Matroska supports storage of related files and data in the
Attachment Elements can be used to store related cover art,
font files, transcripts, reports, error recovery files, picture, or text-based annotations,
copies of specifications, or other ancillary files related to the
Matroska Readers MUST NOT execute files stored as
This section defines a set of guidelines for the storage of cover art in Matroska files.
Matroska Reader MAY use embedded cover art to display a representational
still-image depiction of the multimedia contents of the Matroska file.
Only JPEG and PNG image formats SHOULD be used for cover art pictures.
There can be two different covers for a movie/album: a portrait style (e.g., a DVD case) and a landscape style (e.g., a wide banner ad).
There can be two versions of the same cover, the
normal cover and the
The dimension of the
normal cover SHOULD be 600 pixels on the smallest side – for example,
960x600 for landscape, 600x800 for portrait, or 600x600 for square. The dimension of
small cover SHOULD be 120 pixels on the smallest side – for example, 192x120 or 120x160.
Versions of cover art can be differentiated by the filename, which is stored in the
FileName Element. The default filename of the
normal cover in square or portrait mode
cover.(jpg|png). When stored, the
normal cover SHOULD be the first Attachment in
storage order. The
small cover SHOULD be prefixed with “small_”, such as
small_cover.(jpg|png). The landscape variant SHOULD be suffixed with “_land”,
cover_land.(jpg|png). The filenames are case sensitive.
The following table provides examples of file names for cover art in Attachments.
|FileName||Image Orientation||Pixel Length of Smallest Side|
|cover.jpg||Portrait or square||600|
|small_cover.png||Portrait or square||120|