TS-Files ...
... are called "Transport Streams" and are the raw MPEG2 data files, which are transmitted via digital cable, satellite or terrestrial digital video broadcast systems. Its muxxed Audio, Video and possibly data streams. Here in Europe those systems are shorted DVB-C, DVB-S and DVB-T.
Now, to join those TS-files, you can use the software "ProjectX". Its most recent version comes in source code, but I have compiled it myself. In general joining could be done via terminal commands, too, as TS files can be put together without any special additional coding. But its much easier via some kind of interface.
Also, the software "MPEG Streamclip" is very handy. It is very easy usable to cut those TS-Files, but in general it can be used for any MPEG2 based file editing and transcoding in any format Quicktime supports.
Both applications are freeware, I put them on my server for download:
http://faddh.dyndns.org/ts/
ProjectX is somehow looking complex, as you not only can join, but also cut, demux and repair those TS files. Don´t fear to use it, though.
To get started, in the lower left part of the application window you´ll find a "+" button to add the files you want to work with. There you add them in the order you want them to be put together. Then you press the "prepare" button and there choose "to TS" as output. Press the "Play" button and here you go.
After you joined them, you can use ProjectX to demuxx - ergo separate the audio and video streams - your files, so you can use them to produce your DVD. Those files are 100% compliant with the requirements for DVD production, so it´s plain easy to work with TS files in order to produce DVD.
Good luck.
