[L2Ork-dev] issues on rasbian 9/10

Fri Apr 9 05:08:54 EDT 2021

Here's the Raspbian 10 deb of my special build in case you want to give
this a try yourself. (I'm rolling back the package on the OBS preview
channel now, so I uploaded a copy of this package to my Google Drive.)

 purr-data_2.16.0+git4809+6d74b30a-1_armhf.deb
<https://drive.google.com/file/d/1Egjb2k_Q3Svbuv1d9irjv_-h-zv-FOKR/view?usp=drive_web>

On Fri, Apr 9, 2021 at 11:00 AM Albert Graef <aggraef at gmail.com> wrote:

> Ok, I gave that a try now, but unfortunately it didn't help much. :( The
> high-pitched noise is gone, so that's an improvement. But the ALSA backend
> still only gets a bunch of xruns and then gives up after printing "restart
> alsa output; alsa xrun recovery apparently failed" a couple of times in the
> terminal, logging "error: audio I/O stuck... closing audio" in the Pd
> console.
>
> One thing I noticed in htop is that the nw.js gui spawns quite a few
> threads all running at a nice level of -7, while the engine itself runs at
> -9. In vanilla you just get the wish gui (a single thread) running at 20,
> while the engine runs at -7. So there are some clear differences between
> purr-data and vanilla even if the ALSA backend is exactly the same (in that
> special build of purr-data I just did). I'm not sure why we run the GUI at
> such a high priority; maybe that's part of the problem. Jonathan might be
> able to shed some light on this.
>
> As I said before, all these issues go away if you just use an external
> sound card, so the dsp *is* part of the equation here. Such a device will
> also work with Jack just fine. Even one of those really cheap and small USB
> audio adapters that you can get on Amazon for a couple of bucks will do the
> trick (I have the one from UGREEN, but the one from Sabrent[1] is also
> available on amazon.com and should do the job as well).
>
> [1] https://www.amazon.com/-/de/dp/B00IRVQ0F8
>
> Sorry Marten, I wished I had better news for you. It would still be nice
> if you could submit a full bug report on this, so that we can document what
> we know about this bug and hopefully fix it some time. But for the time
> being my suggestion for you would be to just get one of those little USB
> audio thingies and call it a day. ;-)
>
> Best,
> Albert
>
>
> On Fri, Apr 9, 2021 at 2:29 AM Albert Graef <aggraef at gmail.com> wrote:
>
>> Just a quick followup: Comparing the source of our s_audio_alsa.c with
>> that of vanilla I do see some substantial differences. In particular, it
>> seems that we never backported two of Miller's commits from way back then,
>> https://github.com/agraef/pure-data/commit/75819aad and
>> https://github.com/agraef/pure-data/commit/de2ba0f6. In particular, the
>> former has an entire chunk of sw parameter initializations which is
>> completely missing in our code.
>>
>> What I can do as a quick check is to pull the latest s_audio_alsa.c from
>> vanilla into my testing branch and do a test build on my OBS preview
>> channel so that we can try it out on the Pi. That way we'll lose Sam
>> Thurston's recent MR concerning the error checking code in the module, but
>> we can always pull that back in again later if needed (vanilla also has
>> some changes there, so Sam's fixes might not be needed any more).
>>
>> Stay tuned,
>> Albert
>>
>>
>>
>> On Fri, Apr 9, 2021 at 1:42 AM Albert Graef <aggraef at gmail.com> wrote:
>>
>>> Hi Marten,
>>>
>>> I have exactly the same issue on my Raspberry Pi4. Purr works mostly
>>> fine even with a cheap USB audio dongle, but not with the built-in
>>> soundcard of the Pi. Pd 0.49.0 straight from the Buster repo works fine. So
>>> clearly there's a bug lurking in our ALSA support somewhere or we're
>>> missing some bit in the backend which makes this work in vanilla.
>>>
>>> This was discussed on the ml before, and IIRC we've blamed it all on the
>>> poor dsp of the Pi. ;-) But this can't be true if it works just fine in
>>> vanilla. So we should try again to track this down. It would help if you
>>> could submit a bug report at
>>> https://git.purrdata.net/jwilkes/purr-data/-/issues, then I'll look
>>> into it asap.
>>>
>>> Thanks,
>>> Albert
>>>
>>>
>>> On Thu, Apr 8, 2021 at 4:58 PM Marten Seedorf <
>>> marten.seedorf at mailbox.org> wrote:
>>>
>>>> Hey everyone,
>>>>
>>>> working on a sound installation with purr-data on the raspberry pi I
>>>> encountered some issues that might be worth mentioning.
>>>>
>>>> I installed the recent rasperry pi os (~ raspbian 10 buster) on a
>>>> raspberry pi 3B and installed purr-data from Albert Gräfs repositories on
>>>> opensuse.org. The installation went smoothly, but the audio engine
>>>> (alsa) didn't work. All I got was a high pitched, distorted noise. I tried
>>>> to use jack, but strangely it wasn't able to communicate with the audio
>>>> hardware via alsa as well. So it seems that the issue is rather in the OS
>>>> than in Purr Data. But: PD Vanilla is working perfectly fine (directly with
>>>> alsa, without jack).
>>>>
>>>> I went back to Raspbian 9 Stretch and installed Purr-Data from the
>>>> latest pre-build deb.-package I could find (2.10.1). That worked great.
>>>>
>>>> I became curious and installed Purr-Data on stretch from the
>>>> opensuse-repositories (Raspbian 9) and encountered the same issues as in
>>>> buster.
>>>>
>>>> So in the end, I found a solution that works for me. Still I figure
>>>> there could be something wrong with the repositories.
>>>>
>>>> Best,
>>>> Marten
>>>> _______________________________________________
>>>> L2Ork-dev mailing list
>>>> L2Ork-dev at disis.music.vt.edu
>>>> https://disis.music.vt.edu/listinfo/l2ork-dev
>>>
>>>
>>>
>>> --
>>> Dr. Albert Gr"af
>>> Computer Music Research Group, JGU Mainz, Germany
>>> Email: aggraef at gmail.com, web: https://agraef.github.io/
>>>
>>
>>
>> --
>> Dr. Albert Gr"af
>> Computer Music Research Group, JGU Mainz, Germany
>> Email: aggraef at gmail.com, web: https://agraef.github.io/
>>
>
>
> --
> Dr. Albert Gr"af
> Computer Music Research Group, JGU Mainz, Germany
> Email: aggraef at gmail.com, web: https://agraef.github.io/
>

-- 
Dr. Albert Gr"af
Computer Music Research Group, JGU Mainz, Germany
Email: aggraef at gmail.com, web: https://agraef.github.io/
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