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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 | |
3 // found in the LICENSE file. | |
4 | |
5 #include "webkit/renderer/media/audio_decoder.h" | |
6 | |
7 #include <vector> | |
8 #include "base/basictypes.h" | |
9 #include "base/strings/string_util.h" | |
10 #include "base/time.h" | |
11 #include "media/base/audio_bus.h" | |
12 #include "media/base/limits.h" | |
13 #include "media/filters/audio_file_reader.h" | |
14 #include "media/filters/in_memory_url_protocol.h" | |
15 #include "third_party/WebKit/public/platform/WebAudioBus.h" | |
16 | |
17 using media::AudioBus; | |
18 using media::AudioFileReader; | |
19 using media::InMemoryUrlProtocol; | |
20 using std::vector; | |
21 using WebKit::WebAudioBus; | |
22 | |
23 namespace webkit_media { | |
24 | |
25 // Decode in-memory audio file data. | |
26 bool DecodeAudioFileData( | |
27 WebKit::WebAudioBus* destination_bus, | |
28 const char* data, size_t data_size, double sample_rate) { | |
29 DCHECK(destination_bus); | |
30 if (!destination_bus) | |
31 return false; | |
32 | |
33 // Uses the FFmpeg library for audio file reading. | |
34 InMemoryUrlProtocol url_protocol(reinterpret_cast<const uint8*>(data), | |
35 data_size, false); | |
36 AudioFileReader reader(&url_protocol); | |
37 | |
38 if (!reader.Open()) | |
39 return false; | |
40 | |
41 size_t number_of_channels = reader.channels(); | |
42 double file_sample_rate = reader.sample_rate(); | |
43 size_t number_of_frames = static_cast<size_t>(reader.number_of_frames()); | |
44 | |
45 // Apply sanity checks to make sure crazy values aren't coming out of | |
46 // FFmpeg. | |
47 if (!number_of_channels || | |
48 number_of_channels > static_cast<size_t>(media::limits::kMaxChannels) || | |
49 file_sample_rate < media::limits::kMinSampleRate || | |
50 file_sample_rate > media::limits::kMaxSampleRate) | |
51 return false; | |
52 | |
53 // Allocate and configure the output audio channel data. | |
54 destination_bus->initialize(number_of_channels, | |
55 number_of_frames, | |
56 file_sample_rate); | |
57 | |
58 // Wrap the channel pointers which will receive the decoded PCM audio. | |
59 vector<float*> audio_data; | |
60 audio_data.reserve(number_of_channels); | |
61 for (size_t i = 0; i < number_of_channels; ++i) { | |
62 audio_data.push_back(destination_bus->channelData(i)); | |
63 } | |
64 | |
65 scoped_ptr<AudioBus> audio_bus = AudioBus::WrapVector( | |
66 number_of_frames, audio_data); | |
67 | |
68 // Decode the audio file data. | |
69 // TODO(crogers): If our estimate was low, then we still may fail to read | |
70 // all of the data from the file. | |
71 size_t actual_frames = reader.Read(audio_bus.get()); | |
72 | |
73 // Adjust WebKit's bus to account for the actual file length | |
74 // and valid data read. | |
75 if (actual_frames != number_of_frames) { | |
76 DCHECK_LE(actual_frames, number_of_frames); | |
77 destination_bus->resizeSmaller(actual_frames); | |
78 } | |
79 | |
80 double duration = actual_frames / file_sample_rate; | |
81 | |
82 DVLOG(1) << "Decoded file data -" | |
83 << " data: " << data | |
84 << " data size: " << data_size | |
85 << " duration: " << duration | |
86 << " number of frames: " << actual_frames | |
87 << " sample rate: " << file_sample_rate | |
88 << " number of channels: " << number_of_channels; | |
89 | |
90 return actual_frames > 0; | |
91 } | |
92 | |
93 } // namespace webkit_media | |
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