Container Format
Video Container Format
A file format that wraps together video, audio, subtitles, and metadata streams (e.g. MP4, MKV, WebM).
Technical Detail
A video container format wraps video, audio, subtitles, and metadata streams into a single file. MP4 (MPEG-4 Part 14) is the most universal container, supporting H.264/H.265 video and AAC audio. MKV (Matroska) is the most flexible, supporting virtually any codec combination. WebM is Google's open container for VP8/VP9/AV1 video and Vorbis/Opus audio. The container determines seeking behavior, streaming compatibility, and chapter/subtitle support, but does not affect video quality — that depends on the codec and encoding settings.
Example
```html <!-- Container Format: HTML5 video with format fallback --> <video controls preload="metadata"> <source src="video.webm" type="video/webm; codecs=vp9,opus"> <source src="video.mp4" type="video/mp4"> Your browser does not support HTML5 video. </video> ```