ffmprb

your audio/video montage pal, based on ffmpeg

A DSL (Damn-Simple Language) and a micro-engine for ffmpeg and ffriends.

Allows for code like

Ffmprb.process('flick.mp4', 'track.wav', 'cine.flv') do |av_input1, a_input1, av_output1|

  in_main = input(av_input1)
  in_sound = input(a_input1)
  output(av_output1, video: {resolution: Ffmprb::HD_720p}) do
    roll in_main.cut(from: 2, to: 5).crop(0.25), transition: {blend: 1}
    roll in_main.cut(from: 6, to: 16).volume(2), after: 2, transition: {blend: 1}
    overlay in_sound.volume(0.8), duck: :audio
  end

end

and saves you from the horrors of (the native ffmpeg equivalent)

ffmpeg -y -i flick.mp4 -i track.wav -filter_complex "[0:v] copy [tmcpsp0:v]; [0:a] anull [tmcpsp0:a]; [tmcpsp0:v] trim=2:5, setpts=PTS-STARTPTS [cpsp0:v]; [tmcpsp0:a] atrim=2:5, asetpts=PTS-STARTPTS [cpsp0:a]; [cpsp0:v] crop=x=in_w*0.25:y=in_h*0.25:w=in_w*0.5:h=in_h*0.5 [sp0:v]; [cpsp0:a] anull [sp0:a]; [sp0:v] scale=iw*min(1280/iw\,720/ih):ih*min(1280/iw\,720/ih), pad=1280:720:(1280-iw*min(1280/iw\,720/ih))/2:(720-ih*min(1280/iw\,720/ih))/2, fps=fps=30 [rl0:v]; [sp0:a] anull [rl0:a]; color=black:d=1.0:s=1280x720:r=30 [bl0:v]; aevalsrc=0:d=1.0 [bl0:a]; [bl0:v] trim=0:1.0, setpts=PTS-STARTPTS [tm0b:v]; [bl0:a] atrim=0:1.0, asetpts=PTS-STARTPTS [tm0b:a]; color=white:d=1.0:s=1280x720:r=30 [rn70152323222540:v]; [tm0b:v] [rn70152323222540:v] alphamerge, fade=out:d=1.0:alpha=1 [xrn70152323222540:v]; [rl0:v] [xrn70152323222540:v] overlay=x=0:y=0:eof_action=pass [tn0:v]; [tm0b:a] afade=out:d=1.0 [rn70152323222540:a]; [rl0:a] afade=in:d=1.0 [xrn70152323222540:a]; [xrn70152323222540:a] [rn70152323222540:a] amix=2:duration=first [tn0:a]; [0:v] copy [tmldsp1:v]; [0:a] anull [tmldsp1:a]; [tmldsp1:v] trim=6, setpts=PTS-STARTPTS [ldsp1:v]; [tmldsp1:a] atrim=6, asetpts=PTS-STARTPTS [ldsp1:a]; [ldsp1:v] copy [sp1:v]; [ldsp1:a] volume='2':eval=frame [sp1:a]; [sp1:v] scale=iw*min(1280/iw\,720/ih):ih*min(1280/iw\,720/ih), pad=1280:720:(1280-iw*min(1280/iw\,720/ih))/2:(720-ih*min(1280/iw\,720/ih))/2, fps=fps=30 [rl1:v]; [sp1:a] anull [rl1:a]; color=black:d=3.0:s=1280x720:r=30 [bltn01:v]; aevalsrc=0:d=3.0 [bltn01:a]; [tn0:v] [bltn01:v] concat=2:v=1:a=0 [pdtn01:v]; [tn0:a] [bltn01:a] concat=2:v=0:a=1 [pdtn01:a]; [pdtn01:v] split [pdtn01a:v] [pdtn01b:v]; [pdtn01:a] asplit [pdtn01a:a] [pdtn01b:a]; [pdtn01a:v] trim=0:2, setpts=PTS-STARTPTS [tmtn01a:v]; [pdtn01a:a] atrim=0:2, asetpts=PTS-STARTPTS [tmtn01a:a]; [pdtn01b:v] trim=2:3.0, setpts=PTS-STARTPTS [tm1b:v]; [pdtn01b:a] atrim=2:3.0, asetpts=PTS-STARTPTS [tm1b:a]; color=white:d=1.0:s=1280x720:r=30 [rn70152323237760:v]; [tm1b:v] [rn70152323237760:v] alphamerge, fade=out:d=1.0:alpha=1 [xrn70152323237760:v]; [rl1:v] [xrn70152323237760:v] overlay=x=0:y=0:eof_action=pass [tn1:v]; [tm1b:a] afade=out:d=1.0 [rn70152323237760:a]; [rl1:a] afade=in:d=1.0 [xrn70152323237760:a]; [xrn70152323237760:a] [rn70152323237760:a] amix=2:duration=first [tn1:a]; color=black:d=11.0:s=1280x720:r=30 [bltn12:v]; aevalsrc=0:d=11.0 [bltn12:a]; [tn1:v] [bltn12:v] concat=2:v=1:a=0 [pdtn12:v]; [tn1:a] [bltn12:a] concat=2:v=0:a=1 [pdtn12:a]; [pdtn12:v] split [pdtn12a:v] [pdtn12b:v]; [pdtn12:a] asplit [pdtn12a:a] [pdtn12b:a]; [pdtn12a:v] trim=0:10, setpts=PTS-STARTPTS [tmtn12a:v]; [pdtn12a:a] atrim=0:10, asetpts=PTS-STARTPTS [tmtn12a:a]; color=black:d=1.0:s=1280x720:r=30 [bk2:v]; aevalsrc=0:d=1.0 [bk2:a]; [pdtn12b:v] trim=10:11.0, setpts=PTS-STARTPTS [tm2b:v]; [pdtn12b:a] atrim=10:11.0, asetpts=PTS-STARTPTS [tm2b:a]; color=white:d=1.0:s=1280x720:r=30 [rn70152323255640:v]; [tm2b:v] [rn70152323255640:v] alphamerge, fade=out:d=1.0:alpha=1 [xrn70152323255640:v]; [bk2:v] [xrn70152323255640:v] overlay=x=0:y=0:eof_action=pass [tn2:v]; [tm2b:a] afade=out:d=1.0 [rn70152323255640:a]; [bk2:a] afade=in:d=1.0 [xrn70152323255640:a]; [xrn70152323255640:a] [rn70152323255640:a] amix=2:duration=first [tn2:a]; [tmtn01a:v] [tmtn12a:v] [tn2:v] concat=3:v=1:a=0 [oo:v]; [tmtn01a:a] [tmtn12a:a] [tn2:a] concat=3:v=0:a=1 [oo:a]; [1:a] anull [ldol0:a]; [ldol0:a] volume='0.8':eval=frame [ol0:a]" -map "[oo:v]" -map "[oo:a]" /tmp/inter1a.flv -map "[ol0:a]" /tmp/inter1b.wav

