OLD | NEW |
| (Empty) |
1 /* | |
2 * Copyright (C) 2012 Google Inc. All rights reserved. | |
3 * | |
4 * Redistribution and use in source and binary forms, with or without | |
5 * modification, are permitted provided that the following conditions | |
6 * are met: | |
7 * | |
8 * 1. Redistributions of source code must retain the above copyright | |
9 * notice, this list of conditions and the following disclaimer. | |
10 * 2. Redistributions in binary form must reproduce the above copyright | |
11 * notice, this list of conditions and the following disclaimer in the | |
12 * documentation and/or other materials provided with the distribution. | |
13 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of | |
14 * its contributors may be used to endorse or promote products derived | |
15 * from this software without specific prior written permission. | |
16 * | |
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY | |
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED | |
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY | |
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES | |
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | |
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND | |
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
27 */ | |
28 | |
29 #ifndef AudioFIFO_h | |
30 #define AudioFIFO_h | |
31 | |
32 #include "platform/audio/AudioBus.h" | |
33 #include "wtf/Allocator.h" | |
34 | |
35 namespace blink { | |
36 | |
37 class AudioFIFO { | |
38 USING_FAST_MALLOC(AudioFIFO); | |
39 WTF_MAKE_NONCOPYABLE(AudioFIFO); | |
40 | |
41 public: | |
42 // Create a FIFO large enough to hold |fifoLength| frames of data of | |
43 // |numberOfChannels| channels. | |
44 AudioFIFO(unsigned numberOfChannels, size_t fifoLength); | |
45 | |
46 // Push the data from the bus into the FIFO. | |
47 void push(const AudioBus*); | |
48 | |
49 // Consume |framesToConsume| frames of data from the FIFO and put them in | |
50 // |destination|. The corresponding frames are removed from the FIFO. | |
51 void consume(AudioBus* destination, size_t framesToConsume); | |
52 | |
53 // Number of frames of data that are currently in the FIFO. | |
54 size_t framesInFifo() const { return m_framesInFifo; } | |
55 | |
56 private: | |
57 // Update the FIFO index by the step, with appropriate wrapping around the | |
58 // endpoint. | |
59 int updateIndex(int index, int step) { return (index + step) % m_fifoLength; } | |
60 | |
61 void findWrapLengths(size_t index, | |
62 size_t providerSize, | |
63 size_t& part1Length, | |
64 size_t& part2Length); | |
65 | |
66 // The FIFO itself. In reality, the FIFO is a circular buffer. | |
67 RefPtr<AudioBus> m_fifoAudioBus; | |
68 | |
69 // The total available space in the FIFO. | |
70 size_t m_fifoLength; | |
71 | |
72 // The number of actual elements in the FIFO | |
73 size_t m_framesInFifo; | |
74 | |
75 // Where to start reading from the FIFO. | |
76 size_t m_readIndex; | |
77 | |
78 // Where to start writing to the FIFO. | |
79 size_t m_writeIndex; | |
80 }; | |
81 | |
82 } // namespace blink | |
83 | |
84 #endif // AudioFIFO.h | |
OLD | NEW |