Re: [alsa-devel] USB transfer_buffer allocations on 64bit systems

From: Pedro Ribeiro
Date: Wed May 12 2010 - 19:50:56 EST


On 11 May 2010 18:38, Daniel Mack <daniel@xxxxxxxx> wrote:
> On Tue, May 11, 2010 at 06:32:50PM +0100, Pedro Ribeiro wrote:
>> On 11 May 2010 18:10, Daniel Mack <daniel@xxxxxxxx> wrote:
>> > No surprise here. The 4 channels are mux'ed in an interleaved fashion,
>> > so if the buffers contain rubbish, you will hear artefacts on all
>> > channels.
>>
>> So what would be the testcase you would like me to try?
>
> Would be good to see what happens if you could record audio (with
> arecord would be sufficient), just to see whether the same problem
> exists in the other direction.
>
> Either record an externally generated sine tone and open the resulting
> wave file in an editor. With the amount of artefacts you describe, they
> should easily be visible.

Ok let me see if I got this straight:

I should record some sound with the audio card and see if it impacts
the recording? May take me a few days, I need to get a microphone or
something like that borrowed.

> Another option is to play back any kind of recorded audio thru an audio
> device that does not show the problem (some internal, onboard device?).
>

What do you mean by this? I didn't get it. I usually use my onboard
intel HDA for listening to music and have no problems.

> Thanks,
> Daniel
>

Pedro
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