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1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 //
5 // This file defines the V4L2Device interface which is used by the
6 // V4L2DecodeAccelerator class to delegate/pass the device specific
7 // handling of any of the functionalities.
8 
9 #ifndef CONTENT_COMMON_GPU_MEDIA_V4L2_VIDEO_DEVICE_H_
10 #define CONTENT_COMMON_GPU_MEDIA_V4L2_VIDEO_DEVICE_H_
11 
12 #include "media/base/video_decoder_config.h"
13 #include "media/base/video_frame.h"
14 #include "ui/gfx/size.h"
15 #include "ui/gl/gl_bindings.h"
16 
17 namespace content {
18 
19 class V4L2Device {
20  public:
21   // Utility format conversion functions
22   static media::VideoFrame::Format V4L2PixFmtToVideoFrameFormat(uint32 format);
23   static uint32 VideoFrameFormatToV4L2PixFmt(media::VideoFrame::Format format);
24   static uint32 VideoCodecProfileToV4L2PixFmt(media::VideoCodecProfile profile);
25   // Convert format requirements requested by a V4L2 device to gfx::Size.
26   static gfx::Size CodedSizeFromV4L2Format(struct v4l2_format format);
27 
28   virtual ~V4L2Device();
29 
30   enum Type {
31     kDecoder,
32     kEncoder,
33     kImageProcessor,
34   };
35 
36   // Creates and initializes an appropriate V4L2Device of |type| for the
37   // current platform and returns a scoped_ptr<V4L2Device> on success, or NULL.
38   static scoped_ptr<V4L2Device> Create(Type type);
39 
40   // Parameters and return value are the same as for the standard ioctl() system
41   // call.
42   virtual int Ioctl(int request, void* arg) = 0;
43 
44   // This method sleeps until either:
45   // - SetDevicePollInterrupt() is called (on another thread),
46   // - |poll_device| is true, and there is new data to be read from the device,
47   //   or an event from the device has arrived; in the latter case
48   //   |*event_pending| will be set to true.
49   // Returns false on error, true otherwise.
50   // This method should be called from a separate thread.
51   virtual bool Poll(bool poll_device, bool* event_pending) = 0;
52 
53   // These methods are used to interrupt the thread sleeping on Poll() and force
54   // it to return regardless of device state, which is usually when the client
55   // is no longer interested in what happens with the device (on cleanup,
56   // client state change, etc.). When SetDevicePollInterrupt() is called, Poll()
57   // will return immediately, and any subsequent calls to it will also do so
58   // until ClearDevicePollInterrupt() is called.
59   virtual bool SetDevicePollInterrupt() = 0;
60   virtual bool ClearDevicePollInterrupt() = 0;
61 
62   // Wrappers for standard mmap/munmap system calls.
63   virtual void* Mmap(void* addr,
64                      unsigned int len,
65                      int prot,
66                      int flags,
67                      unsigned int offset) = 0;
68   virtual void Munmap(void* addr, unsigned int len) = 0;
69 
70   // Initializes the V4L2Device to operate as a device of |type|.
71   // Returns true on success.
72   virtual bool Initialize() = 0;
73 
74   // Creates an EGLImageKHR since each V4L2Device may use a different method of
75   // acquiring one and associating it to the given texture. The texture_id is
76   // used to bind the texture to the returned EGLImageKHR. buffer_index can be
77   // used to associate the returned EGLImageKHR by the underlying V4L2Device
78   // implementation.
79   virtual EGLImageKHR CreateEGLImage(EGLDisplay egl_display,
80                                      EGLContext egl_context,
81                                      GLuint texture_id,
82                                      gfx::Size frame_buffer_size,
83                                      unsigned int buffer_index,
84                                      size_t planes_count) = 0;
85 
86   // Destroys the EGLImageKHR.
87   virtual EGLBoolean DestroyEGLImage(EGLDisplay egl_display,
88                                      EGLImageKHR egl_image) = 0;
89 
90   // Returns the supported texture target for the V4L2Device.
91   virtual GLenum GetTextureTarget() = 0;
92 
93   // Returns the preferred V4L2 input format or 0 if don't care.
94   virtual uint32 PreferredInputFormat() = 0;
95 
96   // Returns the preferred V4L2 output format or 0 if don't care.
97   virtual uint32 PreferredOutputFormat() = 0;
98 };
99 
100 }  //  namespace content
101 
102 #endif  //  CONTENT_COMMON_GPU_MEDIA_V4L2_VIDEO_DEVICE_H_
103