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
9namespace media {
10
11static const int kDefaultSampleRate = 44100;
12
13class 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
44TEST_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
72TEST_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
88TEST_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