[gst-devel] Re: gstreamer distortion w/ thinkpad buttons (tpb) polling nvram (CS46xx new DSP)

Brian Heung bheung at berkeley.edu
Mon Apr 26 18:48:05 CEST 2004

Anyone in alsa-devel have any ideas/clues for this bug? Should I file it 

On Apr 26, 2004, at 1:51 AM, Benjamin Otte wrote:

> On Sun, 25 Apr 2004, Brian Heung wrote:
>> I'm not sure if this is a bug or not. In both the 0.6 and 0.8 
>> releases,
>> osssink output is distorted when TPB (Thinkpad Buttons) is running. 
>> TPB
>> is a program that polls /dev/nvram for changes when using extra 
>> builtin
>> buttons on IBM Thinkpads.
>> If I set TPB to a longer polling period, the distortion is minimized,
>> although it doesn't disappear. This only occurs with osssink and not
>> alsasink or esdsink.
>> Is this a bug?
> It's definitely a bug. The interesting question is who is responsible 
> for
> this bug?
> If it only happens with GStreamer/OSS combo and not with other OSS 
> using
> apps and if it happens on any kernel, it's pretty likely that we're at
> fault. It doesn't hurt to file this as a bug in our bugzilla though I
> don't think anybody from the GStreamer team has a Thinkpad so it's not
> very likely that we can do something about it.
> Benjamin

I did some more testing on this problem. It only appears with the
GStreamer/OSS combo when using the cs46xx Alsa driver with OSS
emulation. Specifically, it only occurs on the "New DSP support"
option. The new DSP enables SPDIF and dual codecs but I only use it for
the hardware mixer.

I tested using the old DSP and OSS drivers and the problem did not
appear. No other OSS applications cause the problems using the New DSP 


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