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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 // Linux specific implementation of VideoCaptureDevice. | 5 // Linux specific implementation of VideoCaptureDevice. |
6 // V4L2 is used for capturing. V4L2 does not provide its own thread for | 6 // V4L2 is used for capturing. V4L2 does not provide its own thread for |
7 // capturing so this implementation uses a Chromium thread for fetching frames | 7 // capturing so this implementation uses a Chromium thread for fetching frames |
8 // from V4L2. | 8 // from V4L2. |
9 | 9 |
10 #ifndef MEDIA_VIDEO_CAPTURE_LINUX_VIDEO_CAPTURE_DEVICE_LINUX_H_ | 10 #ifndef MEDIA_VIDEO_CAPTURE_LINUX_VIDEO_CAPTURE_DEVICE_LINUX_H_ |
11 #define MEDIA_VIDEO_CAPTURE_LINUX_VIDEO_CAPTURE_DEVICE_LINUX_H_ | 11 #define MEDIA_VIDEO_CAPTURE_LINUX_VIDEO_CAPTURE_DEVICE_LINUX_H_ |
12 | 12 |
13 #include <string> | 13 #include <string> |
14 | 14 |
15 #include "base/threading/thread.h" | 15 #include "base/threading/thread.h" |
16 #include "media/video/capture/video_capture_device.h" | 16 #include "media/video/capture/video_capture_device.h" |
17 #include "media/video/capture/video_capture_types.h" | 17 #include "media/video/capture/video_capture_types.h" |
18 | 18 |
19 namespace media { | 19 namespace media { |
20 | 20 |
21 class VideoCaptureDeviceLinux : public VideoCaptureDevice1 { | 21 class VideoCaptureDeviceLinux : public VideoCaptureDevice { |
22 public: | 22 public: |
23 explicit VideoCaptureDeviceLinux(const Name& device_name); | 23 explicit VideoCaptureDeviceLinux(const Name& device_name); |
24 virtual ~VideoCaptureDeviceLinux(); | 24 virtual ~VideoCaptureDeviceLinux(); |
25 | 25 |
26 // VideoCaptureDevice implementation. | 26 // VideoCaptureDevice implementation. |
27 virtual void Allocate(const VideoCaptureCapability& capture_format, | 27 virtual void AllocateAndStart(const VideoCaptureCapability& capture_format, |
28 VideoCaptureDevice::Client* client) OVERRIDE; | 28 scoped_ptr<Client> client) OVERRIDE; |
29 virtual void Start() OVERRIDE; | 29 |
30 virtual void Stop() OVERRIDE; | 30 virtual void StopAndDeAllocate() OVERRIDE; |
31 virtual void DeAllocate() OVERRIDE; | |
32 virtual const Name& device_name() OVERRIDE; | |
33 | 31 |
34 private: | 32 private: |
35 enum InternalState { | 33 enum InternalState { |
36 kIdle, // The device driver is opened but camera is not in use. | 34 kIdle, // The device driver is opened but camera is not in use. |
37 kAllocated, // The camera has been allocated and can be started. | |
38 kCapturing, // Video is being captured. | 35 kCapturing, // Video is being captured. |
39 kError // Error accessing HW functions. | 36 kError // Error accessing HW functions. |
40 // User needs to recover by destroying the object. | 37 // User needs to recover by destroying the object. |
41 }; | 38 }; |
42 | 39 |
43 // Buffers used to receive video frames from with v4l2. | 40 // Buffers used to receive video frames from with v4l2. |
44 struct Buffer { | 41 struct Buffer { |
45 Buffer() : start(0), length(0) {} | 42 Buffer() : start(0), length(0) {} |
46 void* start; | 43 void* start; |
47 size_t length; | 44 size_t length; |
48 }; | 45 }; |
49 | 46 |
50 // Called on the v4l2_thread_. | 47 // Called on the v4l2_thread_. |
51 void OnAllocate(int width, | 48 void OnAllocateAndStart(int width, |
52 int height, | 49 int height, |
53 int frame_rate, | 50 int frame_rate, |
54 VideoCaptureDevice::Client* client); | 51 scoped_ptr<Client> client); |
55 void OnStart(); | 52 void OnStopAndDeAllocate(); |
56 void OnStop(); | |
57 void OnDeAllocate(); | |
58 void OnCaptureTask(); | 53 void OnCaptureTask(); |
59 | 54 |
60 bool AllocateVideoBuffers(); | 55 bool AllocateVideoBuffers(); |
61 void DeAllocateVideoBuffers(); | 56 void DeAllocateVideoBuffers(); |
62 void SetErrorState(const std::string& reason); | 57 void SetErrorState(const std::string& reason); |
63 | 58 |
64 InternalState state_; | 59 InternalState state_; |
65 VideoCaptureDevice::Client* client_; | 60 scoped_ptr<VideoCaptureDevice::Client> client_; |
66 Name device_name_; | 61 Name device_name_; |
67 int device_fd_; // File descriptor for the opened camera device. | 62 int device_fd_; // File descriptor for the opened camera device. |
68 base::Thread v4l2_thread_; // Thread used for reading data from the device. | 63 base::Thread v4l2_thread_; // Thread used for reading data from the device. |
69 Buffer* buffer_pool_; | 64 Buffer* buffer_pool_; |
70 int buffer_pool_size_; // Number of allocated buffers. | 65 int buffer_pool_size_; // Number of allocated buffers. |
71 int timeout_count_; | 66 int timeout_count_; |
72 | 67 |
73 DISALLOW_IMPLICIT_CONSTRUCTORS(VideoCaptureDeviceLinux); | 68 DISALLOW_IMPLICIT_CONSTRUCTORS(VideoCaptureDeviceLinux); |
74 }; | 69 }; |
75 | 70 |
76 } // namespace media | 71 } // namespace media |
77 | 72 |
78 #endif // MEDIA_VIDEO_CAPTURE_LINUX_VIDEO_CAPTURE_DEVICE_LINUX_H_ | 73 #endif // MEDIA_VIDEO_CAPTURE_LINUX_VIDEO_CAPTURE_DEVICE_LINUX_H_ |
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