Command-line cinema

Some Sources of copyleft materials online

• archive.org

example: Fats Waller on archive.org

• Librivox
• Europeana

Wget

Wget is a simple way to download things from the web. These can be webpages, videos, sounds -- basically anything that has a proper URL to access it (for youtube videos or other "closed" sources see youtube-dl)

wget URL

Youtube-dl

youtube-dl URL

There are *many* interesting options with youtube-dl

Show formats available:

youtube-dl -F URL

Download a particular format (using its numeric code)

youtube-dl -f43 URL

Download a video + the automatically generated subtitles!

youtube-dl --write-auto-sub URL

Mplayer

Basic key commands when playing a movie with mplayer

SPACE: Pause/Play
. : Forward one frame
Left + Right : Jump
9 0 : Volume
[ ] : Speed
o   : Toggle display mode (shows current time and duration)
f   : Toggle fullscreen
s   : Save current frame (with -vf screenshot, see Mplayer Snapshots)
q   : Quit

Time options

Play from 10 seconds to 1 minute 6 seconds.

mplayer -ss 10 -endpos 56

Play from 01:10:30 - 01:11:00

mplayer -ss 01:10:30 -endpos 30

Extracting Frames from a Movie: Mplayer Snapshots

mplayer -vf screenshot <source>

Then while the movie is playing ... press the s key each time you want to save a frame. You should find files named like:

shot0001.png
shot0002.png
shot0003.png
shot0004.png

Extracting Frames from a Movie: ffmpeg

ffmpeg uses a "printf" style code for working with image sequences. They also look like "%04d" where the number (4 in this case) means how many numbers to use in total so for instance, "foo%04d.jpg" would produce filenames like:

foo0001.jpg
...
foo0123.jpg

And a code like "%09d.png" would produce things like:

000000001.png
000000002.png
...
999999999.png

To extract all of the frames of a video:

ffmpeg -i <source> <destination%06d.jpg>

ffmpeg -ss 12:00 -i <source> -vframes 100 <destination%04d.jpg>

Timing (start + stop) can be controlled with -ss (skip start) and -t (total time of result)

When -ss is before the -i ffmpeg attempts to JUMP which is fast only precise to the nearest key frame.

Extract 3 seconds starting at (near) 05:47 and save as snip.mp4

ffmpeg -ss 05:47 -i ten.mp4 -t 3 snip.mp4

When you put -ss after the -i, the timing is more precise but it's slower as the movie is actually played (quickly) up to that precise point.

Extract 3 seconds starting at (exactly) 05:47 and save as snip.mp4

ffmpeg -i ten.mp4 -ss 05:47 -t 3 snip.mp4

ffmpeg -ss 05:47 -i powersof10/ten.mp4 -vframes 10 snip%04d.jpg

Starting at 05:47 output one frame every 5 seconds for 10 frames, save using names starting snip0001.jpg

ffmpeg -ss 05:47 -i powersof10/ten.mp4 -r 1/5 -vframes 10 snip%04d.jpg

Combine Image Sequence starting frames000001.jpg and the audio in soundtrack.wav, save result as result.mp4:

ffmpeg -i frames%06d.jpg -i soundtrack.wav result.mp4

Example:

ffmpeg -ri 10 -i frame%06d.jpg -i apologie.wav apologie.mp4

To force ffmpeg to OVERWRITE any previously existing file (useful when inside a larger script that you want to run again and again) -- add the -y to AUTO-YES the question about replacing the output.

ffmpeg -r 10 -i frame%06d.jpg -i apologie.wav -y apologie.mp4

Extraction de sons

ffmpeg -i <source> output.wav

or

ffmpeg -i <source> output.mp3

If you have a video and you want to simply separate the audio, without recompressing it (which is faster and doesn't change the quality / data), you can say something like:

Copying just the ogg audio from a webm:

ffmpeg -i mysource.webm -vn -c:a copy output.ogg

Copying just the AAC audio from an MP4:

ffmpeg -i mysource.mp4 -vn -c:a copy output.aac

Padding audio

Add 10 seconds to start and 30 seconds to end of input, save as output:

sox input.wav output.wav pad 10 30

Mixing audio

with ffmpeg

ffmpeg -i apologie.wav -i badmusic.wav -filter_complex amerge mix.mp3

it uses the duration of the shortest file.

you can also explicitly limit the number of audio channels with:

ffmpeg -i apologie.wav -i badmusic.wav -filter_complex amerge -ac 1 mix.mp3

Sequence (concatenate) audio / video

For audio, you can use sox like this:

sox a.wav b.wav c.wav output.wav

For video, you can use mlt / melt .....

melt a.mp4 b.mp4 c.mp4 -consumer avformat:output.mp4 b=1000k

You can also use melt to combine still images as "inter-titles", the numbers with "out" are frames (so for output at 25 fps, 50 = 2 seconds):

melt title2-0.png out=50 \
video.mp4 \
title2-1.png out=100 \
-consumer avformat:output.mp4 b=1000k

To do this with ffmpeg you need to make a sort of playlist file that looks like:

Create a file called playlist.txt:

file 'a.wav'
file 'b.wav'
file 'c.wav'

Then the command to put the pieces together is:

ffmpeg -f concat -i concat.txt concat.mp3

See: https://trac.ffmpeg.org/wiki/Concatenate

Text / Titles

Imagemagick! http://www.imagemagick.org/Usage/text/

convert -size 640x480 -gravity center -pointsize 72 -font CoupeurBoldBlock.otf -background lightblue -fill blue caption:'HEY what about a very long text then?' title.png

with a newline:

convert -size 640x480 -gravity center -pointsize 72 -font CoupeurBoldBlock.otf -background lightblue -fill blue caption:'HEY!what about a very long text then?' title.png

What colors?

convert -list color

Random color!

convert -list color | cut -d" " -f1 | shuf | head -n1

There's also label:, but it doesn't do word wrap.

convert -size 640x480 -gravity center -pointsize 72 -font ~/.fonts/coupeur-boldblock/CoupeurBoldBlock.otf -background lightblue -fill blue caption:'HEY what about a very long text then?' title.png</source>

convert -size 640x480 -gravity center -pointsize 72 -font -background lightblue -fill blue label:'magic\nmagic!!!' whoami.png

title with random colors:

convert -size 640x480 -gravity center -pointsize 72 \
   -font ~/.fonts/coupeur-boldblock/CoupeurBoldBlock.otf \
   -background $(convert -list color | cut -d" " -f1 | shuf | head -n1) \
   -fill $(convert -list color | cut -d" " -f1 | shuf | head -n1) \
   label:'Surprise!!!' surprise.png

TITLE

c1=`shuf imcolornames.txt | head -n 1`
c2=`shuf imcolornames.txt | head -n 1`
convert -size 640x480 -background $c1 -fill $c2 -pointsize 72 -gravity center -f ont /home/murtaugh/.fonts/OSP_Libertinage/Libertinage-s.ttf label:Contemporaneit y contemporaneity.png

NB: Using the @ sign with label to read from a file seems to be blocked (by some kind of security policy).... back quoting a file might work though?!