dmasound_pmac in 2_4_devel

dmasound_pmac in 2_4_devel

[Matt Brubeck]

I'm doing work that requires sound input.  In order to use the built-in
microphone on my iMac (screamerawacs) I compiled the current 2_4_devel
source, which has Iain Sandoe's dmasound_pmac patches. There were several
issues I hope to resolve.

I found a very audible clicking and popping during audio playback.  This
is noticeable e.g. when playing normal MP3 files with xmms.  The clicking
does not occur with the driver in the (non-devel) 2_4 tree.  I also had
some programs lock up while playing sound.

There were some other sound problems I haven't tracked down yet.  Before I
continue working on this, I'd like to find out who is actively working on
the dmasound_pmac driver, and where I can get more information.  I'm
willing to work on the driver, but I'm new to the code and could use some
help getting started.


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Re: dmasound_pmac in 2_4_devel

[Benjamin Herrenschmidt]

>I'm doing work that requires sound input.  In order to use the built-in
>microphone on my iMac (screamerawacs) I compiled the current 2_4_devel
>source, which has Iain Sandoe's dmasound_pmac patches. There were several
>issues I hope to resolve.
>
>I found a very audible clicking and popping during audio playback.  This
>is noticeable e.g. when playing normal MP3 files with xmms.  The clicking
>does not occur with the driver in the (non-devel) 2_4 tree.  I also had
>some programs lock up while playing sound.
>
>There were some other sound problems I haven't tracked down yet.  Before I
>continue working on this, I'd like to find out who is actively working on
>the dmasound_pmac driver, and where I can get more information.  I'm
>willing to work on the driver, but I'm new to the code and could use some
>help getting started.

I don't think anybody is actively working on it, I'm doing some
maintainance work. It's possible that the semaphore I added to
protect the entire driver is causing some latency, thus intruducing
the clicking. Did you try using more buffers ?

Ben.


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Re: dmasound_pmac in 2_4_devel

[Bryce McKinlay]

Matt Brubeck wrote:

>I found a very audible clicking and popping during audio playback.  This
>is noticeable e.g. when playing normal MP3 files with xmms.  The clicking
>does not occur with the driver in the (non-devel) 2_4 tree.
>
Likewise on my PowerBook G4. Have you looked at the ALSA drivers?
Unfortunatly they (as of 0.9.0beta8a) don't compile against 2.4.14-pre
when I last checked, but I've heard reports of success on earlier
kernels and with earlier ALSA releases.

regards

Bryce.


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Re: dmasound_pmac in 2_4_devel

[Iain Sandoe]

Ben wrote:
>>I'm doing work that requires sound input.  In order to use the built-in
>>microphone on my iMac (screamerawacs) I compiled the current 2_4_devel
>>source, which has Iain Sandoe's dmasound_pmac patches. There were several
>>issues I hope to resolve.
>>
>>I found a very audible clicking and popping during audio playback.  This
>>is noticeable e.g. when playing normal MP3 files with xmms.  The clicking
>>does not occur with the driver in the (non-devel) 2_4 tree.  I also had
>>some programs lock up while playing sound.
>>
>>There were some other sound problems I haven't tracked down yet.  Before I
>>continue working on this, I'd like to find out who is actively working on
>>the dmasound_pmac driver, and where I can get more information.  I'm
>>willing to work on the driver, but I'm new to the code and could use some
>>help getting started.
>
> I don't think anybody is actively working on it, I'm doing some
> maintainance work. It's possible that the semaphore I added to
> protect the entire driver is causing some latency, thus intruducing
> the clicking. Did you try using more buffers ?

I'm kinda out of circulation at the moment ... so no active stuff.
Will be back to it tho ... when work schedule permits.

ciao,
Iain.

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