uaudio, M-Audio FastTrack Pro device - sound distorted

[Marcel Bonnet]

On 26 April 2011 05:47, Hans Petter Selasky <hselasky at c2i.net> wrote:

> On Tuesday 26 April 2011 10:10:21 Clemens Ladisch wrote:
> > Marcel Bonnet wrote:
> > > I'm using the M-AUDIO FastTrack Pro USB audio interface, but every time
> I
> > > play or record, the sound get distorted.
> > >
> > > uaudio0: Play: 44100 Hz, 2 ch, 16-bit S-LE PCM format
> > > uaudio0: Record: 48000 Hz, 2 ch, 16-bit S-LE PCM format
> >
> > This device uses one internal sample rate; using different rates for the
> > playback and capture interfaces won't work.
> >
> > AFAIK there are some undocumented constraints on which configurations
> > and alternate settings can be used; and in some alternate settings, the
> > device uses big-endian samples.  This cannot be handled with the generic
> > parts of the uaudio driver; it requires device-specific workarounds.
> >
> > There is an outdated patch that tries to make this device work on Linux
> > on this page:
> https://bugtrack.alsa-project.org/alsa-bug/view.php?id=3249
> >
> >
>
> Try to set:
>
> sysctl hw.usb.uaudio.default_rate=44100
>
> Then replug the device.
>
> We could possible make a workaround for this.
>

Hey, that worked!! (guys, sorry for taking much time for responding, too
much busy these days)
Thanks, Hans Petter.

I made 4 tests for keeping record of the way your trick works, hope it's
usefull: (the trick #3 was the best 'cause I don't need to configure every
boot)

1) NICE TRICK

System booted with snd_uaudio_load="YES"
M-AUDIO USB Device is disconnected (turned off)

$ sysctl hw.usb.uaudio
hw.usb.uaudio.default_channels: 0
hw.usb.uaudio.default_bits: 32
hw.usb.uaudio.default_rate: 0
hw.usb.uaudio.debug: 0

$ sudo sysctl hw.usb.uaudio.default_rate=44100
hw.usb.uaudio.default_rate: 0 -> 44100

M-AUDIO USB Device is now connected

$ audacious
The same MP3 (128kbps 44100 Hz) now played very clean. Sounds perfect.
Closed the application.

$ sudo sysctl hw.usb.uaudio.default_rate=0
hw.usb.uaudio.default_rate: 44100 -> 0

$ audacious
The same MP3 still playing perfect.
Closed the application.


2) NICE TRICK

Another test, but the system maintains the last statet (not rebooted)
M-AUDIO USB Device was disconnect (turned off)

$ audacious
The same MP3 sounds distorted.
Closed the application.

$ sudo sysctl hw.usb.uaudio.default_rate=44100
hw.usb.uaudio.default_rate: 0 -> 44100

$ audacious
The same MP3 sounds distorted.
Closed the application.


3) NICE TRICK

System rebooted with snd_uaudio_load="YES"
M-AUDIO USB Device is connected (powered on)

Added entry to /boot/loader.conf:
hw.usb.uaudio.default_rate=44100

$ dmesg | grep uaudio
uaudio0: <FastTrack Pro> on usbus0
uaudio0: Play: 44100 Hz, 2 ch, 16-bit S-LE PCM format
uaudio0: Record: 44100 Hz, 2 ch, 16-bit S-LE PCM format
uaudio0: MIDI sequencer
pcm0: <USB audio> on uaudio0

* without setting the default_rate the device announces itself as 44100 Hz
for playback, 48000 for recording

$ sysctl hw.usb.uaudio
hw.usb.uaudio.default_channels: 0
hw.usb.uaudio.default_bits: 32
hw.usb.uaudio.default_rate: 44100
hw.usb.uaudio.debug: 0

$ audacious
The same MP3 still playing perfect.
Closed the application.



4) THE PROBLEM

* The same happens if I don't change the default_rate.

System rebooted with snd_uaudio_load="YES"
M-AUDIO USB Device is connected (powered on)

$ sysctl hw.usb.uaudio
hw.usb.uaudio.default_channels: 0
hw.usb.uaudio.default_bits: 32
hw.usb.uaudio.default_rate: 0
hw.usb.uaudio.debug: 0

$ sudo sysctl hw.usb.uaudio.default_rate=44100
hw.usb.uaudio.default_rate: 0 -> 44100

$ audacious
The same MP3 sounds distorted.
Closed the application.


-- Marcel Bonnet


>
> --HPS
>


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*