Dash Timeline Validator

This tool allows you to validate your MPEG Dash manifest to find if there are errors related to the presentation timeline model.

Docker Usage

docker run --rm -it anafrombr/dash_timeline_validator https://storage.googleapis.com/shaka-live-assets/player-source.mpd --verify_segments_duration false 

Installation

Add this line to your application's Gemfile:

gem 'dash_timeline_validator'

And then execute:

$ bundle

Or install it yourself as:

$ gem install dash_timeline_validator

Usage

Run this program passing the manifest path. It can be either a URI or local path.

dash_timeline_validator https://storage.googleapis.com/shaka-live-assets/player-source.mpd

Running the program without any parameters or using h will show usage instruction along with optional parameters.

Options

• acceptable_drift *(default 2)* - the minimum duration drift acceptable between the sequential segments
• presentation_delay *(default 10)* - the delay in seconds of the live edge
• buffered_segments *(default 2)* - the number of segments buffered by the player to generate the live edge
• verify_segments_duration *(default false)* - check the duration of every segment when setted to true (warn: this will download every segment of the manifest)
• analyzer_folder *(default "data/[HASH]")* - folder used to download the files
• analyzer_manifest_path *(default "#{analyzer_folder}/manifest.mpd")* - manifest path

Example:

dash_timeline_validator https://storage.googleapis.com/shaka-live-assets/player-source.mpd --acceptable_drift 2

What does it validates?

1. The advised timeline segments - basically, if the <S t=<x> d=<y>> is summing up right. Our audio segments were drifting (due to a round we made) and this made the exoplayer behave as if it were buffering while most of the other players didn't show any problem at all. It optionally download and check whether the advised duration equals to the one being served.
2. The advised timeline - if the possible live edge is contained within the advised timeline (to use client wall clock, ast, mbt, player buffer to see what should be one possible live edge)

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the 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.

Contributing

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