dash-mpd

A Rust library for parsing and downloading media content from a DASH MPD file, as used by video services such as on-demand replay of TV content and video streaming services like YouTube.

Documentation

DASH (dynamic adaptive streaming over HTTP), also called MPEG-DASH, is a technology used for media streaming over the web, commonly used for video on demand (VOD) services. The Media Presentation Description (MPD) is a description of the resources (manifest or “playlist”) forming a streaming service, that a DASH client uses to determine which assets to request in order to perform adaptive streaming of the content. DASH MPD manifests can be used both with content encoded as MPEG and as WebM.

This library provides a serde-based parser for the DASH MPD format, as formally defined in ISO/IEC standard 23009-1:2019. XML schema files are available for no cost from ISO. When MPD files in practical use diverge from the formal standard, this library prefers to interoperate with existing practice.

The library also provides experimental support for downloading content (audio or video) described by an MPD manifest. This involves selecting the alternative with the most appropriate encoding (in terms of bitrate, codec, etc.), fetching segments of the content using HTTP or HTTPS requests (this functionality depends on the reqwest crate) and muxing audio and video segments together (using ffmpeg via the ac_ffmpeg crate).

This crate does not support content encrypted with DRM such as Encrypted Media Extensions (EME) and Media Source Extension (MSE). It currently does not provide download support for dynamic MPD manifests, that are used for live streaming. It currently only provides support for downloading audio and video streams, and not subtitles (eg. WebVTT streams).

Usage

use std::time::Duration;
use dash_mpd::{MPD, parse};

fn main() {
    let client = reqwest::blocking::Client::builder()
        .timeout(Duration::new(30, 0))
        .gzip(true)
        .build()
        .expect("Couldn't create reqwest HTTP client");
    let xml = client.get("http://rdmedia.bbc.co.uk/dash/ondemand/testcard/1/client_manifest-events.mpd")
        .header("Accept", "application/dash+xml")
        .send()
        .expect("Requesting MPD content")
        .text()
        .expect("Fetching MPD content");
    let mpd: MPD = parse(&xml)
        .expect("parsing MPD");
    if let Some(pi) = mpd.ProgramInformation {
        if let Some(title) = pi.Title {
            println!("Title: {:?}", title.content);
        }
        if let Some(source) = pi.Source {
            println!("Source: {:?}", source.content);
        }
    }
    for p in mpd.periods {
        if let Some(d) = p.duration {
            println!("Contains Period of duration {:?}", d);
        }
    }
}

The experimental support for downloading content from an MPD manifest:

use std::time::Duration;
use dash_mpd::fetch_mpd;

fn main() {
    let client = reqwest::blocking::Client::builder()
        .timeout(Duration::new(30, 0))
        .gzip(true)
        .build()
        .expect("Couldn't create reqwest HTTP client");
    let url = "http://rdmedia.bbc.co.uk/dash/ondemand/testcard/1/client_manifest-ctv-events.mpd";
    if let Err(e) = fetch_mpd(&client, url, "/tmp/BBC-MPD-test.mp4") {
        eprintln!("Error downloading DASH MPD file: {:?}", e);
    }
}

Installation

Add to your Cargo.toml file:

[dependencies]
dash-mpd = "0.1"

License

This project is licensed under the MIT license. For more information, see the LICENSE-MIT file.