8
votes
Accepted
Correct "stripes" in VHS record
Those are interlacing artifacts. They become visible when the motion in the video is faster than the field rate, so that when both fields are combined into a progressive scan image, the movement is ...
- 2,404
6
votes
How to set pts time format when using ffmpeg filter to add timestamp
Do
In order to draw Timestamp: 01:25., you should specify this one to (feed) ffmpeg:
drawtext = text = 'Timestamp\: %{pts\:gmtime\:0\:%M\\\:%S}.'
Don't
If you specify this one to (feed) ffmpeg:
...
- 161
6
votes
Accepted
replace black frames with previous frames
It's possible to have the black frames removed and earlier frames duplicated.
ffmpeg -i in.mp4 -vf blackframe=0,metadata=select:key=lavfi.blackframe.pblack:value=50:function=less -vsync cfr -c:a copy ...
- 33.6k
4
votes
Accepted
Color leakage effects with ffmpeg blend=all_expr
The default pixel format for testsrc filter is rgb24, which gets converted to yuv444p for encoding to H264. The default pixel format for color is yuv420p, which is kept as-is.
The blend filter ...
- 33.6k
4
votes
Accepted
mplayer/ffmpeg How to set caca filter's output size
Found. Caca library is driven mostly by environment variables rather than filter params.
export CACA_GEOMETRY=200x78
mplayer -vo caca $INPUT
- 219
4
votes
Accepted
How to concatenate multiple videos with fades (from- and to-black) in-between?
So here is what I came up with.
A not fully one-liner solution
1) Generate black clips
ffmpeg -f lavfi -i "color=black:s=1920x1080:r=30" \
-f lavfi -i "anullsrc=r=48000:cl=stereo" ...
- 111
3
votes
Accepted
How to improve quality of a WebCam video?
More Light
You're seeing noise for two reasons. One is the tiny sensor of your webcam, but since you don't want to buy a new one right now, you can't do anything about that. However, the sensor size ...
- 5,452
3
votes
Accepted
How to set pts time format when using ffmpeg filter to add timestamp
Use
text='timestamp \: %{pts\:gmtime\:0\:%H\\\:%M\\\:%S}'
- 33.6k
3
votes
Accepted
Add semi-transparent box around subtitle
Use
ffmpeg -i movie.mkv -strict -2 -vf "subtitles=subtitle.srt:force_style='FontName=ubuntu,fontsize=30,BorderStyle=3,OutlineColour=&H80000000',scale=720:-1" -qscale:v 3 Movie.avi
See Style ...
- 33.6k
3
votes
"ffmpeg" set fontsize and font
I did solved this with " "
"subtitles=subtitle.srt:force_style='FontName=ubuntu,Fontsize=30'"
- 235
3
votes
Accepted
FFmpeg: afade plugin, how to specify time 1:55 if colon separates filter parameters? Escape
Enclose the time argument in single quotes and escape the colons within.
So,
afade=t=out:curve=hsin:st='00\:0\:30':d='00\:00\:10'
- 33.6k
3
votes
Accepted
ffmpeg blend mode multiply results in green overlay
I solved my problem thanks to @Gyan comment:
ffmpeg -i bg.mp4 -i fg.mov -filter_complex "[0:v] format=rgba [bg]; [1:v] format=rgba [fg]; [bg][fg] blend=all_mode='multiply':all_opacity=1, format=rgba" ...
- 41
2
votes
Accepted
Stack images with "hstack"-filter from video or image sequence in ffmpeg
You're better off using the tile filter for this:
ffmpeg -i INPUT.mov -vf fps=1,scale=192:108,tile=54x1 output.jpg
The tile argument is the size of a rectangle. So for a 54 second video, 54x1 ...
- 33.6k
2
votes
What -preset medium stand for in ffmpeg
On the page you linked to it explains it fairly well:
A preset is a collection of options that will provide a certain encoding speed to compression ratio. A slower preset will provide better ...
