This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Runnin BT_MSP_AUDSINK / BT_MSP_AUDSOURCE in mono mode?

Is it possible to set the default connection to mono instead of stereo?  I'd like to be able to power on a source/sink pair and have them auto pair with a MONO connection instead of the default STEREO.

Thanks!

  • Thanks for your follow up, but I need more than just an API reference.  If calling a function (as opposed to changing a configuration setting) is the solution, then I need to know where it is appropriate to call that function, and what other modifications need to be made to the existing software to prevent other conflicts.

    The function referenced in your link doesn't appear in any header file or source file that I can find.  I did find something that looks similar in the function VS_A3DP_Codec_Configuration located in btvs.c  It sets up a command buffer using a #define named VS_A3DP_CODEC_CONFIGURATION_COMMAND_OPCODE.  It then calls HCI_Send_Raw_Command().

    In VS_A3DP_Codec_Configuration I found this line:

    CommandBuffer[2] = (Byte_t)(((AudioFormat & AVRP_AUDIO_FORMAT_SBC_MODE_MASK) == AVRP_AUDIO_FORMAT_SBC_MODE_MONO)?1:2);

    Which looks promising.  However, I can't find from where this function is called so that I can modify the AudioFormat parameter - perhaps from within a libary?  

    I have also been looking at the following call chain:

    AUD_Event_Callback > OpenA3DPStream > ReconfigureA3DPStream

    This call chain occurs whenever the source connects with the sink.  It seems to me that the "NumberChannels" member of the structure referenced by the parameter of the ReconfigureA3DPStream function is critical to producing the results I am looking for.  That parameter is passed in to the AUD_Event_Callback function and propagates all the way down, but from where it comes, I cannot tell.

    As another strategy, I also tried removing all but the desired audio stream formats from this list found in both the source and sink:

    static BTPSCONST AUD_Stream_Format_t AudioSNKSupportedFormats[] =

    {
    { 44100, 2, 0 },
    { 48000, 2, 0 },
    { 48000, 1, 0 },
    { 44100, 1, 0 }
    } ;

    That just produced white noise on the speaker attached to the sink.

    Thanks for looking into this.