pupil

pupil is a server that is made useful by how it uses the morsel & memento libraries.

pupil can be used to create HLS streams from Audio & Video packets.

It does so by using the morsel library.

It uploads those HLS streams to the cloud.

It also creates jpeg thumbnails of the stream at set keyframe intervals.

This is accomplished by using the memento library (a very thin wrapper around libavcodec for h264 decompression)

Requirements

If building with memento support the following dependencies need to be installed.

• libavcodec (57.107.100)
• libavutil (55.78.100)
• libswscale (4.8.100)
• libswresample (2.9.100)

All of the above packages are available in ffmpeg release 3.4.1

Configuring

pupil can be configured via a config file or environment variables.

Properties that need to be configured are:

• port The port the server will run on
• root The directory that pupil will create subdirectories in for writing media files
• host The hostname for the API that publishes content (coming soon...)
• bucket The bucket that media files should be uploaded to
• keyID The AWS key ID to use when uploading to the bucket
• keySecret The AWS key secret to use when uploading to the bucket
• thumbnailInterval How many key frames to count before creating a jpeg thumbnail of the stream

Default values

By default pupil's port will be set to 42000

It will treat the current working directory as it's root

It will create a jpeg thumbnail every 30 keyframes

File Configuration

The project contains an example.conf file demonstrating how to set server values.

If you wish to use a config file you have two options.

• Have a file called config.json current working directory
• Specify the path to the config file with a command line flag.

An example of using a file at a specific path:

pupil -c /path/to/config.json

Environment Configuration

You can set environment variables to configure pupil.

Just run pupil normally and it will detect them.

This makes working with things like Docker or OpsWorks very easy.

Below are a list of the environment variables you should set:

• PUPIL_PORT
• PUPIL_ROOT
• PUPIL_BUCKET
• PUPIL_API_HOST
• PUPIL_THUMBNAIL_INTERVAL
• AWS_REGION
• AWS_KEYID
• AWS_KEYSECRET

These should all be fairly self explanatory.

Roadmap

• In future releases, memento support should become a build time option, so the ffmpeg libs won't be a hard requirement.
• Pluggable support for different cloud providers.