FFmpeg notes

Some options and filters I used in FFmpeg.

EDIT: Hah that's a nice and memorable URL, "Software development kit, java edition, (version) 8.8.9"

I downloaded a pre-compiled binary from www.gyan.dev (thanks!) because I didn't know how to compile it manually back then...

Version:
ffmpeg version 6.0-essentials_build-www.gyan.dev Copyright (c) 2000-2023 the FFmpeg developers
  built with gcc 12.2.0 (Rev10, Built by MSYS2 project)

Sources:
ffmpeg.org/ffmpeg-filters.html
trac.ffmpeg.org
video.stackexchange.com
superuser.com
(Possibly other StackExchange sites)

==General==

%i% is path to your input file
%i1%, %i2%, ... are used when multiple input files are needed
%o% is path to your output file

-r sets framerate/tbr, usually same with fps
-framerate sets framerate/fps, usually same with tbr.
Nevertheless, one must set both manually, otherwise the result asrom-izu.
-f [format]
-t [duration]s
-to [stop time]s
-ss [start time]s (with -seek_timestamp)
-timestamp ["now"|time]
-r:v [rate]Hz
-fpsmax [rate]Hz
-s size [width]x[height]

==Recording==
Procedure:
1. Turn off power save mode
2. Toggle resolution to 1024x768
3. Record
4. Crop with -vf crop=w=1024:h=768:x=0:y=0 for further processing

Uses Screen Capturer Recorder, open source project from GitHub.

chdir C:\Program Files (x86)\Screen Capturer Recorder\configuration_setup_utility\vendor\ffmpeg\bin
ffmpeg -f dshow -i video="screen-capture-recorder" -r 30 -filter:v crop=800:600:0:0 -y D:/_o.mp4
-f dshow -i audio="virtual-audio-capturer" D:/_o.wav
-f dshow -i audio="Mic (Conexant SmartAudio HD)" D:/_o.wav
-f dshow -i video="screen-capture-recorder" -r 30 -framerate 30 -maxrate 30 -bufsize 1000000 -vcodec libx264 -preset:v ultrafast D:/_putout.mp4

ffmpeg -hide_banner -f dshow -i audio="Mic (Conexant SmartAudio HD)" -y D:/_output.wav
ffmpeg -hide_banner -f dshow -i audio="virtual-audio-capturer" -y D:/_output.wav


==Basic==

'''Aas'''
ffmpeg -i lbla.src lbla.ass
ffmpeg -i video.mp4 -vf ass=filename=lbla.ass video-with-subtitles.mp4

'''Combine images'''
-framerate 25 -i pic%3d.png -c copy -y D:/vid0.mp4
NOTE: pic%3d.png expands to pic001.png, pic002.png, etc

'''Combine video and audio'''
-i D:/video.mp4 -i D:/audio.mp3 -c:v copy -map 0:v -map 1:a -y D:/video-with-sound.mp4

'''Concat'''
1. Generate concat.txt
Windows: (for %i in (*.wav) do @echo file '%i') > concat.txt
Batch file: (for %%i in (*.wav) do @echo file '%%i') > concat.txt
2. -f concat -i D:/input.txt -codec copy %o%

'''Cut without reencoding'''
-ss 1:02 -to 1:50  -i %i% -map 0 -c copy %o%

'''Crop'''
-i %i% -vf crop=w=1280:h=720:x=0:y=0 %o%

'''Edgedetect'''
-i d:/motion-2.mp4 -vf edgedetect=low=0.2:high=0.3 d:/motion-3.mp4
NOTE: (high - low): closer means more details, farther means less

'''Fade'''
-i %i% -vf fade=type=in:st=4:d=0.5 -af afade=in:st=0:d=5 %o%

'''Fade into another video'''
-i %i1% -i %i2% -lavfi xfade=transition=fade:duration=1:offset=5.5 %o%
NOTE: duration is length of effect, offset is (length_of_video1 - duration/2), use n=300*15, which is frames

'''First frame as png'''
-i %i% -c:v copy -frames:v 1 first-frame.png
-f image2 -start_number 100 -i img%d.jpg video-from-jpgs.mp4

'''Framerate'''
-vf fps=25 %o1%

'''Last frame'''
ffmpeg -sseof -2 -i %o2% -update 1 -q:v 1 last-frame.png
NOTE: read last 2 seconds, and take 1 frame

'''Looping'''
-loop 1 -t 5 -i %i% %o%
-i %i% -f lavfi -i anullsrc -vcodec copy -af apad -t 10 %o%
-stream_loop 10 -i %i% -c copy D:/%o%

'''Pitch'''
-i %i% -af asetrate=44100*8/9,atempo=9/8 %temp%
-i %temp% -ar 44100 %o%
NOTE: This changes the sample rate so we must reset it...

