Hi Stefan,
On Oct 26 2014 21:00, Stefan Richter wrote:
Conclusion:
In my tests, the patch set does not regress with LaCie FireWire Speakers, does not regress with Griffin FireWave + Jack, and it fixes FireWave for stereo playback through ALSA client applications. Therefore and for the much extended device support and features (which I could not test myself due to lack of hardware), I would be glad if these patches were to be queued up for mainline merge and am offering a
Tested-by: Stefan Richter stefanr@s5r6.in-berlin.de (Speakers, FireWave)
tag. Thank you,
Thanks for your test and report. And I'm sorry to notice your message after I posted my patches to alsa-devel...
[alsa-devel] [PATCH 00/29 v2] ALSA: Enhancement for existed FireWire drivers http://mailman.alsa-project.org/pipermail/alsa-devel/2014-October/082844.htm...
Stock, i.e. snd-firewire-speakers: Patched, i.e. snd-oxfw: Card: FireWire Speakers Card: FWSpeakers Chip: OXFW970 Chip: FWSpeakers
...
Alsamixer displays different chip names. Stock, i.e. snd-firewire-speakers: Patched, i.e. snd-oxfw: Card: FireWave Card: FireWave Chip: OXFW970 Chip: FireWave
This is due to second parameter for snd_pcm_new().
[alsa-devel] [PATCH 18/29] ALSA: oxfw: Split PCM functionality to a new file http://mailman.alsa-project.org/pipermail/alsa-devel/2014-October/082857.htm...
In my patchset, the parameter refers to 'struct snd_card.driver'. For these two models, this member refers to 'struct device_info.driver_name' and it's hard-coded. This may be a bit meddling.
There is distortion on channel 2 (R) channel. The type of distortion depends on the audio which is played back. It can be pops, buzzing, or a high continuous hissing tone (I guess a 22.05 kHz tone).
I heard it.
I understand it's due to the difference of stream format. $ cat /proc/asound/FireWave/firewire/formation Input Stream to device: Rate PCM MIDI 48000 6 0 32000 6 0 44100 6 0 96000 6 0 32000 2 0 * 44100 2 0 48000 2 0
Old snd-firewire-speakers just change sampling rate without changing stream format. If the device wait for 6ch PCM samples in a data block of AMDTP packet but the driver transfer 2ch PCM samples in a data block of AMDTP packet (or vice versa), the device handles the samples badly and sounds hiss noise.
This is the same behavior as I remember it from the time when snd-firewire-speakers was merged into the mainline in 2.6.39.
If so, you and Clemens should have mentioned about it anywhere (maybe in commit message). It brings a new device to my home ;)
Anyway, thanks for your and Clemens' work. Enjoy playing music!
Regards
Takashi Sakamoto o-takashi@sakamocchi.jp