- 13.8k
2
votes
Accepted
What -preset medium stand for in ffmpeg
preset is a private option that may be defined for an encoder, such as libx264. It is a shorthand method to set a whole bunch of options at once, and won't have any effect if set when using an encoder ...
- 33.6k
2
votes
Accepted
ffmpeg fade to specific color values over time
The lut filter expressions don't work with time. geq does.
geq=r='(1-0.7*min((T-S)/D,1))*p(X,Y)':g={the same as r}:b={the same}:enable='gte(t,S)'
S should be your start time in second. D is duration ...
- 33.6k
2
votes
If I use a normal build of ffmpeg how take advantage of video acceleration for scale?
The answer to your second question is yes. Change -c:v libx264 to -c:v h264_nvenc. I use those builds as well. If you use the option -encoders you can see a list of included video and audio codecs.
...
- 106
2
votes
Accepted
Replace all completely black frames with interpolated frames
After poring over the documentation all weekend, I figured out how to use the minterpolate filter to do motion interpolation. The full command is
ffmpeg -i in.mp4 -vf blackframe=0,metadata=select:...
2
votes
Accepted
Combine -vf yadif,format=yuv420p and -filter_complex for watermark
Use
ffmpeg -i input.mp4 -i logo.png \
-filter_complex "[0]yadif,format=yuv420p[main];[1][main]scale2ref=iw/5:ow*450/450[wm][vid];[vid][wm]overlay=W-w-W*3/100:H-h-H*1/100:enable='gt(t,30)'" \
-...
- 33.6k
2
votes
Accepted
What are brightness, gamma, and lut filters doing to my video? What's the difference, which should I prefer?
Here's what all these settings do, typically. Some pieces of software define or apply them differently, but this should give a general idea.
Brightness simply changes the brightness value of each ...
- 266
1
vote
How to use ffmpeg to fade in/out a veriable frame rate video clip with unknown duration
This works here
ffmpeg -i VID_1.mp4 -sseof -2 -copyts -i VID_1.mp4 -lavfi "[1]fade=out:s=1:d=2[tail];[0][tail]overlay,fade=in:s=0:d=2,scale=640:-2[video];anullsrc,atrim=0:2.1[audiotail];[0][audiotail]...
- 33.6k
1
vote
Video player with motion blur or frame averaging
VLC has a motion blur option under Tools > Effects and Filters > Video Effects > Advanced.
As a bonus, it can natively take the URL of some video sites, like YouTube.
- 111
1
vote
Accepted
Combining two video fields into one (to create an interlaced video)
Use
ffmpeg -i top.avi -i bottom.avi -filter_complex vstack,il=l=i:c=i -c:v ffv1 il.avi
See docs for http://www.ffmpeg.org/ffmpeg-filters.html#vstack and http://www.ffmpeg.org/ffmpeg-filters.html#il
- 33.6k
1
vote
Accepted
What do I need to take into consideration to take video of molten glass which I will later postprocess?
What this comes down to is what's referred to as dynamic range. The wider the dynamic range the more detail you will see between the darkest darks and brightest lights. The human eye has a very large ...
- 26
1
vote
How to apply different filters to different parts of a video using AviSynth?
This can be done using the filter ClipClop. Here is an example script from the docs of the filter:
Avisource("D:\avs\test.avi")
ORG=Last
V1 = FFT3DFilter(Plane=0,Sigma=1.6) # Light Luma
V2 = ...
- 121
1
vote
Accepted
How to overlay 2 videos using depth layers
The main issue was, that the Z-Layer was not accurate enough, as Gyan said. Addtionally the condition needed to be changed from lt(A,B) to lte(A,B).
1
vote
Why when I overlay a logo on top of the video, the white color part of the logo is transparent?
There is no white color. That's the background color of the page showing through. Your input PNG is palettized 8-bit image where black color indicates transparency.
Apply the following filter to the ...
- 33.6k
Only top scored, non community-wiki answers of a minimum length are eligible