From c48c9cfc683617cc41f7ddeb69f60a8cf57e624d Mon Sep 17 00:00:00 2001
From: Jonas Smedegaard <dr@jones.dk>
Date: Wed, 1 Oct 2014 16:41:03 +0200
Subject: Adjust (radically) assumption of bitrate for VP9 from 1/2 of H.264 to
 27% bigger, and apply similar for VP8.

---
 localvideowebencode | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/localvideowebencode b/localvideowebencode
index 60164aa..7d6eaee 100755
--- a/localvideowebencode
+++ b/localvideowebencode
@@ -125,6 +125,11 @@ formats=webm,vp9,mp4
 samplestart=0
 samplelength=150
 compression=normal
+# VP8 is rumored to compress ~20% worse than H.264
+factor_vp8=120/100
+# VP9 compresses natural video ~27% worse than H.264 (i.e. excluding animation)
+# <http://infoscience.epfl.ch/record/200925/files/article-vp9-submited-v2.pdf>
+factor_vp9=127/100
 
 # parse cmdline options
 TEMP="`getopt -s sh -o hp:s:a:r:b:t: -l help,profile:,size:,aspect:,rate:,video:,refbpp:,formats:,audio:,audioprefilter:,loudness,loudness-data:,filter:,stem:,title:,sample,sample-start:,sample-length:,compression: -n "$PRG" -- "$@"`" || exit1 "Internal getopt error."
@@ -311,10 +316,13 @@ if [ -n "$_pixels" ] && [ $_pixels -ge $((1024*768)) ]; then
 fi
 
 # compute average bitrate from reference data and "power of .75" rule
+bitrate_vp8="$bitrate"
+bitrate_vp9="$bitrate"
 if [ -n "$_pixels" ] && [ -n "$_frames" ]; then
 	bitrate=$(perl -E '$refsize=640*360;' \
 		-E "say int( +(($_pixels/\$refsize)**0.75*\$refsize*$_frames*$refbpp) )")
-	bitrate_vp9=$(perl -E "say int( $bitrate/2 )") #"
+	bitrate_vp8=$(perl -E "say int( +($bitrate*$factor_vp8) )") #"
+	bitrate_vp9=$(perl -E "say int( +($bitrate*$factor_vp9) )") #"
 fi
 
 # default per-codec-channel bitrates
@@ -362,7 +370,7 @@ _melt_sample="$infile_first ${sample:+in=${samplestart:-0} out=$((${samplestart:
 _melt_video="progressive=1${framerate:+ frame_rate_num="$framerate_num" frame_rate_den="$framerate_den"}${size:+ s=${width:+$width}x${height:+$height}}${aspect:+ aspect=$aspect}"
 _melt_ogg="$_melt_video f=ogg vcodec=libtheora${bitrate:+ vb=$bitrate} qscale=$qscale_theora"
 _melt_h264="$_melt_video f=mp4 vcodec=libx264 vpreset=$speedpreset_h264 vprofile=baseline${x264tune:+ tune=$x264tune} threads=0 movflags=+faststart crf=$crf_h264"
-_melt_webm="$_melt_video f=webm vcodec=libvpx vpreset=libvpx-$webmpreset${bitrate:+ vb=$bitrate} crf=$crf_vp8 cpu-used=$cpu_vp8"
+_melt_webm="$_melt_video f=webm vcodec=libvpx vpreset=libvpx-$webmpreset${bitrate_vp8:+ vb=$bitrate_vp8} crf=$crf_vp8 cpu-used=$cpu_vp8"
 _melt_img="$_melt_video f=image2"
 # CRF ignored with libvpx 1.3
 _melt_vp9="$_melt_video f=webm vcodec=libvpx-vp9 vpreset=libvpx-$webmpreset${bitrate_vp9:+ vb=$bitrate_vp9} crf=$crf_vp9 cpu-used=$cpu_vp9"
@@ -374,7 +382,7 @@ _melt_opus="$_melt_audio acodec=libopus${channels:+ ab=$(($channels*$bitrate_opu
 _melt_aac="$_melt_audio acodec=aac${channels:+ ab=$(($channels*$bitrate_aac))k}"
 
 avconv="avconv -threads auto -y -v warning"
-_avconv_vp8="-c:v libvpx -pre:v libvpx-$webmpreset${bitrate:+ -b:v $bitrate} -crf $crf_vp8 -cpu-used $cpu_vp8"
+_avconv_vp8="-c:v libvpx -pre:v libvpx-$webmpreset${bitrate_vp8:+ -b:v $bitrate_vp8} -crf $crf_vp8 -cpu-used $cpu_vp8"
 _avconv_vp9="-c:v libvpx-vp9 -pre:v libvpx-$webmpreset${bitrate_vp9:+ -b:v $bitrate_vp9} -crf $crf_vp9 -cpu-used $cpu_vp9"
 
 # resolve EBU R128 audio normalizing
-- 
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