Viper, sound in mono or stereo

Hello,

I work whith a Viper from Arcom with a National audio codec LM4548AA. It runs on Linux.

I want to record sound from a microphone in mono. It is impossible. When I configure the sound device (/dev/dsp or /dev/audio) it's always in stereo.

int tmp = 1; ioctl(_devHandle, SOUND_PCM_WRITE_CHANNELS, &tmp); printf("channels : %d\n", tmp);

=> channels : 2

I would like : => channels : 1

Can you help me ?

Thanks,

Bernard.