Hey Ron, On Sun, 2003-06-29 at 06:41, Ron Keller wrote: > I am puzzled by the performance of my Studio DC10plus capture > card. using lavrec (from mjpegtools-1.6.1), I don't LOSE frames, > but frames do get INSERTED - at the rate of 15 per hour. I have > played with buffer_size and buffer_number; and also with quality > of the capture video. I don't see any noticeable A/V sync > errors, but I am curious as to why these extra frames arew being > inserted. Are you able to answer this for me? Thanks It's for keeping synchronization. We program the audio clock and the video clock at a certain rate (say, 25 fps and 44,1kHz) but they will slightly differ (this is mostly the audio clock, which is ususlaly not 100% correct). Normally, this means that video/audio would drift apart and you'd get wrong synchronization (voice coming one second after video person moves his mouth, that kind of things). We use software frame inserting/dropping to correct for this. So once in a while, it drops or inserts a frame so that the video and audio clock drift are corrected for. Nothing to worry about, you basically don't see it in the end result anyway. :). Ronald -- Ronald Bultje <rbultje@xxxxxxxxxxxxxxxxxxx>
