Old KVCD Matrix verses new Notch Matrix
 

Kwag,

I don't know if i've made a mistake but i accidentally encode a sample of a TV Capture using the old KVCD matrix for one minutes worth of capture and the resulting filesize came out smaller than the newer KVCD Notch matrix. For 1 minute of capture the old matrix made the file 2 Mb smaller. For a 2 hour film that amounts to 240MB. The details of the encode:

Capture: 720x576 Mjpeg q 19

Script : PixieDust
TemporalCleaner
sampler(60)

Encode: KDVD - 4:3 - CQ 70

My question is - do you think this is specific to my situation or is the old matrix better? Is suppose it could be Pal, or Tv capture related. I will test on a DVD rip later

Hi jamesp,

It shouldn't. The new "Notch" matrix should produce slightly smaller file size than the older matrix, because of the lower quantization on low frequency areas. That is if you keep the same reference CQ on both templates :!:

-kwag

Thats what i thought. Will do some more tests tonight. The CQ was the same on both encodes (in fact - everything was the same apart form the Q Matrix). I only wonder if the matrix or gop structure isn't set up right on the PAL KDVD template

Right, its the same for DVD encodes too. My script:

LoadPlugin("C:\Program Files\DVD2SVCD\MPEG2Dec\MPEG2DEC2.dll")
mpeg2source("C:\Conversions\OrdCrim\test.d2v")
Sampler(60)
Peachsmoother()
LegalClip()

The film - Ordinary Decent Criminal. KDVD encode. The results for 1 minute:

OldMatrix - 16,254,623 bytes
NotchMatrix - 17,031,147 bytes

Almost 1mb difference per minute? 8O
Is this only with PAL? Does anyone else get the same result?

Jim

Hmm.., I'm not sure about PAL Jim, but it was clearly proved here: http://www.kvcd.net/forum/viewtopic.php?t=2073 the quality difference with the new "Notch" matrix. It's really a huge difference on dark and gray scenes. That's why the current matrix superceeded the old one. Do a file prediction comparison ( as on the link above ) and you'll see that targeted at the same file size with both matrixes, the new matrix looks far better :)

-kwag