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1 // Copyright (c) 2011 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/glue/media/audio_decoder.h" | |
6 | |
7 #include <vector> | |
8 #include "base/basictypes.h" | |
9 #include "base/string_util.h" | |
10 #include "base/time.h" | |
11 #include "media/base/limits.h" | |
12 #include "media/filters/audio_file_reader.h" | |
13 #include "media/filters/in_memory_url_protocol.h" | |
14 #include "third_party/WebKit/Source/WebKit/chromium/public/WebAudioBus.h" | |
15 | |
16 using media::AudioFileReader; | |
17 using media::InMemoryUrlProtocol; | |
18 using std::vector; | |
19 using WebKit::WebAudioBus; | |
20 | |
21 namespace webkit_glue { | |
22 | |
23 // Decode in-memory audio file data. | |
24 bool DecodeAudioFileData( | |
25 WebKit::WebAudioBus* destination_bus, | |
26 const char* data, size_t data_size, double sample_rate) { | |
27 DCHECK(destination_bus); | |
28 if (!destination_bus) | |
29 return false; | |
30 | |
31 // Uses the FFmpeg library for audio file reading. | |
32 InMemoryUrlProtocol url_protocol(reinterpret_cast<const uint8*>(data), | |
33 data_size, false); | |
34 AudioFileReader reader(&url_protocol); | |
35 | |
36 if (!reader.Open()) | |
37 return false; | |
38 | |
39 size_t number_of_channels = reader.channels(); | |
40 double file_sample_rate = reader.sample_rate(); | |
41 double duration = reader.duration().InSecondsF(); | |
42 size_t number_of_frames = static_cast<size_t>(reader.number_of_frames()); | |
43 | |
44 // Apply sanity checks to make sure crazy values aren't coming out of | |
45 // FFmpeg. | |
46 if (!number_of_channels || | |
47 number_of_channels > static_cast<size_t>(media::Limits::kMaxChannels) || | |
48 file_sample_rate < media::Limits::kMinSampleRate || | |
49 file_sample_rate > media::Limits::kMaxSampleRate) | |
50 return false; | |
51 | |
52 // TODO(crogers) : do sample-rate conversion with FFmpeg. | |
53 // For now, we're ignoring the requested 'sample_rate' and returning | |
54 // the WebAudioBus at the file's sample-rate. | |
55 // double destination_sample_rate = | |
56 // (sample_rate != 0.0) ? sample_rate : file_sample_rate; | |
57 double destination_sample_rate = file_sample_rate; | |
58 | |
59 DLOG(INFO) << "Decoding file data -" | |
60 << " data: " << data | |
61 << " data size: " << data_size | |
62 << " duration: " << duration | |
63 << " number of frames: " << number_of_frames | |
64 << " sample rate: " << file_sample_rate | |
65 << " number of channels: " << number_of_channels; | |
66 | |
67 // Change to destination sample-rate. | |
68 number_of_frames = static_cast<size_t>(number_of_frames * | |
69 (destination_sample_rate / file_sample_rate)); | |
70 | |
71 // Allocate and configure the output audio channel data. | |
72 destination_bus->initialize(number_of_channels, | |
73 number_of_frames, | |
74 destination_sample_rate); | |
75 | |
76 // Wrap the channel pointers which will receive the decoded PCM audio. | |
77 vector<float*> audio_data; | |
78 audio_data.reserve(number_of_channels); | |
79 for (size_t i = 0; i < number_of_channels; ++i) { | |
80 audio_data.push_back(destination_bus->channelData(i)); | |
81 } | |
82 | |
83 // Decode the audio file data. | |
84 return reader.Read(audio_data, number_of_frames); | |
85 } | |
86 | |
87 } // namespace webkit_glue | |
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