xref: /aosp_15_r20/external/v4l2_codec2/components/include/v4l2_codec2/components/VideoFramePool.h (revision 0ec5a0ec62797f775085659156625e7f1bdb369f)
1 // Copyright 2020 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef ANDROID_V4L2_CODEC2_COMPONENTS_VIDEO_FRAME_POOL_H
6 #define ANDROID_V4L2_CODEC2_COMPONENTS_VIDEO_FRAME_POOL_H
7 
8 #include <atomic>
9 #include <memory>
10 #include <optional>
11 #include <queue>
12 
13 #include <C2Buffer.h>
14 #include <base/callback.h>
15 #include <base/memory/weak_ptr.h>
16 #include <base/sequenced_task_runner.h>
17 #include <base/threading/thread.h>
18 #include <ui/Size.h>
19 
20 #include <v4l2_codec2/common/VideoTypes.h>
21 #include <v4l2_codec2/components/VideoFrame.h>
22 
23 namespace android {
24 
25 // Fetch C2GraphicBlock from C2BlockPool and wrap to VideoFrame.
26 // Provide asynchronous call which avoid the caller busy-polling while
27 // C2BlockPool::fetchGraphicBlock() times out.
28 class VideoFramePool {
29 public:
30     using FrameWithBlockId = std::pair<std::unique_ptr<VideoFrame>, uint32_t>;
31     using GetVideoFrameCB = ::base::OnceCallback<void(std::optional<FrameWithBlockId>)>;
32 
33     static std::unique_ptr<VideoFramePool> Create(
34             std::shared_ptr<C2BlockPool> blockPool, const size_t numBuffers, const ui::Size& size,
35             HalPixelFormat pixelFormat, bool isSecure,
36             scoped_refptr<::base::SequencedTaskRunner> taskRunner);
37     ~VideoFramePool();
38 
39     // Get a VideoFrame instance, which will be passed via |cb|.
40     // If any error occurs, then nullptr will be passed via |cb|.
41     // Return false if the previous callback has not been called, and |cb| will
42     // be dropped directly.
43     bool getVideoFrame(GetVideoFrameCB cb);
44 
45 private:
46     // |blockPool| is the C2BlockPool that we fetch graphic blocks from.
47     // |maxBufferCount| maximum number of buffer that should should provide to client
48     // |size| is the resolution size of the required graphic blocks.
49     // |pixelFormat| is the pixel format of the required graphic blocks.
50     // |isSecure| indicates the video stream is encrypted or not.
51     // All public methods and the callbacks should be run on |taskRunner|.
52     VideoFramePool(std::shared_ptr<C2BlockPool> blockPool, const size_t maxBufferCount,
53                    const ui::Size& size, HalPixelFormat pixelFormat, C2MemoryUsage memoryUsage,
54                    scoped_refptr<::base::SequencedTaskRunner> taskRunner);
55     bool initialize();
56     void destroyTask();
57 
58     static void getVideoFrameTaskThunk(scoped_refptr<::base::SequencedTaskRunner> taskRunner,
59                                        std::optional<::base::WeakPtr<VideoFramePool>> weakPool);
60     void getVideoFrameTask();
61     void onVideoFrameReady(std::optional<FrameWithBlockId> frameWithBlockId);
62 
63     // Returns true if a buffer shall not be handed to client.
64     bool shouldDropBuffer(uint32_t bufferId);
65 
66     static std::optional<uint32_t> getBufferIdFromGraphicBlock(C2BlockPool& blockPool,
67                                                                const C2Block2D& block);
68 
69     std::shared_ptr<C2BlockPool> mBlockPool;
70 
71     // Holds the number of maximum amount of buffers that VideoFramePool
72     // should provide to client.
73     size_t mMaxBufferCount;
74     // Contains known buffer ids that are valid for the pool.
75     std::set<uint32_t> mBuffers;
76 
77     const ui::Size mSize;
78     const HalPixelFormat mPixelFormat;
79     const C2MemoryUsage mMemoryUsage;
80 
81     GetVideoFrameCB mOutputCb;
82 
83     scoped_refptr<::base::SequencedTaskRunner> mClientTaskRunner;
84     ::base::Thread mFetchThread{"VideoFramePoolFetchThread"};
85     scoped_refptr<::base::SequencedTaskRunner> mFetchTaskRunner;
86 
87     ::base::WeakPtr<VideoFramePool> mClientWeakThis;
88     ::base::WeakPtr<VideoFramePool> mFetchWeakThis;
89     ::base::WeakPtrFactory<VideoFramePool> mClientWeakThisFactory{this};
90     ::base::WeakPtrFactory<VideoFramePool> mFetchWeakThisFactory{this};
91 };
92 
93 }  // namespace android
94 
95 #endif  // ANDROID_V4L2_CODEC2_COMPONENTS_VIDEO_FRAME_POOL_H
96