src/content/renderer/media/video_frame_deliverer.cc

   1 // Copyright 2014 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 "content/renderer/media/video_frame_deliverer.h"
   6
   7 #include "base/bind.h"
   8 #include "base/location.h"
   9
  10 namespace content {
  11 namespace {
  12 void ResetCallback(scoped_ptr<VideoCaptureDeliverFrameCB> callback) {
  13   // |callback| will be deleted when this exits.
  14 }
  15 }  // namespace
  16
  17 VideoFrameDeliverer::VideoFrameDeliverer(
  18     const scoped_refptr<base::MessageLoopProxy>& io_message_loop)
  19     : io_message_loop_(io_message_loop) {
  20   DCHECK(io_message_loop_);
  21 }
  22
  23 VideoFrameDeliverer::~VideoFrameDeliverer() {
  24   DCHECK(callbacks_.empty());
  25 }
  26
  27 void VideoFrameDeliverer::AddCallback(
  28     void* id,
  29     const VideoCaptureDeliverFrameCB& callback) {
  30   DCHECK(thread_checker_.CalledOnValidThread());
  31   io_message_loop_->PostTask(
  32       FROM_HERE,
  33       base::Bind(&VideoFrameDeliverer::AddCallbackOnIO,
  34                  this, id, callback));
  35 }
  36
  37 void VideoFrameDeliverer::AddCallbackOnIO(
  38     void* id,
  39     const VideoCaptureDeliverFrameCB& callback) {
  40   DCHECK(io_message_loop_->BelongsToCurrentThread());
  41   callbacks_.push_back(std::make_pair(id, callback));
  42 }
  43
  44 void VideoFrameDeliverer::RemoveCallback(void* id) {
  45   DCHECK(thread_checker_.CalledOnValidThread());
  46   io_message_loop_->PostTask(
  47       FROM_HERE,
  48       base::Bind(&VideoFrameDeliverer::RemoveCallbackOnIO,
  49                  this, id, base::MessageLoopProxy::current()));
  50 }
  51
  52 void VideoFrameDeliverer::RemoveCallbackOnIO(
  53     void* id, const scoped_refptr<base::MessageLoopProxy>& message_loop) {
  54   DCHECK(io_message_loop_->BelongsToCurrentThread());
  55   std::vector<VideoIdCallbackPair>::iterator it = callbacks_.begin();
  56   for (; it != callbacks_.end(); ++it) {
  57     if (it->first == id) {
  58       // Callback is copied to heap and then deleted on the target thread.
  59       // The following code ensures that the callback is not referenced on
  60       // the stack.
  61       scoped_ptr<VideoCaptureDeliverFrameCB> callback;
  62       {
  63         callback.reset(new VideoCaptureDeliverFrameCB(it->second));
  64         callbacks_.erase(it);
  65       }
  66       message_loop->PostTask(
  67           FROM_HERE, base::Bind(&ResetCallback, base::Passed(&callback)));
  68       return;
  69     }
  70   }
  71 }
  72
  73 void VideoFrameDeliverer::DeliverFrameOnIO(
  74     const scoped_refptr<media::VideoFrame>& frame,
  75     const media::VideoCaptureFormat& format,
  76     const base::TimeTicks& estimated_capture_time) {
  77   DCHECK(io_message_loop_->BelongsToCurrentThread());
  78   for (std::vector<VideoIdCallbackPair>::iterator it = callbacks_.begin();
  79        it != callbacks_.end(); ++it) {
  80     it->second.Run(frame, format, estimated_capture_time);
  81   }
  82 }
  83
  84 }  // namespace content