Adding cbr support for Opus

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 22 matching lines @@
 const size_t kOpus20msFrameSamples = kOpusRateKhz * 20;
 // Number of samples-per-channel in a 10 ms frame, sampled at 48 kHz.
 const size_t kOpus10msFrameSamples = kOpusRateKhz * 10;
 
 class OpusTest : public TestWithParam<::testing::tuple<int, int>> {
  protected:
   OpusTest();
 
   void TestDtxEffect(bool dtx, int block_length_ms);
 
+  void TestCbrEffect(bool dtx, int block_length_ms);
+
   // Prepare |speech_data_| for encoding, read from a hard-coded file.
   // After preparation, |speech_data_.GetNextBlock()| returns a pointer to a
   // block of |block_length_ms| milliseconds. The data is looped every
   // |loop_length_ms| milliseconds.
   void PrepareSpeechData(size_t channel,
                          int block_length_ms,
                          int loop_length_ms);
 
   int EncodeDecode(WebRtcOpusEncInst* encoder,
                    rtc::ArrayView<const int16_t> input_audio,
@@ skipping 240 matching lines @@
     EXPECT_EQ(0, opus_decoder_->in_dtx_mode);
     EXPECT_EQ(0, audio_type);  // Speech.
   }
 
   // Free memory.
   delete[] output_data_decode;
   EXPECT_EQ(0, WebRtcOpus_EncoderFree(opus_encoder_));
   EXPECT_EQ(0, WebRtcOpus_DecoderFree(opus_decoder_));
 }
 
+// Test if CBR does what we expect.
+void OpusTest::TestCbrEffect(bool cbr, int block_length_ms) {
+  PrepareSpeechData(channels_, block_length_ms, 2000);
+  const size_t samples = kOpusRateKhz * block_length_ms;
+
+  int32_t max_pkt_size_diff = 0;
+  int32_t prev_pkt_size = 0;
+
+  // Create encoder memory.
+  EXPECT_EQ(0,
+            WebRtcOpus_EncoderCreate(&opus_encoder_, channels_, application_));
+  EXPECT_EQ(0, WebRtcOpus_DecoderCreate(&opus_decoder_, channels_));
+
+  // Set bitrate.
+  EXPECT_EQ(
+      0, WebRtcOpus_SetBitRate(opus_encoder_, channels_ == 1 ? 32000 : 64000));
+
+  // Setting CBR.
+  EXPECT_EQ(0, cbr ? WebRtcOpus_EnableCbr(opus_encoder_)
+                   : WebRtcOpus_DisableCbr(opus_encoder_));
+
+  int16_t audio_type;
+  std::vector<int16_t> audio_out(samples * channels_);
+  for (int i = 0; i < 100; ++i) {
+    EXPECT_EQ(samples, static_cast<size_t>(EncodeDecode(
+                           opus_encoder_, speech_data_.GetNextBlock(),
+                           opus_decoder_, audio_out.data(), &audio_type)));
+
+    if (prev_pkt_size > 0) {
+      int32_t diff = std::abs((int32_t)encoded_bytes_ - prev_pkt_size);
+      max_pkt_size_diff = std::max(max_pkt_size_diff, diff);
+    }
+    prev_pkt_size = encoded_bytes_;
+  }
+
+  if (cbr) {
+    EXPECT_EQ(max_pkt_size_diff, 0);
+  } else {
+    EXPECT_GT(max_pkt_size_diff, 0);
+  }
+
+  // Free memory.
+  EXPECT_EQ(0, WebRtcOpus_EncoderFree(opus_encoder_));
+  EXPECT_EQ(0, WebRtcOpus_DecoderFree(opus_decoder_));
+}
+
 // Test failing Create.
 TEST(OpusTest, OpusCreateFail) {
   WebRtcOpusEncInst* opus_encoder;
   WebRtcOpusDecInst* opus_decoder;
 
   // Test to see that an invalid pointer is caught.
   EXPECT_EQ(-1, WebRtcOpus_EncoderCreate(NULL, 1, 0));
   // Invalid channel number.
   EXPECT_EQ(-1, WebRtcOpus_EncoderCreate(&opus_encoder, 3, 0));
   // Invalid applciation mode.
@@ skipping 205 matching lines @@
   TestDtxEffect(false, 20);
   TestDtxEffect(false, 40);
 }
 
 TEST_P(OpusTest, OpusDtxOn) {
   TestDtxEffect(true, 10);
   TestDtxEffect(true, 20);
   TestDtxEffect(true, 40);
 }
 
+TEST_P(OpusTest, OpusCbrOff) {
+  TestCbrEffect(false, 10);
+  TestCbrEffect(false, 20);
+  TestCbrEffect(false, 40);
+}
+
+TEST_P(OpusTest, OpusCbrOn) {
+  TestCbrEffect(true, 10);
+  TestCbrEffect(true, 20);
+  TestCbrEffect(true, 40);
+}
+
 TEST_P(OpusTest, OpusSetPacketLossRate) {
   // Test without creating encoder memory.
   EXPECT_EQ(-1, WebRtcOpus_SetPacketLossRate(opus_encoder_, 50));
 
   // Create encoder memory.
   EXPECT_EQ(0, WebRtcOpus_EncoderCreate(&opus_encoder_,
                                         channels_,
                                         application_));
 
   EXPECT_EQ(0, WebRtcOpus_SetPacketLossRate(opus_encoder_, 50));
@@ skipping 155 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