Work on flexible mode and screen sharing.

webrtc/modules/video_coding/codecs/vp9/screenshare_layers.h

Index: webrtc/modules/video_coding/codecs/vp9/screenshare_layers.h
diff --git a/webrtc/modules/video_coding/codecs/vp9/screenshare_layers.h b/webrtc/modules/video_coding/codecs/vp9/screenshare_layers.h
new file mode 100644
index 0000000000000000000000000000000000000000..73709ce6ec7a161fcc5855fdce78c8c6760f79ba
--- /dev/null
+++ b/webrtc/modules/video_coding/codecs/vp9/screenshare_layers.h
@@ -0,0 +1,44 @@
+/* Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.

[sprang_webrtc, 2015/09/15 15:41:21]

2015

[philipel, 2015/09/16 09:35:53]

Done.

+*
+*  Use of this source code is governed by a BSD-style license
+*  that can be found in the LICENSE file in the root of the source
+*  tree. An additional intellectual property rights grant can be found
+*  in the file PATENTS.  All contributing project authors may
+*  be found in the AUTHORS file in the root of the source tree.
+*/
+
+#ifndef WEBRTC_SCREENSHARE_LAYERS_H
+#define WEBRTC_SCREENSHARE_LAYERS_H
+
+#include <stdint.h>
+#include "webrtc/modules/video_coding/codecs/vp9/vp9_impl.h"
+
+namespace webrtc {
+
+class ScreenshareLayersVP9 {
+ public:
+  ScreenshareLayersVP9();
+  void ConfigureBitrate(int threshold_kbps);

[sprang_webrtc, 2015/09/15 15:41:22]

Rename and/or comment to make it clear that this is the threshold above which
packets will be pushed to the higher layer.
This also assumes we have just two layers. Since we probably want to use more
than two spatial layers when libvpx supports it, perhaps this interface should
be made flexible enough now?

[philipel, 2015/09/16 09:35:53]

Acknowledged.

+  int CurrentLayer() const;
+  void LayerFrameEncoded(unsigned int size_bytes, int layer_id);
+  VP9EncoderImpl::SuperFrameRefSettings SfSettings(uint32_t timestamp,
+                                                   bool is_keyframe);

[sprang_webrtc, 2015/09/15 15:41:22]

Pls avoid abbreviations whenever possible! How 'bout GetSuperFrameSettings() ?

[philipel, 2015/09/16 09:35:53]

Done.

+
+ private:
+  // Target kbps for layer 0

[sprang_webrtc, 2015/09/15 15:41:21]

Always end comments with a period.

[philipel, 2015/09/16 09:35:53]

Done.

+  float threshold_kbps_;
+
+  // How many bits that has been used so far. Increased in FrameEncoded() by
+  // the size of the encoded frame and decreased in SfSettings() depending
+  // on the time between frames.
+  float l0_bits_used_;
+
+  // Timestamp of last frame

[sprang_webrtc, 2015/09/15 15:41:22]

.

[philipel, 2015/09/16 09:35:53]

Done.

+  uint32_t last_ts_;
+
+  int current_layer_;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_SCREENSHARE_LAYERS_H