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VA_TAPER
23rd March 2005, 18:27
Hello all,

I'm tried and tested many a codec and am really happy with ND AVC. I seem to get an overall better quality picture than even high bitrate MPEG-2 (DVD max settings in TMPenc) when working from SDI imported video from analog sources.

I am trying to find settings that will provide archival type quality for my conversions. My main problem is that in darker areas of the picture I am getting blocking between different gradiations of black and can't seem to get rid of them. All the material has been corrected for the lumiance levels, but it is still an issue.

I am using 704x420 4:3 anamorphic resolution with bitrates up to 3kbps for the video.

What settings are reccommended for the highest quality for archival sources?

Also, a quick side question, I can import an .avs scrip in to recode, but how do I get it to find an audio file as well to mux or convert/mux into the .mp4 stream?

Thanks all in advance for the help.

peace, chris

azsd
24th March 2005, 11:01
video = Mpeg2Source("your.d2v")
audio = WavSource/DriectShowSource/Ac3Source("your.wav")

#do ivtc/etc

video = AudioDub(video,audio)

return video

Latexxx
24th March 2005, 12:09
too complicated.

avisource("video.avi")
audiodub(wavsource("video.wav"))

temporance
24th March 2005, 12:40
Originally posted by VA_TAPER
My main problem is that in darker areas of the picture I am getting blocking between different gradiations of black and can't seem to get rid of them. All the material has been corrected for the lumiance levels, but it is still an issue.This is one of my main bones with H.264: in areas of flattish color (especially dark colors) it seems to generate blocking and/or graduated banding. Suspect this is to do with the 4x4 block size and the way it does DC quantization. I guess you could up the strength of the in-loop filtering to see if it helps.

SeeMoreDigital
25th March 2005, 11:00
Originally posted by VA_TAPER
I am using 704x420 4:3 anamorphic resolution... Why?

All Mpeg2/DVD sources contains either 720x480 (for NTSC) or 720x576 (for PAL) for both 4:3 and 16:9 anamorphic DVD's.

Reducing the vertical resolution looses overall definition, especially if you are intending to view your archived content via a large display screen... at some time!


Cheers

Latexxx
25th March 2005, 11:47
Originally posted by SeeMoreDigital
Why?

All Mpeg2/DVD sources contains either 720x480 (for NTSC) or 720x576 (for PAL) for both 4:3 and 16:9 anamorphic DVD's.

Reducing the vertical resolution looses overall definition, especially if you are intending to view your archived content via a large display screen... at some time!


Cheers

Read the original post!

when working from SDI imported video from analog sources.

SeeMoreDigital
25th March 2005, 12:08
Originally posted by Latexxx
Read the original post! Yes... but is it his source that has a resoulution of 704x420 4:3 anamorphic. Or is it his encode?

I have access to SDI equipment too (most of it is at work) and regually convert analogue 4:3 content to digital 16:9 anamorphic. But what sort of SDI equipment is Chris using... does it have scaling!

Even a camcorder with DV in/out can convert analogue to digital on-the-fly and re-scale the video to 480/576 vertical


Cheers

VA_TAPER
25th March 2005, 12:58
Originally posted by SeeMoreDigital
Yes... but is it his source that has a resoulution of 704x420 4:3 anamorphic. Or is it his encode?

I have access to SDI equipment too (most of it is at work) and regually convert analogue 4:3 content to digital 16:9 anamorphic. But what sort of SDI equipment is Chris using... does it have scaling!

Even a camcorder with DV in/out can convert analogue to digital on-the-fly and re-scale the video to 480/576 vertical


Cheers

The SDI A/D converter outputs 704x480 native as that is from what I've been told the broadcast standard, not the common DVD standard but a DVD standard nonetheless. The converter does no scaling but my SDI input card on the PC can. I see no reason to upscale the content as 704x480 is more resolution than the source (consumer VHS and SuperBeta). Even laserdiscs dont come close to 720 lines of vertical resolution.
After cropping off the scan lines around the frame that are distored due to the tape sync signal, and filtering for noise, using IVTC, decimation (if its not a mixed source), and deinterlacing when needed. I lanczos resize back up to 704x480 for archiving.
So I am keeping the same resolution as the source for the archive.
My big problem is that even with high bitrates (3mbps) I have been unable so far to eliminate the blockiness in deep black gradiations, I am running some test encodes right now with some suggestions to turn off weighted prediction and b-frames, but it'll be a few more hours before I can see the results.
The motion quality and overall quality of the video in AVC is superior to MPEG-2 encodes I have done save for this issue, that is why I am trying to find settings that work for archival purposes, to keep these in the best possible format for the future. I understand I could save them as Huffy avis but I can't afford that type of storage cost.
I tried XviD quant 2 with the 6of9 matrix and the problem was worse there. On a normal montior or projection screen, the problem is not visible much, but on my TFT LCD it is an issue, with LCD screens getting larger and more prominant in the market I want to ensure that I do not encode faults in to the archive.

Hope that helps give you an idea of the issue.

peace, chris

SeeMoreDigital
25th March 2005, 13:20
That's more like it...

Your doing much the same as I do when converting analogue to Mpeg2 (or DVPAL 5:1 compression 4:2:0) via SDI.

Where you confused me is with your 704x420 remark!

Now it sounds to me like you're in an NTSC land. As a matter of interest, can you confirm whether any of your analogue sources contain mattes above and below your image?


Cheers

VA_TAPER
25th March 2005, 13:22
Yes, NTSC land here =)

no matted sources yet but I'm sure some will come.

VA_TAPER
25th March 2005, 13:24
ahhh the joys of PAL DV being the same as MPEG-2/4 colorspace, NTSC DV used 4:1:0 so NTSC DV -> anything 4:2:0 looks like shit, to me at least as its really 4:1:0 after the conversion.

too much color loss.

peace, chris

VA_TAPER
25th March 2005, 13:29
one other note, most of the video I am working with is archival tapes from the band Toad The Wet Sprocket. With the help of the lead singer and several others connected with the band I'm converting them for the internet archive www.archive.org . So you can check out the fruits of this labor once I get done!

Then for my own use I'm going to do some laserdisc conversions that aren't on DVD (When the Wind Blows, british cartoon about nuclear war),(The Fountain Head),(Roger Waters Radio KAOS) etc.

peace, chris

eqbal
27th March 2005, 05:16
can i set bitrate for movie in neroRecode?