• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (C) 2012 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ANDROID_GUI_CPUCONSUMER_H
18 #define ANDROID_GUI_CPUCONSUMER_H
19 
20 #include <gui/ConsumerBase.h>
21 
22 #include <ui/GraphicBuffer.h>
23 
24 #include <utils/String8.h>
25 #include <utils/Vector.h>
26 #include <utils/threads.h>
27 
28 
29 namespace android {
30 
31 class BufferQueue;
32 
33 /**
34  * CpuConsumer is a BufferQueue consumer endpoint that allows direct CPU
35  * access to the underlying gralloc buffers provided by BufferQueue. Multiple
36  * buffers may be acquired by it at once, to be used concurrently by the
37  * CpuConsumer owner. Sets gralloc usage flags to be software-read-only.
38  * This queue is synchronous by default.
39  */
40 
41 class CpuConsumer : public ConsumerBase
42 {
43   public:
44     typedef ConsumerBase::FrameAvailableListener FrameAvailableListener;
45 
46     struct LockedBuffer {
47         uint8_t    *data;
48         uint32_t    width;
49         uint32_t    height;
50         PixelFormat format;
51         uint32_t    stride;
52         Rect        crop;
53         uint32_t    transform;
54         uint32_t    scalingMode;
55         int64_t     timestamp;
56         android_dataspace dataSpace;
57         uint64_t    frameNumber;
58         // this is the same as format, except for formats that are compatible with
59         // a flexible format (e.g. HAL_PIXEL_FORMAT_YCbCr_420_888). In the latter
60         // case this contains that flexible format
61         PixelFormat flexFormat;
62         // Values below are only valid when using HAL_PIXEL_FORMAT_YCbCr_420_888
63         // or compatible format, in which case LockedBuffer::data
64         // contains the Y channel, and stride is the Y channel stride. For other
65         // formats, these will all be 0.
66         uint8_t    *dataCb;
67         uint8_t    *dataCr;
68         uint32_t    chromaStride;
69         uint32_t    chromaStep;
70 
LockedBufferLockedBuffer71         LockedBuffer() :
72             data(NULL),
73             width(0),
74             height(0),
75             format(PIXEL_FORMAT_NONE),
76             stride(0),
77             crop(Rect::EMPTY_RECT),
78             transform(0),
79             scalingMode(NATIVE_WINDOW_SCALING_MODE_FREEZE),
80             timestamp(0),
81             dataSpace(HAL_DATASPACE_UNKNOWN),
82             frameNumber(0),
83             flexFormat(PIXEL_FORMAT_NONE),
84             dataCb(NULL),
85             dataCr(NULL),
86             chromaStride(0),
87             chromaStep(0)
88         {}
89     };
90 
91     // Create a new CPU consumer. The maxLockedBuffers parameter specifies
92     // how many buffers can be locked for user access at the same time.
93     CpuConsumer(const sp<IGraphicBufferConsumer>& bq,
94             size_t maxLockedBuffers, bool controlledByApp = false);
95 
96     virtual ~CpuConsumer();
97 
98     // set the name of the CpuConsumer that will be used to identify it in
99     // log messages.
100     void setName(const String8& name);
101 
102     // Gets the next graphics buffer from the producer and locks it for CPU use,
103     // filling out the passed-in locked buffer structure with the native pointer
104     // and metadata. Returns BAD_VALUE if no new buffer is available, and
105     // NOT_ENOUGH_DATA if the maximum number of buffers is already locked.
106     //
107     // Only a fixed number of buffers can be locked at a time, determined by the
108     // construction-time maxLockedBuffers parameter. If INVALID_OPERATION is
109     // returned by lockNextBuffer, then old buffers must be returned to the queue
110     // by calling unlockBuffer before more buffers can be acquired.
111     status_t lockNextBuffer(LockedBuffer *nativeBuffer);
112 
113     // Returns a locked buffer to the queue, allowing it to be reused. Since
114     // only a fixed number of buffers may be locked at a time, old buffers must
115     // be released by calling unlockBuffer to ensure new buffers can be acquired by
116     // lockNextBuffer.
117     status_t unlockBuffer(const LockedBuffer &nativeBuffer);
118 
119   private:
120     // Maximum number of buffers that can be locked at a time
121     size_t mMaxLockedBuffers;
122 
123     status_t releaseAcquiredBufferLocked(size_t lockedIdx);
124 
125     virtual void freeBufferLocked(int slotIndex);
126 
127     // Tracking for buffers acquired by the user
128     struct AcquiredBuffer {
129         // Need to track the original mSlot index and the buffer itself because
130         // the mSlot entry may be freed/reused before the acquired buffer is
131         // released.
132         int mSlot;
133         sp<GraphicBuffer> mGraphicBuffer;
134         void *mBufferPointer;
135 
AcquiredBufferAcquiredBuffer136         AcquiredBuffer() :
137                 mSlot(BufferQueue::INVALID_BUFFER_SLOT),
138                 mBufferPointer(NULL) {
139         }
140     };
141     Vector<AcquiredBuffer> mAcquiredBuffers;
142 
143     // Count of currently locked buffers
144     size_t mCurrentLockedBuffers;
145 
146 };
147 
148 } // namespace android
149 
150 #endif // ANDROID_GUI_CPUCONSUMER_H
151