[alsa-devel] Need expert's advice - Fast Track Ultra (8R) dropping samples

[Felix Homann]

Thanks Clemens for your quick response!

Am 06.10.2010 16:38, schrieb Clemens Ladisch:
>>
>> Playback:
>>     Status: Running
>>       Interface = 1
>>       Altset = 1
>>       URBs = 3 [ 57 57 57 ]
>>       Packet Size = 312
>>       Momentary freq = 48000 Hz (0x6.0000)
>>     Interface 1
>>       Altset 1
>>       Format: S24_3LE
>>       Channels: 8
>>       Endpoint: 1 OUT (ADAPTIVE)
>>       Rates: 44100, 48000, 88200, 96000
>>       Data packet interval: 125 us
>>
>> Does it tell us anything?
>>      
> That this device does not use frequency feedback.
>
> What happens when you are recording something and then try to play
> something else with a different sample rate? (use arecord/aplay with
> "-D hw:X")
>
>    

When I start recording at 44.1 kHz while playing a wav at 48 kHz the 
playback gets very distorted, sounds like lots of missing samples. I get 
this from stream0:

M-Audio Fast Track Ultra 8R at usb-0000:00:1a.7-4, high speed : USB Audio

Playback:
   Status: Running
     Interface = 1
     Altset = 1
     URBs = 2 [ 5 6 ]
     Packet Size = 312
     Momentary freq = 48000 Hz (0x6.0000)
   Interface 1
     Altset 1
     Format: S24_3LE
     Channels: 8
     Endpoint: 1 OUT (ADAPTIVE)
     Rates: 44100, 48000, 88200, 96000
     Data packet interval: 125 us

Capture:
   Status: Running
     Interface = 2
     Altset = 1
     URBs = 8 [ 8 8 8 8 8 8 8 8 ]
     Packet Size = 312
     Momentary freq = 44100 Hz (0x5.8333)
   Interface 2
     Altset 1
     Format: S24_3LE
     Channels: 8
     Endpoint: 1 IN (ASYNC)
     Rates: 44100, 48000, 88200, 96000
     Data packet interval: 125 us


The sound stays corrupted until I record at 48 kHz again. Then 
everything sounds as before, i.e. with thos noticable clicks we're 
trying to sort out.

Do you need more infos?

Regards,

Felix