From c54df7a0458001693ddd996dc4222e3ff00ad487 Mon Sep 17 00:00:00 2001
From: Leo Vivier <zaeph@zaeph.net>
Date: Fri, 2 Dec 2022 08:51:04 +0100
Subject: Prototype upwards fps-limiter

---
 roles/prerec/templates/reencode.sh | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

(limited to 'roles/prerec')

diff --git a/roles/prerec/templates/reencode.sh b/roles/prerec/templates/reencode.sh
index 5a0128b..c9c87e1 100755
--- a/roles/prerec/templates/reencode.sh
+++ b/roles/prerec/templates/reencode.sh
@@ -8,7 +8,12 @@ cpu=4
 time_limit=""
 print_only=false
 limit_resolution=1080
-limit_fps=30.01
+limit_fps=29.99
+
+with_suffix() {
+    suffix="$1"
+    echo "$input" | sed "s/--original\.\([a-z0-9]*\$\)/--$suffix\.\\1/"
+}
 
 while getopts :q:c:t:s OPT; do
     case $OPT in
@@ -33,16 +38,24 @@ shift `expr $OPTIND - 1`
 OPTIND=1
 
 input="$1"
+input_limited="$(with_suffix "original-limited")"
 output="$2"
 
 command="$(cat<<EOF
+# Preliminary pass to limit resolution and fps
 ffmpeg -y -i "$input" $time_limit \
+       -vf "scale='-1':'min($limit_resolution,ih)',
+            select='eq(n,0)+if(gt(t-prev_selected_t,1/$limit_fps),1,0)'" \
+        -c:v rawvideo -c:a pcm_s16le -f nut - | ffmpeg -y -f nut -i - -vf "fps=$limit_fps" "$input_limited"
+
+# Reencode
+ffmpeg -y -i "$input_limited" $time_limit \
        -vf "scale='-1':'min($limit_resolution,ih)',
             select='eq(n,0)+if(gt(t-prev_selected_t,1/$limit_fps),1,0)'" \
        -c:v libvpx-vp9 -b:v 0 -crf $q -an \
        -row-mt 1 -tile-columns 2 -tile-rows 2 -cpu-used $cpu -g 240 \
        -pass 1 -f webm -threads $cpu /dev/null &&
-    ffmpeg -y -i "$input" $time_limit \
+    ffmpeg -y -i "$input_limited" $time_limit \
            -vf "scale='-1':'min($limit_resolution,ih)',
                 select='eq(n,0)+if(gt(t-prev_selected_t,1/$limit_fps),1,0)'" \
                -c:v libvpx-vp9 -b:v 0 -crf $q -c:a libopus \
-- 
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