Waveform with moving head via ffmpeg from audio file
28. 6. 2023Triggered by this thread: https://hydrogenaud.io/index.php/topic,124316.
Main ↓
Get the waveform image at dual HD resolution for example
ffmpeg -i "music.m4a" -filter_complex "aformat=channel_layouts=mono,showwavespic=s=3840x2160:colors=999999" -frames:v 1 waveformbig.png
scale down
ffmpeg -i waveformbig.png -vf "scale=w=1920:h=1080:flags=lanczos" waveform.png
compose with custom background, make sure bg is also 1920x1080
ffmpeg -i bg.png -i waveform.png -filter_complex "overlay" comp.png
get the composed image to be the same length as audio
ffmpeg -loop 1 -i comp.png -i music.m4a -acodec copy -shortest tmp.mp4
get the duration into variable
duration="$(ffprobe -i tmp.mp4 -show_entries format=duration -v quiet -of csv="p=0")"
echo $duration
ffmpeg, generate 2x200 px line
ffmpeg -f lavfi -i color=c=white:s=2x200 -frames:v 1 overlay.png
Last
ffmpeg -i tmp.mp4 -i overlay.png -filter_complex "[0:v][1:v]overlay=x='if(gte(t,0), -w+(t)*(main_w-overlay_w)/$duration, NAN)':y='(main_h-overlay_h)/2'" -c:a copy final.mp4
scrot: https://i.imgur.com/YtrqzeH.png
Notes: This can be a lot shorter and could make an interesting script. It appears as if head is not completely in sync with audio. The final container format may be MATROŠKA (mkv), since it supports wide variety of audio codecs (AAC, FLAC, mp3…), so audio transcoding may be omitted.
FIXME: 1. audio not exactly in sync with head, 2. use modern ffmpeg syntax.
Misc ↓
Overlay some text with font
https://fonts.google.com/specimen/Lacquer?query=Lacquer
wget https://github.com/Lacquer-Font/Lacquer/blob/master/fonts/ttf/Lacquer-Regular.ttf\?raw\=true -O font.ttf
ffmpeg -i penguins.png -filter_complex "[0:v]scale=w=1920:h=1080,drawtext=text='Penguins - glade to glory':fontsize=45:fontfile=font.ttf:x=50:y=50:fontcolor=black:box=1:boxcolor=white@0.5[text]" -map "[text]" -c:v png -y text.png
gives
or for multiline text
# replace
text='Penguins - glade to glory'
# with
textfile=text.txt
Possibly good tmp storage for font.ttf would be
"$HOME/.cache/audio2videoWaveform/font.ttf"
Preliminary script ↓
This takes the ideas ^, but it’s a different beast:
test 1:
https://youtu.be/iMeYtMcmjug
test 2, with this font:
https://fonts.google.com/specimen/Agdasima?query=agda
gives:
https://youtu.be/-PRiJsJKx8U
https://youtu.be/X738_PfQS8M
