experts help make decision, which method to convert?

[jhr1948]

hello, i've searched for answers, but did not seem to find my exact situation(even googled, but nothing). please be nice, i'm still a noob
Last year i bought a canopus advc-100 for the purpose of archiving shows from my satellite. this method works fine, and i end up w/a dvd that is compliant w/my standalone. recently, i bought a dirctivo receiver, and a friend fixed it so i could extract shows directly. extracting a show does not alter the mpeg 2 file at all. so it's exactly how the tivo stored it bit per bit. problem w/ extraction is that the mpeg2 stored is a 480x480 resolution and my standalone does not play it. I have thought of 2 methods i can make the mpeg 2 dvd compliant.

1. the way i was archiving, use the advc-100 to transfer the show to my pc, i end up w/a dv avi that has a resolution of 720x480, edit in vdub, encode in tmpenc and baaammmm ... dvd compliant.

2. new idea(w/a few questions): extract very perfect, untouched mpeg2 from tivo(if it weren't for that darn 480x480 resolution). then open in vdub-mpeg2 and save it as avi uncompressed. the shows end up only being about 13 to 20 minutes after editing, so hard drive space is not an issue. i guess this brings up one question, that i didn't seem to find an answer for. if i save the mpeg2 as an uncompressed avi, will it degrade in quality? and if it doesn't degrade, are there some settings i should be aware of to keep the perfect quality? also, i assume the avi will still keep the original 480x480 resolution. so when i go to encode the avi to mpeg2, i will need to change the resolution to something like 352x480, correct?

which one will result in better quality? i assume there will be little difference between the 2. as far as time goes, it seems they will both take just as long. the reason i wanted to shy away from the canopus was the dv codec. i notice its a bit darker and the reds seem oversaturated. with method 2, i would save as an uncompressed avi, so i shouldn't have to worry about the dv codec. any opinions are welcome. sorry for such a long post

[indolikaa]

That's an excellent question. You may have to experiment with this one and see what you think of the results...

If it was me, I'd rip the streams and decompress them into *.avi files for further processing and encoding. I would then author them at 352x480.

You have mentioned that the TiVo captures the stream at 480x480. The last time I checked (and we've discussed this extensively on this forum) DirecTV was using multiple frame resolutions, anywhere from 352x480 up to full D1. How sure are you about this 480x480 resolution?

[jhr1948]

thanks for the quick response
so far, i've extracted about 3 files and all were 480x480.
i also think to try decompressing to raw avi, but i've never seen anyone note whether the avi would be an exact replica of the mpeg (since there isn't any additional compression). at least that's what i'd assume(however, i'm still new to all this so i don't trust all of my thoughts hehe).

[indolikaa]

I'll leave that thought to others with more technical experience. You might be losing a very slight amount of quality by decompressing from MPEG to .avi, but I can't imagine how...

[jhr1948]

hey thanks again for input
i also see many people say that every time the file is changed there is a reduction in quality. i'm just curious how much if it is changed to an uncompressed avi.
one thing seems certain, the uncompressed avi will probably suffer less than if i transfer the file via the advc-100 which of course uses dv codec. like i mentioned, the dv codec just seems a bit dark and reds are saturated.
i'm going to have to give up tonight, it's late. i'll check back in the morning

[redwudz]

I don't know what the audio format or the bitrate of the MPG is, but since 480x480 is a SVCD format, I was wondering if it could be transcoded with something like SVCD2DVD into a DVD format?

[duhmez]

If you save uncopressed it is a perfect copy, period. I suggest you compress with huffyuv codec, it's still perfect copy but about 1/3 the size. Huffyuv is an avi codec that is lossless, and it is free.

(In the codec options as long as you choose any of the rgb compressions and it will be perfect. I recommend you hunt down huffyuv version 2.1.1 there are soe issues with 2.2 at the moment (Apr 18, 2004)

Then use tmpgenc to encode the final output. start with a dvd template, unlock it, and tweak it up a little as youisee fit. Also I recomend 352x480 res and 2500-3500 kbps video bitrate, 2 pass vbr.

[jhr1948]

hey thanks for the responses, this forum is a blessing. i've learned so much just by reading (i usually can find my questions by searching).

just out of curiousity, do i lose much when i encode the 480x480 avi to a 352x480 mpeg? also, i haven't tried it, but are any dvd players picky about half dvd resolution?
thanks

[jimmalenko]

i've learned so much just by reading (i usually can find my questions by searching).

My hat goes off to you, sir. If only more NOOBs were like you instead of posting mindless questions...

[jhr1948]

hey thanks for all the help. i believe i'll give the 2nd method a try. just a few more questions(and i won't bother anymore):
1. i forgot i could resize the avi in vdub-mpeg2. does matter at what step i resize the 480x480 to 352x480? in other words, is it better to resize when i save as an avi in vdub or should i resize when i am encoding the avi to an mpeg? or does it really matter?
2. i noticed different options in the both audio & video tabs in vdub, specifically: full processing mode and direct stream copy. if i want to take that mpeg and save it as an untouced avi, does it matter what mode i use?(direct stream or full processing)
3. final question, i promise: i asked previously whether changing the resolution would hurt the quality. i assume it won't really change much, but just curious.

[jhr1948]

hello again,
i think i found the answers to 2 of my last questions. but one of them i can't seem to find.
at what step would it be better to resize the video(from 480x480 to 352x480). should i resize in virtualdub-mpeg2 or in tmpgenc? or does it really matter?

[duhmez]

Do it in virtualdub. Use one of the precise resizers, NOT nearest neighbor.

Losing quality @ 352x480? A little yes, but you wont notice it when viewing on your TV. And 352,480 that is requried for DVD, and no payer wil have a probelm with that res.Also do a forum search for
"determine field order"
This is impottant step you need to know before you encode to mpg.

[jhr1948]

thanks so much, i should be trying this soon, so wish me luck