On Mittwoch, 27. Oktober 2010, Monty Montgomery wrote: > On Wed, Oct 27, 2010 at 4:17 PM, Johannes Sixt <[email protected]> wrote: > > When I back out the "Correct timing bug in the alsa driver" > > patch, things work well again. That is, I do not have to turn on "Disable > > hardware synchronization" to have fluent playback from the beginning. > > > > I'm on OpenSUSE 11.1. This is some 2.6.27.48 kernel flavor. > > What hardware? Latency feedback is implemented per-driver. If this is > happening one multiple chipsets, that's important to know.
lspci says: 00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 02) The driver is obviously snd_hda_intel. > > The change to ALSA, BTW, was simply to move the latency calculation to > where it actually reflected the buffer fill; the old code was always > one fragment off because it calculated latency not accounting for the > fragment it was about to write. Does the old code have proper sync > for you if you set the fragment size to something large? Audio is not well synchronized. With a "Playback buffer size" of 16384 it is awful, and much better with 4096, but not perfect. With your patch and "Disable hardware synch" switched off, synchronization is very good, regardless of the buffer size. But there is this jerky video that catches up with the audio only after a few seconds. > I also wonder if this is not actually something directly to do with > the audio driver, but is tickling some other timing issue; eg, if the > audio was always late/early before, then it changes the timing of when > video frames need to arrive relative to decode time. If the playback > cursor is *also* jumping around or jerky... then it's definitely the > sound driver. If the cursor is smooth, that implicates other things. The playback cursor does jump around while the video lags behind. -- Hannes _______________________________________________ Cinelerra mailing list [email protected] https://init.linpro.no/mailman/skolelinux.no/listinfo/cinelerra
