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How to specify the channel number of USB audio interface.

  • I want to create a program to import audio signals from USB audio interface.
    I've read the Qt specifications,
    but I can't find a function to specify the channel number to be recognized.
    Is there a function to specify a channel other than channel number 1 in Qt?

  • Lifetime Qt Champion

    Hi and welcome to devnet,

    Which OS are you on ?
    How is your card seen by the system ?
    What are you using to do the capture ?
    How does Qt get when you enumerate the devices from it ?

  • Thanks for the reply.
    I am using Windows 10 and MacOS 10.14.
    On the USB audio interface I have, the "QAudioDeviceInfo" returns the following.

    supportedByteOrder : [LittleEndian][BigEndian].
    supportedSampleType : [SignedInt][UnSignedInt][Float].
    supportedSampleRates : [128000][32000][48000][64000][192000][96000][88200][44100][176400]]
    supportedChannelCounts : [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]
    supportedSampleSizes : [8][16][24][32][64].
    supportedCodecs : [audio/pcm]

    However, this audio interface is originally a 64-channel product,
    so I think the "supportedChannelCounts" number is wrong.

    No matter how I set it, only the input of channel number 1 was recognized.
    Does this mean that Qt can't properly recognize USB audio interfaces with more than 16 channels?
    I would like Qt to recognize a number other than channel number 1 and run the program.

  • Lifetime Qt Champion

    Looks like the kind of hardware that is out of league for QtMultimedia.

    Depending on what you want to do next, I think that PortAudio is worth checking.

  • @SGaist
    So that's what it was after all.
    I had expected that since there was no setting for it, but...

    Thank you very much for the good information!
    I'll check out PortAudio.

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