fuchsia/engine/cast_streaming_session.mojom

// Copyright 2020 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.

module mojom;

import "media/mojo/mojom/media_types.mojom";

// Renderer-implemented interface that is used to receive metadata for buffers.
interface CastStreamingBufferReceiver {
  // Provide metadata for a buffer to the Cast Streaming Receiver in the
  // renderer process. The buffer data itself is on the associated |data_pipe|,
  // from AudioStreamInfo or VideoStreamInfo.
  // This is called for every new buffer pushed in the associated |data_pipe|.
  ProvideBuffer(media.mojom.DecoderBuffer buffer);

  // Signals the audio decoder configuration has changed. After this call,
  // CastStreamingBufferReceiver.ProvideBuffer() will be called on every new
  // frame. The buffer data itself is on |data_pipe|.
  OnNewAudioConfig(media.mojom.AudioDecoderConfig decoder_config,
                   handle<data_pipe_consumer> data_pipe);

  // Signals the video configuration has changed. After this call,
  // CastStreamingBufferReceiver.ProvideBuffer() will be called on every new
  // frame. The buffer data itself is on |data_pipe|.
  OnNewVideoConfig(media.mojom.VideoDecoderConfig decoder_config,
                   handle<data_pipe_consumer> data_pipe);
};

// Information about a Cast Streaming audio stream.
struct AudioStreamInfo {
  // Audio decoder configuration.
  media.mojom.AudioDecoderConfig decoder_config;

  // Audio buffer metadata receiver.
  pending_receiver<CastStreamingBufferReceiver> buffer_receiver;

  // Mojo data pipe over which audio buffer data is sent.
  handle<data_pipe_consumer> data_pipe;
};

// Information about a Cast Streaming video stream.
struct VideoStreamInfo {
  // Video decoder configuration.
  media.mojom.VideoDecoderConfig decoder_config;

  // Video buffer metadata receiver.
  pending_receiver<CastStreamingBufferReceiver> buffer_receiver;

  // Mojo data pipe over which video buffer data is sent.
  handle<data_pipe_consumer> data_pipe;
};

// Implemented by the renderer, used to start the Cast Streaming Session.
// Closure of the Mojo channel will trigger the end of the Cast Streaming
// Session.
interface CastStreamingReceiver {
  // Used for synchronization between the browser and the renderer. The browser
  // should invoke this after binding the interface, and wait for the reply
  // callback to know when the renderer is ready to receive and render frames.
  EnableReceiver() => ();

  // Called when the streams have been successfully initialized. At least one of
  // |audio_stream_info| or |video_stream_info| must be set. This will only be
  // called once per the lifetime of CastStreamingReceiver. After this call,
  // CastStreamingBufferReceiver.ProvideBuffer() will be called on every new
  // frame.
  OnStreamsInitialized(
      AudioStreamInfo? audio_stream_info,
      VideoStreamInfo? video_stream_info);
};