Media Containers

A container determines how audio, video, subtitles, metadata, and other media streams are stored inside a media file.

The container does not determine media quality. Quality mainly depends on the codecs and encoding settings used for the audio and video streams.

For example:

movie.mp4
Container → MP4
Video codec → H.264
Audio codec → AAC

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Example

await NyxConverter.convertTo(
  inputPath,
  outputDirectory,
  container: NyxContainer.mp4,
);

---

Supported Containers

Video Containers

Container	Description
MP4	Excellent compatibility and recommended for most video files.
MKV	Flexible container supporting multiple tracks, subtitles, and chapters.
AVI	Older container with broad legacy support.
MOV	Apple QuickTime container.
WebM	Web-focused container commonly used for online video.
MPEG	MPEG container commonly used with MPEG-1/2 media.
WMV	Windows Media format commonly associated with ASF/WMV files.

Audio Formats

Format	Description
MP3	Highly compatible compressed audio format.
AAC	Efficient compressed audio format commonly used for AAC audio streams.
WAV	Commonly used for uncompressed PCM audio.
FLAC	Lossless compressed audio format.
OGG	Open container commonly used with Vorbis or Opus audio.

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Recommendations

Goal	Recommended Format
Maximum video compatibility	MP4
Multiple tracks / subtitles	MKV
Apple / QuickTime workflows	MOV
Web video	WebM
MPEG workflows	MPEG
Windows Media	WMV
Universal audio	MP3
Lossless audio	FLAC
Uncompressed audio	WAV

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Container vs Codec

A container and a codec are different things.

For example:

movie.mp4
├── Container: MP4
├── Video codec: H.264
└── Audio codec: AAC

Another file could use:

movie.mkv
├── Container: MKV
├── Video codec: H.265
└── Audio codec: Opus

The same codec can often be stored in different containers, depending on compatibility and format support.