video_decoder_broker.h | Explore in Territory

// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_WEBCODECS_VIDEO_DECODER_BROKER_H_
#define THIRD_PARTY_BLINK_RENDERER_MODULES_WEBCODECS_VIDEO_DECODER_BROKER_H_

#include <memory>
#include <optional>
#include <string>
#include <vector>

#include "base/functional/callback.h"
#include "base/memory/scoped_refptr.h"
#include "base/memory/weak_ptr.h"
#include "base/sequence_checker.h"
#include "media/base/decoder_status.h"
#include "media/base/video_decoder.h"
#include "media/base/video_frame.h"
#include "media/video/gpu_video_accelerator_factories.h"
#include "third_party/blink/renderer/core/execution_context/execution_context.h"
#include "third_party/blink/renderer/modules/modules_export.h"
#include "third_party/blink/renderer/modules/webcodecs/hardware_preference.h"
#include "third_party/blink/renderer/platform/wtf/hash_map.h"

namespace base {
class SequencedTaskRunner;
}  // namespace base

namespace blink {

// Implementation detail of VideoDecoderBroker. Helps safely perform decoder
// tasks on the media thread.
class MediaVideoTaskWrapper;

// Client interface for MediaVideoTaskWrapper. Implementation detail of
// VideoDecoderBroker, but we need to define it here to implement it below.
//
// This avoids having pass-through callbacks from main->media task sequence,
// which is unsafe because the public callers of broker APIs may be broken if
// their callback is destructed on another thread.
//
// An int "cb_id" is used for those that are traditionally OnceCallbacks to
// lookup the correct public callback.
class CrossThreadVideoDecoderClient { … };

// This class brokers the connection between WebCodecs and an underlying
// media::VideoDecoder. It abstracts away details of construction and selection
// of the media/ decoder. It also handles thread-hopping as required by
// underlying APIS.
//
// A new underlying decoder is selected anytime Initialize() is called.
// TODO(chcunningham): Elide re-selection if the config has not significantly
// changed.
//
// All API calls and callbacks must occur on the main thread.
class MODULES_EXPORT VideoDecoderBroker : public media::VideoDecoder,
                                          public CrossThreadVideoDecoderClient { … };

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_MODULES_WEBCODECS_VIDEO_DECODER_BROKER_H_
chromium/third_party/blink/renderer/modules/webcodecs/video_decoder_broker.h