ffmpeg -y -i /tmp/inter1a.flv -filter_complex "silencedetect=d=2:n=-30dB" /tmp/inter2.flv

ffmpeg -y -i /tmp/inter2.flv -i /tmp/inter1b.wav -filter_complex "[0:v] copy [sp0:v]; [0:a] anull [sp0:a]; [sp0:v] scale=iw*min(1280/iw\,720/ih):ih*min(1280/iw\,720/ih), pad=1280:720:(1280-iw*min(1280/iw\,720/ih))/2:(720-ih*min(1280/iw\,720/ih))/2, fps=fps=30 [rl0:v]; [sp0:a] anull [rl0:a]; [rl0:v] concat=1:v=1:a=0 [oo:v]; [rl0:a] concat=1:v=0:a=1 [oo:a]; [1:a] anull [ldol0:a]; [ldol0:a] volume='if(between(t, 9.5, 10.5), (-0.8*t + 8.500000000000002)/1.0, if(between(t, 0.5, 9.5), 0.9, if(between(t, -0.5, 0.5), (0.8*t + 0.5)/1.0, if(between(t, 0.0, -0.5), 0.1, if(between(t, 0.0, 0.0), 0.1, 0.1)))))':eval=frame [ol0:a]; [oo:v] copy [oo0:v]; [oo:a] [ol0:a] amix=2:duration=first [oo0:a]" -map "[oo0:v]" -map "[oo0:a]" cine.flv

Umm... That's the idea. The docs, as well as any other part of this gem, are a work in progress. So you're very welcome to look around the specs for the current functionality coverage.

