Advanced Linux Sound Architecture

On 11/17/2011 06:13 PM, athos bacchiocchi wrote:
> hello everyone,
> 
> I just got an old Sound Devices Usbpre (not the "2", the old one), and i
> would like to use it with gnu-linux (ubuntu).

I'm surprised this works at all, as Sound Devices offers[*] drivers even
for Mac OS X, which normally handles class compliant audio devices quite
well. I had a look at the installer package and indeed, it contains a
driver that operates on device-level, which has precedence over the
generic, class-compliant driver.

This is usually a sign that the device is in fact incompatible to the
audio class, even though appearantly, it has class compliant headers.
Can you send the output of "lsusb -v"?

Daniel


[*] http://www.sounddevices.com/download/usbpre-drivers.htm

Bus 005 Device 002: ID 0926:0100  
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.00
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0         8
  idVendor           0x0926 
  idProduct          0x0100 
  bcdDevice            1.00
  iManufacturer           1 Sound Devices
  iProduct                2 USBPre Microphone Interface
  iSerial                 0 
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength          635
    bNumInterfaces          3
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              500mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass         1 Audio
      bInterfaceSubClass      1 Control Device
      bInterfaceProtocol      0 
      iInterface              0 
      AudioControl Interface Descriptor:
        bLength                10
        bDescriptorType        36
        bDescriptorSubtype      1 (HEADER)
        bcdADC               1.00
        wTotalLength           65
        bInCollection           2
        baInterfaceNr( 0)       1
        baInterfaceNr( 1)       2
      AudioControl Interface Descriptor:
        bLength                12
        bDescriptorType        36
        bDescriptorSubtype      2 (INPUT_TERMINAL)
        bTerminalID             1
        wTerminalType      0x0101 USB Streaming
        bAssocTerminal          0
        bNrChannels             2
        wChannelConfig     0x0003
          Left Front (L)
          Right Front (R)
        iChannelNames           0 
        iTerminal               0 
      AudioControl Interface Descriptor:
        bLength                13
        bDescriptorType        36
        bDescriptorSubtype      6 (FEATURE_UNIT)
        bUnitID                 2
        bSourceID               1
        bControlSize            2
        bmaControls( 0)      0x01
        bmaControls( 0)      0x00
          Mute
        bmaControls( 1)      0x02
        bmaControls( 1)      0x00
          Volume
        bmaControls( 2)      0x02
        bmaControls( 2)      0x00
          Volume
        iFeature                0 
      AudioControl Interface Descriptor:
        bLength                 9
        bDescriptorType        36
        bDescriptorSubtype      3 (OUTPUT_TERMINAL)
        bTerminalID             3
        wTerminalType      0x0603 Line Connector
        bAssocTerminal          0
        bSourceID               2
        iTerminal               0 
      AudioControl Interface Descriptor:
        bLength                12
        bDescriptorType        36
        bDescriptorSubtype      2 (INPUT_TERMINAL)
        bTerminalID             4
        wTerminalType      0x0201 Microphone
        bAssocTerminal          0
        bNrChannels             2
        wChannelConfig     0x0003
          Left Front (L)
          Right Front (R)
        iChannelNames           0 
        iTerminal               0 
      AudioControl Interface Descriptor:
        bLength                 9
        bDescriptorType        36
        bDescriptorSubtype      3 (OUTPUT_TERMINAL)
        bTerminalID             7
        wTerminalType      0x0101 USB Streaming
        bAssocTerminal          0
        bSourceID               4
        iTerminal               0 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       1
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           1
        bDelay                  0 frames
        wFormatTag              1 PCM
      AudioStreaming Interface Descriptor:
        bLength                14
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             1
        bSubframeSize           1
        bBitResolution          8
        bSamFreqType            0 Continuous
        tLowerSamFreq        4990
        tUpperSamFreq       55010
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x04  EP 4 OUT
        bmAttributes            9
          Transfer Type            Isochronous
          Synch Type               Adaptive
          Usage Type               Data
        wMaxPacketSize     0x0038  1x 56 bytes
        bInterval               1
        bRefresh                0
        bSynchAddress           0
        AudioControl Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay            512 Decoded PCM samples
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       2
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           1
        bDelay                  0 frames
        wFormatTag              1 PCM
      AudioStreaming Interface Descriptor:
        bLength                14
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             2
        bSubframeSize           1
        bBitResolution          8
        bSamFreqType            0 Continuous
        tLowerSamFreq        4990
        tUpperSamFreq       55010
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x04  EP 4 OUT
        bmAttributes            9
          Transfer Type            Isochronous
          Synch Type               Adaptive
          Usage Type               Data
        wMaxPacketSize     0x0070  1x 112 bytes
        bInterval               1
        bRefresh                0
        bSynchAddress           0
        AudioControl Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay            512 Decoded PCM samples
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       3
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           1
        bDelay                  0 frames
        wFormatTag              1 PCM
      AudioStreaming Interface Descriptor:
        bLength                14
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             1
        bSubframeSize           2
        bBitResolution         16
        bSamFreqType            0 Continuous
        tLowerSamFreq        4990
        tUpperSamFreq       55010
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x04  EP 4 OUT
        bmAttributes            9
          Transfer Type            Isochronous
          Synch Type               Adaptive
          Usage Type               Data
        wMaxPacketSize     0x0070  1x 112 bytes
        bInterval               1
        bRefresh                0
        bSynchAddress           0
        AudioControl Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay            512 Decoded PCM samples
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       4
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           1
        bDelay                  0 frames
        wFormatTag              1 PCM
      AudioStreaming Interface Descriptor:
        bLength                14
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             2
        bSubframeSize           2
        bBitResolution         16
        bSamFreqType            0 Continuous
        tLowerSamFreq        4990
        tUpperSamFreq       55010
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x04  EP 4 OUT
        bmAttributes            9
          Transfer Type            Isochronous
