Interfaces for encoded video sources

media/video/encoded_video_source.h

+// Copyright (c) 2013 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_ENCODED_VIDEO_SOURCE_H_
+#define MEDIA_VIDEO_ENCODED_VIDEO_SOURCE_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "media/base/encoded_bitstream_buffer.h"
+#include "media/video/video_encode_types.h"
+
+namespace media {
+
+// Class to represent encoded video bitstream.
+class MEDIA_EXPORT EncodedVideoBitstream :
+    public base::RefCountedThreadSafe<EncodedVideoBitstream> {
+ public:
+  class MEDIA_EXPORT Client {
+   public:
+    // After OnStreaming callback stream shall be considered to be streaming.
+    virtual void OnBitstreamStreaming(
+        scoped_refptr<EncodedVideoBitstream> bitstream, bool modifiable) = 0;
+
+    // After OnRemoved client has to stop using the bitstream object and
+    // expecting bitstream buffers for that stream. OnRemoved will be called
+    // also in case of any unrecoverable failure in the capturer. After
+    // OnRemoved is called from a stream it is guaranteed that that there will
+    // be no longer pending calls coming in.
+    virtual void OnBitstreamRemoved(
+        scoped_refptr<EncodedVideoBitstream> bitstream) = 0;
+
+    // OnBitstreamReady delivers the captured bitstream buffer by buffer to the
+    // client.
+    virtual void OnBitstreamReady(
+        scoped_refptr<EncodedVideoBitstream> bitstream,
+        scoped_refptr<const EncodedBitstreamBuffer> buffer) = 0;
+
+    // OnBitstreamConfigChanged informs about change in bitstream parameters.
+    virtual void OnBitstreamConfigChanged(
+        scoped_refptr<EncodedVideoBitstream> bitstream,
+        const RuntimeVideoEncodingParameters& params) = 0;
+  };
+
+  // TrySetBitstreamConfig issues a reconfiguration request. Old configuration

[wjia(left Chromium), 2013/02/28 18:46:26]

comment doesn't match function name.

[vmr, 2013/03/01 14:24:00]

Done.

+  // must be considered to be the valid configuration until
+  // OnBitstreamConfigChanged callback has been issued with value signalling
+  // successful change.
+  virtual void TryConfigure(
+      const RuntimeVideoEncodingParameters& params) = 0;
+
+  // RequestSpecialFrame allows the client to request special frames from the
+  // encoded video bitstream. The effect of the request is only visible in the
+  // bitstream buffers passed to client through the OnBitstreamReady callback.
+  // This request is served on best-effort basis and client is not given any
+  // guarantees of the realization or timing of the request. Flags parameters
+  // will be interpreted in format specific manner using enumerations.
+  virtual void RequestSpecialFrame(int flags) = 0;
+
+ protected:
+  virtual ~EncodedVideoBitstream() {};
+  friend class base::RefCountedThreadSafe<EncodedVideoBitstream>;
+};
+
+// Class to represent any encoded video source. Anything that provides encoded
+// video can be an EncodedVideoSource. Notable examples of this can be video
+// encoder (duh!) and webcam that has encoding capability.
+class MEDIA_EXPORT EncodedVideoSource {
+ public:
+  virtual ~EncodedVideoSource() {};
+
+  // GetCapabilities informs the client what type of encoded bitstream encoder
+  // is capable to provide. Constraints in the reported capabilities should be
+  // obeyed when configuring bitstreams.
+  virtual VideoEncodingCapability GetCapabilities() = 0;
+
+  // OpenBitstream returns object for the stream being added. Client must
+  // consider the returned stream valid until OnBitstreamRemoved callback is
+  // called with the id. Client should check the parameters agains limits
+  // reported by GetCapabilities before trying to issue an request to add an
+  // encoded bitstream. EncodedVideoSource retains the ownership of
+  // EncodedVideoBitstream and client just has the pointer to it.
+  virtual scoped_refptr<EncodedVideoBitstream> OpenBitstream(
+      base::WeakPtr<EncodedVideoBitstream::Client> client,
+      const VideoEncodingParameters& params) = 0;
+};
+
+}  // namespace media
+
+#endif  // MEDIA_VIDEO_ENCODED_VIDEO_SOURCE_H_
+