On Mon, Nov 06, 2006 at 03:59:46PM +0000, Torgeir Veimo wrote: > On Mon, 2006-11-06 at 16:45 +0100, Wolfgang Wegner wrote: > > The more difficult part is to synchronize the playback part (audio > > sample > > clock and video clock (frame rate)) to this new system clock - this is > > simply > > not possible with any of the PC hardware I currently know about. > > (Except > > the FF DVB cards, which do it internally.) > > What about the scenario where you're either using a budget dvb-t card > with playback using a FF dvb-s card, or have two FF card, but playing > back the stream from the other card? What clock does the FF card then > sync to?
to be honest: I don't know, because I only used the FF card with VDR, but used only budget cards for my own programming. In case the FF card gets a (partial) transport stream, it could still synchronize to the contained PCR packets - depending on interrupt and transport latency (DMA?), the jitter will be higher than with direct processing, though. If there are no PCR packets in the stream, it can only use a free-running clock adjusted by guessing from PTS. But still, you will have audio and video in sync without lost/double frames... (as long as the intermediate stream has PTS) Regards, Wolfgang _______________________________________________ linux-dvb mailing list linux-dvb@linuxtv.org http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
