VOB demuxer: PGCDemux or VOBEdit ?

[gabier]

I am trying to figure out what is the best VOB demuxer, I mean the demuxer that keeps the quality of the original streams. I tried PGCDemux and VOBEdit, demuxing the same VOB file, wich is 4259 MB.

PGCDemux demuxed it in 3.5 mn and output the elementary streams : video 1635 MB, 2 audios each 187 MB.

VOBEdit demuxed the VOB in 8 mn, and the following sizes : video 3382 MB, audios 392 MB each.

VOBEdit is longer but the size of the output is more or less the same as the size of the input, whereas for PGCDemux it is less than half of it. Does this mean that PGCDemux downgrades the quality of the streams ? Or am I using it the wrong way ?

gabier

[manono]

Does this mean that PGCDemux downgrades the quality of the streams ?

Of course not. The various assets are unchanged in any way.

You're trying to compare apples and oranges. VobEdit demuxes entire VOBs. PGCDemux demuxes by PGC (using the IFO). My guess is that there's at least one more PGC in that VOB that wasn't demuxed. Check the other IFOs (if any) for more PGCs, or check the drop-down box of the IFO you're using for the presence of additional PGCs.

[gabier]

Check the other IFOs (if any) for more PGCs, or check the drop-down box of the IFO you're using for the presence of additional PGCs.

I didn't find any. The input is very simple. It is a single VOB output of DVDShrink of a reauthored DVD, with only one PGC (a movie with audios and subtitles).
There are 2 IFOs, the VIDEO_TS.IFO, with no PGC, and the VTS_01_0.IFO with 1 PGC. Nothing else in the dropbox of PGCDemux.

It seems to me that if nothing is reprocessed, a demuxed stream, for instance the video stream of my movie, should be the same size in both cases, should'nt it ?

??

Gabier

[manono]

It seems to me that if nothing is reprocessed, a demuxed stream, for instance the video stream of my movie, should be the same size in both cases, should'nt it ?

Well then, given that it's just a reauthored DVD Shrink job, you'd think so, wouldn't you? But PGCEdit definitely does not process in any way the stuff it demuxes. Maybe it stopped the demux early for some reason, some sort of corruption, maybe. Are the lengths of the 2 outputs different? It's easier to compare by checking the audio lengths than the video lengths, as players almost always give the wrong figures for M2V lengths.

[gabier]

Maybe it stopped the demux early for some reason, some sort of corruption, maybe. Are the lengths of the 2 outputs different? It's easier to compare by checking the audio lengths than the video lengths, as players almost always give the wrong figures for M2V lengths.

You are right, Manono , the audio file is 01:07:57 long, whereas it should be 02:22.45. I am sorry about that. I should have checked from the beginning.
Nevertheless, I probably don't understand how PGCDemux works, for its behaviour looks quite peculiar to me. When I open the IFO, the PGC displayed is : "PGC#01 2:22.45.10". So it knows the time length of the PGC. Then, if I ask for demuxing all the streams and hit "Process!", it starts demuxing, the progress bar goes on until about half way, and then it stops with an info message : "Finished OK". The problem is that it has output only 1:07:57 thus it is not OK at all.
If it has encountered a corruption, as you say, or any reason to stop, it should send an error message, eather to the user or to the log file. It does none of these actions. This is not very pleasant.

Gabier