Adding OnReceivedOverhead to AudioEncoder.

webrtc/modules/audio_coding/codecs/audio_encoder_unittest.cc

+/*
+ *  Copyright (c) 2016 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.
+ */
+
+#include "webrtc/modules/audio_coding/codecs/audio_encoder.h"
+#include "webrtc/modules/audio_coding/codecs/mock/mock_audio_encoder.h"
+#include "webrtc/test/field_trial.h"
+#include "webrtc/test/gmock.h"
+#include "webrtc/test/gtest.h"
+
+namespace webrtc {
+
+using testing::_;

[michaelt, 2016/11/28 09:26:57]

testing::_ not used at the moment. 

+using testing::Invoke;

[michaelt, 2016/11/28 09:26:57]

testing::Invoke not used at the moment.

+using testing::Return;
+using testing::StrictMock;
+
+TEST(AudioEncoderTest, DoNotInvokeSetTargetBitrateIfOverheadUnknown) {
+  test::ScopedFieldTrials override_field_trials(
+      "WebRTC-SendSideBwe-WithOverhead/Enabled/");
+
+  // In this test, we want to test logics within
+  // |AudioEncoder::OnReceivedTargetAudioBitrate|, we use |MockAudioEncoder|
+  // since this method is not mocked. If it needs to be mocked in the future, we
+  // can maintain the test by letting the mocked method invoke the original
+  // method.

[michaelt, 2016/11/28 09:26:57]

I think i would prefer to add the mock function and invoke it. Other wise if we
once add the mock function, this tests will fail. 

+  StrictMock<MockAudioEncoder> mock_audio_encoder;
+  EXPECT_CALL(mock_audio_encoder, Die());
+  mock_audio_encoder.OnReceivedTargetAudioBitrate(12345);
+  // Since |OnReceivedOverhead| has not been called,
+  // |mock_audio_encoder.SetTargetBitrate| should not be invoked.
+}
+
+TEST(AudioEncoderTest, OverheadRemovedFromTargetAudioBitrate) {
+  test::ScopedFieldTrials override_field_trials(
+      "WebRTC-SendSideBwe-WithOverhead/Enabled/");
+
+  // In this test, we want to test logics within
+  // |AudioEncoder::OnReceivedOverhead| and
+  // |AudioEncoder::OnReceivedTargetAudioBitrate|, we use |MockAudioEncoder|
+  // since these methods are not mocked. If they needs to be mocked in the
+  // future, we can maintain the test by letting the mocked methods invoke the
+  // original methods.
+  StrictMock<MockAudioEncoder> mock_audio_encoder;
+  EXPECT_CALL(mock_audio_encoder, Die());
+
+  constexpr int kFrameLengthMs = 60;
+  constexpr size_t kNum10MsFramesPerPacket = kFrameLengthMs / 10;
+  EXPECT_CALL(mock_audio_encoder, Num10MsFramesInNextPacket())
+      .WillOnce(Return(kNum10MsFramesPerPacket));
+
+  constexpr size_t kOverheadBytesPerPacket = 64;
+  mock_audio_encoder.OnReceivedOverhead(kOverheadBytesPerPacket);
+
+  constexpr size_t kTargetBitrateBps = 12345;
+  EXPECT_CALL(mock_audio_encoder, SetTargetBitrate(kTargetBitrateBps -
+                                                   kOverheadBytesPerPacket * 8 *
+                                                       1000 / kFrameLengthMs));
+  mock_audio_encoder.OnReceivedTargetAudioBitrate(kTargetBitrateBps);
+}
+
+TEST(AudioEncoderTest, BitrateNeverBecomesNegative) {
+  test::ScopedFieldTrials override_field_trials(
+      "WebRTC-SendSideBwe-WithOverhead/Enabled/");
+
+  // In this test, we want to test logics within
+  // |AudioEncoder::OnReceivedOverhead| and
+  // |AudioEncoder::OnReceivedTargetAudioBitrate|, we use |MockAudioEncoder|
+  // since these methods are not mocked. If they needs to be mocked in the
+  // future, we can maintain the test by letting the mocked methods invoke the
+  // original methods.
+  StrictMock<MockAudioEncoder> mock_audio_encoder;
+  EXPECT_CALL(mock_audio_encoder, Die());
+
+  constexpr int kFrameLengthMs = 60;
+  constexpr size_t kNum10MsFramesPerPacket = kFrameLengthMs / 10;
+  EXPECT_CALL(mock_audio_encoder, Num10MsFramesInNextPacket())
+      .WillOnce(Return(kNum10MsFramesPerPacket));
+
+  constexpr size_t kOverheadBytesPerPacket = 64;
+  mock_audio_encoder.OnReceivedOverhead(kOverheadBytesPerPacket);
+
+  // Set a target rate smaller than overhead rate, the bitrate is bounded by 0.
+  constexpr size_t kTargetBitrateBps =
+      kOverheadBytesPerPacket * 8 * 1000 / kFrameLengthMs - 1;
+  EXPECT_CALL(mock_audio_encoder, SetTargetBitrate(0));
+  mock_audio_encoder.OnReceivedTargetAudioBitrate(kTargetBitrateBps);
+}
+
+}  // namespace webrtc