Bug 1656438 - Get rid of NUM_OF_FRAMES from MockCubeb. r=padenot

This allows us to configure the number of frames more dynamically, and update it
on the fly to simulate drift.

Differential Revision: https://phabricator.services.mozilla.com/D89763

dom/media/gtest/MockCubeb.h

@@ -14,7 +14,6 @@
 using namespace std::chrono_literals;
 using namespace mozilla;
 
-const long NUM_OF_FRAMES = 512;
 const uint32_t NUM_OF_CHANNELS = 2;
 
 #ifdef LOG
@@ -223,13 +222,19 @@ class MockCubebStream {
 
   void ThreadFunction() {
     while (!mStreamStop) {
+      // The drift factor affects the callback interval, while the callback
+      // always contains 10ms of audio frames.
+      const uint32_t audioIntervalMs = 10;
+      const uint32_t nrFrames = static_cast<uint32_t>(
+          (mHasOutput ? mOutputParams.rate : mInputParams.rate) *
+          audioIntervalMs / 1000);
       if (mInputParams.rate) {
-        mAudioGenerator.GenerateInterleaved(mInputBuffer, NUM_OF_FRAMES);
+        mAudioGenerator.GenerateInterleaved(mInputBuffer, nrFrames);
       }
       cubeb_stream* stream = reinterpret_cast<cubeb_stream*>(this);
-      long outframes = mDataCallback(
-          stream, mUserPtr, mInputParams.rate ? mInputBuffer : nullptr,
-          mOutputParams.rate ? mOutputBuffer : nullptr, NUM_OF_FRAMES);
+      long outframes =
+          mDataCallback(stream, mUserPtr, mHasInput ? mInputBuffer : nullptr,
+                        mHasOutput ? mOutputBuffer : nullptr, nrFrames);
 
       mAudioVerifier.AppendDataInterleaved(mOutputBuffer, outframes,
                                            NUM_OF_CHANNELS);
@@ -238,7 +243,7 @@ class MockCubebStream {
         mFramesProcessedEvent.Notify(outframes);
       }
 
-      if (outframes < NUM_OF_FRAMES) {
+      if (outframes < nrFrames) {
         mStateCallback(stream, mUserPtr, CUBEB_STATE_DRAINED);
         break;
       }
@@ -272,8 +277,8 @@ class MockCubebStream {
   // Signal to the audio thread that stream is stopped.
   std::atomic_bool mStreamStop{true};
   // The audio buffer used on data callback.
-  AudioDataValue mOutputBuffer[NUM_OF_CHANNELS * NUM_OF_FRAMES] = {};
-  AudioDataValue mInputBuffer[NUM_OF_CHANNELS * NUM_OF_FRAMES] = {};
+  AudioDataValue mOutputBuffer[NUM_OF_CHANNELS * 1920] = {};
+  AudioDataValue mInputBuffer[NUM_OF_CHANNELS * 1920] = {};
   // The audio callback
   cubeb_data_callback mDataCallback = nullptr;
   // The stream state callback
@@ -580,7 +585,7 @@ static int cubeb_mock_stream_set_volume(cubeb_stream* stream, float volume) {
 
 int cubeb_mock_get_min_latency(cubeb* context, cubeb_stream_params params,
                                uint32_t* latency_ms) {
-  *latency_ms = NUM_OF_FRAMES;
+  *latency_ms = 10;
   return CUBEB_OK;
 }
 

dom/media/gtest/TestAudioTrackGraph.cpp

@@ -339,6 +339,7 @@ TEST(TestAudioTrackGraph, SourceTrack)
     sourceTrack->Destroy();
   });
 
+  uint32_t inputRate = stream->InputSampleRate();
   uint32_t inputFrequency = stream->InputFrequency();
   uint64_t preSilenceSamples;
   uint32_t estimatedFreq;
@@ -347,7 +348,7 @@ TEST(TestAudioTrackGraph, SourceTrack)
       WaitFor(stream->OutputVerificationEvent());
 
   EXPECT_EQ(estimatedFreq, inputFrequency);
-  EXPECT_GE(preSilenceSamples, static_cast<uint32_t>(NUM_OF_FRAMES));
+  EXPECT_GE(preSilenceSamples, inputRate / 100 /* 10 ms */);
   // Waveform may start after the beginning. In this case, there is a gap
   // at the beginning and the end which is counted as discontinuity.
   EXPECT_GE(nrDiscontinuities, 0U);