Posting Opus's set-force-channels functionality to WebRTC.

webrtc/modules/audio_coding/codecs/opus/opus_unittest.cc

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 391 matching lines @@
                                         application_));
 
   EXPECT_EQ(0, WebRtcOpus_SetComplexity(opus_encoder_, 0));
   EXPECT_EQ(0, WebRtcOpus_SetComplexity(opus_encoder_, 10));
   EXPECT_EQ(-1, WebRtcOpus_SetComplexity(opus_encoder_, 11));
 
   // Free memory.
   EXPECT_EQ(0, WebRtcOpus_EncoderFree(opus_encoder_));
 }
 
+TEST_P(OpusTest, OpusForceChannels) {

[tlegrand-webrtc, 2016/09/22 12:15:42]

This test will always run either the channels_ == 2 part OR the channels_ = 1.
Why not always run both?

[minyue-webrtc, 2016/09/22 15:02:19]

It actually runs both cases. It will be split into multiple (4) cases, due to
TEST_P.

[tlegrand-webrtc, 2016/09/23 11:37:41]

Acknowledged.

+  // Test without creating encoder memory.
+  EXPECT_EQ(-1, WebRtcOpus_SetForceChannels(opus_encoder_, 1));
+
+  ASSERT_EQ(0,
+            WebRtcOpus_EncoderCreate(&opus_encoder_, channels_, application_));
+
+  if (channels_ == 2) {
+    EXPECT_EQ(-1, WebRtcOpus_SetForceChannels(opus_encoder_, 3));
+    EXPECT_EQ(0, WebRtcOpus_SetForceChannels(opus_encoder_, 2));
+    EXPECT_EQ(0, WebRtcOpus_SetForceChannels(opus_encoder_, 1));
+    EXPECT_EQ(0, WebRtcOpus_SetForceChannels(opus_encoder_, 0));
+  } else {
+    EXPECT_EQ(-1, WebRtcOpus_SetForceChannels(opus_encoder_, 2));
+    EXPECT_EQ(0, WebRtcOpus_SetForceChannels(opus_encoder_, 1));
+    EXPECT_EQ(0, WebRtcOpus_SetForceChannels(opus_encoder_, 0));
+  }
+
+  EXPECT_EQ(0, WebRtcOpus_EncoderFree(opus_encoder_));
+}
+
 // Encode and decode one frame, initialize the decoder and
 // decode once more.
 TEST_P(OpusTest, OpusDecodeInit) {
   PrepareSpeechData(channels_, 20, 20);
 
   // Create encoder memory.
   EXPECT_EQ(0, WebRtcOpus_EncoderCreate(&opus_encoder_,
                                         channels_,
                                         application_));
   EXPECT_EQ(0, WebRtcOpus_DecoderCreate(&opus_decoder_, channels_));
@@ skipping 250 matching lines @@
   EXPECT_EQ(0, WebRtcOpus_EncoderFree(opus_encoder_));
   EXPECT_EQ(0, WebRtcOpus_DecoderFree(opus_decoder_));
 }
 
 INSTANTIATE_TEST_CASE_P(VariousMode,
                         OpusTest,
                         Combine(Values(1, 2), Values(0, 1)));
 
 
 }  // namespace webrtc