Installation

Add this line to your application's Gemfile:

gem 'ffmprb'

And then execute:

$ bundle

Or install it yourself as:

$ gem install ffmprb

DSL & Usage

The DSL strives to provide for the most common script cases in the most natural way: you just describe what should be shown -- in an action sequence, like the following.

Play your episode teaser snippet:

lay episode.cut(to: 60), transition: {blend: 3}

Overlay anything after that with your channel logo:

overlay logo.loop.cut(to: 33), after: 3, transition: {blend: 1}  # both ways

Start with rolling some intro flick:

lay intro, transition: {blend: 1}

Overlay it with some special badge sprite:

overlay badge.loop, at: 1, transition: {burn: 1}

Show title:

lay title, transition: {blend: 2}

Play some of your episode:

lay episode.cut(from: 60, to: 540)

Oh well, roll some promo material:

lay promo, transition: {pixel: 2}

Play most of your episode:

lay episode.cut(from: 540, to: 1080)

Roll the credits:

overlay credits, at: 1075

Finish by playing your special outro:

lay outro, transition: {blend: 1}

Anything that follows this order will work -- the script may be generated on the fly:

transitions = [:blend, :burn, :zoom]
photos.shuffle.each do |photo|
  lay photo.loop.cut(to: rand * 3), transition: {transitions.shuffle.first => 1}
end

All inputs mentioned above must be supplied to Ffmprb::process as following (the complete script as can be run with ffmprb CLI, see below):

# script.ffmprb
|episode, logo, intro, badge, title, promo, credits, outro|

lay episode.cut(to: 60), transition: {blend: 3}
overlay logo.loop.cut(to: 33), after: 3, transition: {blend: 1}
lay intro, transition: {blend: 1}
overlay badge.loop, at: 1, transition: {burn: 1}
lay title, transition: {blend: 2}
lay episode.cut(from: 60, to: 540)
lay promo, transition: {pixel: 2}
lay episode.cut(from: 540, to: 1080)
overlay credits, at: 535
lay outro, transition: {blend: 1}

Attention

Ffmprb is a work in progress, and even more so than Ffmpeg itself; use at your own risk and check thoroughly for production fitness in your project.
Ffmprb uses threads internally, however, it is not thread-safe interface-wise: you must not share its objects between different threads.

General structure

Inside a process block, there are input definitions and output definitions; naturally, the latter use the former:

Ffmprb.process('flick.mp4', 'film.flv') do |av_input1, av_output1|

  in_main = input(av_input1)
  output(av_output1, video: {resolution: Ffmprb::HD_720p, fps: 25}) do
    roll in_main.crop(0.05), transition: {blend: 1}
  end

end

Development

After checking out the repo, run bin/setup to install dependencies. Then, run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release to create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Threading policy

Generally, avoid using threads, but not at any cost. If you have to use threads -- like they're already in use in the code -- please follow these simple principles:

A parent thread, when in normal operation, will join all its child threads -- either via #join or #value.
A child thread, when in normal long-running operation, will check on its parent thread periodically -- probably together with logging/quitting operation itself on timeouts (either with a use of Timeout.timeout or otherwise): if it's dead with exception (status=nil), the child should die with exception as well.
To avoid confusion, do not allow Timeout exception (or other thread-management-related errors) to escape threads (otherwise the joining parent must distinguish between its own timout and that of a joined thread)

Contributing

Fork it ( https://github.com/showbox-oss/ffmprb/fork )
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create a new Pull Request