Qu’est-ce que M3U8 ?
Guide pratique du format de playlist M3U8 et du protocole HLS streaming.
Introduction
M3U8 est un format de playlist UTF-8 utilisé par HLS (HTTP Live Streaming). Il ne contient généralement pas la vidéo, mais pointe vers segments, variantes, clés et métadonnées.
HLS a été introduit par Apple et sert aujourd’hui largement au live streaming et à la VOD dans les navigateurs, apps et plateformes OTT.
Fonctionnement de M3U8
1. Server segmentation
The server splits a video into short TS or fMP4 segments and writes an M3U8 index file.
2. M3U8 index
The playlist records segment URLs, playback order, duration, variants, and related metadata.
3. Progressive download
The player downloads segments in order and starts playback before the full video is available.
4. Adaptive bitrate
A master playlist can provide multiple qualities, so the player switches according to network conditions.
Structure du fichier M3U8
#EXTM3U
#EXT-X-VERSION:3
#EXT-X-TARGETDURATION:10
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:9.009,
http://media.example.com/first.ts
#EXTINF:9.009,
http://media.example.com/second.ts
#EXTINF:3.003,
http://media.example.com/third.ts
#EXT-X-ENDLIST#EXTM3U - file header for an M3U playlist
#EXT-X-VERSION - HLS protocol version
#EXT-X-TARGETDURATION - maximum segment duration
#EXTINF - segment duration and URL
#EXT-X-ENDLIST - marks VOD playlist end
M3U8 vs MP4
Avantages de M3U8
- Supports live streaming.
- Adapts quality to bandwidth.
- Starts quickly without downloading the full file.
- Works well with CDN caching.
- Supports encryption.
Limites de M3U8
- Not ideal for local file playback without an HTTP server.
- Many files can be harder to manage.
- Latency can be higher than direct file playback.
- Older devices may need a compatible player.
- Saving offline is less simple than MP4.
Cas d’usage courants
Live video
Sports, news, events, and game streams.
VOD platforms
Video sites, online education, and OTT libraries.
Mobile apps
Video playback in phone and tablet applications.
Comment utiliser M3U8
Online playback
Open a direct M3U8 URL in an HLS-capable player such as M3U8 Player.
Download and save
Use an M3U8 downloader to fetch segments and merge them when you have permission.
Format conversion
Use FFmpeg or a converter to create MP4 from an allowed M3U8 source.