On Thu, Mar 25, 2010 at 9:13 AM, TJ <one.timothy.jones at gmail.com> wrote: > Hiya, > > When playing HD files encoded with h.264, video progressively goes out of > sync > with (lags behind) the audio. I tried it on 2 different computers. Here are > the > commands I used: > > mplayer -cache 8192 - < capture-00.flv > mplayer -vo vdpau -vc ffh264vdpau -cache 8192 - < capture-00.flv > > Without VDPAU acceleration, CPU usage does not go above 50% (it's Core 2 > Duo > 1.83GHz computer). With VDPAU CPU usage is below 10%. But still in both > cases > video slowly lags more and more behind the audio. > > If I add -framedrop option, it fixes the problem, but I see jerks once in a > while. Without the option the video plays smoothly. > > I am using MPlayer SVN-r29796-4.3.4. > > The original files are encoded using ffmpeg with the following command: > > ffmpeg \ > -f rawvideo -s 1280x720 -pix_fmt uyvy422 -r 59.94 -i /dev/sdivideorx0 \ > -f s16le -ar 48000 -ac 2 -i /dev/sdiaudiorx0 \ > -vcodec libx264 -vpre custom -vb 4000000 -threads 0 \ > -acodec libfaac -ab 256k \ > -f flv - > capture-00.flv > > I know the original files are good, as I can play them on the mac with no > glitches. I tried using different container (-f mpegts) but that didn't > help. > > I was thinking maybe this has something to do with the monitor refresh rate > being 60Hz while the video is 59.94Hz. > > Does anybody have any suggestions on what I can do to fix this? > > Thank you. > > -TJ > TJ, this is certainly not a general symptom. I use the Hauppage HD PVR which captures at 59.94 and must have compressed 100 shows by now (same resolutions as you). I have noticed two things: The stream is glitchy at some times but due to PTS mencoder manages to keep it in sync. *Sometimes* (very rarely) it starts off with the wrong sync and I compensate via multiplexer. However, that is never a drift. If you do framerate conversion you may be asking for trouble, though, but your command does not do this. Here is what I use: "C:\Bin\mencoder.exe" "E:\rip\Tudors - S03E03.TS.12.TS" -o "D:\Enc_Out\Tudors - S03E03.TS.12.mkv" -ovc x264 -x264encopts threads=0:bframes=5:b-adapt=2:partitions=all:cabac:nopsnr:nossim:mixed_refs:frameref=6:weight_b:b_pyramid=normal:me=umh:merange=16:subme=6:analyse=all:8x8dct=1:trellis=1:psy-rd=1,1:no-fast-pskip=1:crf=23 -oac copy -vf crop=1264:704:8:10,scale=720:480 -fps 60000/1001 Note that I do this quite a bit differently. I also force the framerate since the beginning of the clip at times shows a different frame rate (25fps) due to some cutting and mencoder sometimes guesses wrong. You can, of course, drop the cropping and scaling.
