Accepted input formats and codecs

This user guide explains which input formats for video and audio recordings are compatible with the u:stream servers.

Audio and video clips are generally optimised to be played locally on a desktop device or other devices. These are only suitable to a limited extent for distribution via streaming. If they are recordings from camcorders, the quality and characteristics can vary greatly.

For this reason, audio and video files are not published directly after the upload, but are processed using a converter for retrieval on the web.

This ffmpeg-based converter supports all common formats (containers) and codecs. Accordingly, only files with the following file name extensions are recognised and processed by the converter:

  • Video: AVI, MPG, MPEG, ASF, WMV, PS, TS, MP3, OGG, SWF, FLV, MP4, MOV, MKV
  • Audio: MP3, OGG

If the AV format is available in a different format or if processing is interrupted due to an incompatible codec, further intermediate steps are necessary in order to make this processable for the u:stream server.

Recordings from digital camcorders

The spectrum of devices used for recordings ranges from private consumer camcorders to professional cameras; This results in great differences in the quality and thus also in the space requirements of the material produced.
(Semi-) professional cameras in particular produce recordings with sizes (>40 GB per hour), that are not suitable for being uploaded to the streaming server unprocessed.

If you edit your recordings, make sure that you choose a sensible bit rate in addition to common AV codecs when saving. The quality is very good even with moderate video bit rates, and a higher bit rate hardly improves the result of the video delivered to the user, if at all.

In the case of recordings from (semi-) professional devices that are not processed, it is advisable to transcode the material into standard codecs and moderate sizes.