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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 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 | 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 // MSVC++ requires this to be set before any other includes to get M_PI. |
| 5 #define _USE_MATH_DEFINES |
| 6 #include <cmath> |
4 | 7 |
5 #include "media/audio/simple_sources.h" | 8 #include "media/audio/simple_sources.h" |
6 | 9 |
7 #include <math.h> | |
8 #include <algorithm> | 10 #include <algorithm> |
9 | 11 |
10 #include "base/basictypes.h" | |
11 #include "base/logging.h" | 12 #include "base/logging.h" |
12 #include "base/memory/ref_counted.h" | 13 #include "media/audio/audio_util.h" |
13 #include "media/audio/audio_io.h" | |
14 #include "media/base/data_buffer.h" | |
15 | 14 |
16 namespace media { | 15 namespace media { |
17 | 16 |
18 ////////////////////////////////////////////////////////////////////////////// | 17 ////////////////////////////////////////////////////////////////////////////// |
19 // SineWaveAudioSource implementation. | 18 // SineWaveAudioSource implementation. |
20 | 19 |
21 SineWaveAudioSource::SineWaveAudioSource(Format format, int channels, | 20 SineWaveAudioSource::SineWaveAudioSource(int channels, |
22 double freq, double sample_freq) | 21 double freq, double sample_freq) |
23 : format_(format), | 22 : channels_(channels), |
24 channels_(channels), | 23 f_(freq / sample_freq), |
25 freq_(freq), | 24 time_state_(0), |
26 sample_freq_(sample_freq), | 25 cap_(0) { |
27 time_state_(0) { | |
28 // TODO(cpu): support other formats. | |
29 DCHECK((format_ == FORMAT_16BIT_LINEAR_PCM) && (channels_ == 1)); | |
30 } | 26 } |
31 | 27 |
32 // The implementation could be more efficient if a lookup table is constructed | 28 // The implementation could be more efficient if a lookup table is constructed |
33 // but it is efficient enough for our simple needs. | 29 // but it is efficient enough for our simple needs. |
34 uint32 SineWaveAudioSource::OnMoreData( | 30 int SineWaveAudioSource::OnMoreData(AudioBus* audio_bus, |
35 uint8* dest, uint32 max_size, AudioBuffersState audio_buffers) { | 31 AudioBuffersState audio_buffers) { |
36 const double kTwoPi = 2.0 * 3.141592653589; | 32 base::AutoLock auto_lock(time_lock_); |
37 double f = freq_ / sample_freq_; | |
38 int16* sin_tbl = reinterpret_cast<int16*>(dest); | |
39 uint32 len = max_size / sizeof(int16); | |
40 | 33 |
41 // The table is filled with s(t) = kint16max*sin(Theta*t), | 34 // The table is filled with s(t) = kint16max*sin(Theta*t), |
42 // where Theta = 2*PI*fs. | 35 // where Theta = 2*PI*fs. |
43 // We store the discrete time value |t| in a member to ensure that the | 36 // We store the discrete time value |t| in a member to ensure that the |
44 // next pass starts at a correct state. | 37 // next pass starts at a correct state. |
45 for (uint32 n = 0; n < len; ++n) { | 38 int max_frames = cap_ > 0 ? |
46 double theta = kTwoPi * f; | 39 std::min(audio_bus->frames(), cap_ - time_state_) : audio_bus->frames(); |
47 double ksinx = kint16max * sin(theta * time_state_); | 40 for (int i = 0; i < max_frames; ++i) |
48 sin_tbl[n] = (ksinx > 0.0f) ? static_cast<int16>(ksinx + 0.5) : | 41 audio_bus->channel(0)[i] = sin(2.0 * M_PI * f_ * time_state_++); |
49 static_cast<int16>(ksinx - 0.5); | 42 for (int i = 1; i < audio_bus->channels(); ++i) { |
50 ++time_state_; | 43 memcpy(audio_bus->channel(i), audio_bus->channel(0), |
| 44 max_frames * sizeof(*audio_bus->channel(i))); |
51 } | 45 } |
52 return max_size; | 46 return max_frames; |
53 } | 47 } |
54 | 48 |
55 void SineWaveAudioSource::OnError(AudioOutputStream* stream, int code) { | 49 void SineWaveAudioSource::OnError(AudioOutputStream* stream, int code) { |
56 NOTREACHED(); | 50 NOTREACHED(); |
57 } | 51 } |
58 | 52 |
59 ////////////////////////////////////////////////////////////////////////////// | 53 void SineWaveAudioSource::CapSamples(int cap) { |
60 // PushSource implementation. | 54 base::AutoLock auto_lock(time_lock_); |
61 | 55 DCHECK_GT(cap_, 0); |
62 PushSource::PushSource() | 56 cap_ = cap; |
63 : buffer_(0, 0) { | |
64 } | 57 } |
65 | 58 |
66 PushSource::~PushSource() { } | 59 void SineWaveAudioSource::Reset() { |
67 | 60 base::AutoLock auto_lock(time_lock_); |
68 uint32 PushSource::OnMoreData( | 61 time_state_ = 0; |
69 uint8* dest, uint32 max_size, AudioBuffersState buffers_state) { | |
70 return buffer_.Read(dest, max_size); | |
71 } | |
72 | |
73 void PushSource::OnError(AudioOutputStream* stream, int code) { | |
74 NOTREACHED(); | |
75 } | |
76 | |
77 // TODO(cpu): Manage arbitrary large sizes. | |
78 bool PushSource::Write(const void *data, uint32 len) { | |
79 if (len == 0) { | |
80 NOTREACHED(); | |
81 return false; | |
82 } | |
83 buffer_.Append(static_cast<const uint8*>(data), len); | |
84 return true; | |
85 } | |
86 | |
87 uint32 PushSource::UnProcessedBytes() { | |
88 return buffer_.forward_bytes(); | |
89 } | |
90 | |
91 void PushSource::CleanUp() { | |
92 buffer_.Clear(); | |
93 } | 62 } |
94 | 63 |
95 } // namespace media | 64 } // namespace media |
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