media/base/channel_mixer_unittest.cc

   1 // Copyright (c) 2012 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 // MSVC++ requires this to be set before any other includes to get M_SQRT1_2.
   6 #define _USE_MATH_DEFINES
   7
   8 #include <cmath>
   9
  10 #include "base/strings/stringprintf.h"
  11 #include "media/audio/audio_parameters.h"
  12 #include "media/base/audio_bus.h"
  13 #include "media/base/channel_mixer.h"
  14 #include "testing/gtest/include/gtest/gtest.h"
  15
  16 namespace media {
  17
  18 // Number of frames to test with.
  19 enum { kFrames = 16 };
  20
  21 // Test all possible layout conversions can be constructed and mixed.
  22 TEST(ChannelMixerTest, ConstructAllPossibleLayouts) {
  23   for (ChannelLayout input_layout = CHANNEL_LAYOUT_MONO;
  24        input_layout <= CHANNEL_LAYOUT_MAX;
  25        input_layout = static_cast<ChannelLayout>(input_layout + 1)) {
  26     for (ChannelLayout output_layout = CHANNEL_LAYOUT_MONO;
  27          output_layout < CHANNEL_LAYOUT_STEREO_DOWNMIX;
  28          output_layout = static_cast<ChannelLayout>(output_layout + 1)) {
  29       // DISCRETE can't be tested here based on the current approach.
  30       // CHANNEL_LAYOUT_STEREO_AND_KEYBOARD_MIC is not mixable.
  31       if (input_layout == CHANNEL_LAYOUT_DISCRETE ||
  32           input_layout == CHANNEL_LAYOUT_STEREO_AND_KEYBOARD_MIC ||
  33           output_layout == CHANNEL_LAYOUT_DISCRETE ||
  34           output_layout == CHANNEL_LAYOUT_STEREO_AND_KEYBOARD_MIC) {
  35         continue;
  36       }
  37
  38       SCOPED_TRACE(base::StringPrintf(
  39           "Input Layout: %d, Output Layout: %d", input_layout, output_layout));
  40       ChannelMixer mixer(input_layout, output_layout);
  41       scoped_ptr<AudioBus> input_bus = AudioBus::Create(
  42           ChannelLayoutToChannelCount(input_layout), kFrames);
  43       scoped_ptr<AudioBus> output_bus = AudioBus::Create(
  44           ChannelLayoutToChannelCount(output_layout), kFrames);
  45       for (int ch = 0; ch < input_bus->channels(); ++ch)
  46         std::fill(input_bus->channel(ch), input_bus->channel(ch) + kFrames, 1);
  47
  48       mixer.Transform(input_bus.get(), output_bus.get());
  49     }
  50   }
  51 }
  52
  53 struct ChannelMixerTestData {
  54   ChannelMixerTestData(ChannelLayout input_layout, ChannelLayout output_layout,
  55                        float* channel_values, int num_channel_values,
  56                        float scale)
  57       : input_layout(input_layout),
  58         output_layout(output_layout),
  59         channel_values(channel_values),
  60         num_channel_values(num_channel_values),
  61         scale(scale) {
  62     input_channels = ChannelLayoutToChannelCount(input_layout);
  63     output_channels = ChannelLayoutToChannelCount(output_layout);
  64   }
  65
  66   ChannelMixerTestData(ChannelLayout input_layout, int input_channels,
  67                        ChannelLayout output_layout, int output_channels,
  68                        float* channel_values, int num_channel_values)
  69       : input_layout(input_layout),
  70         input_channels(input_channels),
  71         output_layout(output_layout),
  72         output_channels(output_channels),
  73         channel_values(channel_values),
  74         num_channel_values(num_channel_values),
  75         scale(1.0f) {
  76   }
  77
  78   std::string DebugString() const {
  79     return base::StringPrintf(
  80         "Input Layout: %d, Output Layout %d, Scale: %f", input_layout,
  81         output_layout, scale);
  82   }
  83
  84   ChannelLayout input_layout;
  85   int input_channels;
  86   ChannelLayout output_layout;
  87   int output_channels;
  88   float* channel_values;
  89   int num_channel_values;
  90   float scale;
  91 };
  92
  93 std::ostream& operator<<(std::ostream& os, const ChannelMixerTestData& data) {
  94   return os << data.DebugString();
  95 }
  96
  97 class ChannelMixerTest : public testing::TestWithParam<ChannelMixerTestData> {};
  98
  99 // Verify channels are mixed and scaled correctly.  The test only works if all
 100 // output channels have the same value.
 101 TEST_P(ChannelMixerTest, Mixing) {
 102   ChannelLayout input_layout = GetParam().input_layout;
 103   int input_channels = GetParam().input_channels;
 104   scoped_ptr<AudioBus> input_bus = AudioBus::Create(input_channels, kFrames);
 105   AudioParameters input_audio(AudioParameters::AUDIO_PCM_LINEAR,
 106                               input_layout,
 107                               input_layout == CHANNEL_LAYOUT_DISCRETE ?
