third_party/WebKit/public/platform/WebAudioBus.h

   1 /*
   2  * Copyright (C) 2010, 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  * 1.  Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2.  Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  16  * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  17  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  18  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  19  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  20  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  22  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  23  */
  24
  25 #ifndef WebAudioBus_h
  26 #define WebAudioBus_h
  27
  28 #include "WebCommon.h"
  29
  30 #if INSIDE_BLINK
  31 namespace WTF { template <typename T> class PassRefPtr; }
  32 #endif
  33
  34 namespace blink {
  35
  36 class AudioBus;
  37
  38 // A container for multi-channel linear PCM audio data.
  39 //
  40 // WARNING: It is not safe to pass a WebAudioBus across threads!!!
  41 //
  42 class BLINK_PLATFORM_EXPORT WebAudioBus {
  43 public:
  44     WebAudioBus() : m_private(0) { }
  45     ~WebAudioBus() { reset(); }
  46
  47     // initialize() allocates memory of the given length for the given number of channels.
  48     void initialize(unsigned numberOfChannels, size_t length, double sampleRate);
  49
  50     // resizeSmaller() can only be called after initialize() with a new length <= the initialization length.
  51     // The data stored in the bus will remain undisturbed.
  52     void resizeSmaller(size_t newLength);
  53
  54     // reset() releases the memory allocated from initialize().
  55     void reset();
  56
  57     unsigned numberOfChannels() const;
  58     size_t length() const;
  59     double sampleRate() const;
  60
  61     float* channelData(unsigned channelIndex);
  62
  63 #if INSIDE_BLINK
  64     WTF::PassRefPtr<AudioBus> release();
  65 #endif
  66
  67 private:
  68     // Disallow copy and assign.
  69     WebAudioBus(const WebAudioBus&);
  70     void operator=(const WebAudioBus&);
  71
  72     AudioBus* m_private;
  73 };
  74
  75 } // namespace blink
  76
  77 #endif // WebAudioBus_h