media/base/video_frame_pool.cc

   1 // Copyright 2013 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 #include "media/base/video_frame_pool.h"
   6
   7 #include <list>
   8
   9 #include "base/bind.h"
  10 #include "base/memory/ref_counted.h"
  11 #include "base/synchronization/lock.h"
  12
  13 namespace media {
  14
  15 class VideoFramePool::PoolImpl
  16     : public base::RefCountedThreadSafe<VideoFramePool::PoolImpl> {
  17  public:
  18   PoolImpl();
  19
  20   // See VideoFramePool::CreateFrame() for usage.
  21   scoped_refptr<VideoFrame> CreateFrame(VideoPixelFormat format,
  22                                         const gfx::Size& coded_size,
  23                                         const gfx::Rect& visible_rect,
  24                                         const gfx::Size& natural_size,
  25                                         base::TimeDelta timestamp);
  26
  27   // Shuts down the frame pool and releases all frames in |frames_|.
  28   // Once this is called frames will no longer be inserted back into
  29   // |frames_|.
  30   void Shutdown();
  31
  32   size_t GetPoolSizeForTesting() const { return frames_.size(); }
  33
  34  private:
  35   friend class base::RefCountedThreadSafe<VideoFramePool::PoolImpl>;
  36   ~PoolImpl();
  37
  38   // Called when the frame wrapper gets destroyed.
  39   // |frame| is the actual frame that was wrapped and is placed
  40   // in |frames_| by this function so it can be reused.
  41   void FrameReleased(const scoped_refptr<VideoFrame>& frame);
  42
  43   base::Lock lock_;
  44   bool is_shutdown_;
  45   std::list<scoped_refptr<VideoFrame> > frames_;
  46
  47   DISALLOW_COPY_AND_ASSIGN(PoolImpl);
  48 };
  49
  50 VideoFramePool::PoolImpl::PoolImpl() : is_shutdown_(false) {}
  51
  52 VideoFramePool::PoolImpl::~PoolImpl() {
  53   DCHECK(is_shutdown_);
  54 }
  55
  56 scoped_refptr<VideoFrame> VideoFramePool::PoolImpl::CreateFrame(
  57     VideoPixelFormat format,
  58     const gfx::Size& coded_size,
  59     const gfx::Rect& visible_rect,
  60     const gfx::Size& natural_size,
  61     base::TimeDelta timestamp) {
  62   base::AutoLock auto_lock(lock_);
  63   DCHECK(!is_shutdown_);
  64
  65   scoped_refptr<VideoFrame> frame;
  66
  67   while (!frame.get() && !frames_.empty()) {
  68       scoped_refptr<VideoFrame> pool_frame = frames_.front();
  69       frames_.pop_front();
  70
  71       if (pool_frame->format() == format &&
  72           pool_frame->coded_size() == coded_size &&
  73           pool_frame->visible_rect() == visible_rect &&
  74           pool_frame->natural_size() == natural_size) {
  75         frame = pool_frame;
  76         frame->set_timestamp(timestamp);
  77         break;
  78       }
  79   }
  80
  81   if (!frame.get()) {
  82     frame = VideoFrame::CreateFrame(format, coded_size, visible_rect,
  83                                     natural_size, timestamp);
  84
  85     // Zero-initialize each plane of the buffer.
  86     const size_t num_planes = VideoFrame::NumPlanes(frame->format());
  87     for (size_t i = 0; i < num_planes; ++i) {
  88       memset(frame->data(i),
  89              0,
  90              VideoFrame::PlaneSize(frame->format(),
  91                                    i,
  92                                    frame->coded_size()).GetArea());
  93     }
  94   }
  95
  96   scoped_refptr<VideoFrame> wrapped_frame = VideoFrame::WrapVideoFrame(
  97       frame, frame->visible_rect(), frame->natural_size());
  98   wrapped_frame->AddDestructionObserver(
  99       base::Bind(&VideoFramePool::PoolImpl::FrameReleased, this, frame));
 100   return wrapped_frame;
 101 }
 102
 103 void VideoFramePool::PoolImpl::Shutdown() {
 104   base::AutoLock auto_lock(lock_);
 105   is_shutdown_ = true;
 106   frames_.clear();
 107 }
 108
 109 void VideoFramePool::PoolImpl::FrameReleased(
 110     const scoped_refptr<VideoFrame>& frame) {
 111   base::AutoLock auto_lock(lock_);
 112   if (is_shutdown_)
 113     return;
 114
 115   frames_.push_back(frame);
 116 }
 117
 118 VideoFramePool::VideoFramePool() : pool_(new PoolImpl()) {
 119 }
 120
 121 VideoFramePool::~VideoFramePool() {
 122   pool_->Shutdown();
 123 }
 124
 125 scoped_refptr<VideoFrame> VideoFramePool::CreateFrame(
 126     VideoPixelFormat format,
 127     const gfx::Size& coded_size,
 128     const gfx::Rect& visible_rect,
 129     const gfx::Size& natural_size,
 130     base::TimeDelta timestamp) {
 131   return pool_->CreateFrame(format, coded_size, visible_rect, natural_size,
 132                             timestamp);
 133 }
 134
 135 size_t VideoFramePool::GetPoolSizeForTesting() const {
 136   return pool_->GetPoolSizeForTesting();
 137 }
 138
 139 }  // namespace media