#13 Error when using bluetooth headset

[Rich]

When connecting to the 9999 node with a bluetooth headset in use for input and/or output the following error message is seen. This has been observed on an iMac running OS-X 10.4 and on a MacMini running OS-X10.5.

Sometimes it scrolls repeatedly.

Echolinux error: An error occured while using the portaudio stream
Error number: -9999

Echolinux error: Error message: Invalid number of channels.

[vk6hdx]

I have also had this problem.

Running EchoMac version 1.16.1
Mac OS X 10.6 (Snow Leopard)

This is not just related to bluetooth headset, but any audio output device with a single channel. I am using a Plantronics monaural USB headset (MX500i). The input device works fine, however when I select this as the output device I also get the error:

Echolinux error: An error occured while using the portaudio stream
Error number: -9999
Error message: Invalid number of channels.

Regards,
Troy VK6HDX

[Quentin Smith]

With the following patch, I'm able to use EchoMac with my bluetooth headset. I'm not sure why it was using stereo audio before - maybe there are audio output devices that can ONLY handle stereo?

commit 3e5289789108d2704be80f29576454bc5edd9778
Author: Quentin Smith quentin@mit.edu
Date: Thu Dec 30 23:57:16 2010 -0500

Support mono audio output devices like bluetooth headsets

diff --git a/echomac/echolinux/vox_portaudio.c b/echomac/echolinux/vox_portaudio.c
index ab54191..3422570 100755
--- a/echomac/echolinux/vox_portaudio.c
+++ b/echomac/echolinux/vox_portaudio.c
@@ -496,7 +496,6 @@ int recvAudio(void){
// int z;
PaError err;
PABLIO_Stream *aStream;

• short stereobuff[700], *out;
  // long writableByteCount;

  /**** PortAudio end *******/
  @@ -510,7 +509,7 @@ int recvAudio(void){
  fflush(NULL);

  err = OpenAudioStream ( &aStream, SAMPLE_RATE, SAMPLE_TYPE,

• (PABLIO_WRITE | PABLIO_STEREO) );

• (PABLIO_WRITE | PABLIO_MONO) );
  if ( err != paNoError ) goto error;

  raw_tty(1);
  @@ -573,17 +572,7 @@ int recvAudio(void){
  temp = (unsigned char )&(voicePacket->data);
  gsm_decode(gsmh, temp+(i33), sbuff);

• // temporary hack: source data is mono, output is stereo

• // we have to manually interleave data...
• //
• // Something isn't right, just ignore for now
• //
• out = stereobuff;
• for (j=0; j<=159; j++) {
• *out++ = sbuff[j];
• *out++ = sbuff[j];
• }
• WriteAudioStream( aStream, stereobuff, FRAMES_PER_BLOCK );
• WriteAudioStream( aStream, sbuff, FRAMES_PER_BLOCK );
  for(j=0;j<160;j+=2) {
  pTemp = &sbuff[j];
  average = average + abs(*pTemp);