src/media/cast/receiver/audio_decoder_unittest.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/bind.h"
   6 #include "base/bind_helpers.h"
   7 #include "base/synchronization/condition_variable.h"
   8 #include "base/synchronization/lock.h"
   9 #include "base/sys_byteorder.h"
  10 #include "base/time/time.h"
  11 #include "media/cast/cast_config.h"
  12 #include "media/cast/receiver/audio_decoder.h"
  13 #include "media/cast/test/utility/audio_utility.h"
  14 #include "media/cast/test/utility/standalone_cast_environment.h"
  15 #include "testing/gtest/include/gtest/gtest.h"
  16 #include "third_party/opus/src/include/opus.h"
  17
  18 namespace media {
  19 namespace cast {
  20
  21 namespace {
  22 struct TestScenario {
  23   Codec codec;
  24   int num_channels;
  25   int sampling_rate;
  26
  27   TestScenario(Codec c, int n, int s)
  28       : codec(c), num_channels(n), sampling_rate(s) {}
  29 };
  30 }  // namespace
  31
  32 class AudioDecoderTest : public ::testing::TestWithParam<TestScenario> {
  33  public:
  34   AudioDecoderTest()
  35       : cast_environment_(new StandaloneCastEnvironment()),
  36         cond_(&lock_) {}
  37
  38   virtual ~AudioDecoderTest() {
  39     // Make sure all threads have stopped before the environment goes away.
  40     cast_environment_->Shutdown();
  41   }
  42
  43  protected:
  44   virtual void SetUp() OVERRIDE {
  45     audio_decoder_.reset(new AudioDecoder(cast_environment_,
  46                                           GetParam().num_channels,
  47                                           GetParam().sampling_rate,
  48                                           GetParam().codec));
  49     CHECK_EQ(STATUS_AUDIO_INITIALIZED, audio_decoder_->InitializationResult());
  50
  51     audio_bus_factory_.reset(
  52         new TestAudioBusFactory(GetParam().num_channels,
  53                                 GetParam().sampling_rate,
  54                                 TestAudioBusFactory::kMiddleANoteFreq,
  55                                 0.5f));
  56     last_frame_id_ = 0;
  57     seen_a_decoded_frame_ = false;
  58
  59     if (GetParam().codec == CODEC_AUDIO_OPUS) {
  60       opus_encoder_memory_.reset(
  61           new uint8[opus_encoder_get_size(GetParam().num_channels)]);
  62       OpusEncoder* const opus_encoder =
  63           reinterpret_cast<OpusEncoder*>(opus_encoder_memory_.get());
  64       CHECK_EQ(OPUS_OK, opus_encoder_init(opus_encoder,
  65                                           GetParam().sampling_rate,
  66                                           GetParam().num_channels,
  67                                           OPUS_APPLICATION_AUDIO));
  68       CHECK_EQ(OPUS_OK,
  69                opus_encoder_ctl(opus_encoder, OPUS_SET_BITRATE(OPUS_AUTO)));
  70     }
  71
  72     total_audio_feed_in_ = base::TimeDelta();
  73     total_audio_decoded_ = base::TimeDelta();
  74   }
  75
  76   // Called from the unit test thread to create another EncodedFrame and push it
  77   // into the decoding pipeline.
  78   void FeedMoreAudio(const base::TimeDelta& duration,
  79                      int num_dropped_frames) {
  80     // Prepare a simulated EncodedFrame to feed into the AudioDecoder.
  81     scoped_ptr<EncodedFrame> encoded_frame(
  82         new EncodedFrame());
  83     encoded_frame->dependency = EncodedFrame::KEY;
  84     encoded_frame->frame_id = last_frame_id_ + 1 + num_dropped_frames;
  85     encoded_frame->referenced_frame_id = encoded_frame->frame_id;
  86     last_frame_id_ = encoded_frame->frame_id;
  87
  88     const scoped_ptr<AudioBus> audio_bus(
  89         audio_bus_factory_->NextAudioBus(duration).Pass());
  90
  91     // Encode |audio_bus| into |encoded_frame->data|.
  92     const int num_elements = audio_bus->channels() * audio_bus->frames();
  93     std::vector<int16> interleaved(num_elements);
  94     audio_bus->ToInterleaved(
  95         audio_bus->frames(), sizeof(int16), &interleaved.front());
  96     if (GetParam().codec == CODEC_AUDIO_PCM16) {
  97       encoded_frame->data.resize(num_elements * sizeof(int16));
  98       int16* const pcm_data =
  99           reinterpret_cast<int16*>(encoded_frame->mutable_bytes());
 100       for (size_t i = 0; i < interleaved.size(); ++i)
 101         pcm_data[i] = static_cast<int16>(base::HostToNet16(interleaved[i]));
 102     } else if (GetParam().codec == CODEC_AUDIO_OPUS) {
 103       OpusEncoder* const opus_encoder =
 104           reinterpret_cast<OpusEncoder*>(opus_encoder_memory_.get());
 105       const int kOpusEncodeBufferSize = 4000;
 106       encoded_frame->data.resize(kOpusEncodeBufferSize);
 107       const int payload_size =
 108           opus_encode(opus_encoder,
 109                       &interleaved.front(),
 110                       audio_bus->frames(),
 111                       encoded_frame->mutable_bytes(),
 112                       encoded_frame->data.size());
 113       CHECK_GT(payload_size, 1);
 114       encoded_frame->data.resize(payload_size);
 115     } else {
 116       ASSERT_TRUE(false);  // Not reached.
 117     }
 118
 119     {
 120       base::AutoLock auto_lock(lock_);
 121       total_audio_feed_in_ += duration;
 122     }
 123
 124     cast_environment_->PostTask(
 125         CastEnvironment::MAIN,
 126         FROM_HERE,
 127         base::Bind(&AudioDecoder::DecodeFrame,
 128                    base::Unretained(audio_decoder_.get()),
 129                    base::Passed(&encoded_frame),
 130                    base::Bind(&AudioDecoderTest::OnDecodedFrame,
 131                               base::Unretained(this),
 132                               num_dropped_frames == 0)));
 133   }
 134
 135   // Blocks the caller until all audio that has been feed in has been decoded.
