From 73234c633bb79d0a83788f08e7e17d10ec7cff29 Mon Sep 17 00:00:00 2001
From: Jonas Smedegaard <dr@jones.dk>
Date: Wed, 10 Feb 2021 01:02:12 +0100
Subject: fix theora 2-pass, and tune quality and size

---
 localvideowebencode | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/localvideowebencode b/localvideowebencode
index 75dfcdb..1f22272 100755
--- a/localvideowebencode
+++ b/localvideowebencode
@@ -154,7 +154,7 @@ html favoring open formats with optional non-JavaScript Flash fallback.
                       hq       high      exact     slow    2xCQ¹
                       exact    medium    exact     slow    2xCQ¹
                       quality  medium    vary      medium     Q²
-                    ¹ avc uses 1-pass
+                    ¹ theora uses CBR, avc uses 1-pass
                     ² vp8 uses "soft-CQ" (CQ with very high bitrate)
                     (default: normal)
   --quality         Quality rate factor: auto [integer] none
@@ -227,6 +227,10 @@ compression=normal
 # 5) optionally pick dirty/hq settings
 #    * check that --compression=quality has similar filesize as normal
 
+# Theora seems to compress ~100% worse than H.264
+# (reportedly 76% worse in 2010, and libtheora has not improved since)
+# <http://compression.ru/video/codec_comparison/h264_2010/>
+factor_theora=200/100
 # VP8 is rumored to compress ~20% worse than H.264
 factor_vp8=120/100
 # VP9 compresses ~30% better than H.264 for practical use-cases
@@ -307,7 +311,7 @@ qkey_theora=q
 qkey_vp8=crf
 qkey_vp9=crf
 qkey_avc=crf
-q_theora=5
+q_theora=6
 q_vp8=33
 cpu_vp8=2
 q_vp9=33
@@ -321,16 +325,14 @@ case "$compression" in
     normal) :;;
     dirty)
 	gpu=${gpu:-auto}
-	q_theora=1
 	cpu_vp8=4
 	cpu_vp9=4
 	preset_avc=veryfast
 	;;
     hq)
 	multipass=yes
-	no_multipass_theora=yes # TODO: try with ffmpeg2theora
+	no_q_theora=yes
 	no_multipass_avc=yes
-	q_theora=6
 	cpu_vp8=0
 	cpu_vp9=1
 	preset_avc=veryslow
@@ -534,7 +536,7 @@ fi
 if [ -n "$_pixels" ] && [ -n "$_frames" ]; then
 	bitrate_avc=$(perl -E '$refsize=640*360;' \
 		-E "say int( +(($_pixels/\$refsize)**0.75*\$refsize*$_frames*$refbpp) )")
-	bitrate_theora=$bitrate_avc # FIXME
+	bitrate_theora=$(perl -E "say int( +($bitrate_avc*$factor_theora) )") #"
 	bitrate_vp8=$(perl -E "say int( +($bitrate_avc*$factor_vp8) )") #"
 	bitrate_vp9=$(perl -E "say int( +($bitrate_avc*$factor_vp9) )") #"
 fi
@@ -720,8 +722,8 @@ _ffmpeg_misc_avc="${no_gpu:+ -movflags +faststart}"
 
 # format options
 # emulate VP8 Constant Quality using "loose" Constrained Quality
-_melt_theora="vcodec=libtheora$_melt_bitrate_theora $qkey_theora=$q_theora"
-_ffmpeg_theora="-c:v libtheora$_ffmpeg_bitrate_theora -$qkey_theora:v $q_theora"
+_melt_theora="vcodec=libtheora$_melt_bitrate_theora${q_theora:+ $qkey_theora=$q_theora}"
+_ffmpeg_theora="-c:v libtheora$_ffmpeg_bitrate_theora${q_theora:+ -$qkey_theora:v $q_theora}"
 _melt_vp8="vcodec=$encoder_vp8${pre_vp8:+ vpreset=$pre_vp8}${preset_vp8:+ preset=$preset_vp8}$_melt_bitrate_vp8${q_vp8:+ ${no_bitrate_vp8:+vb=$((bitrate_vp8*10)) }$qkey_vp8=$q_vp8}$_melt_misc_vp8"
 _ffmpeg_vp8="-c:v $encoder_vp8${pre_vp8:+ -vpre $pre_vp8}${preset_vp8:+ preset $preset_vp8}$_ffmpeg_bitrate_vp8${q_vp8:+ ${no_bitrate_vp8:+-b:v $((bitrate_vp8*10)) }-$qkey_vp8 $q_vp8}$_ffmpeg_misc_vp8"
 _vpxenc_vp8="--codec=vp8$_vpxenc_bitrate_vp8 --end-usage=${no_q_vp8:+vbr}${q_vp8:+cq --cq-level=$q_vp8}$_vpxenc_misc_vp8"
@@ -791,6 +793,8 @@ fi
 if [ -n "${ogv:+$multipass_theora}${webm:+$multipass_vp8}${webm_vp9:+$multipass_vp9}${mp4:+$multipass_avc}" ]; then
 	echo >&2 "Analyzing video complexity..."
 	render melt $_melt_infiles $filters \
+		${ogv:+${use_melt_theora:+-consumer avformat:$stem.ogv $_melt_ogv \
+			pass=1 passlogfile=${stem}_theora}} \
 		${webm:+${use_melt_vp8:+-consumer avformat:$stem.webm $_melt_webm \
 			pass=1 passlogfile=${stem}_vp8}} \
 		${webm_vp9:+${use_melt_vp9:+-consumer avformat:${stem}_vp9.webm $_melt_webm_vp9 \
-- 
cgit v1.2.3