'''Resize'''
-s 1280x720
-i %i%.png -update -frames:v 1 -s 1366x706 %o%

'''Rotate without reencoding'''
-i %i% -metadata:s:v rotate=90 -map 0 -c copy %o%

'''Rotate'''
-vf rotate=PI/6+2*PI*t/10

'''Scaling'''
-i %o% -vf scale=w=500:h=500:flags=neighbor %o%

'''Speed up/Slow down'''
-vf "setpts=2*PTS" %o%
NOTE: may cause strange desync problems

'''Subtitles'''
-i %i% -vf ass=filename=subtitles.ass %o%
NOTE: This will not work unless in %usr% directory!!!

'''Zoom'''
-i %i% -vf zoompan=z='min(zoom+0.005,2.0)':x=600:y=10:d=125 -t 5.0s %o%

==Video advanced==

Valid constants and expressions in expr:
random(1)	min(x, y)	sin(x)		floor(expr)
lt(x, y)	lte(x, y)	hypot(x, y)	gauss(x)
squish(x) 		1/(1 + exp(4*x))
if(x, y, z) 	return y if x isn't 0, else return z
if(x, y)    	return y if x isn't 0, else return 0
while(x, expr)	loop and take expr if x isn't 0, and return expr when end
print(x)
T time		X pixel at x	Y pixel at y	W video width		H video height
PI 3.14159...

'''Blend'''
-filter_complex blend=all_expr='if(eq(mod(X,2),mod(Y,2)),A,B)' D:/%o%

'''FFT filter'''
-vf fftfilt=dc_Y=128:weight_Y='squish(1-(Y+X)/100)' D:/details-high-pass.mp4

'''Brightness, contrast, and the like'''
-vf "curves=all='0/0 0.5/1 1/1'" D:/_brighten.mp4
-vf eq=contrast=10:gamma_r=0.2:gamma_b=0.2 D:/_green.mp4
-vf eq=brightness=0.06:saturation=2 D:/_brighten.mp4
(other choices include colorize and hue)

'''geq, rapidly morphing spectacle'''
-vf geq=lum='...':cb='...':cr='...' %o%
(cb=cr=127: black&white)
-vf geq=a='...':r='...':g='...':b='...' %o%
(either YUV or RGB)
-f lavfi color,geq='st(3,pow(X-(W/2),2)+pow(Y-(H/2),2));if(lte(ld(3),80*80),255,0)':128:128
-i %i% -vf geq=lum='125':cb='100*sin(X/50)-100*tan(X/50)' -t 1 %o%
-lavfi nullsrc=s=256x256,geq=random(1)/hypot(X-cos(N*0.07)*W/2-W/2\,Y-sin(N*0.09)*H/2-H/2)^2*1000000*sin(N*0.02):128:128
-i %i% -vf geq=lum='gauss(400)':cb='100+100*sin(PI/10*T*X)':cr='0' -t 5 %o%
-i %i% -vf geq=lum='random(1)*20*T':cb='min(T*50,X)' -t 5 %o%

-f lavfi -t 5 -i allyuv -vf crop=w=1280:h=720 %p%
-i %i% -vf geq=lum=127:cb='127':cr='127' -t 2 -y %o%
-i %i% -vf geq=lum='127+T/2*mod(1/2/T*sqrt(pow(X-640,2)+pow(Y-360,2)),255)' %o%
-i %i% -vf geq=lum='128+T*32*sin(squish(T)*X)+(64-32*T)*random(1)' %o%

'''Generate video'''
-f lavfi -t 10 -i color=black:s=1280x720 %o%

'''Motion Interpolation'''
-vf minterpolate=fps=30:me=esa (exhaustive search)
NOTE: Also with scene change detection method and 20 modes of interpolate. Very processing-intensive

