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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.
#ifndef MEDIA_CAPTURE_VIDEO_LINUX_V4L2_CAPTURE_DELEGATE_H_
#define MEDIA_CAPTURE_VIDEO_LINUX_V4L2_CAPTURE_DELEGATE_H_
#include <stddef.h>
#include <stdint.h>
#include <memory>
#include <string>
#include <vector>
#include "base/containers/queue.h"
#include "base/files/scoped_file.h"
#include "base/macros.h"
#include "build/build_config.h"
#include "media/capture/video/linux/scoped_v4l2_device_fd.h"
#include "media/capture/video/linux/v4l2_capture_device_impl.h"
#include "media/capture/video/video_capture_device.h"
#if defined(OS_OPENBSD)
#include <sys/videoio.h>
#else
#include <linux/videodev2.h>
#endif
namespace base {
class Location;
} // namespace base
namespace media {
// Class doing the actual Linux capture using V4L2 API. V4L2 SPLANE/MPLANE
// capture specifics are implemented in derived classes. Created on the owner's
// thread, otherwise living, operating and destroyed on |v4l2_task_runner_|.
class CAPTURE_EXPORT V4L2CaptureDelegate final {
public:
// Retrieves the #planes for a given |fourcc|, or 0 if unknown.
static size_t GetNumPlanesForFourCc(uint32_t fourcc);
// Returns the Chrome pixel format for |v4l2_fourcc| or PIXEL_FORMAT_UNKNOWN.
static VideoPixelFormat V4l2FourCcToChromiumPixelFormat(
uint32_t v4l2_fourcc);
// Composes a list of usable and supported pixel formats, in order of
// preference, with MJPEG prioritised depending on |prefer_mjpeg|.
static std::vector<uint32_t> GetListOfUsableFourCcs(bool prefer_mjpeg);
V4L2CaptureDelegate(
V4L2CaptureDevice* v4l2,
const VideoCaptureDeviceDescriptor& device_descriptor,
const scoped_refptr<base::SingleThreadTaskRunner>& v4l2_task_runner,
int power_line_frequency);
~V4L2CaptureDelegate();
// Forward-to versions of VideoCaptureDevice virtual methods.
void AllocateAndStart(int width,
int height,
float frame_rate,
std::unique_ptr<VideoCaptureDevice::Client> client);
void StopAndDeAllocate();
void TakePhoto(VideoCaptureDevice::TakePhotoCallback callback);
void GetPhotoState(VideoCaptureDevice::GetPhotoStateCallback callback);
void SetPhotoOptions(mojom::PhotoSettingsPtr settings,
VideoCaptureDevice::SetPhotoOptionsCallback callback);
void SetRotation(int rotation);
base::WeakPtr<V4L2CaptureDelegate> GetWeakPtr();
private:
friend class V4L2CaptureDelegateTest;
class BufferTracker;
// Running DoIoctl() on some devices, especially shortly after (re)opening the
// device file descriptor or (re)starting streaming, can fail but works after
// retrying (https://crbug.com/670262). Returns false if the |request| ioctl
// fails too many times.
bool RunIoctl(int request, void* argp);
// Simple wrapper to do HANDLE_EINTR(v4l2_->ioctl(device_fd_.get(), ...)).
int DoIoctl(int request, void* argp);
// Creates a mojom::RangePtr with the (min, max, current, step) values of the
// control associated with |control_id|. Returns an empty Range otherwise.
mojom::RangePtr RetrieveUserControlRange(int control_id);
// Sets all user control to their default. Some controls are enabled by
// another flag, usually having the word "auto" in the name, see
// IsSpecialControl() in the .cc file. These flags are preset beforehand, then
// set to their defaults individually afterwards.
void ResetUserAndCameraControlsToDefault();
// VIDIOC_QUERYBUFs a buffer from V4L2, creates a BufferTracker for it and
// enqueues it (VIDIOC_QBUF) back into V4L2.
bool MapAndQueueBuffer(int index);
void DoCapture();
void SetErrorState(VideoCaptureError error,
const base::Location& from_here,
const std::string& reason);
V4L2CaptureDevice* const v4l2_;
const scoped_refptr<base::SingleThreadTaskRunner> v4l2_task_runner_;
const VideoCaptureDeviceDescriptor device_descriptor_;
const int power_line_frequency_;
// The following members are only known on AllocateAndStart().
VideoCaptureFormat capture_format_;
v4l2_format video_fmt_;
std::unique_ptr<VideoCaptureDevice::Client> client_;
ScopedV4L2DeviceFD device_fd_;
base::queue<VideoCaptureDevice::TakePhotoCallback> take_photo_callbacks_;
// Vector of BufferTracker to keep track of mmap()ed pointers and their use.
std::vector<scoped_refptr<BufferTracker>> buffer_tracker_pool_;
bool is_capturing_;
int timeout_count_;
base::TimeTicks first_ref_time_;
// Clockwise rotation in degrees. This value should be 0, 90, 180, or 270.
int rotation_;
base::WeakPtrFactory<V4L2CaptureDelegate> weak_factory_;
DISALLOW_COPY_AND_ASSIGN(V4L2CaptureDelegate);
};
} // namespace media
#endif // MEDIA_CAPTURE_VIDEO_LINUX_V4L2_CAPTURE_DELEGATE_H_