Remove restrictions on --channels

stream.c

@@ -2552,13 +2552,16 @@ static void preconfigure_microphone() {
         log_debug("cannot use mono audio; trying stereo\n");
       }
       audio_channels = 2;
-    } else {
+    } else if (audio_channels == 2) {
       if (is_audio_channels_specified) {
         log_info("cannot use stereo audio; trying mono\n");
       } else {
         log_debug("cannot use stereo audio; trying mono\n");
       }
       audio_channels = 1;
+    } else { // user has specified audio channels
+      log_info("cannot use %d channels audio; trying mono\n", audio_channels);
+      audio_channels = 1;
     }
     err = snd_pcm_hw_params_set_channels(capture_handle, alsa_hw_params, audio_channels);
     if (err < 0) {
@@ -5715,10 +5718,6 @@ int main(int argc, char **argv) {
             print_usage();
             return EXIT_FAILURE;
           }
-          if (value != 1 && value != 2) {
-            log_fatal("error: invalid channels: %ld (must be 1 or 2)\n", value);
-            return EXIT_FAILURE;
-          }
           audio_channels = value;
           is_audio_channels_specified = 1;
           break;