OcttKB/Wiki-OcttKB/tiddlers/Normal/FFmpeg/_Snippets.tid

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created: 20221008141221923
creator: Octt
modified: 20231112232329809
modifier: Octt
tags: Snippets $:/i18n:en
title: FFmpeg/Snippets
!! Flags
* Specify an input file: `-i ${File}`
* Framerate: `-r ${r}`, `-framerate ${r}` (//use both because one sometimes doesn't work//) ([[other ways|https://stackoverflow.com/questions/45462731/using-ffmpeg-to-change-framerate#45465730]])
!!! Filter Flags
//These are specified by prefixing an argument://
* Audio: `-filter:a` or `-af`
* Video: `-filter:v` or `-vf`
!!!! Audio Filters
* Volume: `volume=`
** `±{n}dB`: Adding or Subtracting to absolute value in dB
** `{%/100}`: Target percentage divided by 100 (e.g: //150% -> 1.5//)
* Detecting volume details: `volumedetect -f null /dev/null` (just prints to console)
!!!! Video Filters
* Scaling: `scale=${w}:${h}`
* [[Cropping|https://video.stackexchange.com/questions/4563/how-can-i-crop-a-video-with-ffmpeg]]: `crop=${w}:${h}:${x}:${y}`
!!! Audio/Video Flags
//These are specified as `-flag:a` or `-flag:v`.//
* Bitrate: `-b:{a|v} ${n}{k|m|...}`
* Codec: `-c:{a|v} ${codec}`
!!!! Audio Flags
* Audio channels: `-ac ${n}`
!! Codecs List
!!! Special
* `copy`: Copy data stream without re-encoding (if supported by container)
!!! Audio Codecs
* `libopus`
!!! Video Codecs
* `h263`, `h264`, `libx265`
* `libvpx-vp8`, `libvpx-vp9`
* `libaom-av1`
!! Tips
* [[Trim Video|https://shotstack.io/learn/use-ffmpeg-to-trim-video]]
* [[Image+Audio -> Video|https://superuser.com/questions/1041816/combine-one-image-one-audio-file-to-make-one-video-using-ffmpeg]]