Variable quality in burnt dvd...?chickenman!

vbimport

#1

i am using tmpgenc plus and tmpgenc dvd author to convert mpg files to dvd’s.

some end results are good and some have a slight blocking effect on dark scenes on the movie and overall.

is it best to increase the bitrates to maximum that will fit on the dvd(which i am doing) or should i just leave it at what it is originally set at by the software(roughly double the original file),or is the problem in converting a 4.3 format to 16.9…is it best to convert to 4.3 if the original file is 4.3i don’t know what the problem is really…??

how can you increase quality when converting,i was thinking about creating larger bitrate files and then shrinking them with dvd shink down to 4.7g for burning.

any help much appreciated… :confused:


#2

You can never increase quality; your source material is what it is. If the original clip was MPEG1 or low-bitrate MPEG2 (or god forbid highly compressed MPEG4), there is nothing you can do to recover ‘perfect’ quality. Every time you reencode with a lossy codec, you will inevitably reduce the amount of information available and further degrade the quality.

That being said, you should of course give the final copy as high a bitrate as possible. It is conceivable that if you are reencoding VBR source to VBR final, the allocation of bitrate might cause a reduction in quality at certain points.

If you want to improve the perceptible quality of the final product, you could try switching to CCE (IMO, a slightly better MPEG2 encoder than tmpgenc). And you could also try frameserving the original through virtualdub after applying filters with avisynth.


#3

It’s impossible to increase the quality of the original file. In fact, each time you transcode your original file, you’ll lose quality. In other words, your DVD will never look as good as the original source file. A “slight blocking effect” is to be expected. Adding DVD Shrink to the mix only adds a second transcode to the process and will degrade the quality even more.

If the source file is 4:3, there’s no need to convert it to 16:9.

It looks to me like you’re already using the best method for conversion (using the max bitrate that will fit on the DVD).

edit: btspm and I wrote our replies at the same time. He’s right, but I’ll leave my answer here anyway.


#4

thanks grey and btspm,thats sorted that …

the files i am converting play in perfect quality dvd on my laptop so i’m going to try CCE or procoder and see the results.

one thing more,i’ve just tried a trial of canopus procoder but it is flipping my mpg files and they are converted upside down,i’ve read on here someone else has had the same problem…how do i fix this??

thanks for anymore advice…

dazza


#5

If you haven’t checked it out before, you might want to hop on over to http://www.doom9.org - They are much more focused on the type of coversion work with A/V formats that you are doing.