From 5c8fb8533f611e0ce537f7b9c43052908a28219d Mon Sep 17 00:00:00 2001
From: Kévin Le Gouguec <kevin.legouguec@gmail.com>
Date: Sun, 9 Jan 2022 23:00:42 +0100
Subject: Add ffmpeg recipes

---
 guides/ffmpeg.org | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 guides/ffmpeg.org

diff --git a/guides/ffmpeg.org b/guides/ffmpeg.org
new file mode 100644
index 0000000..eded0e9
--- /dev/null
+++ b/guides/ffmpeg.org
@@ -0,0 +1,22 @@
+ffmpeg recipes I should stuff into config files or scripts, but
+haven't yet.
+* Extracting parts of videos
+~-c copy -map 0~ ensures all streams (audio & subtitles) are kept.
+The timestamp syntax is described in the "Time duration" section of
+=ffmpeg-utils(1)=; =MM:SS= works fine.
+
+#+begin_src sh
+ffmpeg -i $input -c copy -map 0 \
+       -ss $tstart -to $tend    \
+       $output
+#+end_src
+
+* Reduce file size
+** with =-vf=: ~-vf "scale=iw/2:ih/2"~
+** with H.265
+openSUSE Tumbleweed's ffmpeg is not built with H.265 support AFAICT.
+
+1. Install =libx265-devel=
+2. Clone =https://git.ffmpeg.org/ffmpeg.git=
+3. ~./configure --enable-libx265 --enable-gpl~
+4. ~ffmpeg -i $input -vcodec libx265 -crf 28~
-- 
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