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klimas

Member

Registered: 2009-07-03

Posts: 25

Half speed microphone

Hello,

I have an issue with my laptop webcam microphone (Fitipower Integrated Technology Inc Webcam Microphone). All sound recorded by it appears to be roughly "half-speed". The webcam has the following specifics:

Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass          239 Miscellaneous Device
  bDeviceSubClass         2 ?
  bDeviceProtocol         1 Interface Association
  bMaxPacketSize0        64
  idVendor           0x18e3 Fitipower Integrated Technology Inc
  idProduct          0x9512 Webcam
  bcdDevice            1.00
  iManufacturer           2 FITI LINKCORP.
  iProduct                1 USB 2.0 Camera
  iSerial                 0 
  bNumConfigurations      1

-------------- MICROPHONE SPECIFIC INTERFACE DESCRIPOR --------------------
AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           3
        bDelay                  1 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]        48000
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x84  EP 4 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0100  1x 256 bytes
        bInterval               4
        bRefresh                0
        bSynchAddress           0
        AudioControl Endpoint Descriptor:
          bLength                 7
          bDescriptorType        37
          bDescriptorSubtype      1 (EP_GENERAL)
          bmAttributes         0x01
            Sampling Frequency
          bLockDelayUnits         0 Undefined
          wLockDelay              0 Undefined
        ** UNRECOGNIZED:  28 ff 42 49 53 54 00 01 06 05 01 00 00 00 00 00 01 06 00 13 02 07 00 13 03 08 00 13 04 09 00 13 05 0
a 00 13 06 0b 00 13

Supposedly the microphone's native recording is done at 16 bit 48000Hz. However, no matter how I try to specify my arecord command, the resulting recording appears to be "half speed". For example, the following command still results in a "half speed" wav file:

arecord -D plughw:0,0 -f S16_LE -r 48000 record.wav

Obviously, this isn't program specific. Skype, Audacity etc. also have the same problem.

Any help would be greatly appriciated.