[mythtv-users] Corrupt audio with i8x0 (sis7012)

[Frank Martelli]

I just tried setting to 80% on Master and Capture, but get the same
feedback loop.  Thanks for the suggestion, though.

My suspicion is that this is a bug in the i8x0 ALSA driver when used with
the SiS7012 chipset, so I have also posted a note to the alsa-users list.

I was able to get the commercial OSS driver working with MythTV on the
SiS7012 this morning, but I am not convinced that I want to go that route
(the OSS driver occasionally dumped strange buffer errors after working
for a short period).  Hopefully, someone in ALSA-land knows what is going
on and we'll get the sis7012 working with the ALSA module.

-F

> I get a ton of distortion when I use these settings.  Going to '80%'
> rather than '100%' work a lot better for me (built-in sound for
> pundit)...
>
> Reza
>
> On Thu, Aug 14, 2003 at 09:32:25AM -0500, Frank Martelli sent me this...
>> I think the mixer is set OK -- I used the commands from section 7.2 of
>> the HowTo:
>>
>> $ amixer set Master,0 100%,100% unmute
>> $ amixer set Line,0 75%,75% mute captur
>> $ amixer set Capture,0 100%,100% mute captur
>> $ su
>> # alsactl store
>> # exit
>>
>> The test 'aplay /dev/dsp' while running xawtv results in the same
>> problem.
>>
>> Possibly this is an issue with the ALSA driver?
>>
>> -T
>>
>> > On Thu, 2003-08-14 at 15:05, Frank Martelli wrote:
>> >>
>> >> When I 'watch TV' the audio is only good for ~2 seconds
>> >> -- it then begins to 'echo,' where the first two seconds of audio
>> are apparent in the loop (overlayed with new audio) until the audio
>> stream degrades into unintelligible 'ringing'.
>> >>
>> >> If I actually record a program, I can then watch my recording
>> without problem.  However, if I begin to playback a recording
>> in-progress, the playback is fine until I hit the point where
>> (real-time) I began the playback (i.e., the recording becomes
>> corrupt when I start using the audio for output).
>> >>
>> >> Has anyone seen this problem before?  I am using the latest ALSA
>> (0.9.6) and MythTV (0.10) versions under the 2.4.18 kernel.  Does
>> this simply mean that my on-board audio is too feeble for MythTV?
>> Is this a general problem with the sis7012 soundcard?  Or do I just
>> have some mixer setting all-wrong?
>> >>
>> >
>> > It sounds like you have your recording input set wrongly on your
>> sound card. You need to have it set just to record the line input.
>> If you set it to record everything you will find myth records it's
>> own output and plays it back over itself until you are in feedback
>> hell!
>> >
>> > Just change this setting using your favourite mixer (kmixer, gmix,
>> smixer) and hopefully that will help.
>> >
>> > Adam.
>> >
>> >
>> >> Thanks!
>> >>
>> >> -Frank
>> >>
>> >>
>> >>
>> >>
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>>
>>
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