Revert of Linux Video Capture: Add V4L2VideoCaptureDelegate{Single,Multi}Plane.

media/video/capture/linux/v4l2_capture_delegate.h

-// 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_VIDEO_CAPTURE_LINUX_V4L2_VIDEO_CAPTURE_DELEGATE_H_
-#define MEDIA_VIDEO_CAPTURE_LINUX_V4L2_VIDEO_CAPTURE_DELEGATE_H_
-
-#if defined(OS_OPENBSD)
-#include <sys/videoio.h>
-#else
-#include <linux/videodev2.h>
-#endif
-
-#include "base/files/scoped_file.h"
-#include "base/memory/ref_counted.h"
-#include "base/memory/scoped_vector.h"
-#include "media/video/capture/video_capture_device.h"
-
-namespace media {
-
-// Class doing the actual Linux capture using V4L2 API. V4L2 SPLANE/MPLANE
-// capture specifics are implemented in derived classes. Created and destroyed
-// on the owner's thread, otherwise living and operating on |v4l2_task_runner_|.
-class V4L2CaptureDelegate
-    : public base::RefCountedThreadSafe<V4L2CaptureDelegate> {
- public:
-  // Creates the appropiate VideoCaptureDelegate according to parameters.
-  static scoped_refptr<V4L2CaptureDelegate> CreateV4L2CaptureDelegate(
-      const VideoCaptureDevice::Name& device_name,
-      const scoped_refptr<base::SingleThreadTaskRunner>& v4l2_task_runner,
-      int power_line_frequency);
-
-  // 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::list<uint32_t> GetListOfUsableFourCcs(bool prefer_mjpeg);
-
-  // Forward-to versions of VideoCaptureDevice virtual methods.
-  void AllocateAndStart(int width,
-                        int height,
-                        float frame_rate,
-                        scoped_ptr<VideoCaptureDevice::Client> client);
-  void StopAndDeAllocate();
-
-  void SetRotation(int rotation);
-
- protected:
-  // Class keeping track of SPLANE/MPLANE V4L2 buffers, mmap()ed on construction
-  // and munmap()ed on destruction. Destruction is syntactically equal for
-  // S/MPLANE but not construction, so this is implemented in derived classes.
-  // Internally it has a vector of planes, which for SPLANE will contain only
-  // one element.
-  class BufferTracker : public base::RefCounted<BufferTracker> {
-   public:
-    BufferTracker();
-    // Abstract method to mmap() given |fd| according to |buffer|, planarity
-    // specific.
-    virtual bool Init(int fd, const v4l2_buffer& buffer) = 0;
-
-    uint8_t* const GetPlaneStart(size_t plane) const {
-      DCHECK_LT(plane, planes_.size());
-      return planes_[plane].start;
-    }
-
-   protected:
-    friend class base::RefCounted<BufferTracker>;
-    virtual ~BufferTracker();
-    // Adds a given mmap()ed plane to |planes_|.
-    void AddMmapedPlane(uint8_t* const start, size_t length);
-
-   private:
-    struct Plane {
-      uint8_t* start;
-      size_t length;
-    };
-    std::vector<Plane> planes_;
-  };
-
-  V4L2CaptureDelegate(
-      const VideoCaptureDevice::Name& device_name,
-      const scoped_refptr<base::SingleThreadTaskRunner>& v4l2_task_runner,
-      int power_line_frequency);
-  virtual ~V4L2CaptureDelegate();
-
-  // Creates the necessary, planarity-specific, internal tracking schemes,
-  virtual scoped_refptr<BufferTracker> CreateBufferTracker() const = 0;
-
-  // Fill in |format| with the given parameters, in a planarity dependent way.
-  virtual bool FillV4L2Format(v4l2_format* format,
-                              uint32_t width,
-                              uint32_t height,
-                              uint32_t pixelformat_fourcc) const = 0;
-
-  // Finish filling |buffer| struct with planarity-dependent data.
-  virtual void FinishFillingV4L2Buffer(v4l2_buffer* buffer) const = 0;
-
-  // Sends the captured |buffer| to the |client_|, synchronously.
-  virtual void SendBuffer(
-      const scoped_refptr<BufferTracker>& buffer_tracker,
-      const v4l2_format& format) const = 0;
-
-  // A few accessors for SendBuffer()'s to access private member variables.
-  VideoCaptureFormat capture_format() const { return capture_format_; }
-  VideoCaptureDevice::Client* client() const { return client_.get(); }
-  int rotation() const { return rotation_; }
-
- private:
-  friend class base::RefCountedThreadSafe<V4L2CaptureDelegate>;
-
-  // Returns the input |fourcc| as a std::string four char representation.
-  static std::string FourccToString(uint32_t fourcc);
-  // VIDIOC_QUERYBUFs a buffer from V4L2, creates a BufferTracker for it and
-  // enqueues it (VIDIOC_QBUF) back into V4L2.
-  bool MapAndQueueBuffer(int index);
-  // Fills all common parts of |buffer|. Delegates to FinishFillingV4L2Buffer()
-  // for filling in the planar-dependent parts.
-  void FillV4L2Buffer(v4l2_buffer* buffer, int i) const;
-  void DoCapture();
-  void SetErrorState(const std::string& reason);
-
-  const v4l2_buf_type capture_type_;
-  const scoped_refptr<base::SingleThreadTaskRunner> v4l2_task_runner_;
-  const VideoCaptureDevice::Name device_name_;
-  const int power_line_frequency_;
-
-  // The following members are only known on AllocateAndStart().
-  VideoCaptureFormat capture_format_;
-  v4l2_format video_fmt_;
-  scoped_ptr<VideoCaptureDevice::Client> client_;
-  base::ScopedFD device_fd_;
-
-  // 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_;
-
-  // Clockwise rotation in degrees. This value should be 0, 90, 180, or 270.
-  int rotation_;
-
-  DISALLOW_COPY_AND_ASSIGN(V4L2CaptureDelegate);
-};
-
-}  // namespace media
-
-#endif  // MEDIA_VIDEO_CAPTURE_LINUX_V4L2_VIDEO_CAPTURE_DELEGATE_H_