libvpx: Pull from upstream

source/libvpx/examples/force_keyframe.txt

Index: source/libvpx/examples/force_keyframe.txt
===================================================================
--- source/libvpx/examples/force_keyframe.txt	(revision 247498)
+++ source/libvpx/examples/force_keyframe.txt	(working copy)
@@ -1,28 +0,0 @@
-@TEMPLATE encoder_tmpl.c
-Forcing A Keyframe
-==================
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ INTRODUCTION
-This is an example demonstrating how to control placement of keyframes
-on a frame-by-frame basis.
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ INTRODUCTION
-
-
-Configuration
--------------
-Keyframes can be forced by setting the VPX_EFLAG_FORCE_KF bit of the
-flags passed to `vpx_codec_control()`. In this example, we force a
-keyframe every 8 frames.
-
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  PER_FRAME_CFG
-if(!(frame_cnt & 7))
-    flags |= VPX_EFLAG_FORCE_KF;
-else
-    flags &= ~VPX_EFLAG_FORCE_KF;
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PER_FRAME_CFG
-
-
-Observing The Effects
----------------------
-The output of the encoder examples shows a 'K' rather than a dot '.'
-when the encoder generates a keyframe. Note that every 8 frames a 'K'
-is output.