create a separate WebMediaPlayer for URL derived from media stream

webkit/media/simple_video_frame_provider.cc

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "webkit/media/simple_video_frame_provider.h"
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/message_loop_proxy.h"
+#include "media/base/video_frame.h"
+
+namespace webkit_media {
+
+SimpleVideoFrameProvider::SimpleVideoFrameProvider(
+    const gfx::Size& size,
+    const base::TimeDelta& frame_duration,
+    const base::Closure& error_cb,
+    const VideoFrameProvider::RepaintCB& repaint_cb)
+    : message_loop_proxy_(base::MessageLoopProxy::current()),
+      size_(size),
+      state_(kStopped),
+      frame_duration_(frame_duration),
+      error_cb_(error_cb),
+      repaint_cb_(repaint_cb) {
+}
+
+SimpleVideoFrameProvider::~SimpleVideoFrameProvider() {}
+
+void SimpleVideoFrameProvider::Start() {
+  DVLOG(1) << "SimpleVideoFrameProvider::Start";
+  DCHECK(message_loop_proxy_->BelongsToCurrentThread());
+  state_ = kStarted;
+  message_loop_proxy_->PostTask(
+      FROM_HERE,
+      base::Bind(&SimpleVideoFrameProvider::GenerateFrame, this));
+}
+
+void SimpleVideoFrameProvider::Stop() {
+  DVLOG(1) << "SimpleVideoFrameProvider::Stop";
+  DCHECK(message_loop_proxy_->BelongsToCurrentThread());
+  state_ = kStopped;
+}
+
+void SimpleVideoFrameProvider::Play() {
+  DVLOG(1) << "SimpleVideoFrameProvider::Play";
+  DCHECK(message_loop_proxy_->BelongsToCurrentThread());
+  if (state_ == kPaused)
+    state_ = kStarted;
+}
+
+void SimpleVideoFrameProvider::Pause() {
+  DVLOG(1) << "SimpleVideoFrameProvider::Pause";
+  DCHECK(message_loop_proxy_->BelongsToCurrentThread());
+  if (state_ == kStarted)
+    state_ = kPaused;
+}
+
+void SimpleVideoFrameProvider::GenerateFrame() {
+  DVLOG(1) << "SimpleVideoFrameProvider::GenerateFrame";
+  DCHECK(message_loop_proxy_->BelongsToCurrentThread());
+  if (state_ == kStopped)
+    return;
+
+  if (state_ == kStarted) {
+    // Always allocate a new frame.
+    scoped_refptr<media::VideoFrame> video_frame =
+        media::VideoFrame::CreateFrame(media::VideoFrame::YV12,
+                                       size_,
+                                       size_,
+                                       current_time_);
+
+    // TODO(wjia): set pixel data to pre-defined patterns if it's desired to
+    // verify frame content.
+
+    repaint_cb_.Run(video_frame);
+  }
+
+  current_time_ += frame_duration_;
+  message_loop_proxy_->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&SimpleVideoFrameProvider::GenerateFrame, this),
+      frame_duration_);
+}
+
+}  // namespace webkit_media