          Synch Type               Adaptive
          Usage Type               Data
        wMaxPacketSize     0x00e0  1x 224 bytes
        bInterval               1
        bRefresh                0
        bSynchAddress           0
        AudioControl Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay            512 Decoded PCM samples
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       5
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           1
        bDelay                  0 frames
        wFormatTag              1 PCM
      AudioStreaming Interface Descriptor:
        bLength                14
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             1
        bSubframeSize           3
        bBitResolution         20
        bSamFreqType            0 Continuous
        tLowerSamFreq        4990
        tUpperSamFreq       55010
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x04  EP 4 OUT
        bmAttributes            9
          Transfer Type            Isochronous
          Synch Type               Adaptive
          Usage Type               Data
        wMaxPacketSize     0x00a8  1x 168 bytes
        bInterval               1
        bRefresh                0
        bSynchAddress           0
        AudioControl Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay            512 Decoded PCM samples
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       6
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           1
        bDelay                  0 frames
        wFormatTag              1 PCM
      AudioStreaming Interface Descriptor:
        bLength                14
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             2
        bSubframeSize           3
        bBitResolution         20
        bSamFreqType            0 Continuous
        tLowerSamFreq        4990
        tUpperSamFreq       55010
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x04  EP 4 OUT
        bmAttributes            9
          Transfer Type            Isochronous
          Synch Type               Adaptive
          Usage Type               Data
        wMaxPacketSize     0x0150  1x 336 bytes
        bInterval               1
        bRefresh                0
        bSynchAddress           0
        AudioControl Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay            512 Decoded PCM samples
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       1
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           7
        bDelay                  0 frames
        wFormatTag              1 PCM
      AudioStreaming Interface Descriptor:
        bLength                11
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             1
        bSubframeSize           1
        bBitResolution          8
        bSamFreqType            1 Discrete
        tSamFreq[ 0]        44100
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x85  EP 5 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0031  1x 49 bytes
        bInterval               1
        bRefresh                0
        bSynchAddress           0
        AudioControl Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay              0 Decoded PCM samples
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       2
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           7
        bDelay                  0 frames
        wFormatTag              1 PCM
      AudioStreaming Interface Descriptor:
        bLength                11
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             2
        bSubframeSize           1
        bBitResolution          8
        bSamFreqType            1 Discrete
        tSamFreq[ 0]        44100
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x85  EP 5 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0062  1x 98 bytes
        bInterval               1
        bRefresh                0
        bSynchAddress           0
        AudioControl Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay              0 Decoded PCM samples
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       3
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           7
        bDelay                  0 frames
        wFormatTag              1 PCM
      AudioStreaming Interface Descriptor:
        bLength                11
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             1
        bSubframeSize           2
        bBitResolution         16
        bSamFreqType            1 Discrete
        tSamFreq[ 0]        44100
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x85  EP 5 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0062  1x 98 bytes
        bInterval               1
        bRefresh                0
        bSynchAddress           0
        AudioControl Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay              0 Decoded PCM samples
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       4
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           7
        bDelay                  0 frames
        wFormatTag              1 PCM
      AudioStreaming Interface Descriptor:
        bLength                11
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             2
        bSubframeSize           2
        bBitResolution         16
        bSamFreqType            1 Discrete
        tSamFreq[ 0]        44100
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x85  EP 5 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x00c4  1x 196 bytes
        bInterval               1
        bRefresh                0
        bSynchAddress           0
        AudioControl Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay              0 Decoded PCM samples
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       5
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           7
        bDelay                  0 frames
        wFormatTag              1 PCM
      AudioStreaming Interface Descriptor:
        bLength                11
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             1
        bSubframeSize           3
        bBitResolution         20
        bSamFreqType            1 Discrete
        tSamFreq[ 0]        44100
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x85  EP 5 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0093  1x 147 bytes
        bInterval               1
        bRefresh                0
        bSynchAddress           0
        AudioControl Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay              0 Decoded PCM samples
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       6
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0 
      iInterface              0 
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           7
        bDelay                  0 frames
        wFormatTag              1 PCM
      AudioStreaming Interface Descriptor:
        bLength                11
        bDescriptorType        36
        bDescriptorSubtype      2 (FORMAT_TYPE)
        bFormatType             1 (FORMAT_TYPE_I)
        bNrChannels             2
        bSubframeSize           3
        bBitResolution         20
        bSamFreqType            1 Discrete
        tSamFreq[ 0]        44100
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x85  EP 5 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0126  1x 294 bytes
        bInterval               1
        bRefresh                0
        bSynchAddress           0
        AudioControl Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x00
          bLockDelayUnits         2 Decoded PCM samples
          wLockDelay              0 Decoded PCM samples
Device Status:     0x0000
  (Bus Powered)