-vf tmix=frames=8:weights="1 1 1 1 1 1 1 1"
-vf tmix=frames=3:weights="-1 3 -1" - with temporal convolution (weird color-inverse-flash)

'''Play video side by side'''
ffplay -v warning -f rawvideo -s 800x400 -i /dev/zero -vf 'movie=video1.mkv,scale=400x400 [mv2] ; movie=video2.mkv,scale=400x400 [mv1]; [in][mv1] overlay=0:0 [tmp]; [tmp][mv2] overlay=400:0'
ffmpeg -v warning -i video1.mkv -i video2.mkv -filter_complex '[0:v]scale=400:400,pad=800:400 [0:q]; [1:v]scale=400:400[1:q]; [0:q][1:q]overlay=400:0' -f nut -c:v rawvideo -c:a copy - | mplayer -noconsolecontrols -cache-min 1 -cache 1024000 -
ffplay -f lavfi "movie=org[a];movie=enc[b];[a][b]blend=all_mode=difference"

==Audio==

'''aevalsrc'''
ffmpeg -i d:/anb.wav -lavfi aevalsrc="sin(440*2*PI*t):s=44100:d=1s" d:/sine-440.wav
NOTE: Remember to specify d, or it will generate forever!

'''Compress or expand dynamic range: Noise-gate, 1:2 compression'''
-lavfi compand=(louding time):(quieting time):(line x)/(line y)
-lavfi "compand=attacks=0.3:decays=0.8:points=-36/-900|-35/-35|0/0|20/20" D:/0.wav
-lavfi compand=.1|.1:.2|.2:-900/-900|-50.1/-900|-50/-50:.01:0:-90:.1
-lavfi compand=.1|.1:.1|.1:-45.1/-45.1|-45/-900|0/-900:.01:45:-90:.1 D:/high_noise_gate.wav

'''Bass'''
-af bass=(freq):(gain):(width or steepness):(mix):(normalize)
-af bass=frequency=100:gain=-50 %o%

'''Bandreject'''
-af bandreject=f=200:width_type=h:width=200 %o%

'''Dynaudnorm'''
dynaudnorm=f=500:g=5:p=0.5
f - frame length
g - gaussian size (number of frames taken into consideration each step)
p - peak loudness
m - maximum gain

'''Equalizer'''
-af equalizer=f=1000:t=q:w=1:g=2,equalizer=f=100:t=q:w=2:g=-5 %o%
-af equalizer=f=1000:width_type=h:width=600:g=-30 %o%

'''Flanger'''
-af flanger=delay=29:depth=5:regen=60 %o%

'''Fade'''
-i %i% -af afade=t=in:d=2s %o%
-i %i%.wav -af afade=t=out:st=40:d=2s %o%
NOTE: st (start time) must be specified for fade out otherwise it will fade out at the beginning and most of the track will be silence

'''Magic'''
-af "asplit[a],aphasemeter=video=0,ametadata=select:key=lavfi.aphasemeter.phase:value=-0.005:function=less,pan=1c|c0=c0,aresample=async=1:first_pts=0,[a]amix"

'''Mix'''
-i %i1% -i %i2% -filter_complex amix=inputs=2:normalize=0 %o%

'''Sample rate'''
-i %i% -af aresample=44100 %o%

'''Spectrogram'''
-i D:/vowel.wav -lavfi showspectrumpic D:/vowel.png

'''Split to mono'''
-lavfi "[0:a]channelsplit=channel_layout=stereo:channels=FR[right]" -map "[right]" front-right.wav

'''Silence remove'''
-af silenceremove=start_periods=1:start_threshold=-35dB %o%
-af silenceremove=start_periods=1:start_duration=5:start_threshold=0.02 %o%

'''Sound generation'''
-f lavfi -i "sine=duration=3:f=220"
aevalsrc="sine(220*2*PI*t):sample_rate=44100":duration=1
anoisesrc=sample_rate=44100:amplitude=0.5:duration=4:color=brown

'''Normalization'''
-af speechnorm=compression=5:raise=0.0001:l=1 %o%
-af dynaudionorm=f=500:g=31:maxgain=10.0 %o%

'''Chorus'''
-af "chorus=0.5:0.9:50|60|40:0.4|0.32|0.3:0.25|0.4|0.3:2|2.3|1.3" %o%