imlib2.c
# Remember to set the path to your fonts
FONTPATH="/cygdrive/c/WINDOWS/Fonts/"
FONTPATH="$FONTPATH:/usr/share/imlib2/data/fonts/"
FONTPATH="$FONTPATH:/usr/X11R6/lib/X11/fonts/TTF/"
export FONTPATH
# Bulb dancing in a Lissajous pattern
ffmpeg -i input.avi -vhook \
'vhook/imlib2.dll -x W*(0.5+0.25*sin(N/47*PI))-w/2 -y H*(0.5+0.50*cos(N/97*PI))-h/2 -i /usr/share/imlib2/data/images/bulb.png' \
-acodec copy -sameq output.avi
# Text scrolling
ffmpeg -i input.avi -vhook \
'vhook/imlib2.dll -c red -F Vera.ttf/20 -x 150+0.5*N -y 70+0.25*N -t Hello' \
-acodec copy -sameq output.avi
# Date and time stamp, security-camera style:
ffmpeg -r 29.97 -s 320x256 -f video4linux -i /dev/video0 \
-vhook 'vhook/imlib2.so -x 0 -y 0 -i black-260x20.png' \
-vhook 'vhook/imlib2.so -c white -F VeraBd.ttf/12 -x 0 -y 0 -t %A-%D-%T' \
output.avi
In this example the video is captured from the first video capture card as a
320x256 AVI, and a black 260 by 20 pixel PNG image is placed in the upper
left corner, with the day, date and time overlaid on it in Vera Bold 12
point font. A simple black PNG file 260 pixels wide and 20 pixels tall
was created in the GIMP for this purpose.
# Scrolling credits from a text file
ffmpeg -i input.avi -vhook \
'vhook/imlib2.so -c white -F VeraBd.ttf/16 -x 100 -y -1.0*N -f credits.txt' \
-sameq output.avi
In this example, the text is stored in a file, and is positioned 100
pixels from the left hand edge of the video. The text is scrolled from the
bottom up. Making the y factor positive will scroll from the top down.
Increasing the magnitude of the y factor makes the text scroll faster,
decreasing it makes it scroll slower. Hint: Blank lines containing only
a newline are treated as end-of-file. To create blank lines, use lines
that consist of space characters only.
# Scrolling credits with custom color from a text file
ffmpeg -i input.avi -vhook \
'vhook/imlib2.so -C rgb.txt -c CustomColor1 -F VeraBd.ttf/16 -x 100 -y -1.0*N -f credits.txt' \
-sameq output.avi
This example does the same as the one above, but specifies an rgb.txt file
to be used, which has a custom-made color in it.
# Variable colors
ffmpeg -i input.avi -vhook \
'vhook/imlib2.so -t Hello -R abs(255*sin(N/47*PI)) -G abs(255*sin(N/47*PI)) -B abs(255*sin(N/47*PI))' \
-sameq output.avi
In this example, the color for the text goes up and down from black to
white.
# Text fade-out
ffmpeg -i input.avi -vhook \
'vhook/imlib2.so -t Hello -A max(0,255-exp(N/47))' \
-sameq output.avi
In this example, the text fades out in about 10 seconds for a 25 fps input
video file.
# scrolling credits from a graphics file
ffmpeg -sameq -i input.avi \
-vhook 'vhook/imlib2.so -x 0 -y -1.0*N -i credits.png' output.avi
In this example, a transparent PNG file the same width as the video
(e.g. 320 pixels), but very long, (e.g. 3000 pixels), was created, and
text, graphics, brushstrokes, etc, were added to the image. The image
is then scrolled up, from the bottom of the frame.
drawtext.c
# Remember to set the path to your fonts
FONTPATH="/cygdrive/c/WINDOWS/Fonts/"
FONTPATH="$FONTPATH:/usr/share/imlib2/data/fonts/"
FONTPATH="$FONTPATH:/usr/X11R6/lib/X11/fonts/TTF/"
export FONTPATH
# Time and date display
ffmpeg -f video4linux2 -i /dev/video0 \
-vhook 'vhook/drawtext.so -f VeraBd.ttf -t %A-%D-%T' movie.mpg
This example grabs video from the first capture card and outputs it to an
MPEG video, and places "Weekday-dd/mm/yy-hh:mm:ss" at the top left of the
frame, updated every second, using the Vera Bold TrueType Font, which
should exist in: /usr/X11R6/lib/X11/fonts/TTF/
watermark.c
ffmpeg -i infile -vhook '/path/watermark.so -f wm.gif' -an out.mov
ffmpeg -i infile -vhook '/path/watermark.so -f wm.gif -m 1 -t 222222' -an out.mov
