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 <system/window.h>
21
22#include <gui/ConsumerBase.h>
23#include <gui/BufferQueue.h>
24
25#include <utils/Vector.h>
26
27
28namespace android {
29
30class BufferQueue;
31class GraphicBuffer;
32class String8;
33
34/**
35 * CpuConsumer is a BufferQueue consumer endpoint that allows direct CPU
36 * access to the underlying gralloc buffers provided by BufferQueue. Multiple
37 * buffers may be acquired by it at once, to be used concurrently by the
38 * CpuConsumer owner. Sets gralloc usage flags to be software-read-only.
39 * This queue is synchronous by default.
40 */
41
42class CpuConsumer : public ConsumerBase
43{
44  public:
45    typedef ConsumerBase::FrameAvailableListener FrameAvailableListener;
46
47    struct LockedBuffer {
48        uint8_t    *data;
49        uint32_t    width;
50        uint32_t    height;
51        PixelFormat format;
52        uint32_t    stride;
53        Rect        crop;
54        uint32_t    transform;
55        uint32_t    scalingMode;
56        int64_t     timestamp;
57        android_dataspace dataSpace;
58        uint64_t    frameNumber;
59        // this is the same as format, except for formats that are compatible with
60        // a flexible format (e.g. HAL_PIXEL_FORMAT_YCbCr_420_888). In the latter
61        // case this contains that flexible format
62        PixelFormat flexFormat;
63        // Values below are only valid when using HAL_PIXEL_FORMAT_YCbCr_420_888
64        // or compatible format, in which case LockedBuffer::data
65        // contains the Y channel, and stride is the Y channel stride. For other
66        // formats, these will all be 0.
67        uint8_t    *dataCb;
68        uint8_t    *dataCr;
69        uint32_t    chromaStride;
70        uint32_t    chromaStep;
71
72        LockedBuffer() :
73            data(NULL),
74            width(0),
75            height(0),
76            format(PIXEL_FORMAT_NONE),
77            stride(0),
78            crop(Rect::EMPTY_RECT),
79            transform(0),
80            scalingMode(NATIVE_WINDOW_SCALING_MODE_FREEZE),
81            timestamp(0),
82            dataSpace(HAL_DATASPACE_UNKNOWN),
83            frameNumber(0),
84            flexFormat(PIXEL_FORMAT_NONE),
85            dataCb(NULL),
86            dataCr(NULL),
87            chromaStride(0),
88            chromaStep(0)
89        {}
90    };
91
92    // Create a new CPU consumer. The maxLockedBuffers parameter specifies
93    // how many buffers can be locked for user access at the same time.
94    CpuConsumer(const sp<IGraphicBufferConsumer>& bq,
95            size_t maxLockedBuffers, bool controlledByApp = false);
96
97    virtual ~CpuConsumer();
98
99    // set the name of the CpuConsumer that will be used to identify it in
100    // log messages.
101    void setName(const String8& name);
102
103    // Gets the next graphics buffer from the producer and locks it for CPU use,
104    // filling out the passed-in locked buffer structure with the native pointer
105    // and metadata. Returns BAD_VALUE if no new buffer is available, and
106    // NOT_ENOUGH_DATA if the maximum number of buffers is already locked.
107    //
108    // Only a fixed number of buffers can be locked at a time, determined by the
109    // construction-time maxLockedBuffers parameter. If INVALID_OPERATION is
110    // returned by lockNextBuffer, then old buffers must be returned to the queue
111    // by calling unlockBuffer before more buffers can be acquired.
112    status_t lockNextBuffer(LockedBuffer *nativeBuffer);
113
114    // Returns a locked buffer to the queue, allowing it to be reused. Since
115    // only a fixed number of buffers may be locked at a time, old buffers must
116    // be released by calling unlockBuffer to ensure new buffers can be acquired by
117    // lockNextBuffer.
118    status_t unlockBuffer(const LockedBuffer &nativeBuffer);
119
120  private:
121    // Maximum number of buffers that can be locked at a time
122    size_t mMaxLockedBuffers;
123
124    status_t releaseAcquiredBufferLocked(size_t lockedIdx);
125
126    virtual void freeBufferLocked(int slotIndex);
127
128    // Tracking for buffers acquired by the user
129    struct AcquiredBuffer {
130        // Need to track the original mSlot index and the buffer itself because
131        // the mSlot entry may be freed/reused before the acquired buffer is
132        // released.
133        int mSlot;
134        sp<GraphicBuffer> mGraphicBuffer;
135        void *mBufferPointer;
136
137        AcquiredBuffer() :
138                mSlot(BufferQueue::INVALID_BUFFER_SLOT),
139                mBufferPointer(NULL) {
140        }
141    };
142    Vector<AcquiredBuffer> mAcquiredBuffers;
143
144    // Count of currently locked buffers
145    size_t mCurrentLockedBuffers;
146
147};
148
149} // namespace android
150
151#endif // ANDROID_GUI_CPUCONSUMER_H
152