Bug 936981 - Setup GTest for content/media and add a test case for OpusTrackEncoder. r=rillian

content/media/encoder/OpusTrackEncoder.cpp

@@ -17,6 +17,11 @@
 
 namespace mozilla {
 
+// The Opus format supports up to 8 channels, and supports multitrack audio up
+// to 255 channels, but the current implementation supports only mono and
+// stereo, and downmixes any more than that.
+static const int MAX_SUPPORTED_AUDIO_CHANNELS = 8;
+
 // http://www.opus-codec.org/docs/html_api-1.0.2/group__opus__encoder.html
 // In section "opus_encoder_init", channels must be 1 or 2 of input signal.
 static const int MAX_CHANNELS = 2;
@@ -143,15 +148,15 @@ OpusTrackEncoder::Init(int aChannels, int aSamplingRate)
   // This monitor is used to wake up other methods that are waiting for encoder
   // to be completely initialized.
   ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+
+  NS_ENSURE_TRUE((aChannels <= MAX_SUPPORTED_AUDIO_CHANNELS) && (aChannels > 0),
+                 NS_ERROR_FAILURE);
+
   // This version of encoder API only support 1 or 2 channels,
   // So set the mChannels less or equal 2 and
   // let InterleaveTrackData downmix pcm data.
   mChannels = aChannels > MAX_CHANNELS ? MAX_CHANNELS : aChannels;
 
-  if (aChannels <= 0) {
-    return NS_ERROR_FAILURE;
-  }
-
   // According to www.opus-codec.org, creating an opus encoder requires the
   // sampling rate of source signal be one of 8000, 12000, 16000, 24000, or
   // 48000. If this constraint is not satisfied, we resample the input to 48kHz.
@@ -171,6 +176,7 @@ OpusTrackEncoder::Init(int aChannels, int aSamplingRate)
     }
   }
   mSamplingRate = aSamplingRate;
+  NS_ENSURE_TRUE(mSamplingRate > 0, NS_ERROR_FAILURE);
 
   int error = 0;
   mEncoder = opus_encoder_create(GetOutputSampleRate(), mChannels,

content/media/encoder/OpusTrackEncoder.h

@@ -41,13 +41,13 @@ protected:
 
   nsresult Init(int aChannels, int aSamplingRate) MOZ_OVERRIDE;
 
-private:
   /**
    * Get the samplerate of the data to be fed to the Opus encoder. This might be
-   * different from the intput samplerate if resampling occurs.
+   * different from the input samplerate if resampling occurs.
    */
   int GetOutputSampleRate();
 
+private:
   /**
    * The Opus encoder from libopus.
    */

content/media/gtest/TestTrackEncoder.cpp

@@ -0,0 +1,85 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "gtest/gtest.h"
+#include "OpusTrackEncoder.h"
+
+using namespace mozilla;
+
+class TestOpusTrackEncoder : public OpusTrackEncoder
+{
+public:
+  // Return true if it has successfully initialized the Opus encoder.
+  bool TestOpusCreation(int aChannels, int aSamplingRate)
+  {
+    if (Init(aChannels, aSamplingRate) == NS_OK) {
+      if (GetPacketDuration()) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  // Return the sample rate of data to be fed to the Opus encoder, could be
+  // re-sampled if it was not one of the Opus supported sampling rates.
+  // Init() is expected to be called first.
+  int TestGetOutputSampleRate()
+  {
+    return mInitialized ? GetOutputSampleRate() : 0;
+  }
+};
+
+static bool
+TestOpusInit(int aChannels, int aSamplingRate)
+{
+  TestOpusTrackEncoder encoder;
+  return encoder.TestOpusCreation(aChannels, aSamplingRate);
+}
+
+static int
+TestOpusResampler(int aChannels, int aSamplingRate)
+{
+  TestOpusTrackEncoder encoder;
+  EXPECT_TRUE(encoder.TestOpusCreation(aChannels, aSamplingRate));
+  return encoder.TestGetOutputSampleRate();
+}
+
+TEST(Media, OpusEncoder_Init)
+{
+  // Expect false with 0 or negative channels of input signal.
+  EXPECT_FALSE(TestOpusInit(0, 16000));
+  EXPECT_FALSE(TestOpusInit(-1, 16000));
+
+  // The Opus format supports up to 8 channels, and supports multitrack audio up
+  // to 255 channels, but the current implementation supports only mono and
+  // stereo, and downmixes any more than that.
+  // Expect false with channels of input signal exceed the max supported number.
+  EXPECT_FALSE(TestOpusInit(8 + 1, 16000));
+
+  // Should accept channels within valid range.
+  for (int i = 1; i <= 8; i++) {
+    EXPECT_TRUE(TestOpusInit(i, 16000));
+  }
+
+  // Expect false with 0 or negative sampling rate of input signal.
+  EXPECT_FALSE(TestOpusInit(1, 0));
+  EXPECT_FALSE(TestOpusInit(1, -1));
+}
+
+TEST(Media, OpusEncoder_Resample)
+{
+  // Sampling rates of data to be fed to Opus encoder, should remain unchanged
+  // if it is one of Opus supported rates (8000, 12000, 16000, 24000 and 48000
+  // (kHz)) at initialization.
+  EXPECT_TRUE(TestOpusResampler(1, 8000) == 8000);
+  EXPECT_TRUE(TestOpusResampler(1, 12000) == 12000);
+  EXPECT_TRUE(TestOpusResampler(1, 16000) == 16000);
+  EXPECT_TRUE(TestOpusResampler(1, 24000) == 24000);
+  EXPECT_TRUE(TestOpusResampler(1, 48000) == 48000);
+
+  // Otherwise, it should be resampled to 48kHz by resampler.
+  EXPECT_FALSE(TestOpusResampler(1, 9600) == 9600);
+  EXPECT_FALSE(TestOpusResampler(1, 44100) == 44100);
+}

content/media/gtest/moz.build

@@ -0,0 +1,22 @@
+# -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+LIBRARY_NAME = 'media_gtest'
+
+UNIFIED_SOURCES += [
+    'TestTrackEncoder.cpp',
+]
+
+LIBXUL_LIBRARY = True
+
+EXPORT_LIBRARY = True
+
+include('/ipc/chromium/chromium-config.mozbuild')
+
+LOCAL_INCLUDES += [
+    '/content/media/encoder',
+]
+

content/media/moz.build

@@ -49,7 +49,10 @@ if CONFIG['MOZ_OMX_DECODER']:
 
 PARALLEL_DIRS += ['webspeech']
 
-TEST_DIRS += ['test']
+TEST_DIRS += [
+    'test',
+    'gtest',
+]
 
 EXPORTS += [
     'AbstractMediaDecoder.h',

toolkit/library/Makefile.in

@@ -448,6 +448,7 @@ COMPONENT_LIBS += \
   gfxtest \
   ssltest \
   xpcom_glue_gtest \
+  media_gtest \
   $(NULL)
 endif