Update tests and DTX check for Opus 1.1.3.

webrtc/modules/audio_coding/codecs/opus/opus_interface.c

Index: webrtc/modules/audio_coding/codecs/opus/opus_interface.c
diff --git a/webrtc/modules/audio_coding/codecs/opus/opus_interface.c b/webrtc/modules/audio_coding/codecs/opus/opus_interface.c
index bcb05966445ba389291e40382fbc16a1a0ac2673..7cf020ff68ce8fb94119703969e12022678033a0 100644
--- a/webrtc/modules/audio_coding/codecs/opus/opus_interface.c
+++ b/webrtc/modules/audio_coding/codecs/opus/opus_interface.c
@@ -95,7 +95,7 @@ int WebRtcOpus_Encode(OpusEncInst* inst,
                     encoded,
                     (opus_int32)length_encoded_buffer);
 
-  if (res == 1) {
+  if (res <= 2) {

[minyue-webrtc, 2016/07/26 10:24:42]

Should it be the following

if (res == 0)
  return -1

if (res <= 2) {
  do DTX stuff
} else {
  inst->in_dtx_mode = 0;
  return res;
}
  

[flim-webrtc, 2016/07/26 11:40:41]

Good catch. I've used res <= 0 since Opus may return negative numbers
corresponding to different error codes.

[minyue-webrtc, 2016/07/26 11:52:06]

Good catch :P

     // Indicates DTX since the packet has nothing but a header. In principle,
     // there is no need to send this packet. However, we do transmit the first
     // occurrence to let the decoder know that the encoder enters DTX mode.