Rendering interlaced videos

[John Rofrano]

[nmou nmou] “if i encode them on vegas with mp4 avc bitrate at 760 kbps witg same resolution will i have almost the same quality as original”

Almost but not quite. You can expect about a 5-to-1 reduction in size from MPEG2 to MPEG4 at the same quality. Most DVD’s are recorded the an average bit-rate of 6 Mbps and 1/5th of that is 1.2 Mbps so you would need at least 1200 kbps to maintain the same quality. How much less quality 760 kbps yields you’ll have to see for yourself.

[nmou nmou] “if i check the interlaced “upper field first” option will my videos keep the same interlaced quality of my dvds ?”

You don’t want to do that. The reason DVD’s are interlaced is because the TV’s you watch them on are interlaced. Your PC monitor, however, is not interlaced so you don’t want your MP4 videos to be interlaced. Keep them progressive if you plan to watch them on your PC.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Nmou Nmou]

But I want to watch them on the TV so how can I keep the interlaced quality ?

[John Rofrano]

[nmou nmou] “But I want to watch them on the TV so how can I keep the interlaced quality ?”

Oh I see… you play them on your PC but it is connected to your TV. In that case you can select Lower Field First if the are NTSC DVD’s and it will maintain the interlacing. Some DVD’s may actually be Upper Field first so you might want to check the field order of the source before you decide but most were Lower Field First.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Nmou Nmou]

My dvd are PAL interlaced upper first i am french so i check “upper field first” but will it keep the originl interlaced process ?

[John Rofrano]

[nmou nmou] “My dvd are PAL interlaced upper first i am french so i check “upper field first” but will it keep the originl interlaced process ?”

Yes, PAL is Upper and NTSC is Lower. Keep them Upper if they are coming from PAL DVDs.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Nmou Nmou]

Ok so i will have the same interlaced quality at all ? Thank you

[John Rofrano]

[nmou nmou] “Ok so i will have the same interlaced quality at all ? “

You should if you bump the bit-rate up to 1200Kbps.

~jr

http://www.johnrofrano.com
http://www.vasst.com