMAIL PROTECTED]> Date: 30/08/2008 23:55 Subject: Timing MPEG4 frames for RTP/RTSP To: Libav* user questions and discussions <[email protected]> Hi. I would like to bring this issue forward again, as is one of the issues that I'm constantly battling, and couldn't resolve sufficiently well. My biggest problem here, is that I'm dealing with unreliable source, which does not send the frames with a constant FPS. It changes all the time, and sometimes is larger, sometimes is smaller, then the once set FPS that I'm working with. What it leads to is: 1) If the FPS becomes larger then the one I calculated and set in my encoding, I get a growing delay. 2) When it's smaller, I small hangs and visual artifacts (i.e. blocky outlines for motion and etc...). I'm using the timing formula that Luca kindly provided, i.e: sleep_time = currenttime - (time_of_first_frame + av_rescale_q(pkt.dts, st->time_base, AV_TIME_BASE_Q)). The problem with this approach, that almost immediately I'm starting to get negative values, and basically the loop never sleeps but sends the frame immediately. This causes the above mentioned-issues with visual artifacts. I presume that in normal operation, the formula should always produce positive values, timed according to expected FPS (which is unfortunately not in my case). So, to better paraphrase my question, what are the recommended strategics for working with variable FPS on video data source? Thanks in advance for any information. _______________________________________________ libav-user mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/libav-user
