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View Full Version : Trailers from DivX.com are strange ... ???

Sagittaire
2nd February 2006, 20:34
http://www.divx.com/movies/detail.php?movieID=68&hp3x3

Direct link for XMEN3 Trailer
http://trailers.divx.com/Fox/XMen3.avi

My XMEN3 Trailer encoding with best possible encoding methodology
http://multimediacom.free.fr/Video/XMen3.avi

DXN trailer encoding
- 720*480 with bad DAR
- 29.970 fps with duplicate frame
- Very low quality (average q4 for PFrame)

My trailer encoding
- 720*400 with good DAR
- 23.976 fps without duplicate frame
- Very high quality (average q2.75 for PFrame)


Quality for your trailers is not a very good publicity for your codec ...
And why not make real full HD high quality trailers ...
http://forum.surdvd.com/viewtopic.php?t=43651
robU*4
2nd February 2006, 21:38
I suppose they'll use Dr. DivX soon for that ;)
SeeMoreDigital
2nd February 2006, 22:06
Jeez.... that DivX trailer has got to be one of the worst encodes I've seen!

You can't go round providing 720x480 samples without adding the correct amount of AR signalling? And what's the deal with releasing progressively encoded content at 29.970fps?


Not very good all round :scared:
unskinnyboy
2nd February 2006, 23:26
DXN's @ Frame 1758 (0:00:58.659) [K] [8.39 MB] :

http://img139.imageshack.us/img139/586/divxxmen3qq.png

Sagittaire's @ Frame 1410 (0:00:58.809) [K] [9.98 MB]:

http://img396.imageshack.us/img396/6992/sagxmen6rq.png

As if the bad cropping + bad aspect ratio in the DXN trailer wasn't bad enough, how come you didn't crop the image to 720x304 either? AR is correct though. Also, for a fair comparison, you should have also encoded in DivX and not XviD (doesn't change the mentioned defects though).

Pretty bad for their PR anyway.
SeeMoreDigital
2nd February 2006, 23:35
To correct the aspect ratio, all DivX had to do was add 8:9 AR signalling.... But that does not explain why they released a 29.970fps progressive encode!
Gej
3rd February 2006, 01:29
I think it has to do with the source we receive. Most of the trailers come on Beta tape, some BetaDigital some BetaSP, in some case, it's obviously several generation old... We do our best to encode using the best posible tools, but in some case the source is just too crappy...
Sagittaire
3rd February 2006, 01:32
As if the bad cropping + bad aspect ratio in the DXN trailer wasn't bad enough, how come you didn't crop the image to 720x304 either? AR is correct though. Also, for a fair comparison, you should have also encoded in DivX and not XviD (doesn't change the mentioned defects though).

Simply to show that if you respect DCT structure (mod16 for all image part) then crop black borders is useless. My sample respect mod16 repartition and you can see perfect transition between real image and black borders.

My post is not to show other XviD vs DivX comparison (I can make the same quality with DivX 6.1.1). I use simply complex and optimal avisynth script for best possible picture quality. The problem here is encoding methodology and DXN use simply very bad encoding methodology because my XMen3 encoding is better than DXN's XMen3 encoding and by far ...


I think it has to do with the source we receive. Most of the trailers come on Beta tape, some BetaDigital some BetaSP, in some case, it's obviously several generation old... We do our best to encode using the best posible tools, but in some case the source is just too crappy...

Certainely but ...

- Bad Aspect Ratio
- duplicate frame
- Bad DCT crop
- Certainely bad avisynth filtering

... are only DXN problem ... :)
unskinnyboy
3rd February 2006, 02:00
Strange that Sagittaire was able to procure good HD material to use as source while DXN who uses these trailers as promotional materials for their codec was able to procure only a crappy source. Perhaps Sagittaire should reveal his sources to them. ;)

@Sagittaire: Not to get into an argument about the merits of cropping, but I do wonder what the average quant would be sans the black. Even if it doesn't make much of a difference to a sample, surely a whole movie encode should benefit from perfect cropping?

P.S: Any link to the HD source you used and also what filtering did you apply?
DigitAl56K
3rd February 2006, 02:12
Sometimes you get good sources, sometimes you don't.
Gej
3rd February 2006, 02:34
We can't really use sources "from the internet"...
DigitAl56K
3rd February 2006, 03:58
We can't really use sources "from the internet"...

Sure we can! Just don't tell anyone!




... oh wait... :S
IgorC
3rd February 2006, 04:54
Apple has an access to high original source for its HD trailers.