lip sync varies with v4l2 input and oss input-slave, and viewing over http h.264 / AAC stream
When using this streaming command, and watching over the network using vlc (http://host:9191), some times the audio will by synced with the video, and other times it will be off by as much as three seconds, but usually between 0 seconds and 1/3 seconds.
The audio sync does not vary with respect to the video but stays either in sync or out of sync as long as the stream is running.
It seems to be off more frequently when the hard drive is busy. For example if you run a "dd if=/dev/zero of=/tmp/large_file bs=1M count=1024" in the back ground.
If you restart the stream enough times, eventually you get a very off lip sync but it seems to be highly random.
vlc --v4l2-standard 3 v4l2:///dev/video0 --input-slave oss:///dev/dsp --sout '#transcode{deinterlace,deinterlace-module=ffmpeg-deinterlace,vcodec=h264,venc=x264{keyint=30,profile=baseline,vbv-init=0.5,vbv-ratetol=50,vbv-bufsize=768,vbv-maxrate=768},acodec=mp4a,ab=128,channels=1,samplerate=44100}:duplicate{dst=standard{access=http,mux=ts,dst=0.0.0.0:9191}}'
VLC version 1.2.0-git Twoflower (1.1.0-pre1-2022-g668d4b8)
Linux Ubuntu 10.04
Linux localhost 2.6.32-24-generic #43 (closed)-Ubuntu SMP Thu Sep 16 14:17:33 UTC 2010 i686 GNU/Linux
Video hardware, bttv driver, pcie provideo.
[ 15.623046] bttv0: Bt878 (rev 17) at 0000:08:00.0, irq: 17, latency: 64, mmio: 0xf8efe000
[ 15.623064] bttv0: detected: Provideo PV150A-1 [card=98], PCI subsystem ID is aa00:1460
[ 15.623067] bttv0: using: ProVideo PV150 [card=98,autodetected]
Audio hardware, happens with every audio card we've tried (3-4). We're currently using an onboard Intel HDA sound card.