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/* Copyright 2015 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 <code>PPB_AudioEncoder</code> interface.
*/
[generate_thunk]
label Chrome {
[channel=dev] M47 = 0.1
};
/**
* Audio encoder interface.
*
* Typical usage:
* - Call Create() to create a new audio encoder resource.
* - Call GetSupportedProfiles() to determine which codecs and profiles are
* available.
* - Call Initialize() to initialize the encoder for a supported profile.
* - Call GetBuffer() to get an empty buffer and fill it in, or get an audio
* buffer from another resource, e.g. <code>PPB_MediaStreamAudioTrack</code>.
* - Call Encode() to push the audio buffer to the encoder. If an external
* buffer is pushed, wait for completion to recycle the buffer.
* - Call GetBitstreamBuffer() continuously (waiting for each previous call to
* complete) to pull encoded buffers from the encoder.
* - Call RecycleBitstreamBuffer() after consuming the data in the bitstream
* buffer.
* - To destroy the encoder, the plugin should release all of its references to
* it. Any pending callbacks will abort before the encoder is destroyed.
*
* Available audio codecs vary by platform.
* All: opus.
*/
interface PPB_AudioEncoder {
/**
* Creates a new audio encoder resource.
*
* @param[in] instance A <code>PP_Instance</code> identifying the instance
* with the audio encoder.
*
* @return A <code>PP_Resource</code> corresponding to an audio encoder if
* successful or 0 otherwise.
*/
PP_Resource Create([in] PP_Instance instance);
/**
* Determines if the given resource is an audio encoder.
*
* @param[in] resource A <code>PP_Resource</code> identifying a resource.
*
* @return <code>PP_TRUE</code> if the resource is a
* <code>PPB_AudioEncoder</code>, <code>PP_FALSE</code> if the resource is
* invalid or some other type.
*/
PP_Bool IsAudioEncoder([in] PP_Resource resource);
/**
* Gets an array of supported audio encoder profiles.
* These can be used to choose a profile before calling Initialize().
*
* @param[in] audio_encoder A <code>PP_Resource</code> identifying the audio
* encoder.
* @param[in] output A <code>PP_ArrayOutput</code> to receive the supported
* <code>PP_AudioProfileDescription</code> structs.
* @param[in] callback A <code>PP_CompletionCallback</code> to be called upon
* completion.
*
* @return If >= 0, the number of supported profiles returned, otherwise an
* error code from <code>pp_errors.h</code>.
*/
int32_t GetSupportedProfiles([in] PP_Resource audio_encoder,
[in] PP_ArrayOutput output,
[in] PP_CompletionCallback callback);
/**
* Initializes an audio encoder resource. The plugin should call Initialize()
* successfully before calling any of the functions below.
*
* @param[in] audio_encoder A <code>PP_Resource</code> identifying the audio
* encoder.
* @param[in] channels The number of audio channels to encode.
* @param[in] input_sampling_rate The sampling rate of the input audio buffer.
* @param[in] input_sample_size The sample size of the input audio buffer.
* @param[in] output_profile A <code>PP_AudioProfile</code> specifying the
* codec profile of the encoded output stream.
* @param[in] initial_bitrate The initial bitrate for the encoder.
* @param[in] acceleration A <code>PP_HardwareAcceleration</code> specifying
* whether to use a hardware accelerated or a software implementation.
* @param[in] callback A <code>PP_CompletionCallback</code> to be called upon
* completion.
*
* @return An int32_t containing an error code from <code>pp_errors.h</code>.
* Returns PP_ERROR_NOTSUPPORTED if audio encoding is not available, or the
* requested codec profile is not supported.
*/
int32_t Initialize([in] PP_Resource audio_encoder,
[in] uint32_t channels,
[in] PP_AudioBuffer_SampleRate input_sample_rate,
[in] PP_AudioBuffer_SampleSize input_sample_size,
[in] PP_AudioProfile output_profile,
[in] uint32_t initial_bitrate,
[in] PP_HardwareAcceleration acceleration,
[in] PP_CompletionCallback callback);
/**
* Gets the number of audio samples per channel that audio buffers must
* contain in order to be processed by the encoder. This will be the number of
* samples per channels contained in buffers returned by GetBuffer().
