Transcoding Media

The device you play back media on might be a powerful desktop PC or maybe a mobile phone. These devices are quite different in several important ways.

Desktop PCs usually:

  • Have an extremely powerful processor and so it can process high-resolution files with ease
  • Can play a broad array of media encodings (H.264, VC-9, WMV, etc.)
  • Is usually attached to a high-resolution display

Mobile Devices usually:

  • Have a low powered, power efficient processor that isn't capable of processing high-resolution files smoothly
  • Have a restricted set of media types it can play back (H.264)
  • Have a small, lower-resolution integrated display

Mobile devices are still in their infancy and are not nearly as powerful or flexible as a desktop PC. They have special requirements when it comes to playing back media. Ideally, the media should be sent in:

  • The ideal resolution
  • The right media encoding (H.264, etc.)
  • A compatible file container

The Server acts as a Universal Translator. It understands what types of file and format–language if you will–a particular client can handle and translates your media into that language. This process is handled by a Transcoder. The great thing is, you don't have to worry too much about this.

There are some things that you need to know around controlling the transcoder, but they're easy settings.

Old and Universal Transcoder

There are currently two transcoders built into the Plex Media Server:

  • Plex Transcoder: The original Plex Transcoder is based on FFMPEG — as is the new one. As the Server has evolved, development of the original Plex Transcoder has stopped and it will be phased out. It is still included with the Server for compatibility reasons.
  • Plex Universal Transcoder: The original Plex Transcoder will be replaced completely by the Plex Universal Transcoder. It includes all the smarts of the old transcoder but is much more powerful, faster and smarter. If you see an option in a client to use the Universal Transcoder, it should generally be enabled. If you're having problems with certain media, try turning the Universal Transcoder off.

Full Transcode

Media that is incompatible with your device will be transcoded to a playable format. The process is automatic and you don't need to worry about specific details. However, there are some things that happen during transcoding that deserve your consideration.

  • Processor Usage: Transcoding a media file can be CPU intensive. Generally, the more powerful the Plex Media Server's CPU the better, as transcoding is a CPU intensive process. If you have a choice between adding more RAM (assuming there's enough RAM for the operating system to run well) or a faster/better CPU, choose CPU for better Plex transcoding performance.
  • Disk Usage: The transcoding process uses temporary disk storage for the converted media. If you're using Mobile Sync, or your Plex Media Server is transcoding for several users, it can use gigabytes of temporary storage. By default, the temporary files are stored on the OS boot disk. This can cause problems if your boot drive is very small (e.g., a small SSD). You can change the location for the temporary files in the Plex Media Server settings.

Related Pages: Plex Media Server > Server Settings > Transcoder