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
29namespace android {
30
31class 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
41class 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        uint64_t    frameNumber;
57        // this is the same as format, except for formats that are compatible with
58        // a flexible format (e.g. HAL_PIXEL_FORMAT_YCbCr_420_888). In the latter
59        // case this contains that flexible format
60        PixelFormat flexFormat;
61        // Values below are only valid when using HAL_PIXEL_FORMAT_YCbCr_420_888
62        // or compatible format, in which case LockedBuffer::data
63        // contains the Y channel, and stride is the Y channel stride. For other
64        // formats, these will all be 0.
65        uint8_t    *dataCb;
66        uint8_t    *dataCr;
67        uint32_t    chromaStride;
68        uint32_t    chromaStep;
69    };
70
71    // Create a new CPU consumer. The maxLockedBuffers parameter specifies
72    // how many buffers can be locked for user access at the same time.
73    CpuConsumer(const sp<IGraphicBufferConsumer>& bq,
74            uint32_t maxLockedBuffers, bool controlledByApp = false);
75
76    virtual ~CpuConsumer();
77
78    // set the name of the CpuConsumer that will be used to identify it in
79    // log messages.
80    void setName(const String8& name);
81
82    // setDefaultBufferSize is used to set the size of buffers returned by
83    // requestBuffers when a width and height of zero is requested.
84    // A call to setDefaultBufferSize() may trigger requestBuffers() to
85    // be called from the client. Default size is 1x1.
86    status_t setDefaultBufferSize(uint32_t width, uint32_t height);
87
88    // setDefaultBufferFormat allows CpuConsumer's BufferQueue to create buffers
89    // of a defaultFormat if no format is specified by producer. Formats are
90    // enumerated in graphics.h; the initial default is
91    // HAL_PIXEL_FORMAT_RGBA_8888.
92    status_t setDefaultBufferFormat(uint32_t defaultFormat);
93
94    // Gets the next graphics buffer from the producer and locks it for CPU use,
95    // filling out the passed-in locked buffer structure with the native pointer
96    // and metadata. Returns BAD_VALUE if no new buffer is available, and
97    // NOT_ENOUGH_DATA if the maximum number of buffers is already locked.
98    //
99    // Only a fixed number of buffers can be locked at a time, determined by the
100    // construction-time maxLockedBuffers parameter. If INVALID_OPERATION is
101    // returned by lockNextBuffer, then old buffers must be returned to the queue
102    // by calling unlockBuffer before more buffers can be acquired.
103    status_t lockNextBuffer(LockedBuffer *nativeBuffer);
104
105    // Returns a locked buffer to the queue, allowing it to be reused. Since
106    // only a fixed number of buffers may be locked at a time, old buffers must
107    // be released by calling unlockBuffer to ensure new buffers can be acquired by
108    // lockNextBuffer.
109    status_t unlockBuffer(const LockedBuffer &nativeBuffer);
110
111  private:
112    // Maximum number of buffers that can be locked at a time
113    uint32_t mMaxLockedBuffers;
114
115    status_t releaseAcquiredBufferLocked(int lockedIdx);
116
117    virtual void freeBufferLocked(int slotIndex);
118
119    // Tracking for buffers acquired by the user
120    struct AcquiredBuffer {
121        // Need to track the original mSlot index and the buffer itself because
122        // the mSlot entry may be freed/reused before the acquired buffer is
123        // released.
124        int mSlot;
125        sp<GraphicBuffer> mGraphicBuffer;
126        void *mBufferPointer;
127
128        AcquiredBuffer() :
129                mSlot(BufferQueue::INVALID_BUFFER_SLOT),
130                mBufferPointer(NULL) {
131        }
132    };
133    Vector<AcquiredBuffer> mAcquiredBuffers;
134
135    // Count of currently locked buffers
136    uint32_t mCurrentLockedBuffers;
137
138};
139
140} // namespace android
141
142#endif // ANDROID_GUI_CPUCONSUMER_H
143