CloneDVD 100% bug

Movie Copy Software
#1

I was just doing Jurassic Park 3 tonight with CloneDVD 2.0.9.4. With the France DTS removed, CloneDVD showed 100%. When I started the process it did not state “transcoder disable”. Looking at the bitrate viewer I could see it was still transcoding, and at a noticable amount. I then remove the director commentary in addiction to the France DTS and it still was 100%. The trancoder was still turned on. I went back and set the taget size to 9000mb and finally it stated the transcoder was disable. I probably didn’t need to set it that high by I just did it anyway. I was using the default DVD-5 setting of CloneDVD that always yeilds the right size.

This seem to be a bug that need to be fixed.

#2

Hi,

In order to interpret your observations it is useful to state two facts about CloneDVD:

  1. The Quality displayed during the stream selection is merely an estimation.

  2. The reduction rate displayed in the bitrate viewer does not distinguish between real
    data compression and removal of redundant data from the video information.

Given these facts the following questions (which are motivated by your observations)
may be answered:

  • Quality bar shows 100% but the transcoder is not disabled?

The transcoder is disabled if and only if CloneDVD concludes WITHOUT considering the
estimated Quality that the target size will be sufficient.

  • Quality bar shows 100% but the transcoder actually applies some compression?

This may happen if either the intial Quality estimation is inaccurate or the transcoder
is removing redundant data (which will not affect picture quality).

In one of the next versions we will add a refined initial Quality estimation.
Hope this helps.

Gor

#3

1.) As I stated It read 100% and transcoded when only one dts track was removed.
2.)Then even with one dts track and the directors commentary(another 250-300mb) removed it read 100% and transcoded.

3.)After setting the target really high and leaving the directors commentary in it stated transcoder disabled and the final result was well under dvd5 size.

So in the first two attempts it was transcoding something that was really far from needing transcoding.

#4

Hi,

As far as I can see the following is happening:

  1. one dts removed, target size = DVD-5
  2. one dts and directors comments removed, target size = DVD-5

CloneDVD estimates that the quality is 100% (we know this is correct because of
your third test). It still passes the data through the transcoder because the
target size will only be sufficient if the initial Quality estimation is correct
(which CloneDVD at this point really cannot be sure about). The transcoder finds
that nothing has to be compressed but nevertheless removes existing redundant
information from the video data.

  1. one dts removed, target size = really high
    CloneDVD concludes (without having to rely on the Quality estimation) that the
    target size will be sufficient: the video data is not processed at all.

The picture quality of 1. and 3. should be identical. If this is not the case and
the transcoder is removing anything else than redundant data then this is certainly
a bug. It would be very helpful if you could repeat the tests 1 and 3 and send the
according logs to bugs@elby.ch.

Thank you,

Gor

#5

Probably I should add, that when gor says “redundant data” he really means it.
I recently learned, that the bitrate graph shows the overall video bitrate.
If the transcoder removes padding bytes, the resulting bitrate decreases, and you might think, that the quality decreases because the bitrate of the resulting video is less than the original.
This is of course NOT THE CASE.
(I didn’t knew this unless gor recently explained it to me)
So, the bitrate graph can in fact be misleading, because the conclusion bitrate equals quality is NOT true.
Sigh.

#6

Thanks
Sound like a good explanation of what I was seeing.