fix resampling if frame doesn't have number of channels set

fixes #336

Change-Id: Ic84734e4296ff8c807a605c67074b8b285c92666

recording-daemon/resample.c

@@ -37,6 +37,10 @@ resample:
 		if (!resample->avresample)
 			goto err;
 
+		if (!frame->channel_layout)
+			frame->channel_layout = av_get_default_channel_layout(
+				av_frame_get_channels(frame));
+
 		err = "failed to set resample option";
 		if ((errcode = av_opt_set_int(resample->avresample, "in_channel_layout",
 				frame->channel_layout, 0)))