Universal Media Server | Forum

This is normal. The files "without size" are those that are transcoded because they aren't supported by your renderer (or at least UMS thinks so). It's not possible to know the size in advance (UMS would have to first do a "test transcode" of the whole file to find the size), which is why no size is available. The same issue is the reason why seeking isn't possible for some renderers when transcoding.

There are two "types" of seeking, byte based and time based. When the size is unknown, byte based seeking/positions aren't available, so only those that can handle time-based seeking supports seeking while transcoding.

The above is a bit over-simplified, but I'm sure you get the general idea. The only thing you can actually do about it, is to make sure that those files actually aren't supported by your renderer. If they are supported, it means they are transcoded when they don't have to be, and the whole issue could have been avoided. A simple way to test it a file is supported is to use the "# TRANSCODE #" folder from your renderer. In there you can manually choose what transcoding configuration to use or not to transcode at all. Try playing the "no transcode" entry in there, and if it plays, it means that your renderer can read the file.

There are many details that determine if a file has to be transcoded or not. The codecs, codec profile and levels are examples of things that can play a role. Subtitles are another issue, only relatively few renderers support subtitles which means that the files often have to be transcoded to have the subtitles "burnt in".

But, if the files play fine from "no transcode", it means that the renderer configuration file is incorrect. You can find information about renderer configuration files and also some examples/user contributions that might work fine for you buy searching this forum. Alternatively, create debug files as described in red above while you play some of the files that are transcoded when they shouldn't, and somebody might look in the log and find the problem for you.