[L2Ork-dev] issues on rasbian 9/10

Fri Apr 9 10:00:40 EDT 2021

> 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.

What happens when you run with relatime priority?

-Jonathan

On Fri, Apr 9, 2021 at 5:09 AM Albert Graef <aggraef at gmail.com> wrote:

> 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/
> _______________________________________________
> L2Ork-dev mailing list
> L2Ork-dev at disis.music.vt.edu
> https://disis.music.vt.edu/listinfo/l2ork-dev
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