Vary vp8 speed based on height.

1 files changed, 11 insertions, 10 deletions

diff --git a/bin/loop+encode+stream b/bin/loop+encode+stream
index 4151789..5331121 100755
--- a/bin/loop+encode+stream
+++ b/bin/loop+encode+stream
@@ -22,16 +22,17 @@ ABITRATE_OPUS=48000
 # TODO
 HEIGHT=360
 
-# TODO: Vary vpx quality based on height
-SPEED_VP8=15
-
-# inspired by Apple HLS recommendations
-  if [ $HEIGHT -le 234 ]; then VBITRATE=145000;
-elif [ $HEIGHT -le 270 ]; then VBITRATE=365000;
-elif [ $HEIGHT -le 360 ]; then VBITRATE=730000;
-elif [ $HEIGHT -le 432 ]; then VBITRATE=1100000;
-elif [ $HEIGHT -le 540 ]; then VBITRATE=2000000;
-elif [ $HEIGHT -le 720 ]; then VBITRATE=3000000;
+# * height steps and bitrates based on https://developer.apple.com/library/content/documentation/General/Reference/HLSAuthoringSpec/Requirements.html
+# * speeds tuned to just below 100% cpu usage for each combination on a multi-core computer
+# TODO: adjust height steps or bitrates for 4:3 aspect ratio
+# TODO: resolve steps from source height using http://aarmstrong.org/tutorials/aspect-ratios-and-h264
+# TODO: Externalize speeds to site-specific configfile
+  if [ $HEIGHT -le 234 ]; then VBITRATE=145000; SPEED_VP8=2;
+elif [ $HEIGHT -le 270 ]; then VBITRATE=365000; SPEED_VP8=2;
+elif [ $HEIGHT -le 360 ]; then VBITRATE=730000; SPEED_VP8=3;
+elif [ $HEIGHT -le 432 ]; then VBITRATE=1100000; SPEED_VP8=4;
+elif [ $HEIGHT -le 540 ]; then VBITRATE=2000000; SPEED_VP8=5;
+elif [ $HEIGHT -le 720 ]; then VBITRATE=3000000; SPEED_VP8=15;
 fi
 
 # based on http://www.webmproject.org/docs/encoder-parameters/#real-time-cbr-encoding-and-streaming