1 /*
2  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef WEBRTC_COMMON_VIDEO_INCLUDE_VIDEO_FRAME_BUFFER_H_
12 #define WEBRTC_COMMON_VIDEO_INCLUDE_VIDEO_FRAME_BUFFER_H_
13 
14 #include "webrtc/base/callback.h"
15 #include "webrtc/base/refcount.h"
16 #include "webrtc/base/scoped_ptr.h"
17 #include "webrtc/base/scoped_ref_ptr.h"
18 #include "webrtc/system_wrappers/include/aligned_malloc.h"
19 
20 namespace webrtc {
21 
22 enum PlaneType {
23   kYPlane = 0,
24   kUPlane = 1,
25   kVPlane = 2,
26   kNumOfPlanes = 3,
27 };
28 
29 // Interface of a simple frame buffer containing pixel data. This interface does
30 // not contain any frame metadata such as rotation, timestamp, pixel_width, etc.
31 class VideoFrameBuffer : public rtc::RefCountInterface {
32  public:
33   // Returns true if this buffer has a single exclusive owner.
34   virtual bool HasOneRef() const = 0;
35 
36   // The resolution of the frame in pixels. For formats where some planes are
37   // subsampled, this is the highest-resolution plane.
38   virtual int width() const = 0;
39   virtual int height() const = 0;
40 
41   // Returns pointer to the pixel data for a given plane. The memory is owned by
42   // the VideoFrameBuffer object and must not be freed by the caller.
43   virtual const uint8_t* data(PlaneType type) const = 0;
44 
45   // Non-const data access is disallowed by default. You need to make sure you
46   // have exclusive access and a writable buffer before calling this function.
47   virtual uint8_t* MutableData(PlaneType type);
48 
49   // Returns the number of bytes between successive rows for a given plane.
50   virtual int stride(PlaneType type) const = 0;
51 
52   // Return the handle of the underlying video frame. This is used when the
53   // frame is backed by a texture.
54   virtual void* native_handle() const = 0;
55 
56   // Returns a new memory-backed frame buffer converted from this buffer's
57   // native handle.
58   virtual rtc::scoped_refptr<VideoFrameBuffer> NativeToI420Buffer() = 0;
59 
60  protected:
61   virtual ~VideoFrameBuffer();
62 };
63 
64 // Plain I420 buffer in standard memory.
65 class I420Buffer : public VideoFrameBuffer {
66  public:
67   I420Buffer(int width, int height);
68   I420Buffer(int width, int height, int stride_y, int stride_u, int stride_v);
69 
70   int width() const override;
71   int height() const override;
72   const uint8_t* data(PlaneType type) const override;
73   // Non-const data access is only allowed if HasOneRef() is true to protect
74   // against unexpected overwrites.
75   uint8_t* MutableData(PlaneType type) override;
76   int stride(PlaneType type) const override;
77   void* native_handle() const override;
78   rtc::scoped_refptr<VideoFrameBuffer> NativeToI420Buffer() override;
79 
80  protected:
81   ~I420Buffer() override;
82 
83  private:
84   const int width_;
85   const int height_;
86   const int stride_y_;
87   const int stride_u_;
88   const int stride_v_;
89   const rtc::scoped_ptr<uint8_t, AlignedFreeDeleter> data_;
90 };
91 
92 // Base class for native-handle buffer is a wrapper around a |native_handle|.
93 // This is used for convenience as most native-handle implementations can share
94 // many VideoFrame implementations, but need to implement a few others (such
95 // as their own destructors or conversion methods back to software I420).
96 class NativeHandleBuffer : public VideoFrameBuffer {
97  public:
98   NativeHandleBuffer(void* native_handle, int width, int height);
99 
100   int width() const override;
101   int height() const override;
102   const uint8_t* data(PlaneType type) const override;
103   int stride(PlaneType type) const override;
104   void* native_handle() const override;
105 
106  protected:
107   void* native_handle_;
108   const int width_;
109   const int height_;
110 };
111 
112 class WrappedI420Buffer : public webrtc::VideoFrameBuffer {
113  public:
114   WrappedI420Buffer(int width,
115                     int height,
116                     const uint8_t* y_plane,
117                     int y_stride,
118                     const uint8_t* u_plane,
119                     int u_stride,
120                     const uint8_t* v_plane,
121                     int v_stride,
122                     const rtc::Callback0<void>& no_longer_used);
123   int width() const override;
124   int height() const override;
125 
126   const uint8_t* data(PlaneType type) const override;
127 
128   int stride(PlaneType type) const override;
129   void* native_handle() const override;
130 
131   rtc::scoped_refptr<VideoFrameBuffer> NativeToI420Buffer() override;
132 
133  private:
134   friend class rtc::RefCountedObject<WrappedI420Buffer>;
135   ~WrappedI420Buffer() override;
136 
137   const int width_;
138   const int height_;
139   const uint8_t* const y_plane_;
140   const uint8_t* const u_plane_;
141   const uint8_t* const v_plane_;
142   const int y_stride_;
143   const int u_stride_;
144   const int v_stride_;
145   rtc::Callback0<void> no_longer_used_cb_;
146 };
147 
148 // Helper function to crop |buffer| without making a deep copy. May only be used
149 // for non-native frames.
150 rtc::scoped_refptr<VideoFrameBuffer> ShallowCenterCrop(
151     const rtc::scoped_refptr<VideoFrameBuffer>& buffer,
152     int cropped_width,
153     int cropped_height);
154 
155 }  // namespace webrtc
156 
157 #endif  // WEBRTC_COMMON_VIDEO_INCLUDE_VIDEO_FRAME_BUFFER_H_
158