Re: [Alsa-user] Configuring ALSA and SCHIIT BIfrost for "bit perfect"

[Daniel M. <zo...@gm...>]

On 13.09.2012 03:40, chris hermansen wrote:

>> clh@nice:/proc/asound/card1$ cat stream0
>> CMEDIA Schiit USB Interface at usb-0000:00:13.5-5, high speed : USB Audio
>>
>> Playback:
>>   Status: Running
>>     Interface = 1
>>     Altset = 2
>>     Packet Size = 208
>>     Momentary freq = 176430 Hz (0x16.0dc0)
>>     Feedback Format = 10.14
>>     Packet Size = 0
>>     Momentary freq = 192000 Hz (0x18.0000)
>>   Interface 1
>>     Altset 1
>>     Format: S16_LE
>>     Channels: 2
>>     Endpoint: 5 OUT (ASYNC)
>>     Rates: 44100, 48000, 88200, 96000, 192000
>>     Data packet interval: 125 us
>>   Interface 1
>>     Altset 2
>>     Format: S32_LE
>>     Channels: 2
>>     Endpoint: 5 OUT (ASYNC)
>>     Rates: 44100, 48000, 88200, 96000, 192000
>>     Data packet interval: 125 us
>>
>> if I crash out of the aplay and start it again, sounds great, and
>> we get back to the proper 192 momentary frequency in
>> /proc/asound/card1/stream0
>>
>> clh@nice:/proc/asound/card1$ cat stream0
>> CMEDIA Schiit USB Interface at usb-0000:00:13.5-5, high speed : USB Audio
>>
>> Playback:
>>   Status: Running
>>     Interface = 1
>>     Altset = 2
>>     Packet Size = 208
>>     Momentary freq = 192031 Hz (0x18.0100)
>>     Feedback Format = 8.16
>>     Packet Size = 0
>>     Momentary freq = 192000 Hz (0x18.0000)
>>   Interface 1
>>     Altset 1
>>     Format: S16_LE
>>     Channels: 2
>>     Endpoint: 5 OUT (ASYNC)
>>     Rates: 44100, 48000, 88200, 96000, 192000
>>     Data packet interval: 125 us
>>   Interface 1
>>     Altset 2
>>     Format: S32_LE
>>     Channels: 2
>>     Endpoint: 5 OUT (ASYNC)
>>     Rates: 44100, 48000, 88200, 96000, 192000
>>     Data packet interval: 125 us
>>
>> I guess I find it weird that aplay thinks it is playing
>> 192kHz data but /proc/asound/card1/stream0 says
>> it's 172kHz.
>>
>> The first time.  But the second, things seem correct.

Ok, then this approach does not work. But thanks for testing. I need to
come up with a different solution.

The thing is: I have such a device on my desk, all I'm missing is an
adequate counter part that is able to reveive sample rates up to 192KHz
so I can tes. What kind of device do you have connected to it?


Thanks for your testing effort, I'll get back to you wonce I have a new
patch for you.


Daniel