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 COMMON_VIDEO_INCLUDE_VIDEO_FRAME_BUFFER_POOL_H_ 12 #define COMMON_VIDEO_INCLUDE_VIDEO_FRAME_BUFFER_POOL_H_ 13 14 #include <stddef.h> 15 16 #include <list> 17 18 #include "api/scoped_refptr.h" 19 #include "api/video/i420_buffer.h" 20 #include "api/video/nv12_buffer.h" 21 #include "rtc_base/race_checker.h" 22 #include "rtc_base/ref_counted_object.h" 23 24 namespace webrtc { 25 26 // Simple buffer pool to avoid unnecessary allocations of video frame buffers. 27 // The pool manages the memory of the I420Buffer/NV12Buffer returned from 28 // Create(I420|NV12)Buffer. When the buffer is destructed, the memory is 29 // returned to the pool for use by subsequent calls to Create(I420|NV12)Buffer. 30 // If the resolution passed to Create(I420|NV12)Buffer changes or requested 31 // pixel format changes, old buffers will be purged from the pool. 32 // Note that Create(I420|NV12)Buffer will crash if more than 33 // kMaxNumberOfFramesBeforeCrash are created. This is to prevent memory leaks 34 // where frames are not returned. 35 class VideoFrameBufferPool { 36 public: 37 VideoFrameBufferPool(); 38 explicit VideoFrameBufferPool(bool zero_initialize); 39 VideoFrameBufferPool(bool zero_initialize, size_t max_number_of_buffers); 40 ~VideoFrameBufferPool(); 41 42 // Returns a buffer from the pool. If no suitable buffer exist in the pool 43 // and there are less than |max_number_of_buffers| pending, a buffer is 44 // created. Returns null otherwise. 45 rtc::scoped_refptr<I420Buffer> CreateI420Buffer(int width, int height); 46 rtc::scoped_refptr<NV12Buffer> CreateNV12Buffer(int width, int height); 47 48 // Changes the max amount of buffers in the pool to the new value. 49 // Returns true if change was successful and false if the amount of already 50 // allocated buffers is bigger than new value. 51 bool Resize(size_t max_number_of_buffers); 52 53 // Clears buffers_ and detaches the thread checker so that it can be reused 54 // later from another thread. 55 void Release(); 56 57 private: 58 rtc::scoped_refptr<VideoFrameBuffer> 59 GetExistingBuffer(int width, int height, VideoFrameBuffer::Type type); 60 61 rtc::RaceChecker race_checker_; 62 std::list<rtc::scoped_refptr<VideoFrameBuffer>> buffers_; 63 // If true, newly allocated buffers are zero-initialized. Note that recycled 64 // buffers are not zero'd before reuse. This is required of buffers used by 65 // FFmpeg according to http://crbug.com/390941, which only requires it for the 66 // initial allocation (as shown by FFmpeg's own buffer allocation code). It 67 // has to do with "Use-of-uninitialized-value" on "Linux_msan_chrome". 68 const bool zero_initialize_; 69 // Max number of buffers this pool can have pending. 70 size_t max_number_of_buffers_; 71 }; 72 73 } // namespace webrtc 74 75 #endif // COMMON_VIDEO_INCLUDE_VIDEO_FRAME_BUFFER_POOL_H_ 76