 136   void WaitForAllAudioToBeDecoded() {
 137     DCHECK(!cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
 138     base::AutoLock auto_lock(lock_);
 139     while (total_audio_decoded_ < total_audio_feed_in_)
 140       cond_.Wait();
 141     EXPECT_EQ(total_audio_feed_in_.InMicroseconds(),
 142               total_audio_decoded_.InMicroseconds());
 143   }
 144
 145  private:
 146   // Called by |audio_decoder_| to deliver each frame of decoded audio.
 147   void OnDecodedFrame(bool should_be_continuous,
 148                       scoped_ptr<AudioBus> audio_bus,
 149                       bool is_continuous) {
 150     DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
 151
 152     // A NULL |audio_bus| indicates a decode error, which we don't expect.
 153     ASSERT_FALSE(!audio_bus);
 154
 155     // Did the decoder detect whether frames were dropped?
 156     EXPECT_EQ(should_be_continuous, is_continuous);
 157
 158     // Does the audio data seem to be intact?  For Opus, we have to ignore the
 159     // first frame seen at the start (and immediately after dropped packet
 160     // recovery) because it introduces a tiny, significant delay.
 161     bool examine_signal = true;
 162     if (GetParam().codec == CODEC_AUDIO_OPUS) {
 163       examine_signal = seen_a_decoded_frame_ && should_be_continuous;
 164       seen_a_decoded_frame_ = true;
 165     }
 166     if (examine_signal) {
 167       for (int ch = 0; ch < audio_bus->channels(); ++ch) {
 168         EXPECT_NEAR(
 169             TestAudioBusFactory::kMiddleANoteFreq * 2 * audio_bus->frames() /
 170                 GetParam().sampling_rate,
 171             CountZeroCrossings(audio_bus->channel(ch), audio_bus->frames()),
 172             1);
 173       }
 174     }
 175
 176     // Signal the main test thread that more audio was decoded.
 177     base::AutoLock auto_lock(lock_);
 178     total_audio_decoded_ += base::TimeDelta::FromSeconds(1) *
 179         audio_bus->frames() / GetParam().sampling_rate;
 180     cond_.Signal();
 181   }
 182
 183   const scoped_refptr<StandaloneCastEnvironment> cast_environment_;
 184   scoped_ptr<AudioDecoder> audio_decoder_;
 185   scoped_ptr<TestAudioBusFactory> audio_bus_factory_;
 186   uint32 last_frame_id_;
 187   bool seen_a_decoded_frame_;
 188   scoped_ptr<uint8[]> opus_encoder_memory_;
 189
 190   base::Lock lock_;
 191   base::ConditionVariable cond_;
 192   base::TimeDelta total_audio_feed_in_;
 193   base::TimeDelta total_audio_decoded_;
 194
 195   DISALLOW_COPY_AND_ASSIGN(AudioDecoderTest);
 196 };
 197
 198 TEST_P(AudioDecoderTest, DecodesFramesWithSameDuration) {
 199   const base::TimeDelta kTenMilliseconds =
 200       base::TimeDelta::FromMilliseconds(10);
 201   const int kNumFrames = 10;
 202   for (int i = 0; i < kNumFrames; ++i)
 203     FeedMoreAudio(kTenMilliseconds, 0);
 204   WaitForAllAudioToBeDecoded();
 205 }
 206
 207 TEST_P(AudioDecoderTest, DecodesFramesWithVaryingDuration) {
 208   // These are the set of frame durations supported by the Opus encoder.
 209   const int kFrameDurationMs[] = { 5, 10, 20, 40, 60 };
 210
 211   const int kNumFrames = 10;
 212   for (size_t i = 0; i < arraysize(kFrameDurationMs); ++i)
 213     for (int j = 0; j < kNumFrames; ++j)
 214       FeedMoreAudio(base::TimeDelta::FromMilliseconds(kFrameDurationMs[i]), 0);
 215   WaitForAllAudioToBeDecoded();
 216 }
 217
 218 TEST_P(AudioDecoderTest, RecoversFromDroppedFrames) {
 219   const base::TimeDelta kTenMilliseconds =
 220       base::TimeDelta::FromMilliseconds(10);
 221   const int kNumFrames = 100;
 222   int next_drop_at = 3;
 223   int next_num_dropped = 1;
 224   for (int i = 0; i < kNumFrames; ++i) {
 225     if (i == next_drop_at) {
 226       const int num_dropped = next_num_dropped++;
 227       next_drop_at *= 2;
 228       i += num_dropped;
 229       FeedMoreAudio(kTenMilliseconds, num_dropped);
 230     } else {
 231       FeedMoreAudio(kTenMilliseconds, 0);
 232     }
 233   }
 234   WaitForAllAudioToBeDecoded();
 235 }
 236
 237 INSTANTIATE_TEST_CASE_P(
 238     AudioDecoderTestScenarios,
 239     AudioDecoderTest,
 240     ::testing::Values(
 241          TestScenario(CODEC_AUDIO_PCM16, 1, 8000),
 242          TestScenario(CODEC_AUDIO_PCM16, 2, 48000),
 243          TestScenario(CODEC_AUDIO_OPUS, 1, 8000),
 244          TestScenario(CODEC_AUDIO_OPUS, 2, 48000)));
 245
 246 }  // namespace cast
 247 }  // namespace media