Define EncodedVideoSource and RtcCapturedEncodingVideoCapturer.

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 "media/base/encoded_bitstream_buffer.h"
+#include "media/video/video_encode_types.h"
+
+namespace media {
+
+// Class to represent any encoded video source. Anything that provides encoded
+// video can be an EncodedVideoSource. Notable examples of this can be video
+// encoder and webcam that has encoding capabilities.

[Ami GONE FROM CHROMIUM, 2013/06/12 01:44:06]

Add a TODO pointing to http://crbug.com/248334.

[hshi1, 2013/06/12 17:52:39]

Done.

+class MEDIA_EXPORT EncodedVideoSource {
+ public:
+  class MEDIA_EXPORT Client {
+   public:
+    // After OnStreaming callback stream shall be considered to be streaming.

[Ami GONE FROM CHROMIUM, 2013/06/12 01:44:06]

I think you missed the point of my comment:

Oh, shall it??
Can you make a pass and cull useless comments and add useful ones where mystery
might exist?

Your response was that you "Got rid of the EVB altogether" but my request was
that you make a pass over the commentary in this CL and make it more useful and
less useless / faux spec'ish.  This particular comment is a shining beacon
example of extremely formal and at the same time extremely pointless.

[hshi1, 2013/06/12 17:52:39]

Done.

+    virtual void OnStreaming(const VideoEncodingParameters& params) = 0;

[Ami GONE FROM CHROMIUM, 2013/06/12 01:44:06]

s/OnStreaming/OnOpened/ to mirror {Open,Close}Bitstream and OnClosed ?

[hshi1, 2013/06/12 17:52:39]

Done.

+
+    // After OnClosed client has to stop using the bitstream object and
+    // expecting bitstream buffers for that stream. OnClosed will be called
+    // also in case of any unrecoverable failure in the capturer. After
+    // OnClosed is called from a stream it is guaranteed that that there will
+    // be no longer pending calls coming in.
+    virtual void OnClosed() = 0;
+
+    // OnBufferReady delivers the captured bitstream buffer by buffer to the
+    // client.
+    virtual void OnBufferReady(
+        scoped_refptr<const EncodedBitstreamBuffer> buffer) = 0;
+
+    // OnConfigChanged informs about change in bitstream parameters.
+    virtual void OnConfigChanged(
+        const RuntimeVideoEncodingParameters& params) = 0;
+  };
+
+  // Callback is invoked once RequestCapabilities() is complete.
+  typedef base::Callback<void(const VideoEncodingCapabilities& capabilities)>
+      RequestCapabilitiesCallback;
+
+  // RequestCapabilities initiates an asynchronous query for the types of
+  // encoded bitstream supported by the encoder. This call should invoked only

[Ami GONE FROM CHROMIUM, 2013/06/12 01:44:06]

s/should/should be/

[hshi1, 2013/06/12 17:52:39]

Done.

+  // once. EncodedVideoSource will invoke |callback| when capabilities become
+  // available.
+  virtual void RequestCapabilities(
+      const RequestCapabilitiesCallback& callback) = 0;
+
+  // OpenBitstream opens the bitstream on the encoded video source. Only one
+  // bitstream can be opened for an encoded video source.
+  virtual void OpenBitstream(Client* client,

[Ami GONE FROM CHROMIUM, 2013/06/12 01:44:06]

I think you missed my comment to the effect of:
here and elsewhere please document lifecycle/ownership semantics when raw
pointers are passed.

[hshi1, 2013/06/12 17:52:39]

I'm going to make a pass and update later today.

+                             const VideoEncodingParameters& params) = 0;

[Ami GONE FROM CHROMIUM, 2013/06/12 01:44:06]

indent is off

[hshi1, 2013/06/12 17:52:39]

Done. ("const" is aligned with "Client", is that correct?)

+
+  // CloseBitstream closes the bitstream.
+  virtual void CloseBitstream() = 0;
+
+  // ReturnBitstreamBuffer notifies that the data within the buffer has been
+  // processed and it can be reused to encode upcoming bitstream.
+  virtual void ReturnBitstreamBuffer(
+      scoped_refptr<const media::EncodedBitstreamBuffer> buffer) = 0;
+
+  // TrySetBitstreamConfig requests to change encoding parameters. Old config
+  // must be considered valid until OnConfigChanged is invoked on the client
+  // signalling successful change.
+  virtual void TrySetBitstreamConfig(
+      const RuntimeVideoEncodingParameters& params) = 0;
+};
+
+}  // namespace media
+
+#endif  // MEDIA_VIDEO_ENCODED_VIDEO_SOURCE_H_
+