Frame type encoding for various sources

walkietv · Post by **walkietv** » Wed Jan 03, 2007 11:41 am

hi, please help in this matter.

I am currently using Ulead Video Studio v10 for making DVDs from my own captured files. I capture them with Leadtek's PVR2000 tuner , mainly in 2 modes: Hardware MPEG-2 and Uncompressed AVI.

I was wondering ig there is a rule for frame type encoding for each of these 2 formats. I mean , one of the 3: frame-based, top field first and lower field first.
This is the info for captured AVI:

here for MPEG-2:

about the captured MPEG-2, I notice it is top-field first(tff) and Interlaced(although the setting in the tuner is "progressive"

).

What are the best settings for frame encoding?

respects

Trevor Andrew · Post by **Trevor Andrew** » Wed Jan 03, 2007 12:24 pm

Hi

The basic rule for using interlaced Upper or Lower relates to the capture source not the video file format.

If you are capturing from a Digital Source (DV camcorder) then Lower Field would be the norm.
If you were capturing from an Analogue source (TV tuner for instance) you should use Upper Field.

Interlaced or Frame Based

This depends on your target audience.
If you intend to view your finished movie on the internet/pc screen only, then use Frame Based
If you intend to create a DVD for viewing on a TV then use Interlaced

Trevor

walkietv · Post by **walkietv** » Wed Jan 03, 2007 6:31 pm

trevor andrew wrote: If you were capturing from an Analogue source (TV tuner for instance) you should use Upper Field.

Interlaced or Frame Based

This depends on your target audience.
If you intend to view your finished movie on the internet/pc screen only, then use Frame Based
If you intend to create a DVD for viewing on a TV then use Interlaced

Trevor

thanks trevor!
so, for my .mpg captured trough the analogue TV-tuner I will use upper field encoding in Ulead Video Studio.(if the file is captured upper field, then I should encode with "upper field" also, and if it is captured lower field, i should encode with lower field, right?)

but for my AVI, sorry if i didn't get it right, i should use "frame based" in Ulead right? I'm not talking about the capturing itself, but the encoding in Ulead. No matter if the avi is interlaced or progressive, I should endode Frame based, is that right?
About the purpose, I mainly intend it for DVD player - TV performance, but occasionally it might be needed for PC playing.
thanks again and sorry for my noobing

Trevor Andrew · Post by **Trevor Andrew** » Wed Jan 03, 2007 7:15 pm

Hi

You should use interlaced 'Upper Field' for both Mpeg and Avi files.

Trevor

Post by **Ken Berry** » Wed Jan 03, 2007 9:24 pm

Even though the AVI may indicate it is captured frame based, your intention is to convert it so it can be burned to DVD. If so, and each and every person you intend to give a copy to has a very modern, digital/HD TV, then leave it as Frame Based because those televisions use 'progressive scan' and can deal with Frame Based perfectly as it is. In that sense, they are the same as your computer monitor which plays back Frame Based without a problem.

But if there is a doubt in your mind about the TVs some of the people have, and your AVIs came from an analogue TV card (which they did), then you need to process the conversion from AVI to DVD-compatible mpeg-2 using Upper Field First. That is because it will then pay on old traditional TVs which can only play interleaved video (which is what UFF and LFF are all about). But modern progressive scan TVs have a device which makes them able to display interleaved as well as frame based video. Capisce?

With apologies to Trevor for expanding somewhat on his last answer!

walkietv · Post by **walkietv** » Wed Jan 03, 2007 10:45 pm

it is clear now

thanks to the both of you!

about the avi's, well, nothing tells me they are progressive or not cause in the TV-tuner the option "progressive/interlaced" is grayed out, and as you can see gspot doesn't tell me that either. that has no matter now, but just wanted to ask if conversion from progressive to interlaced is lowering quality.
Most modern players support progressive scan I think and I will ask the "receivant" if his one supports it- so I can encode frame-based, if indeed the progressive2interleaved is lossy.

Post by **Ken Berry** » Wed Jan 03, 2007 10:57 pm

There is a slight misconception here. The AVI *has* to be converted to DVD-compatible mpeg-2, regardless of what field order it has. And in *any* such conversion -- regardless of which field order you choose, including frame-based -- there will be some loss in quality. That is unavoidable since you are applying compression, which means that a certain amount of the original data in the AVI files is thrown away in order to make them into the much smaller mpeg-2 files. But if you keep the mpeg-2 settings at high quality (which in effect means a high bit rate) the quality loss may not be noticeable to the naked eye.

But the basic message is: (1) your AVI must be recoded to mpeg-2; (2) any recoding like that will entail some loss in quality; and (3) it doesn't matter whether you choose frame-based or LFF or UFF.

But sure, if the person receiving the DVD has a progressive scan TV, then use Frame-Based...