Jsummers: Created page with "{{FormatInfo |formattype=electronic |subcat=Video |extensions={{ext|ogm}} }} '''OGM''' (Ogg Media?) is a multimedia container format that builds on the lower-level Ogg for..."

2018-10-24T14:22:44Z

Created page with "{{FormatInfo |formattype=electronic |subcat=Video |extensions={{ext|ogm}} }} '''OGM''' (Ogg Media?) is a multimedia container format that builds on the lower-level Ogg for..."

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{{FormatInfo
|formattype=electronic
|subcat=Video
|extensions={{ext|ogm}}
}}
'''OGM''' (Ogg Media?) is a multimedia container format that builds on the lower-level [[Ogg]] format. Its purpose seems to be to allow arbitrary multimedia codecs to be used in an [[Ogg]] file.

Its use is not encouraged by the people in charge of Ogg. It seems to have been mostly supplanted by [[MKV]] and other non-Ogg formats, while the true Ogg believers restrict themselves to Ogg-friendly formats including [[Ogg Skeleton]].

== Identification ==
See [[Ogg#Identification]] for identification of Ogg in general.

Based on [[FFmpeg]] source code and other evidence, an OGM file is an Ogg file containing at least one "OGM stream". The known OGM stream types all begin with a signature consisting of an {{magic|0x01}} byte, followed by one of the following ASCII strings: "{{magic|video}}", "{{magic|audio}}", "{{magic|text}}", "{{magic|Direct Show Samples embedded in Ogg}}".

The data for the first stream in an Ogg file normally begins at offset 28, so an OGM signature might be found there. But sometimes the first stream is a non-OGM stream, most likely [[Vorbis]], so an OGM file could superficially look like an Ogg Vorbis file.

== Links ==
* [[Wikipedia: Ogg#OGM]]
* https://www.danielclemente.com/ruido/ogm.en.html

OGM - Revision history

Jsummers: Created page with "{{FormatInfo |formattype=electronic |subcat=Video |extensions={{ext|ogm}} }} '''OGM''' (Ogg Media?) is a multimedia container format that builds on the lower-level Ogg for..."