*
* @param[in] audio_encoder A <code>PP_Resource</code> identifying the audio
* encoder.
* @return An int32_t containing the number of samples required, or an error
* code from <code>pp_errors.h</code>.
* Returns PP_ERROR_FAILED if Initialize() has not successfully completed.
*/
int32_t GetNumberOfSamples([in] PP_Resource audio_encoder);
/**
* Gets a blank audio buffer (with metadata given by the Initialize()
* call) which can be filled with audio data and passed to the encoder.
*
* @param[in] audio_encoder A <code>PP_Resource</code> identifying the audio
* encoder.
* @param[out] audio_buffer A blank <code>PPB_AudioBuffer</code> resource.
* @param[in] callback A <code>PP_CompletionCallback</code> to be called upon
* completion.
*
* @return An int32_t containing an error code from <code>pp_errors.h</code>.
* Returns PP_ERROR_FAILED if Initialize() has not successfully completed.
*/
int32_t GetBuffer([in] PP_Resource audio_encoder,
[out] PP_Resource audio_buffer,
[in] PP_CompletionCallback callback);
/**
* Encodes an audio buffer.
*
* @param[in] audio_encoder A <code>PP_Resource</code> identifying the audio
* encoder.
* @param[in] audio_buffer The <code>PPB_AudioBuffer</code> to be encoded.
* @param[in] callback A <code>PP_CompletionCallback</code> to be called upon
* completion. Plugins that pass <code>PPB_AudioBuffer</code> resources owned
* by other resources should wait for completion before reusing them.
*
* @return An int32_t containing an error code from <code>pp_errors.h</code>.
* Returns PP_ERROR_FAILED if Initialize() has not successfully completed.
*/
int32_t Encode([in] PP_Resource audio_encoder,
[in] PP_Resource audio_buffer,
[in] PP_CompletionCallback callback);
/**
* Gets the next encoded bitstream buffer from the encoder.
*
* @param[in] audio_encoder A <code>PP_Resource</code> identifying the audio
* encoder.
* @param[out] bitstream_buffer A <code>PP_BitstreamBuffer</code> containing
* encoded audio data.
* @param[in] callback A <code>PP_CompletionCallback</code> to be called upon
* completion. The plugin can call GetBitstreamBuffer from the callback in
* order to continuously "pull" bitstream buffers from the encoder.
*
* @return An int32_t containing an error code from <code>pp_errors.h</code>.
* Returns PP_ERROR_FAILED if Initialize() has not successfully completed.
* Returns PP_ERROR_INPROGRESS if a prior call to GetBitstreamBuffer() has
* not completed.
*/
int32_t GetBitstreamBuffer([in] PP_Resource audio_encoder,
[out] PP_AudioBitstreamBuffer bitstream_buffer,
[in] PP_CompletionCallback callback);
/**
* Recycles a bitstream buffer back to the encoder.
*
* @param[in] audio_encoder A <code>PP_Resource</code> identifying the audio
* encoder.
* @param[in] bitstream_buffer A <code>PP_BitstreamBuffer</code> that is no
* longer needed by the plugin.
*/
void RecycleBitstreamBuffer([in] PP_Resource audio_encoder,
[in] PP_AudioBitstreamBuffer bitstream_buffer);
/**
* Requests a change to the encoding bitrate. This is only a request,
* fulfilled on a best-effort basis.
*
* @param[in] audio_encoder A <code>PP_Resource</code> identifying the audio
* encoder.
* @param[in] bitrate The requested new bitrate, in bits per second.
*/
void RequestBitrateChange([in] PP_Resource audio_encoder,
[in] uint32_t bitrate);
/**
* Closes the audio encoder, and cancels any pending encodes. Any pending
* callbacks will still run, reporting <code>PP_ERROR_ABORTED</code> . It is
* not valid to call any encoder functions after a call to this method.
* <strong>Note:</strong> Destroying the audio encoder closes it implicitly,
* so you are not required to call Close().
*
* @param[in] audio_encoder A <code>PP_Resource</code> identifying the audio
* encoder.
*/
void Close([in] PP_Resource audio_encoder);
};
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