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/* Copyright (c) 2010 The Chromium Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef PPAPI_C_DEV_PPB_AUDIO_DEV_H_
#define PPAPI_C_DEV_PPB_AUDIO_DEV_H_
#include "ppapi/c/pp_bool.h"
#include "ppapi/c/pp_instance.h"
#include "ppapi/c/pp_module.h"
#include "ppapi/c/pp_resource.h"
#include "ppapi/c/pp_stdint.h"
#define PPB_AUDIO_DEV_INTERFACE "PPB_Audio(Dev);0.3"
// Callback function type for SetCallback.
typedef void (*PPB_Audio_Callback)(void* sample_buffer,
size_t buffer_size_in_bytes,
void* user_data);
// Callback-based audio interface. User of audio must set the callback that will
// be called each time that the buffer needs to be filled.
//
// A C++ example:
//
// void audio_callback(void* sample_buffer,
// size_t buffer_size_in_bytes,
// void* user_data) {
// ... fill in the buffer with samples ...
// }
//
// uint32_t obtained;
// AudioConfig config(PP_AUDIOSAMPLERATE_44100, 4096, &obtained);
// Audio audio(config, audio_callback, NULL);
// audio.StartPlayback();
//
struct PPB_Audio_Dev {
// Creates a paused audio interface. No sound will be heard until
// StartPlayback() is called. The callback is called with the buffer address
// and given user data whenever the buffer needs to be filled. From within the
// callback, you should not call PPB_Audio functions. The callback will be
// called on a different thread than the one which created the interface. For
// performance-critical applications (i.e. low-latency audio), the callback
// should avoid blocking or calling functions that can obtain locks, such as
// malloc. The layout and the size of the buffer passed to the audio callback
// will be determined by the device configuration and is specified in the
// AudioConfig documentation. If the configuration cannot be honored, or the
// callback is null, the function returns 0.
PP_Resource (*Create)(PP_Instance instance, PP_Resource config,
PPB_Audio_Callback audio_callback, void* user_data);
/**
* Returns PP_TRUE if the given resource is an Audio resource, PP_FALSE
* otherwise.
*/
PP_Bool (*IsAudio)(PP_Resource resource);
// Get the current configuration.
PP_Resource (*GetCurrentConfig)(PP_Resource audio);
// Start the playback. Begin periodically calling the callback. If called
// while playback is already in progress, will return PP_TRUE and be a no-op.
// On error, return PP_FALSE.
PP_Bool (*StartPlayback)(PP_Resource audio);
// Stop the playback. If playback is already stopped, this is a no-op and
// returns PP_TRUE. On error, returns PP_FALSE. If a callback is in progress,
// StopPlayback will block until callback completes.
PP_Bool (*StopPlayback)(PP_Resource audio);
};
#endif /* PPAPI_C_DEV_PPB_DEVICE_CONTEXT_AUDIO_DEV_H_ */
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