media/mojo/mojom/media_foundation_service.mojom

// Copyright 2021 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 media.mojom;

import "media/mojo/mojom/frame_interface_factory.mojom";
import "media/mojo/mojom/interface_factory.mojom";
import "media/mojo/mojom/key_system_support.mojom";
import "mojo/public/mojom/base/file_path.mojom";
import "sandbox/policy/mojom/sandbox.mojom";

// A service to provide Windows MediaFoundation-based InterfaceFactory and
// KeySystemCapability. See comments on MediaFoundationServiceBroker for the
// process/sandbox model.
interface MediaFoundationService {
  // Queries the capabilities of the MediaFoundation-based CDM. The client lives
  // in the browser process.
  IsKeySystemSupported(string key_system)
    => (bool is_supported, KeySystemCapability? key_system_capability);

  // Requests an InterfaceFactory. `frame_interfaces` can optionally be used to
  // provide interfaces hosted by the caller to the remote InterfaceFactory
  // implementation.  The remote `InterfaceFactory` lives in the render process
  // to support media playback. The interface implementations provided by
  // the `frame_interfaces` live in the browser process so they are trusted.
  CreateInterfaceFactory(
      pending_receiver<InterfaceFactory> factory,
      pending_remote<FrameInterfaceFactory> frame_interfaces);
};

// A broker service to get the `MediaFoundationService`, needed to pass
// parameters to preload the CDM before creating the `MediaFoundationService`.
// It runs in the MediaFoundationCdm (utility) process and is connected from the
// browser process (see content/browser/media/service_factory.cc). In the
// process there should only be one `MediaFoundationServiceBroker` and one
// `MediaFoundationService` instance running. As such `GetService()` should only
// be called once and the subsequent calls will simply fail. When
// `MediaFoundationServiceBroker` is connected the process was not sandboxed to
// allow CDM preloading. After `GetService()` the process is fully sandboxed.
[ServiceSandbox=sandbox.mojom.Sandbox.kMediaFoundationCdm]
interface MediaFoundationServiceBroker {
  // Loads the CDM at `cdm_path` into the process and returns the
  // `MediaFoundationService`.
  GetService(
      mojo_base.mojom.FilePath cdm_path,
      pending_receiver<MediaFoundationService> receiver);
};