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 #include "media/base/audio_timestamp_helper.h" 6 #include "media/base/buffers.h" 7 #include "testing/gtest/include/gtest/gtest.h" 8 9 namespace media { 10 11 static const int kDefaultSampleRate = 44100; 12 13 class AudioTimestampHelperTest : public ::testing::Test { 14 public: 15 AudioTimestampHelperTest() : helper_(kDefaultSampleRate) { 16 helper_.SetBaseTimestamp(base::TimeDelta()); 17 } 18 19 // Adds frames to the helper and returns the current timestamp in 20 // microseconds. 21 int64 AddFrames(int frames) { 22 helper_.AddFrames(frames); 23 return helper_.GetTimestamp().InMicroseconds(); 24 } 25 26 int64 FramesToTarget(int target_in_microseconds) { 27 return helper_.GetFramesToTarget( 28 base::TimeDelta::FromMicroseconds(target_in_microseconds)); 29 } 30 31 void TestGetFramesToTargetRange(int frame_count, int start, int end) { 32 for (int i = start; i <= end; ++i) { 33 EXPECT_EQ(frame_count, FramesToTarget(i)) << " Failure for timestamp " 34 << i << " us."; 35 } 36 } 37 38 protected: 39 AudioTimestampHelper helper_; 40 41 DISALLOW_COPY_AND_ASSIGN(AudioTimestampHelperTest); 42 }; 43 44 TEST_F(AudioTimestampHelperTest, Basic) { 45 EXPECT_EQ(0, helper_.GetTimestamp().InMicroseconds()); 46 47 // Verify that the output timestamp is always rounded down to the 48 // nearest microsecond. 1 frame @ 44100 is ~22.67573 microseconds, 49 // which is why the timestamp sometimes increments by 23 microseconds 50 // and other times it increments by 22 microseconds. 51 EXPECT_EQ(0, AddFrames(0)); 52 EXPECT_EQ(22, AddFrames(1)); 53 EXPECT_EQ(45, AddFrames(1)); 54 EXPECT_EQ(68, AddFrames(1)); 55 EXPECT_EQ(90, AddFrames(1)); 56 EXPECT_EQ(113, AddFrames(1)); 57 58 // Verify that adding frames one frame at a time matches the timestamp 59 // returned if the same number of frames are added all at once. 60 base::TimeDelta timestamp_1 = helper_.GetTimestamp(); 61 helper_.SetBaseTimestamp(kNoTimestamp()); 62 EXPECT_TRUE(kNoTimestamp() == helper_.base_timestamp()); 63 helper_.SetBaseTimestamp(base::TimeDelta()); 64 EXPECT_EQ(0, helper_.GetTimestamp().InMicroseconds()); 65 66 helper_.AddFrames(5); 67 EXPECT_EQ(113, helper_.GetTimestamp().InMicroseconds()); 68 EXPECT_TRUE(timestamp_1 == helper_.GetTimestamp()); 69 } 70 71 72 TEST_F(AudioTimestampHelperTest, GetDuration) { 73 helper_.SetBaseTimestamp(base::TimeDelta::FromMicroseconds(100)); 74 75 int frame_count = 5; 76 int64 expected_durations[] = { 113, 113, 114, 113, 113, 114 }; 77 for (size_t i = 0; i < arraysize(expected_durations); ++i) { 78 base::TimeDelta duration = helper_.GetFrameDuration(frame_count); 79 EXPECT_EQ(expected_durations[i], duration.InMicroseconds()); 80 81 base::TimeDelta timestamp_1 = helper_.GetTimestamp() + duration; 82 helper_.AddFrames(frame_count); 83 base::TimeDelta timestamp_2 = helper_.GetTimestamp(); 84 EXPECT_TRUE(timestamp_1 == timestamp_2); 85 } 86 } 87 88 TEST_F(AudioTimestampHelperTest, GetFramesToTarget) { 89 // Verify GetFramesToTarget() rounding behavior. 90 // 1 frame @ 44100 is ~22.67573 microseconds, 91 92 // Test values less than half of the frame duration. 93 TestGetFramesToTargetRange(0, 0, 11); 94 95 // Test values between half the frame duration & the 96 // full frame duration. 97 TestGetFramesToTargetRange(1, 12, 22); 98 99 // Verify that the same number of frames is returned up 100 // to the next half a frame. 101 TestGetFramesToTargetRange(1, 23, 34); 102 103 // Verify the next 3 ranges. 104 TestGetFramesToTargetRange(2, 35, 56); 105 TestGetFramesToTargetRange(3, 57, 79); 106 TestGetFramesToTargetRange(4, 80, 102); 107 TestGetFramesToTargetRange(5, 103, 124); 108 109 // Add frames to the helper so negative frame counts can be tested. 110 helper_.AddFrames(5); 111 112 // Note: The timestamp ranges must match the positive values 113 // tested above to verify that the code is rounding properly. 114 TestGetFramesToTargetRange(0, 103, 124); 115 TestGetFramesToTargetRange(-1, 80, 102); 116 TestGetFramesToTargetRange(-2, 57, 79); 117 TestGetFramesToTargetRange(-3, 35, 56); 118 TestGetFramesToTargetRange(-4, 12, 34); 119 TestGetFramesToTargetRange(-5, 0, 11); 120 } 121 122 } // namespace media 123
