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/* Copyright (c) 2011 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.
*/
/* This file defines the audio API.
*/
/* Callback function type for SetCallback. */
typedef void PPB_Audio_Callback([out] mem_t sample_buffer,
[in] uint32_t buffer_size_in_bytes,
[inout] mem_t 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();
*/
interface PPB_Audio_0_5 {
/* 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(
[in] PP_Instance instance,
[in] PP_Resource config,
[in] PPB_Audio_Callback audio_callback,
[inout] mem_t user_data);
/* Returns PP_TRUE if the given resource is an Audio resource, PP_FALSE
* otherwise.
*/
PP_Bool IsAudio(
[in] PP_Resource resource);
/* Get the current configuration. */
PP_Resource GetCurrentConfig(
[in] 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(
[in] 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(
[in] PP_Resource audio);
};
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