Abrizer

Abrizer takes a source video and creates various derivatives for delivery including adaptive bitrate formats like DASH and HLS. An opinionated work in progress.

Requirements

See ansible/development-playbook.yml for specifics on all requirements.

• ffmpeg with x264 and libvpx
• bento4
• Imagemagick (convert and montage) for sprites

Installation

Add this line to your application's Gemfile:

gem 'abrizer'

And then execute:

$ bundle

Or install it yourself as:

$ gem install abrizer

See Vagrant below for one way to install dependencies and run the scripts.

Versioning

API may change in breaking ways in minor versions until version 1.0.0 when breaking changes will update the major version number.

Usage

Abrizer knows how to run various processes which can take a master or mezzanine video and create various access derivative formats including DASH and HLS streaming formats as well as fallback MP4 and WebM (VP9). The gem is opinionated about what formats to create and what settings to use. The intention is to provide a relatively complete but simple solution for delivering video over HTTP for HTML5 video.

Some steps must be run after others as they have preconditions in order for subsequent steps to run. You can see the latest full set of processes Abrizer can run by looking in lib/abrizer/all.rb. The initial commands before process need to run with the mezzanine file as input. The current order is:

• ffprobe: Saves the output of ffprobe to ffprobe.json. This way the mezzanine file does not have to be present for some later steps.
• adaptations: Saves the precomputed adaptations that will be created in later processes to adaptations.json.
• captions: Copies over captions.
• vp9: Process a progressive download WebM VP9 from original. This takes a long time.
• mp3: Create a progressive download MP3 audio file.
• sprites: Create video thumbnail sprites and metadata WebVTT file retaining all the images in order for a human to later pick a poster image.
  • poster: Copies over a temporary poster image from the output of the sprites command.
• process: Process the adaptations that will be repackaged into ABR formats. Beyond this point the remaining processes can be run without the mezzanine file present.
  • mp4: Process a progressive download MP4 from next to highest quality adaptation.
  • package dash: Package DASH (and HLS with fMP4) using output of process.
  • package hls: Package HLS (TS) using output of process.
• canvas: Non-standard IIIF canvas.
• waveform: Create audio waveform data.
• data: Create the data.json file.
• clean: Clean out the intermediate and log files including MP4 files used for packaging but not required for delivery.

Media Sharing

The canvas and data create files that aid in sharing media. They create canvas.json and data.json files respectively. You must know the base URL that will be used to serve up the media files. The canvas.json is experimental support for the developing IIIF A/V technical specification for canvases. Note that this work is done in advance of a draft standard for including video in a IIIF manifest. The data.json file is a simplified version of the information about the available media.

In order to get information about the files being shared these steps either need the presence of the original video file or the presence of the ffprobe.json and adaptations.json files. In addition these information files are only useful if some media has already been processed. In other words these processes can be run without the presence of the mezzanine file if some preconditions are already met.

Command Line

From the command line you can see help with: abrizer

To see help for a particular command run: abrizer help all

You can run all steps with: abrizer all -i /path/to/video.mp4 -o /path/to/output_directory -u http://localhost:8088/v/output_directory

Or just create various adaptations needed for repackaging to DASH and HLS: abrizer process -i /path/to/video.mp4 -o /path/to/output_directory

Then once process is run it is possible to do packaging to adaptive bitrate formats like DASH:

abrizer package dash -o /path/to/output_directory

The output for DASH will go in the fmp4 directory as the fragmented MP4 can be used for both DASH (stream.mpd) and the latest HLS on iOS 10+ (master.m3u8).

HLS with MPEG-2 TS files can also be created after process is run with the output in the hls directory:

abrizer package hls -o /path/to/output_directory

Using as a Library

If you simply want to run all the steps, you can use the Abrizer::All class like so:

video_path = "/path/to/video.mp4"
output_directory = "/path/to/output_directory"
base_url = "http://localhost:8088/v/output_directory"
Abrizer::All.new(video_path, output_directory, base_url).run

Take a look at lib/abrizer/all.rb for how to use the various classes provided. You can also see more examples in lib/abrizer/cli.rb. All classes expect to be passed the fully expanded path.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests (when there are tests!). You can also 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, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Vagrant

The easiest way to do development on Abrizer or even try out the scripts is to use a Vagrant machine. If you have Vagrant and Virtualbox installed just run vagrant up and all dependencies will be installed.

This includes a web server that can be used for local testing of streams and videos. After vagrant up visit http://localhost:8088/v/ to see the contents of the project's tmp directory. Within the virtual machine (vagrant ssh) you can process a test video with:

cd /vagrant
bundle exec exe/abrizer all \
-i test/videos/FullHDCinemaCountdown720p-8sec.mp4 \
-o tmp/countdown -u http://localhost:8088/v/countdown

Now visit http://localhost:8088/v/countdown/ to see the files that were created. You can then test any of the videos or streams.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/jronallo/abrizer.

License

The gem is available as open source under the terms of the MIT License.