Notes to the source material:
Only DVD compliant files may be used in GFD. There is no automatic transcoding for avi, divx...
An introduction 'What is DVD' can be found here: http://www.videohelp.com/dvd
remark: GFD (with dvdauthor as authoring engine!) will accept
mpeg streams with typical DVB resolutions (528x576 or 480x480) as well.
But if your stand alone DVD player will also accept them, depends on
Basically elementary video streams (mpv, m2v, m1v) and elementary audio streams (mp2, ac3, dts) are recommended, since it is then guaranteed that these get multiplexed with correct settings. There are a lot of demultiplex utilities to be found in the web like ProjectX, pvastrumento, vobedit, pgcdemux, tmpgenc mpeg tools...
overview for demultiplex and
multiplex programs can be found on videohelp: Video
With dvdauthor as authoring engine you may use ready muxed material also, if it is compatible with dvdauthor (contains navigation packs and continuous time code!). That applies e.g. also to VOB files, if these contain only one film (title), thus if a constant timecode is present. If the (single!) film is distributed on several VOB files, these can simply be "copied together" into a large one from the command line (and thereby renamed in mpg). Example:
copy /b VTS_01_1.VOB + VTS_01_2.VOB + VTS_01_3.VOB
VOB files are checked for the usual problems:
-- Several titles within the vob file (=SCR moves backwards)
-- No sequence header within the first 10kB of the file (=probably the file is only a part of a vobset)
-- No padding bytes at the end of the file a (=probably the file is only a part of a vobset)
-- Elementary video file (like from ChapEditGFD)
If the time code is not continuous, dvdauthor will stop with the error message: ERR: SCR moves backwards, remultiplex input.
With MuxMan as authoring engine only elementary streams in dvd compliant resolution (no SVCD or special DVB resolutions!) are supported. If MuxMan complains about your audio file, you can try to fix it with delaycut.
Typical 'preprocessing steps' for video data of different 'origin':
(Only a short overview! The topic is quite complex - therefore consult the relevant forums for problems)
DVB (all the same whether -S, -T or -C) most DVB recording programs supply no DVD conform files, therefore demultiplex (best with ProjectX or pvastrumento), if necessary cut (Mpeg2Schnitt or Cuttermaran) and add the resulting elementary Streams (video: mpv/m2v and audio: mpa/mp2/ac3) in GFD, or multiplex the elementary streams with mplex or imago and add the resulting MPG file in GFD.
VCD/SVCD (or MVCD/KVCD...): In this format the audio is encoded with 44,1 kHz, therefore also here you should demultiplex the file first (e.g. with TMPGEnc MPEG Tools). The audio file must be transcoded 48 kHz with BeSweet or another audio transcoder. Sometimes you may have audio/video sync. problems with this approach, this may be fixed by using an audio offset in Mpeg2Schnitt or Cuttermaran. The resulting elementary Streams can be inserted in GFD as usual.
AVI (usually DivX in any variant): Must be reencoded! Suitable programs: CCE, TMPGEnc, HC, Quenc, FreeEnc, Avidemux...
A separate processing of video and audio is recommended here also, in particular if the audio is present as MP3 (VBR) stream (can be examined with GSpot or AviCodec). During some tests myself, only Avidemux was able to create a correct multiplexed stream (in Avidemux. there is a special 'treatment' for VBR audio - furthermore Avidemux uses the same mplex as GFD, so that a dvdauthor compatible stream incl. navigation packs is produced). Otherwise save the audio first with VirtualDub or VirtualDubMod, transcode the audio in MP2 or AC3 (e.g. with BeSweet or HeadAC3he), encode with TMPGEnc, Quenc... as video only stream (in TMPGEnc select Stream type: (video only), with QuEnc use the function KillAudio in the Avisynth script). The resulting elementary streams (video: mpv/m2v and audio: mp2/ac3) can be inserted in GFD as usual.
For all programs mentioned here you may find guides and download links at http://www.videohelp.com/tools