On 11/17/2011 07:09 PM, athos bacchiocchi wrote:
> 2011/11/17 Daniel Mack <zonque@... <mailto:zonque@...>>
> 
>     This is usually a sign that the device is in fact incompatible to the
>     audio class, even though appearantly, it has class compliant headers.
>     Can you send the output of "lsusb -v"?
> 
> 
> Thanks for the help. The result of lsusb -v is in the textfile attached.

As I suspected - wonderfully class compliant.

Do you have access to a Mac? Would be interesting to see if that device
would be handled well by the generic driver in OS X (that is, without
their proprietary driver). Any chance you can test this?


Daniel

On 17 November 2011 19:26, Daniel Mack <zonque@...> wrote:

>  As I suspected - wonderfully class compliant.
> Do you have access to a Mac? Would be interesting to see if that device
> would be handled well by the generic driver in OS X (that is, without
> their proprietary driver). Any chance you can test this?
>

Sorry  for the delay, getting my hands on a mac took longer than i thought.
I tried to connect the usbpre to a macbook with snow leopard, and without
proprietary drivers the card is seen by the sistem, i can select it in the
audio options, but it doesn't emit any sound. And, like in ubuntu, the led
front panel on the device remains irresponsive.

athos

On 12/26/2011 12:50 PM, athos bacchiocchi wrote:
> On 17 November 2011 19:26, Daniel Mack <zonque@...
> <mailto:zonque@...>> wrote:
> 
>     As I suspected - wonderfully class compliant.
>     Do you have access to a Mac? Would be interesting to see if that device
>     would be handled well by the generic driver in OS X (that is, without
>     their proprietary driver). Any chance you can test this?
> 
> 
> Sorry  for the delay, getting my hands on a mac took longer than i
> thought. I tried to connect the usbpre to a macbook with snow leopard,
> and without proprietary drivers the card is seen by the sistem, i can
> select it in the audio options, but it doesn't emit any sound. And, like
> in ubuntu, the led front panel on the device remains irresponsive.

