Transcoding on Demand

Latest release

Our Transcoding on Demand tool is a Command-Line Interface (CLI) that allows an application to leverage the Livepeer network for video transcoding, thus removing a complex transcoding scalability requirement that usually comes with building a video streaming service. At the same time, it's flexible enough to plug into any bespoke video workflow, because any backend software can easily invoke a cli command. It is open source, and currently in beta.

We welcome your feedback at [email protected] and suggestions about how this tool addresses your needs, or how it can be improved to help you better address your needs.

You’re also welcome to communicate with our team in the Livepeer Discord server #video-dev channel.

Installing livepeer-transcode

What you'll need:

• A Livepeer.com API Key
• A way to unzip packaged files
• MP4 or TS video that you'd like transcoded into other renditions

Steps to install

• Download the binary for your OS (Windows, Linux, Mac) and arch.
• Execute the file
  • NOTE: If you're on a Mac and get an "unidentified developer" security warning, follow this guide to circumvent it while we work on removing this warning.

Using livepeer-transcode

Tool accepts .mp4 and .ts file. Output be .mp4, .ts or .m3u8 (HLS manifest).

For HLS output tool will write master playlist and one media playlist for each transcoding profile.

Examples

MP4 Output:

./livepeer-transcode --api-key {API key} transcode name_of_input_video.mp4 name_of_output_video.mp4 -r 256x144 -b 400 --framerate 47 --profile baseline --gop 20s

or

./livepeer-transcode transcode --api-key API_KEY  input_file_name.mp4 output_file_name.mp4 --profiles config.json

HLS output:

./livepeer-transcode transcode --api-key API_KEY  input_file_name.mp4 output_dir/output_file_name.m3u8 --profiles config.json output_dir

Subcommands

The subcommands are structured like this: livepeer-transcode [subcommand]

• help — Global help about the livepeer-transcode
• list-presets — Lists available transcoding presets
• transcode — Transcodes video file using Livepeer API

You can also use livepeer-transcode [subcommand] --help for more information about a specific subcommand.

Global Flags

The global flags should be specified before the subcommand and are the same for all:

• -h / --help — display help for livepeer-transcode
• -v / --version — display version of livepeer-transcode
• -a / --api-host — API-host string Livepeer API host (default "livepeer.com")
• -k / --api-key — API-key string for Livepeer API key

The transcode subcommand

The transcode subcommand is used like this:

livepeer-transcode transcode input.[ts|mp4] output.[ts|mp4] [flags]

The first argument after transcode is the path to the input file to be transcoded, and the second one is the path for the output file where the transcoded renditions will be written. After that one must specify flags to configure the transcoding job:

• -h / --help — display specific help for the transcode subcommand
• -b / --bitrate — set bitrate of the output in Kbps
• -r / --resolution — set resolution of the output

NOTE: Resolution will automatically adjust to be proportional to the resolution of the input video to avoid stretching of the frames.

• -f / --framerate — set framerate of the output in frames per second (fps)

• -g / --gop — set GOP size of the output, specified as the time between two keyframes, in seconds.

• -p / --presets — comma-separated list of transcoding presets (e.g. P720p30fps16x9). Use list-presets to get a list of presets available to use.

• -o / --profile — determines hardware acceleration for encoding. Options are baseline, main, or high.

• --profiles - file name with desired encoding profiles in JSON format. Example config.json

Profile structure

{
    "name",
    "width", // number
    "height", // number
    "bitrate", // number, in bits per second
    "fps", // number
    "fpsDen" // number, fps denominator, do not set if fractional fps is not needed
    "gop" // string, for example: 2s
    "profile" // one of - H264Baseline - H264Main - H264High - H264ConstrainedHigh
}