Resolution question, again...

andy

Sorry, I know that there is a lot of topics talking about this, but I readed most of them and I still could not find a clear and reasonable answer.

I always capture from a analog TV signal (NTSC). To reach the best quality during the post processing (deinterlace, filters etc), I think that the best it to capture at max resolution (720x480), process the video, and then resize it.

Considering that my final format is XVID, I'm not targeting any standard (like DVD standard), and my capture card is capable to capture the real resolution (and not only half the vertical resolution like some cards). Which would be my resize resolution to achieve the best (visible) quality ?

One more information...

People say that the closest resolution from analog TV cable would be something like 352x480. So, if I use this as my final video resize, it would be better to capture at 704x480 instead of 720x480, since 704/2= 352 ?

As you will encode in XVID finally, means in a PAR 1:1 target pixel aspect ratio, then you also should capture full NTSC TV in a PAR 1:1 Pixel aspect ratio. Means 640x480 (cropped 648x486 active Pixels).

704 gots a PAR of 4320/4739 at 711 active pixels - same in case of 720
~f76998/video/co...nversion_table

Sorry, but could you be more clear ?

About which format I should capture and resize.

If your question is not about AR (who's answer is farily much 640x480 as stated) then ...

Very difficult question to answer.  Let me repharse it to let you know why ....  Which will turn out better ....

A. Capture 720x480 film or TV, cartoons or sports, with unknown hardware, resize it to 640x480, process it a bunch, encode it.

B. Capture 640x480 film or TV, cartoons or sports, with unknown hardware, process it a bunch, encode it.

Easiest thing is to run a test and look for a difference.

Well, sorry, that was not what I was trying to ask...

My bitrate is limited, around 1200, so I don't want to keep my video with a high resolution, like 640x480. BUT, I did some tests and I think its better to capture at a very high resolution (like 720x480), and then resize it to a low one (480x360 for example).

My question is: Which would be the most correct high resolution to cap and the most correct to resize ? Considering that I'm capturing from a analogue cable TV, and my capture card performs horizontal scaling (Asus TV Tuner with Conexant cx2388x chipset). If possible, please, let me know the resize AVISynth script to do that.

There is no all-purpose 'best' resolution to cap at, but I'd suggest just capping at full height and with whatever horizontal resolution your final video will be in, then after IVTCing or deinterlacing (whichever's more appropriate for the content) you'll only have to resize vertically. Thus if you're aiming for 480x360, cap at 480x480 -gt; deinterlace/IVTC -gt; resize down to 480x360.

Originally posted by vigi_lante
My question is: Which would be the most correct high resolution to cap and the most correct to resize ? Considering that I'm capturing from a analogue cable TV, and my capture card performs horizontal scaling (Asus TV Tuner with Conexant cx2388x chipset). If possible, please, let me know the resize AVISynth script to do that.

Post a script and I will change the numbers ...