Ok, then this hardware is provably not class compliant, at least wrt to
streaming. Someone would need to reverse-egineer the protocol and
implement support in the snd-usb Linux driver. Or ask Sound Devices to
reveal some documentation about their protocol.


Daniel

On 12/27/2011 04:20 PM, Daniel Mack wrote:
> On 12/26/2011 12:50 PM, athos bacchiocchi wrote:
>> On 17 November 2011 19:26, Daniel Mack<zonque@...
>> <mailto:zonque@...>>  wrote:
>>
>>      As I suspected - wonderfully class compliant.
>>      Do you have access to a Mac? Would be interesting to see if that device
>>      would be handled well by the generic driver in OS X (that is, without
>>      their proprietary driver). Any chance you can test this?
>>
>>
>> Sorry  for the delay, getting my hands on a mac took longer than i
>> thought. I tried to connect the usbpre to a macbook with snow leopard,
>> and without proprietary drivers the card is seen by the sistem, i can
>> select it in the audio options, but it doesn't emit any sound. And, like
>> in ubuntu, the led front panel on the device remains irresponsive.
> Ok, then this hardware is provably not class compliant, at least wrt to
> streaming. Someone would need to reverse-egineer the protocol and
> implement support in the snd-usb Linux driver. Or ask Sound Devices to
> reveal some documentation about their protocol.
>
>
> Daniel
>
>
I'm guessing it's the usbpre1 ? I have the USBpre2 and it works very 
well on linux, except not in usb2 mode, even tho it's class compliant 
even in usb2 mode.

On 27 December 2011 15:36, alexander <axeldenstore@...> wrote:

> I'm guessing it's the usbpre1 ? I have the USBpre2 and it works very
> well on linux, except not in usb2 mode, even tho it's class compliant
> even in usb2 mode.
>

yes, it's the usbpre 1. I found this old post:
http://mailman.alsa-project.org/pipermail/alsa-devel/2007-June/001404.html

in which the OP stated he asked for specifications, but probably never
received them. I don't think I'm able to write a driver, so i guess i came
to a dead end.

Or maybe i should take this as sign i should start studying :)

I already know C programming (and some audio-related electronics), do you
have references about driver development for linux and snd-usb? General,
"academic" resources would be great. It will probabily take years, but at
least i may learn something.

thanks,
athos

On 12/27/2011 10:06 PM, athos bacchiocchi wrote:
> On 27 December 2011 15:36, alexander <axeldenstore@...
> <mailto:axeldenstore@...>> wrote:
> 
>     I'm guessing it's the usbpre1 ? I have the USBpre2 and it works very
>     well on linux, except not in usb2 mode, even tho it's class compliant
>     even in usb2 mode.
> 
> 
> yes, it's the usbpre 1. I found this old post:
> http://mailman.alsa-project.org/pipermail/alsa-devel/2007-June/001404.html
> 
> in which the OP stated he asked for specifications, but probably never
> received them. I don't think I'm able to write a driver, so i guess i
> came to a dead end.
> 
> Or maybe i should take this as sign i should start studying :)
> 
> I already know C programming (and some audio-related electronics), do
> you have references about driver development for linux and snd-usb?
> General, "academic" resources would be great. It will probabily take
> years, but at least i may learn something.

Just give it a try. With access to the hardware, it's probably not as
hard as it might appear in the first place. A good start is to install
their Windows driver and an USB packet sniffer to trace the
communication between the host and the device. Then compare this to what
the USB audio standard requires, and find the differences.

My guess is that it only takes a different initialization mechanism, but
I might me wrong. Once you have any more insight or any trace dump, post
them here.


Daniel

ok. any advice for the sniffer? i found this:
http://www.pcausa.com/Utilities/UsbSnoop/default.htm

athos

On 28 December 2011 12:05, Daniel Mack <zonque@...> wrote:

> My guess is that it only takes a different initialization mechanism, but
> I might me wrong. Once you have any more insight or any trace dump, post
> them here.
>

On 12/28/2011 10:00 PM, athos bacchiocchi wrote:
> ok. any advice for the sniffer? i found this:
> http://www.pcausa.com/Utilities/UsbSnoop/default.htm

Yes, I'e heard that one does its job. But I can't really proof it, as
I've personally only worked with hardware analyzers.

Daniel