[USB: Distorted Audio via alsa on OrangePi]

Thank you. I will wait for mainline kernel.

[USB: Distorted Audio via alsa on OrangePi]

Thank you for reply. At moment is there any other solutions?

[USB: Distorted Audio via alsa on OrangePi]

Hi All,

 

I have attached an ASUS Xonar Essence One at usb-sunxi-ehci-1, high speed : USB Audio to OrangePi PC.

 

when I use alsa to play sound, the system cannot attain the correct sample rate. After system is booted, the sampling rate is 192000. Now experiment starts

 

Here is the information from /proc/asound/card2/stream0, when nothing is played.

 

Quote

 

ASUS ASUS Xonar Essence One at usb-sunxi-ehci-1, high speed : USB Audio

Playback:
  Status: Stop
  Interface 1
    Altset 1
    Format: S16_LE
    Channels: 2
    Endpoint: 6 OUT (ASYNC)
    Rates: 44100, 48000, 88200, 96000, 176400, 192000
    Data packet interval: 125 us
  Interface 1
    Altset 2
    Format: S32_LE
    Channels: 2
    Endpoint: 6 OUT (ASYNC)
    Rates: 44100, 48000, 88200, 96000, 176400, 192000
    Data packet interval: 125 us

 

 

 

Then I "play" 44100 Hz via alsa, by "cat /dev/urandom | aplay -D hw:2,0 -f S16_LE -c2 -r44100".  Here is the result

 

Quote

Playback:
  Status: Running
    Interface = 1
    Altset = 1
    URBs = 8 [ 8 8 8 8 8 8 8 8 ]
    Packet Size = 104
    Momentary freq = 48000 Hz (0x6.0000)
    Feedback Format = 14.18
  Interface 1
    Altset 1
    Format: S16_LE
    Channels: 2
    Endpoint: 6 OUT (ASYNC)
    Rates: 44100, 48000, 88200, 96000, 176400, 192000
    Data packet interval: 125 us
  Interface 1
    Altset 2
    Format: S32_LE
    Channels: 2
    Endpoint: 6 OUT (ASYNC)
    Rates: 44100, 48000, 88200, 96000, 176400, 192000
    Data packet interval: 125 us

 

It plays at 48000Hz. If I play at 44100 Hz again it will be correct.

 

Quote

Playback:
  Status: Running
    Interface = 1
    Altset = 1
    URBs = 8 [ 8 8 8 8 8 8 8 8 ]
    Packet Size = 104
    Momentary freq = 44109 Hz (0x5.8380)
    Feedback Format = 16.16
  Interface 1
    Altset 1
    Format: S16_LE
    Channels: 2
    Endpoint: 6 OUT (ASYNC)
    Rates: 44100, 48000, 88200, 96000, 176400, 192000
    Data packet interval: 125 us
  Interface 1
    Altset 2
    Format: S32_LE
    Channels: 2
    Endpoint: 6 OUT (ASYNC)
    Rates: 44100, 48000, 88200, 96000, 176400, 192000
    Data packet interval: 125 us

 

If I let it play at 192000Hz after 44100Hz by typing "cat /dev/urandom | aplay -D hw:2,0 -f S16_LE -c2 -r192000", the sampling problem happens again

 

Quote

Playback:
  Status: Running
    Interface = 1
    Altset = 1
    URBs = 8 [ 8 8 8 8 8 8 8 8 ]
    Packet Size = 104
    Momentary freq = 176438 Hz (0x16.0e00)
    Feedback Format = 18.14
  Interface 1
    Altset 1
    Format: S16_LE
    Channels: 2
    Endpoint: 6 OUT (ASYNC)
    Rates: 44100, 48000, 88200, 96000, 176400, 192000
    Data packet interval: 125 us
  Interface 1
    Altset 2
    Format: S32_LE
    Channels: 2
    Endpoint: 6 OUT (ASYNC)
    Rates: 44100, 48000, 88200, 96000, 176400, 192000
    Data packet interval: 125 us

 

There might be a solution here

https://github.com/mopidy/mopidy/issues/613

 

But it is for raspberry Pi. I do not know how to add

dwc_otg.fiq_fix_enable=1 dwc_otg.fiq_split_enable=0

to /boot/cmdline.txt.

 

Many thanks for your help.