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1 // Copyright 2013 The Chromium Authors. All rights reserved. | 1 // Copyright 2013 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 // MSVC++ requires this to be set before any other includes to get M_PI. | 5 // MSVC++ requires this to be set before any other includes to get M_PI. |
6 #define _USE_MATH_DEFINES | 6 #define _USE_MATH_DEFINES |
7 #include <cmath> | 7 #include <cmath> |
8 | 8 |
9 #include "media/base/audio_hash.h" | 9 #include "media/base/audio_hash.h" |
10 | 10 |
11 #include "base/strings/stringprintf.h" | 11 #include "base/strings/stringprintf.h" |
12 #include "media/base/audio_bus.h" | 12 #include "media/base/audio_bus.h" |
13 | 13 |
14 namespace media { | 14 namespace media { |
15 | 15 |
16 AudioHash::AudioHash() | 16 AudioHash::AudioHash() |
17 : audio_hash_(), | 17 : audio_hash_(), |
18 sample_count_(0) { | 18 sample_count_(0) { |
19 } | 19 } |
20 | 20 |
21 AudioHash::~AudioHash() {} | 21 AudioHash::~AudioHash() {} |
22 | 22 |
23 void AudioHash::Update(const AudioBus* audio_bus, int frames) { | 23 void AudioHash::Update(const AudioBus* audio_bus, int frames) { |
24 // Use uint32 to ensure overflow is a defined operation. | 24 // Use uint32_t to ensure overflow is a defined operation. |
25 for (uint32 ch = 0; ch < static_cast<uint32>(audio_bus->channels()); ++ch) { | 25 for (uint32_t ch = 0; ch < static_cast<uint32_t>(audio_bus->channels()); |
| 26 ++ch) { |
26 const float* channel = audio_bus->channel(ch); | 27 const float* channel = audio_bus->channel(ch); |
27 for (uint32 i = 0; i < static_cast<uint32>(frames); ++i) { | 28 for (uint32_t i = 0; i < static_cast<uint32_t>(frames); ++i) { |
28 const uint32 kSampleIndex = sample_count_ + i; | 29 const uint32_t kSampleIndex = sample_count_ + i; |
29 const uint32 kHashIndex = | 30 const uint32_t kHashIndex = |
30 (kSampleIndex * (ch + 1)) % arraysize(audio_hash_); | 31 (kSampleIndex * (ch + 1)) % arraysize(audio_hash_); |
31 | 32 |
32 // Mix in a sine wave with the result so we ensure that sequences of empty | 33 // Mix in a sine wave with the result so we ensure that sequences of empty |
33 // buffers don't result in an empty hash. | 34 // buffers don't result in an empty hash. |
34 if (ch == 0) { | 35 if (ch == 0) { |
35 audio_hash_[kHashIndex] += | 36 audio_hash_[kHashIndex] += |
36 channel[i] + sin(2.0 * M_PI * M_PI * kSampleIndex); | 37 channel[i] + sin(2.0 * M_PI * M_PI * kSampleIndex); |
37 } else { | 38 } else { |
38 audio_hash_[kHashIndex] += channel[i]; | 39 audio_hash_[kHashIndex] += channel[i]; |
39 } | 40 } |
40 } | 41 } |
41 } | 42 } |
42 | 43 |
43 sample_count_ += static_cast<uint32>(frames); | 44 sample_count_ += static_cast<uint32_t>(frames); |
44 } | 45 } |
45 | 46 |
46 std::string AudioHash::ToString() const { | 47 std::string AudioHash::ToString() const { |
47 std::string result; | 48 std::string result; |
48 for (size_t i = 0; i < arraysize(audio_hash_); ++i) | 49 for (size_t i = 0; i < arraysize(audio_hash_); ++i) |
49 result += base::StringPrintf("%.2f,", audio_hash_[i]); | 50 result += base::StringPrintf("%.2f,", audio_hash_[i]); |
50 return result; | 51 return result; |
51 } | 52 } |
52 | 53 |
53 } // namespace media | 54 } // namespace media |
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