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   // Returns a frame from the pool that matches the specified
  21   // parameters or creates a new frame if no suitable frame exists in
  22   // the pool. The pool is drained if no matching frame is found.
  23   scoped_refptr<VideoFrame> CreateFrame(VideoPixelFormat format,
  24                                         const gfx::Size& coded_size,
  25                                         const gfx::Rect& visible_rect,
  26                                         const gfx::Size& natural_size,
  27                                         base::TimeDelta timestamp);
  28
  29   // Shuts down the frame pool and releases all frames in |frames_|.
  30   // Once this is called frames will no longer be inserted back into
  31   // |frames_|.
  32   void Shutdown();
  33
  34   size_t GetPoolSizeForTesting() const { return frames_.size(); }
  35
  36  private:
  37   friend class base::RefCountedThreadSafe<VideoFramePool::PoolImpl>;
  38   ~PoolImpl();
  39
  40   // Called when the frame wrapper gets destroyed.
  41   // |frame| is the actual frame that was wrapped and is placed
  42   // in |frames_| by this function so it can be reused.
  43   void FrameReleased(const scoped_refptr<VideoFrame>& frame);
  44
  45   base::Lock lock_;
  46   bool is_shutdown_;
  47   std::list<scoped_refptr<VideoFrame> > frames_;
  48
  49   DISALLOW_COPY_AND_ASSIGN(PoolImpl);
  50 };
  51
  52 VideoFramePool::PoolImpl::PoolImpl() : is_shutdown_(false) {}
  53
  54 VideoFramePool::PoolImpl::~PoolImpl() {
  55   DCHECK(is_shutdown_);
  56 }
  57
  58 scoped_refptr<VideoFrame> VideoFramePool::PoolImpl::CreateFrame(
  59     VideoPixelFormat format,
  60     const gfx::Size& coded_size,
  61     const gfx::Rect& visible_rect,
  62     const gfx::Size& natural_size,
  63     base::TimeDelta timestamp) {
  64   base::AutoLock auto_lock(lock_);
  65   DCHECK(!is_shutdown_);
  66
  67   scoped_refptr<VideoFrame> frame;
  68
  69   while (!frame.get() && !frames_.empty()) {
  70       scoped_refptr<VideoFrame> pool_frame = frames_.front();
  71       frames_.pop_front();
  72
  73       if (pool_frame->format() == format &&
  74           pool_frame->coded_size() == coded_size &&
  75           pool_frame->visible_rect() == visible_rect &&
  76           pool_frame->natural_size() == natural_size) {
  77         frame = pool_frame;
  78         frame->set_timestamp(timestamp);
  79         break;
  80       }
  81   }
  82
  83   if (!frame.get()) {
  84     frame = VideoFrame::CreateFrame(
  85         format, coded_size, visible_rect, natural_size, timestamp);
  86   }
  87
  88   scoped_refptr<VideoFrame> wrapped_frame = VideoFrame::WrapVideoFrame(
  89       frame, frame->visible_rect(), frame->natural_size());
  90   wrapped_frame->AddDestructionObserver(
  91       base::Bind(&VideoFramePool::PoolImpl::FrameReleased, this, frame));
  92   return wrapped_frame;
  93 }
  94
  95 void VideoFramePool::PoolImpl::Shutdown() {
  96   base::AutoLock auto_lock(lock_);
  97   is_shutdown_ = true;
  98   frames_.clear();
  99 }
 100
 101 void VideoFramePool::PoolImpl::FrameReleased(
 102     const scoped_refptr<VideoFrame>& frame) {
 103   base::AutoLock auto_lock(lock_);
 104   if (is_shutdown_)
 105     return;
 106
 107   frames_.push_back(frame);
 108 }
 109
 110 VideoFramePool::VideoFramePool() : pool_(new PoolImpl()) {
 111 }
 112
 113 VideoFramePool::~VideoFramePool() {
 114   pool_->Shutdown();
 115 }
 116
 117 scoped_refptr<VideoFrame> VideoFramePool::CreateFrame(
 118     VideoPixelFormat format,
 119     const gfx::Size& coded_size,
 120     const gfx::Rect& visible_rect,
 121     const gfx::Size& natural_size,
 122     base::TimeDelta timestamp) {
 123   return pool_->CreateFrame(format, coded_size, visible_rect, natural_size,
 124                             timestamp);
 125 }
 126
 127 size_t VideoFramePool::GetPoolSizeForTesting() const {
 128   return pool_->GetPoolSizeForTesting();
 129 }
 130
 131 }  // namespace media