ref: 7a986008f9efd929ed1e251794c5928cb5f04e27
parent: bc190e538bcaa2786e1a9697d2763153621e1eea
author: Mark Harris <mark.hsj@gmail.com>
date: Wed Sep 30 21:51:00 EDT 2015
opusenc: Don't warn about mono center channel WAV Even if it has only one channel, an input WAV file can contain a channel mask. A warning is issued if it is present but not a supported value. Don't warn about the previously accepted mask of 1 (FL), or 4 (FC). Arguably a channel mask of 1 (FL) should trigger the warning, just as 2 (FR) does, but some tools (including old opusdec when decoding to floating point WAV) actually write an incorrect channel mask of 1 for mono WAV files.
--- a/src/audio-in.c
+++ b/src/audio-in.c
@@ -570,7 +570,8 @@
"remapping speakers to Vorbis 7.1 format.\n"));
break;
case 0: /* default/undeclared */
- case 1: /* mono */
+ case 1: /* mono (left only) */
+ case 4: /* mono (center only) */
case 3: /* stereo */
case 51: /* quad */
case 55: /* 5.0 */