dyndo

Dynamic media packaging for adaptive streaming, in Rust.

dyndo turns your existing CMAF files into an adaptive-streaming service without repackaging or duplicating a single byte of media. You index your sources once into a small JSON descriptor; the server then generates DASH and HLS manifests and serves CMAF segments on the fly, straight from the original files via HTTP byte-range reads.

dyndo is in early development. Both DASH and HLS are implemented, served from the same CMAF sources.

The idea in one picture

  CMAF sources                asset.json                dyndo-server
  (fragmented MP4      dyndo    (thin                       │
   + global sidx)  ──index──▶   descriptor)  ────────▶  ┌───┴────────────────────┐
        │                                               │  GET …/dash/index.mpd  │
        └───────────── byte-range reads ───────────────▶│  GET …/hls/index.m3u8  │
                                                        │  GET …/<repr>/init.mp4 │
                                                        │  GET …/<repr>/<t>.m4s  │
                                                        └────────────────────────┘

1. Index your CMAF files once with the dyndo CLI to produce asset.json.
2. Serve that descriptor with dyndo-server. At request time it parses each source’s header, derives the segment index, and answers manifest and segment requests with ranged reads from the original media.

Because the descriptor stores only per-track metadata and a source path — no segment list, no byte offsets — a single asset.json is a few hundred bytes, and serving an 800 MB source reads the same ~10 KB header region as an 8 MB one. See The thin-pointer approach for why.

The two tools

dyndo is two programs, and you get each the easy way — no Rust toolchain required:

This book covers both programs and the asset.json descriptor that connects them: you produce a descriptor with the CLI, and the server reads it. If neither the installer nor Docker fits your platform, you can also build from source.

Quick install

Install the dyndo CLI (macOS and Linux):

curl -fsSL https://matvp91.github.io/dyndo/install.sh | bash

See Install the CLI for details. For the server, pull the Docker image — see Deploy with Docker.

How to read this book

This documentation follows the Diátaxis framework. Pick the section that matches what you need right now:

• Tutorial — I’m new here. A single guided lesson that takes you from nothing to a playing stream.
• How-to guides — I have a task to do. Focused recipes: index sources, add subtitles, label tracks with roles, run the server, serve from S3, deploy with Docker.
• Reference — I need to look something up. Exact, exhaustive descriptions of every command, route, config key, descriptor field, and track role.
• Explanation — I want to understand why. The design ideas behind dyndo: the thin pointer, bounded-memory parsing, and one source serving two protocols.

Supported codecs

Codec parameters are read from the source and emitted as RFC 6381 strings.

Raw WebVTT (.vtt) files are also accepted as text-track sources, with no packaging step — see Add a subtitle track.