From 812ddf7c72270b816052805d9eadfcd5f20e64fe Mon Sep 17 00:00:00 2001 From: Joey Hafner Date: Tue, 29 Nov 2022 00:19:47 -0800 Subject: [PATCH] Expand interpolation docs --- docs/ffmpeg Notes.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/docs/ffmpeg Notes.md b/docs/ffmpeg Notes.md index 001f5de..d430e7f 100644 --- a/docs/ffmpeg Notes.md +++ b/docs/ffmpeg Notes.md @@ -65,7 +65,7 @@ Creating a slow-mo clip is a two-step process. This assumes your input is encode 1. Copy the video to a raw h264 bitstream: `ffmpeg -i "$input" -map 0:v -c:v copy -bsf:v h264_mp4toannexb 'raw.h264'` 2. Generate new timestamps for each frame with `genpts` (generate presentation timestamps): `ffmpeg -fflags +genpts -r 30 -i raw.h264 -c:v copy -movflags faststart "$output"`. The `-r 30` flag sets the new framerate to 30 frames per second. -3. Optionally, interpolate motion for the newly slowed video: `ffmpeg -i "$input" -filter:v "minterpolate='mi_mode=mci:mc_mode=aobmc:vsbmc=1:fps=60'" "$output"` +3. Optionally, interpolate motion for the newly slowed video: `ffmpeg -i "$input" -filter:v "minterpolate='mi_mode=mci:mc_mode=aobmc:vsbmc=1:fps=60'" "$output"`. This step runs very slowly. Around 2 fps interpolating from 30 to 60 fps on a Ryzen 7 3700X. This performance issues is [well](https://stackoverflow.com/questions/42385502/ffmpeg-motion-interpolation-alternatives-or-speedup) [documented](http://ffmpeg.org/pipermail/ffmpeg-user/2021-January/051603.html). It is trivial to parallelize processing of multiple clips, as they use little CPU for each process. Note that these slow-mo files will have no audio.