interlace from progressive video?

[choirislife923]

while encoding a video, i used HuffyUV, then i placed it in tmpgenc, were i accidentally chose non-interlace and 352x240. on an earlier post, someone said to never use 352x240 for DVDs since only progressive is supported. under normal conditions, i would rerender with the effects, then convert to 352x280i, but i deleted the files cause it was taking alot of space on my HDD (more or less 8 gigs). so should I reencode the 352x240p file thats dvd compliant to 352x280i? my main concern is the quality - i hate noisy and grainy videos.

[xtreemkareem]

The threshold for interlaced video is 280 lines vertical, and this vertical resolution is only supported by PAL (352X288 interlaced VCD, which isn't recommended anyway). NTSC would need a vertical resolution of 480 to be interlaced. Since 352X240p is a valid resolution for NTSC DVD while 352X280i isn't, so keep it at 240p. Anyway, you have already interpolated the data by losing one of the fields and you can never get it back. It won't have any effect on grainyness/noise and actually rencoding at a higher resolution at the same bitrate may only add noise to your video. 240p resolution just doesn't look as sharp as a higher resolution. Keep your file the way it is if you like how it looks. Rencoding will not improve quality.

[choirislife923]

Since 352X240p is a valid resolution for NTSC DVD while 352X280i isn't

but i thought that for NTSC DVD

"352 x 480 pixels MPEG2 (Called Half-D1, same as the CVD Standard)"

https://www.videohelp.com/dvd

thats what its saying. as for the original topic, i'm guessing i will stick with progressive.

[xtreemkareem]

Yes, for NTSC DVD MPEG-2, 720X480, 704X480 and 352X480 are all valid resolutions. However, the DVD standard also supports 352X240 MPEG-1 at 1876 kbps, 48khz audio, often called a VCD-DVD. It should be liusted in the guides. Or you could just make a plain old VCD MPEG-1!