 108                                   input_channels :
 109                                   ChannelLayoutToChannelCount(input_layout),
 110                               AudioParameters::kAudioCDSampleRate, 16,
 111                               kFrames,
 112                               AudioParameters::NO_EFFECTS);
 113
 114   ChannelLayout output_layout = GetParam().output_layout;
 115   int output_channels = GetParam().output_channels;
 116   scoped_ptr<AudioBus> output_bus = AudioBus::Create(output_channels, kFrames);
 117   AudioParameters output_audio(AudioParameters::AUDIO_PCM_LINEAR,
 118                                output_layout,
 119                                output_layout == CHANNEL_LAYOUT_DISCRETE ?
 120                                    output_channels :
 121                                    ChannelLayoutToChannelCount(output_layout),
 122                                AudioParameters::kAudioCDSampleRate, 16,
 123                                kFrames,
 124                                AudioParameters::NO_EFFECTS);
 125
 126   const float* channel_values = GetParam().channel_values;
 127   ASSERT_EQ(input_bus->channels(), GetParam().num_channel_values);
 128
 129   float expected_value = 0;
 130   float scale = GetParam().scale;
 131   for (int ch = 0; ch < input_bus->channels(); ++ch) {
 132     std::fill(input_bus->channel(ch), input_bus->channel(ch) + kFrames,
 133               channel_values[ch]);
 134     expected_value += channel_values[ch] * scale;
 135   }
 136
 137   ChannelMixer mixer(input_audio, output_audio);
 138   mixer.Transform(input_bus.get(), output_bus.get());
 139
 140   // Validate the output channel
 141   if (input_layout != CHANNEL_LAYOUT_DISCRETE) {
 142     for (int ch = 0; ch < output_bus->channels(); ++ch) {
 143       for (int frame = 0; frame < output_bus->frames(); ++frame) {
 144         ASSERT_FLOAT_EQ(output_bus->channel(ch)[frame], expected_value);
 145       }
 146     }
 147   } else {
 148     // Processing discrete mixing. If there is a matching input channel,
 149     // then the output channel should be set. If no input channel,
 150     // output channel should be 0
 151     for (int ch = 0; ch < output_bus->channels(); ++ch) {
 152       expected_value = (ch < input_channels) ? channel_values[ch] : 0;
 153       for (int frame = 0; frame < output_bus->frames(); ++frame) {
 154         ASSERT_FLOAT_EQ(output_bus->channel(ch)[frame], expected_value);
 155       }
 156     }
 157   }
 158 }
 159
 160 static float kStereoToMonoValues[] = { 0.5f, 0.75f };
 161 static float kMonoToStereoValues[] = { 0.5f };
 162 // Zero the center channel since it will be mixed at scale 1 vs M_SQRT1_2.
 163 static float kFiveOneToMonoValues[] = { 0.1f, 0.2f, 0.0f, 0.4f, 0.5f, 0.6f };
 164 static float kFiveDiscreteValues[] = { 0.1f, 0.2f, 0.3f, 0.4f, 0.5f };
 165
 166 // Run through basic sanity tests for some common conversions.
 167 INSTANTIATE_TEST_CASE_P(ChannelMixerTest, ChannelMixerTest, testing::Values(
 168     ChannelMixerTestData(CHANNEL_LAYOUT_STEREO, CHANNEL_LAYOUT_MONO,
 169                          kStereoToMonoValues, arraysize(kStereoToMonoValues),
 170                          0.5f),
 171     ChannelMixerTestData(CHANNEL_LAYOUT_MONO, CHANNEL_LAYOUT_STEREO,
 172                          kMonoToStereoValues, arraysize(kMonoToStereoValues),
 173                          1.0f),
 174     ChannelMixerTestData(CHANNEL_LAYOUT_5_1, CHANNEL_LAYOUT_MONO,
 175                          kFiveOneToMonoValues, arraysize(kFiveOneToMonoValues),
 176                          static_cast<float>(M_SQRT1_2)),
 177     ChannelMixerTestData(CHANNEL_LAYOUT_DISCRETE, 2,
 178                          CHANNEL_LAYOUT_DISCRETE, 2,
 179                          kStereoToMonoValues, arraysize(kStereoToMonoValues)),
 180     ChannelMixerTestData(CHANNEL_LAYOUT_DISCRETE, 2,
 181                          CHANNEL_LAYOUT_DISCRETE, 5,
 182                          kStereoToMonoValues, arraysize(kStereoToMonoValues)),
 183     ChannelMixerTestData(CHANNEL_LAYOUT_DISCRETE, 5,
 184                          CHANNEL_LAYOUT_DISCRETE, 2,
 185                          kFiveDiscreteValues, arraysize(kFiveDiscreteValues))
 186 ));
 187
 188 }  // namespace media