A further data point - the volume control for the tuner audio (sort of) works. Whereas the volume control for the AV inputs does not work.
On Sat, Nov 29, 2008 at 9:02 PM, Andy Walls <[EMAIL PROTECTED]> wrote: > On Sat, 2008-11-29 at 19:35 -0500, Jeff Campbell wrote: > > I stand corrected, the tuner input also suffers from drift. > > > > I checked it around 26 hours of continuous use and there was a > > material drift between the audio and the video, similar to what was > > seen on the AV inputs. The audio is getting ahead of the video. > > OK. Seems like we can blame the encoder or apu. Both of these devices > are a bit of a black box to me, aside from the limited API they expose. > > Do you have enough data to quantify how far ahead the audio is getting > ahead of the video? Short term averages? long term averages? does it > ever seem to resync? It would be nice to have some numbers if I have to > make a query to manufacturers. > > > > I sent the debug=3 log entries under a different thread, nothing too > > strange appeared there. > > > > Is AV_LOCK still enabled in the driver? > > Yes. > > In that particular area of the driver, I can also try and get the AUX > PLL to always have it's VCO run near the VCO center freq (of 400 MHz > IIRC) to minimize the amount of error in the audio sample clock. I'm > not sure it will have significant effect though. > > If I can ever get some time away from guests and family this weekend, I > was also going to develop a buffering fix to allow very small transfer > buffers (as small as 4 kB) between the firmware and driver, but allow > more than the firmware limit of 63 buffers. That way I was hoping to > get lower latency of buffer transfers to hopefully get finer "sync" (I'm > not sure what to call it) between the audio and video. I'm not sure > that will help either though. > > > Regards, > Andy > > > > > -Jeff > > > > On Fri, Nov 28, 2008 at 3:47 PM, Jeff Campbell <[EMAIL PROTECTED]> > > wrote: > > Hi Andy, Hans, > > > > We're still hunting down the audio issues we raised a while > > back. While we thought we had it beat, we have discovered > > through testing that over a period of a few days we end up > > with audio drift (the audio appears to get ahead of a the > > video slightly). Given this, we're still investigating > > itwhich is why we haven't reported back. > > > > We are also actively switching between different inputs > > (Tuner, SVideo, Composite), as well as between NTSC and PAL > > input sources. We have no yet successfully encoded a PAL > > signal from a PAL DVD player. Is there any known issue with > > PAL mode? Does anyone have that working with the latest > > mainline (1.0.3) driver? > > > > A few other observations: > > > > The tuner audio does not appear to drift, although I am > > checking that this weekend (leaving it running for 48 hours > > straight). > > > > Switching from NTSC to PAL format and back for the AV inputs > > appears to result in an unusualble system and requires a > > reboot. > > > > The transport stream of the tuner feed appears to work > > properly (no popping audio or issues), whereas the TS of the > > AV inputs exhibits audio problems. If we apply the changes we > > shared two weeks ago, the audio problem on the AV inputs goes > > away but we eventually see the drift where the audio gets > > ahead of the video. > > > > Andy, out of curiosity, is your primary testing againt tuner > > input or do you often use the AV inputs as well? > > > > We are just at the beginning of digging through the data sheet > > on the cx25840 to start to understand the different pathways > > and how the AV lock differs between the tuner input and the > > other inputs and will share any findings or questions. > > > > I have a wide range of input types I can test against so if > > there is anything you want me to try out and report back on, > > please let me know. > > > > -Jeff > > > > > > _______________________________________________ > > ivtv-devel mailing list > > [email protected] > > http://ivtvdriver.org/mailman/listinfo/ivtv-devel > >
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