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View Full Version : InstantCopy vs DVD2One etc


Richk50
27th March 2003, 02:27
This is not my post I got it from CDfreaks and copied it. Will look for original source. I found it interesting.

"Source: C'T Magazine April 2003 Dutch Version - Page 77

The reason for the extra preformance from DVD2One in comparison with IC7 can be found in a more simple transcoding routine.
In principal both programs work from the same point; they try to take over as much parameters as they can from the original MPEG-file (MPEG-matrix's, GOP-structure, motion vectors).
By doing this they both try to avoid the complicated 'motion estimation' process. However with requantisation DVD2One makes itself a lot easyer then IC7: It doesn't do a video-analasys and strong requantisation on basis of of macroblocks, but just works (like
ReMpeg2) with a uniform compression factor with it uses to resize the frames.

Product: -------------- InstandCopy ----------- DVD2One
Version: -------------- 7.0.0.84 --------------- 1.0.0
Provider: ------------- Pinnacle Systems ------- Erwin van den Berg
URL: ----------------- www.pinnaclesys.nl ----- www.dvd2one.nl
Decoding: ------------ No --------------------- No
Dataformat: ---------- Proprietair -------------- VIDEO_TS-map
Writemodule ---------- Yes -------------------- No
Speed: --------------- Good ------------------- Very Good
Image Quality: -------- Very Good -------------- Good to Very Good
Price: ---------------- 49 Euro ----------------- 47,59 Euro

As testobjects for quality and compatibility controle C'T Magazine used the following movies:
- Bridget Jones's Diary
- Chicken Run
- Enigma
- Lord Of The Rings (SEE, Disc 1 to 4)
- Hollow Man
- Matrix
- Tattoo
- Lola Rennt

Quote:
DaVideo onDVD decodes the whole movie and after that it re-encodes it.
IC7 decodes only up to the level of macroblocks and then aims at the motionvectors
of the original MPEG-stream.
The part of the MPEG-compression that takes the most time, the calculation of these
vectors (motion estimation) is a thing the computer doesn't have to do.
Such trancoders are useally named as: Compressed Domain Transcoder or DCT-Domain Transcoder.
To reduce the the bitratespeed to a tempo that is suited for writable media, the
trancoder requantisizes 'vobtrans.ax' the DCT-coŽfficients (Discrete Cosine Transformation)
with a much bigger raster (much coŽfficients are zero, and most other can directly be
compressed by entropic-coding).
The mistakes that occur with this will be thrown back at the transcoder and it will
correct the requantisation mistakes of the previous frames.
Last but not least, the motionvectors have to be adjusted if images are changed in comparison
with the reference image.
Vodtrans.ax requantise very light and dark blocks very 'rude' and scharp edges and contrasts
have to be processed without much loss.
Instandcopy uses 20 to 30 percent of it's total calculation time, on the quality judgement
of every macroblock.

Quote from the conclusion:
At this moment (if you look at price and preformance) then IC has the advantage.
This because:
- It can make a whole backup of a DVD incl. menu structues.
- Has a reliable buring engine
- It can make (if wanted) (S)VCD's

The complete artice was to long for me for a whole translation and please forgive me
the typos (it's very technical).
Also, Rene B has announced that a 1:1 option will be in the next version and that could
take away the advantage IC7 has.
I think that then they are more or less equal.
Best regards,

Lenco"

brashquido
27th March 2003, 03:26
Interesting read :)

mcentee
27th March 2003, 11:55
Following on from this has anybody got any comparisons of earlier vs later versions of DVD2One ?

There was mention in another thread that the early versions (1.0) reduced bitrate later in the movie to get the space correct, but that this may have been changed in later versions to give a more stable bitrate throughout the length of the movie.