ppapi/cpp/audio.h

   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
   3 // found in the LICENSE file.
   4
   5 #ifndef PPAPI_CPP_AUDIO_H_
   6 #define PPAPI_CPP_AUDIO_H_
   7
   8 #include "ppapi/c/pp_stdint.h"
   9 #include "ppapi/c/ppb_audio.h"
  10 #include "ppapi/cpp/audio_config.h"
  11 #include "ppapi/cpp/resource.h"
  12
  13 /// @file
  14 /// This file defines the API to create realtime stereo audio streaming
  15 /// capabilities.
  16
  17 namespace pp {
  18
  19 class InstanceHandle;
  20
  21 /// An audio resource. Refer to the
  22 /// <a href="/native-client/devguide/coding/audio">Audio</a>
  23 /// chapter in the Developer's Guide for information on using this interface.
  24 class Audio : public Resource {
  25  public:
  26
  27   /// An empty constructor for an Audio resource.
  28   Audio() {}
  29
  30   /// A constructor that creates an Audio resource. No sound will be heard
  31   /// until StartPlayback() is called. The callback is called with the buffer
  32   /// address and given user data whenever the buffer needs to be filled.
  33   /// From within the callback, you should not call <code>PPB_Audio</code>
  34   /// functions. The callback will be called on a different thread than the one
  35   /// which created the interface. For performance-critical applications (such
  36   /// as low-latency audio), the callback should avoid blocking or calling
  37   /// functions that can obtain locks, such as malloc. The layout and the size
  38   /// of the buffer passed to the audio callback will be determined by
  39   /// the device configuration and is specified in the <code>AudioConfig</code>
  40   /// documentation.
  41   ///
  42   /// @param[in] instance The instance with which this resource will be
  43   /// associated.
  44   /// @param[in] config An <code>AudioConfig</code> containing the audio config
  45   /// resource.
  46   /// @param[in] callback A <code>PPB_Audio_Callback</code> callback function
  47   /// that the browser calls when it needs more samples to play.
  48   /// @param[in] user_data A pointer to user data used in the callback function.
  49   Audio(const InstanceHandle& instance,
  50         const AudioConfig& config,
  51         PPB_Audio_Callback callback,
  52         void* user_data);
  53
  54   /// A constructor that creates an Audio resource.
  55   ///
  56   /// @param[in] instance The instance with which this resource will be
  57   /// associated.
  58   /// @param[in] config An <code>AudioConfig</code> containing the audio config
  59   /// resource.
  60   /// @param[in] callback A <code>PPB_Audio_Callback_1_0</code> callback
  61   /// function that the browser calls when it needs more samples to play.
  62   /// @param[in] user_data A pointer to user data used in the callback function.
  63   Audio(const InstanceHandle& instance,
  64         const AudioConfig& config,
  65         PPB_Audio_Callback_1_0 callback,
  66         void* user_data);
  67
  68   /// Getter function for returning the internal <code>PPB_AudioConfig</code>
  69   /// struct.
  70   ///
  71   /// @return A mutable reference to the PPB_AudioConfig struct.
  72   AudioConfig& config() { return config_; }
  73
  74   /// Getter function for returning the internal <code>PPB_AudioConfig</code>
  75   /// struct.
  76   ///
  77   /// @return A const reference to the internal <code>PPB_AudioConfig</code>
  78   /// struct.
  79   const AudioConfig& config() const { return config_; }
  80
  81   /// StartPlayback() starts playback of audio.
  82   ///
  83   /// @return true if successful, otherwise false.
  84   bool StartPlayback();
  85
  86   /// StopPlayback stops playback of audio.
  87   ///
  88   /// @return true if successful, otherwise false.
  89   bool StopPlayback();
  90
  91  private:
  92   AudioConfig config_;
  93   bool use_1_0_interface_;
  94 };
  95
  96 }  // namespace pp
  97
  98 #endif  // PPAPI_CPP_AUDIO_H_
  99