video_capture_buffer_pool.h | Explore in Territory

// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_CAPTURE_VIDEO_VIDEO_CAPTURE_BUFFER_POOL_H_
#define MEDIA_CAPTURE_VIDEO_VIDEO_CAPTURE_BUFFER_POOL_H_

#include "base/memory/ref_counted.h"
#include "media/capture/capture_export.h"
#include "media/capture/mojom/video_capture_buffer.mojom.h"
#include "media/capture/mojom/video_capture_types.mojom.h"
#include "media/capture/video/video_capture_device.h"
#include "media/capture/video_capture_types.h"
#include "mojo/public/cpp/system/buffer.h"
#include "ui/gfx/geometry/size.h"
#include "ui/gfx/gpu_memory_buffer.h"

namespace media {

class VideoCaptureBufferHandle;

// A thread-safe class that does the bookkeeping and lifetime management for a
// pool of pixel buffers cycled between an in-process producer (e.g. a
// VideoCaptureDevice) and a set of out-of-process consumers. The pool is
// intended to be orchestrated by a VideoCaptureDevice::Client, but is designed
// to outlive the controller if necessary. The pixel buffers may be backed by a
// SharedMemory, but this is not compulsory.
//
// Producers get a buffer by calling ReserveForProducer(), and may pass on their
// ownership to the consumer by calling HoldForConsumers(), or drop the buffer
// (without further processing) by calling RelinquishProducerReservation().
// Consumers signal that they are done with the buffer by calling
// RelinquishConsumerHold().
//
// Buffers are allocated on demand, but there will never be more than |count|
// buffers in existence at any time. Buffers are identified by an int value
// called |buffer_id|. -1 (kInvalidId) is never a valid ID, and is returned by
// some methods to indicate failure. The active set of buffer ids may change
// over the lifetime of the buffer pool, as existing buffers are freed and
// reallocated at larger size. When reallocation occurs, new buffer IDs will
// circulate.
class CAPTURE_EXPORT VideoCaptureBufferPool
    : public base::RefCountedThreadSafe<VideoCaptureBufferPool> { … };

}  // namespace media

#endif  // MEDIA_CAPTURE_VIDEO_VIDEO_CAPTURE_BUFFER_POOL_H_
chromium/media/capture/video/video_capture_buffer_pool.h
