Re: [Jack-Devel] About ALSA drivers for Firewire sound devices

Hi

What is the point of FFADO continuing to exist if these drivers are 
going to become part of ALSA ?


Cheers

Chris

On 29/01/14 15:06, Takashi Sakamoto wrote:
> HI,
>
> I'm a newbie for this project. I'm a ALSA/FFADO developer and currently
> working for ALSA drivers of some firewire devices.
>
> [alsa-devel] [RFC v3] [PATCH 00/52] Enhancement for support of firewire
> devices
> http://mailman.alsa-project.org/pipermail/alsa-devel/2014-January/071820.html
>
> And call for testing in 'Linux Audio Devel':
> [LAD] Call for testing (final): ALSA driver for some firewire devices
> http://lists.linuxaudio.org/pipermail/linux-audio-dev/2014-January/034662.html
>
> The drivers have almost the same streaming functionality as FFADO has.
> The drivers are for some devices so-called 'GenericAVC', based on
> Fireworks/BeBoB/OXFORD.
>
> Currently they aren't going to be merged to upstream. i have some
> discussion about adjustment between the new drivers and related projects.
>
> At first, to PulseAudio.
>
> [pulseaudio-discuss] 'Failed to find a working profile' for firewire
> sound devices
> http://lists.freedesktop.org/archives/pulseaudio-discuss/2014-January/019685.html
>
>
> Next, to FFADO.
> http://sourceforge.net/mailarchive/forum.php?thread_name=52D8EE54.1040500%40sakamocchi.jp&forum_name=ffado-devel
>
>
> Finally, to JACK... I have no issue to JACK :p
>
> JACK is still a good friend to Firewire sound devices. But I inform
> three points to you.
>
> 1. Daisy-caining
> With FFADO backend, jackd can handle some firewire devices. But with
> ALSA backend, jack can't. This rule is still applied to the new drivers.
>
> When users want to use several ALSA PCM devices for firewire sound
> devices, they must write ALSA configuration with 'multi' plugin. See in
> detail:
> http://www.alsa-project.org/alsa-doc/alsa-lib/pcm_plugins.html#pcm_plugins_multi
>
>
> 2. conflict between ALSA/FFADO streaming functionality
> Both starts streaming. But generally, one device can handle a pair of
> streams (in and out).  So FFADO/ALSA can conflict for streaming.
>
> To prevent this, I post a patch to FFADO. If this patch is applied, when
> at least one of connected firewire devices is streaming, jackd with
> FFADO backend fails to start streaming.
>
> [FFADO-devel] Adjustment between FFADO/ALSA for Firewire drivers
> http://sourceforge.net/mailarchive/message.php?msg_id=31856195
>
> Here I have to mention about MIDI functionality. When users use ALSA
> MIDI functionality, the new drivers also start streaming because
> firewire streaming includes both of PCM samples/MIDI messages.
>
> Some graphical JACK application such as 'patchage' displays ALSA MIDI
> ports when jackd is running. But users can't do this. Vise versa, when
> users use any ALSA MIDI ports, then jackd always failed.
>
>
> 3. control for internal mixer
> The new drivers don't give this functionality. So users still need
> applications for it, like FFADO Mixer.
>
>
> Regards
>
> Takashi Sakamoto
> 
> Jack-Devel mailing list
> [hidden]
> http://lists.jackaudio.org/listinfo.cgi/jack-devel-jackaudio.org
>

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