On Sat, Jul 18, 2009 at 6:19 AM, Andy Walls<[email protected]> wrote: > On Fri, 2009-07-17 at 19:16 -0400, Andy Walls wrote: >> On Sat, 2009-07-18 at 02:35 +0530, Ravi A wrote: >> > On Tue, Jul 14, 2009 at 6:07 AM, Andy Walls<[email protected]> wrote: > >> > It so happens the driver/utility is setting the input back to Y0 >> > (default, white connector) whenever video format is changed - >> > >> > $sudo v4l2-ctl -s pal >> > sets MUX input to Y0 from wherever it was. However - >> > $sudo v4l2-ctl --log-status >> > still shows the input to be Line-In! >> > >> > $sudo v4l2-ctl -i1 >> > $sudo v4l2-ctl -i2 >> > sets the input back to Y1 and sound re-appears. >> > >> > Is this how the behavior should be? >> >> Nope. Good observation, this is the bug. I checked the source code of >> ivtv-gpio.c and the version history, and it's a bug that's been in the >> ivtv driver since before it was in the mainline kernel. >> >> It should be striaght-forward to fix the behavior, but I'll have to take >> a look and make sure there's not some odd board that needs something >> special. I'll have a patch ready soon. > > Ravi, > > I have pushed a patch to > > http://linuxtv.org/hg/~awalls/ivtv > > > The bug was ancient. It looks like it arose from an old method of > setting the tuner back to TV when exiting from FM radio mode. It had > the side effect of changing the audio input of a GPIO audio mux back to > the tuner whenever the video standard was changed when you were not in > radio mode. > > Apparently no one with a card with a GPIO audio mux ever changed the > standard when set to Composite or SVideo. > > > >> > When MUX is set properly and sound is present, the volume was still a >> > bit low and it seemed very noisy - something like zero-crossing >> > distortion. I could improve it a bit by setting volume all the way >> > high. >> > sudo v4l2-ctl -c volume=65535 >> > Setting bass and treble to '0' helped to reduce the distortion/noise >> > significantly although the volume still seemed low >> > sudo v4l2-ctl -c bass=0 >> > sudo v4l2-ctl -c treble=0 >> > >> > If I can get v4l2-dbg to read/set registers maybe I can try more >> > experiments for the audio quality. > > Yes, it will give you the flexibility to experiment will all sorts of > audio settings. > > Regards, > Andy > >
Hi Andy, With the latest patch, the MUX control becomes stable and the audio stays put with video standard changes! Now that the audio is stable, I notice some possible issue with the PLL VCO center frequency adjustment patch. Both e8fcd13e4ae7 and d7e1eb4b17d8 show some skips/gaps in both video and audio (Composite input). After 10 seconds of playing with mplayer the following is output - "Your system is too SLOW to play this! .. blah" and after another 10 seconds a continuous stream of "Too many video packets in the buffer: (4096 in 8007268 bytes)... blah" appear. Patches 82a264ea2784 and 7ea3e7b9a657 do not show this, both video and audio are smooth. I was able to finally read some registers after compiling the latest v4l2-dbg. I will try tweaking audio registers using 82a264ea2784 next. Regards Ravi _______________________________________________ ivtv-devel mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-devel
