Do you lose quality rerendering mpeg file?

[Hong Kong Phooey]

A newbie question, occasionally I've had to re-edit mpeg files that I'd joined together & had to render the whole file again using the TMPGenc wizard.
Now in those instances,I've already converted the files once when I framserved them from VirtualDub Huffy AVI to TMPGenc PAL VCD mpeg 1 standard.

Will re-rendering the already coverted mpeg 1 file just cause a loss in quality,(eg make it more pixelly),or will it keep it the same quality as it was when it was converted from AVI to mpeg in the first place?

Thanks for anyone's help!

[Craig Tucker]

With every encoding process there is a loss in quality. Why did you have to re-render if you were just joining mpegs together. The merge and cut process in TMPGEnc does not re-render. Just merges and cuts.

Craig

[luxx]

hmm I have to re-encode when I add subtitles, I think there must be a better way to do it... What I do is:

1_Framserve AVI file + subtitles from Vdub to TMPGenc (Result: mpg (VCD) file with subtitles).
2_Cut the mpg in 2 to fit into a VCD (Result: 2 mpg files, but not VCD).
3_encode again the 2 parts to have VCD files(Result: Finally 2 mpg (VCD) 'burnable' files)

Why when I cut he mpg in 2 parts I loose the VCD thing?

Thanks.

luxx

[Hong Kong Phooey]

@Craigtucker. Why do I have to re-render? Well, I've been converting my old home-recorded collection of Robotech,(anime series),episodes. Needless to say, some episodes cut off early in the credits etc.
So on occasions I've had to try & join a couple of different mpegs eg:a full episode until just before the credits roll,& another one where I have a complete "credits" section to finish it off properly.

However,I've been having real hassles trying to do so recently with one particular episode. Basically had about 9 or 10 "fade to black" frames of the main file to connect onto the "credits mpeg".
However, The TmpGenc mpeg tools cut & join results are driving me mad.

I'm either getting 1 of 2 things. First I'll carefully end mark the file at say for example 21mins 41.44secs, & connect to "End credits" mpeg. Instead of slotting together at that moment, TMPGEnc is doing it at 21mins 42secs & ignoring exactly where I've marked the ending,it'll be 1/2 sec to 1sec out which is all the difference. The files join okay,but it means a re-render job using the project wizard's editor,which does a much more finely tuned job.
Bug no.2 would be where the footage joins together fine,but there's an audio "pop" right where the two mpegs merged. Again, the only way to "See" where it occurs & wipe it out is the TmpGenc's project wizard "source editor". The cut & join tool seems pretty clumsy unless you're working in round figures joining mpegs-I really wish that project wizard editor" could be used in the mpeg tools section-it gives visuals, finely edits what you want & you can see the audio....

Why don't I do it in Virtual Dub? Well for some reason, despite the same codecs,AVI_IO settings etc., my original AVI huffy files can never be merged,& I've tried everything to make it work.
Once I've run it through TMPGenc,things can merge fairly well most of the time-if I need it.

I've already done several VCD's, just my latest conversion is proving a real pain in particular. The main file is fine-but I'd rather do a polished job,& do what's wroked previously really!!