Re: [LAU] Ardour session with plain ALSA, without JACK

On 02/19/2016 11:35 PM, Ralf Mardorf wrote:
> On Fri, 19 Feb 2016 22:50:14 +0100, Robin Gareus wrote:
>> On 02/19/2016 10:14 PM, Ralf Mardorf wrote:
>>> Hi Robin,
>>
>>> Errors/Messages:
>>> ERROR: AlsaAudioBackend: failed to allocate parameters.
>>> ERROR: AlsaAudioBackend: failed to allocate parameters.
>>> ERROR: AlsaAudioBackend: failed to allocate parameters.
>>
>> Well that explains why it it won't, but not the reason behind it.
>> What soundcard and settings did you configure?
>
> I didn't configure anything.

I should have been more specific, I meant which settings did you enter
in the Audio/Midi Setup Dialog?

Input-Device, Output-Device, Sample rate, Buffer size, Periods, ...

>>> creating alsa driver ...
>>> hw:HDSPMx579bcc,0|hw:HDSPMx579bcc,0|1024|2|44100|0|0|nomon|swmeter|-|32bit
>>> configuring for 44100Hz, period = 1024 frames (23.2 ms), buffer = 2
>>> periods ALSA: final selected sample format for capture: 32bit
>>> integer little-endian ALSA: use 16 periods for capture ALSA: final
>>> selected sample format for playback: 32bit integer little-endian
>>> ALSA: use 16 periods for playback
>>
>> WTH? 16 periods.
>> Does jackd start with 2 or 3 periods on that given interface?
>
> 2

You tell jack to use 2, but jack actually uses 16.

> Usually I use 48KHz p256 n2:
> [rocketmouse@email-addr-hidden ~]$ jackd -dalsa -dhw:0 -r48000 -p256 -n2
> jackdmp 1.9.10
> Copyright 2001-2005 Paul Davis and others.
> Copyright 2004-2014 Grame.
> jackdmp comes with ABSOLUTELY NO WARRANTY
> This is free software, and you are welcome to redistribute it
> under certain conditions; see the file COPYING for details
> no message buffer overruns
> no message buffer overruns
> no message buffer overruns
> JACK server starting in realtime mode with priority 10
> self-connect-mode is "Don't restrict self connect requests"
> audio_reservation_init
> Acquire audio card Audio0
> creating alsa driver ... hw:0|hw:0|256|2|48000|0|0|nomon|swmeter|-|32bit
> configuring for 48000Hz, period = 256 frames (5.3 ms), buffer = 2 periods
> ALSA: final selected sample format for capture: 32bit integer little-endian
> ALSA: use 64 periods for capture
> ALSA: final selected sample format for playback: 32bit integer little-endian
> ALSA: use 64 periods for playback

and 64.

I dimly recall seeing some message on LAU fly by about some RME devices
requiring 16K buffers.

If you have such a kernel/card, Ardour/ALSA won't currently support it
directly, sorry.

robin
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Received on Sat Feb 20 04:15:02 2016