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// Copyright 2014 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 CONTENT_COMMON_GPU_MEDIA_V4L2_VIDEO_PROCESSOR_H_
#define CONTENT_COMMON_GPU_MEDIA_V4L2_VIDEO_PROCESSOR_H_
#include <queue>
#include <vector>
#include "base/memory/linked_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/threading/thread.h"
#include "content/common/content_export.h"
#include "content/common/gpu/media/v4l2_video_device.h"
#include "media/base/video_frame.h"
namespace content {
// Handles image processing accelerators that expose a V4L2 memory-to-memory
// interface. The threading model of this class is the same as for other V4L2
// hardware accelerators (see V4L2VideoDecodeAccelerator) for more details.
class CONTENT_EXPORT V4L2ImageProcessor {
public:
explicit V4L2ImageProcessor(scoped_ptr<V4L2Device> device);
virtual ~V4L2ImageProcessor();
// Initializes the processor to convert from |input_format| to |output_format|
// and/or scale from |input_visible_size| to |output_visible_size|.
// Request the output buffers to be of at least |output_allocated_size|.
// Provided |error_cb| will be called if an error occurs.
// Return true if the requested configuration is supported.
bool Initialize(media::VideoFrame::Format input_format,
media::VideoFrame::Format output_format,
gfx::Size input_visible_size,
gfx::Size output_visible_size,
gfx::Size output_allocated_size,
const base::Closure& error_cb);
// Returns allocated size required by the processor to be fed with.
gfx::Size input_allocated_size() { return input_allocated_size_; }
// Callback to be used to return a processed image to the client. The client
// should drop references to |frame| once it's done with it.
typedef base::Callback<void(const scoped_refptr<media::VideoFrame>& frame)>
FrameReadyCB;
// Called by client to process |frame|. The resulting processed frame will
// be returned via |cb|. The processor will drop all its references to |frame|
// after it finishes accessing it.
void Process(const scoped_refptr<media::VideoFrame>& frame,
const FrameReadyCB& cb);
// Stop all processing and clean up.
void Destroy();
private:
// Record for input buffers.
struct InputRecord {
InputRecord();
scoped_refptr<media::VideoFrame> frame;
bool at_device;
};
// Record for output buffers.
struct OutputRecord {
OutputRecord();
bool at_device;
bool at_client;
std::vector<int> fds;
};
// Job record. Jobs are processed in a FIFO order. This is separate from
// InputRecord, because an InputRecord may be returned before we dequeue
// the corresponding output buffer. It can't always be associated with
// an OutputRecord immediately either, because at the time of submission we
// may not have one available (and don't need one to submit input to the
// device).
struct JobRecord {
JobRecord();
scoped_refptr<media::VideoFrame> frame;
FrameReadyCB ready_cb;
};
enum {
// Arbitrarily tuned.
kInputBufferCount = 2,
kOutputBufferCount = 2,
};
void ReuseOutputBuffer(int index);
void Enqueue();
void Dequeue();
bool EnqueueInputRecord();
bool EnqueueOutputRecord();
bool CreateInputBuffers();
bool CreateOutputBuffers();
void DestroyInputBuffers();
void DestroyOutputBuffers();
void NotifyError();
void DestroyTask();
void ProcessTask(scoped_ptr<JobRecord> job_record);
void ServiceDeviceTask();
// Attempt to start/stop device_poll_thread_.
bool StartDevicePoll();
bool StopDevicePoll();
// Ran on device_poll_thread_ to wait for device events.
void DevicePollTask(bool poll_device);
// Size and format-related members remain constant after initialization.
// The visible/allocated sizes of the input frame.
gfx::Size input_visible_size_;
gfx::Size input_allocated_size_;
// The visible/allocated sizes of the destination frame.
gfx::Size output_visible_size_;
gfx::Size output_allocated_size_;
media::VideoFrame::Format input_format_;
media::VideoFrame::Format output_format_;
uint32 input_format_fourcc_;
uint32 output_format_fourcc_;
size_t input_planes_count_;
size_t output_planes_count_;
// Our original calling message loop for the child thread.
const scoped_refptr<base::MessageLoopProxy> child_message_loop_proxy_;
// V4L2 device in use.
scoped_ptr<V4L2Device> device_;
// Thread to communicate with the device on.
base::Thread device_thread_;
// Thread used to poll the V4L2 for events only.
base::Thread device_poll_thread_;
// All the below members are to be accessed from device_thread_ only
// (if it's running).
std::queue<linked_ptr<JobRecord> > input_queue_;
std::queue<linked_ptr<JobRecord> > running_jobs_;
// Input queue state.
bool input_streamon_;
// Number of input buffers enqueued to the device.
int input_buffer_queued_count_;
// Input buffers ready to use; LIFO since we don't care about ordering.
std::vector<int> free_input_buffers_;
// Mapping of int index to an input buffer record.
std::vector<InputRecord> input_buffer_map_;
// Output queue state.
bool output_streamon_;
// Number of output buffers enqueued to the device.
int output_buffer_queued_count_;
// Output buffers ready to use; LIFO since we don't care about ordering.
std::vector<int> free_output_buffers_;
// Mapping of int index to an output buffer record.
std::vector<OutputRecord> output_buffer_map_;
// Error callback to the client.
base::Closure error_cb_;
// Weak factory for producing weak pointers on the device_thread_
base::WeakPtrFactory<V4L2ImageProcessor> device_weak_factory_;
DISALLOW_COPY_AND_ASSIGN(V4L2ImageProcessor);
};
} // namespace content
#endif // CONTENT_COMMON_GPU_MEDIA_V4L2_VIDEO_PROCESSOR_H_