Convert and Resize Images and Movies
Mogrify is a commanline utility included with ImageMagick.
To resize an image if you have imageMagick use:
# mogrify -resize 50% rose.jpg
or
# mogrify -resize 1200x1200 *.jpg
or to reduce size and quality
# mogrify -resize 1200x1200 -quality 50 *.jpg
To convert an image use:
# convert rose.jpg rose.png
More Examples of converting with ImageMagick
ImageMagick v6 Examples -- Reference Index
To convert Canon AVI files to mpg and reduce the size by 60%
# ffmpeg -i Origional.AVI -target ntsc-dvd New.mpg
To convert Canon AVI files to mpg and reduce the size by 80%
# ffmpeg -i Origional.AVI -target ntsc-dvd -b 3000k -ab 256k New.mpg
Note that you can adjust the video bit rate from -b 3000k per second, and you can adjust the audio bit rate from -ab 256k (but only in increments of 64k).
To convert AVI to MPG and reduce the size by 90% (Note: higher crf smaller size, 18-27)
# ffmpeg -i Origional.AVI -vcodec libx264 -strict -2 -crf 27 New.mp4
# ffmpeg -i Origional.AVI -target ntsc-vcd New.mpg
To convert MP4 to AVI, change size to 720x480, video bit rate to 450k, audio bit rate to 64k
# ffmpeg -i Origional.mp4 -s 720x480 -b:v 450k -ab 64k -vcodec libx264 -vprofile main New.avi
To convert 1080P to avi 1080p
# ffmpeg -i MVI_0223.MOV -vf -c:v -crf 23 -preset veryslow -c:a copy MVI_0223.avi
To automate converting a batch of avi files to mpg
Create a bash shell script file called avi2mpg.sh with the following contents:
#!/bin/sh
for f in *.AVI;
do
echo "Processing $f"
ffmpeg -i "$f" -target ntsc-dvd -b 2800k -ab 256k "${f%.AVI}.mpg"
done