From 932aedf6007980617f6e864b2371b3387b0d9a02 Mon Sep 17 00:00:00 2001 From: Sacha Chua Date: Wed, 3 Nov 2021 17:58:21 -0400 Subject: Add compression --- 2021/prepare.md | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/2021/prepare.md b/2021/prepare.md index 5316536f..9b16f933 100644 --- a/2021/prepare.md +++ b/2021/prepare.md @@ -100,6 +100,14 @@ WebM format if possible.* > format. The closer to this format submitted video files arrive in, > the easier it will be to process and upload them. +If you would like to compress your video before uploading, the following shell script may be useful: + + Q=56 + ffmpeg -y -i "$1" -c:v libvpx-vp9 -b:v 0 -crf $Q -aq-mode 2 -an -tile-columns 0 -tile-rows 0 -frame-parallel 0 -cpu-used 8 -auto-alt-ref 1 -lag-in-frames 25 -g 240 -pass 1 -f webm -threads 8 /dev/null && + ffmpeg -y -i "$1" -c:v libvpx-vp9 -b:v 0 -crf $Q -c:a copy -tile-columns 2 -tile-rows 2 -frame-parallel 0 -cpu-used -5 -auto-alt-ref 1 -lag-in-frames 25 -pass 2 -g 240 -threads 8 "$2" + +If you put it in a file called `compress-video.sh`, you can execute it from the command line with something like `sh compress-video.sh input-file.webm output-file.webm`. + If you're planning to do live Q&A, you can check your system setup at https://test.bigbluebutton.org/ . We'll set up a tech-check call with you, too. We'll post details here closer to that time. -- cgit v1.2.3