To Zig-zag Or Not??

[KF]

I have a dvd that DVD2AVI says is interlaced NTSC 29.97. I've tried to work out the IVTC pattern but it doesn't seem to have one?? It seems to be genuine interlaced blended frames. I would like to encode this as an SVCD using CCE. The following was my initial AVS script using decomb 2.2, avisynth 1 beta 5, the latest mpeg2dec, dvd2avi 1.82 and CCE 2.50

LoadPlugin("decomb.dll")
LoadPlugin("mpeg2dec.dll")
MPEG2Source("myfilm.d2v")
ConvertToYUY2
Telecide
Decimate15
BicubicResize(480,480)

CCE settings Progressive, linear Quantization and ZIGZAG all ticked.
MPEG 2 one pass vbr with Q 60 min 0 max 2000.
I found this was too slow, My set up is a PIII 1Ghz.
So I changed this to the following

LoadPlugin("mpeg2dec.dll")
MPEG2Source("myfilm.d2v")
BicubicResize(480,480)

And unticked Progressive and ZIGZAG. It now takes a third of the time. However, what I would like to know is, is this the right thing to do? Will the resulting mpeg-2 file be correct? Or is the initial method preferable?

[Doom9]

your 2nd script is much faster because you don't use decomb

cce settings have little effect on speed. but in any case you should activate zigzag. progressive should only be selected if the source is progressive (says so in my guides, doesn't it?)

[Deltis]

Hi doom9!

In your DVD2SVCD-guide you just say "The default for the anti-noise filter seems good to me. Also leave the other options checked."

I already opened a thread for this problem but got no answer:

http://forum.doom9.org/showthread.php?s=&threadid=13922

and

http://rilanparty.com/vbb/showthread.php?s=&threadid=13516

Hope you've got an answer :)

cu
Thomas

[kdiddy]

When being chased by an alligator...ALWAYS zig-zag.

[24hourloop]

Originally posted by Deltis
Hi doom9!

In your DVD2SVCD-guide you just say "The default for the anti-noise filter seems good to me. Also leave the other options checked."

I already opened a thread for this problem but got no answer:

http://forum.doom9.org/showthread.php?s=&threadid=13922

and

http://rilanparty.com/vbb/showthread.php?s=&threadid=13516

Hope you've got an answer :)

cu
Thomas

Always zig-zap on natural video (i.e. regular movie). With computer graphics etc. use linear. DVD2SVD uses the incorrect setting. Check the manual that comes with CCE.

[sterilan]

Let me refer to http://www.edensrising.com/dvd2svcd/dvd2svcd_newbieref.html#10

Linear quantizer scale leave default checked
Upper field first leave default checked
Zigzag scanning order leave default checked
Progressive frames leave default checked


And then I refer to
http://www.edensrising.com/dvd2svcd/dvd2svcd_advref.html#cce

Linear quantizer scale default on
Setting quantization scale type
There are two types of quantization scales: linear and non-linear. Linear quantization scale is a method used for MPEG-1, where the quantization scale is allocated linearly. To set the linear quantization scale, select Linear quantization scale in the video settings screen. However, the nonlinear quantization scale is recommended unless there is a special reason.

Zigzag scanning order default on
Setting block scan order
If Zigzag scanning order is selected in the video settings screen, zigzag scan is used when sequencing DCT coefficients. This is a scan pattern used for H.261, JPEG and MPEG-1. For progressive images, zigzag scan may achieve high image quality.
If Zigzag scanning order is not selected, DCT coefficients are sequenced by alternate scan. Generally, for interlace pictures, alternate scan often achieves high image quality compared with zigzag scan.


So what shall a newbe do?