Add a VideoDecodeContext that provides resources for a VideoDecodeEngine

Also define a Gles2VideoDecodeContext to be used in the chrome renderer.

BUG=53714
TEST=none

Review URL: http://codereview.chromium.org/3233003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@58772 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 51 insertions, 0 deletions

diff --git a/media/video/video_decode_context.h b/media/video/video_decode_context.h
new file mode 100644
index 0000000..0bea382
--- /dev/null
+++ b/media/video/video_decode_context.h
@@ -0,0 +1,51 @@
+// Copyright (c) 2010 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.
+
+#ifndef MEDIA_VIDEO_VIDEO_DECODE_CONTEXT_H_
+#define MEDIA_VIDEO_VIDEO_DECODE_CONTEXT_H_
+
+#include "base/callback.h"
+
+namespace media {
+
+class VideoFrame;
+
+// A VideoDecodeContext provides resources like output video frame storage and
+// hardware decoder handle to a VideoDecodeEngine, it hides all the platform and
+// subsystem details from the decode engine.
+class VideoDecodeContext {
+ public:
+  typedef Callback2<int, VideoFrame*[]>::Type AllocationCompleteCallback;
+  typedef Callback0::Type DestructionCompleteCallback;
+
+  virtual ~VideoDecodeContext() {};
+
+  // Obtain a handle to the hardware video decoder device. The type of the
+  // handle is a contract between the implementation of VideoDecodeContext and
+  // VideoDecodeEngine.
+  //
+  // If a hardware device is not needed this method should return NULL.
+  virtual void* GetDevice() = 0;
+
+  // Allocate |n| video frames with dimension |width| and |height|. |callback|
+  // is called when allocation has completed.
+  virtual void AllocateVideoFrames(int n, size_t width, size_t height,
+                                   AllocationCompleteCallback* callback) = 0;
+
+  // Release video frames allocated by the context. After making this call
+  // VideoDecodeEngine should not use the VideoFrame allocated because they
+  // could be destroyed.
+  virtual void ReleaseVideoFrames(int n, VideoFrame* frames) = 0;
+
+  // Destroy this context asynchronously. When the operation is done |callback|
+  // is called.
+  //
+  // ReleaseVideoFrames() need to be called with all the video frames allocated
+  // before making this call.
+  virtual void Destroy(DestructionCompleteCallback* callback) = 0;
+};
+
+}  // namespace media
+
+#endif  // MEDIA_VIDEO_VIDEO_DECODE_CONTEXT_H_