Comments

ScottW wrote on 8/5/2005, 12:54 PM
No.
johnmeyer wrote on 8/5/2005, 1:37 PM
You can encode at less than 720x480 (for NTSC). This includes:

352 x 480 pixels MPEG2 (Called Half-D1, same as the CVD Standard)
352 x 240 pixels MPEG2

More info here:

DVD specs at Videohelp

You can also use an external encoder (like MainConcept or Procoder). They have lots of additional tweaks that let you get pretty good quality, even when you encode more than two hours on a 4.7 GByte disk. I have special settings for the MainConcept external MPEG-2 encoder, if you're interested.

You could encode on a dual layer disk. Also, you could encode on a two-sided disk, if you don't have a dual-layer burner. (This assumes you absolutely need to get everything onto one disk).
TheHappyFriar wrote on 8/5/2005, 4:23 PM
the only way to reduce the size of an mpeg file is to reduce the bitrate. You can reduce the size, but if the bitrate isstill up there it own't get smaller.

If you reduce the size to 1/4 the origional (352x240 instead of 720x480) then reduce the bitrate 1/4 to decrease the file size. Most likely though it will have the same image quality as a 720x480 at quarter the bitrate. :)
johnmeyer wrote on 8/5/2005, 4:42 PM
but if the bitrate is still up there it won't get smaller ...

Ah, excellent point. I forget this one all the time. The bitrate is just that: the number of bits per second. It is the only thing that determines size. However, if you have 1/4 the number of bits to encode, because you reduced the size to 352x240, then if you leave the bitrate the same, the file size will be the same, but you will encode, spatially speaking, at 4x the quality level. Of course, you have fewer bits for each frame, so each frame will not be as sharp, but the artifacts (mosquito noise, blocks, etc.) will be less. To get the same quality as you would for 720x480, you would encode at 1/4 the bitrate. Since you've reduced the spatial resolution to 352x240, each frame won't be as sharp, but the encoding artifacts will be exactly the same as they would be for a 720x480 source encoded at 4x the bitrate.

What I'd recommend is to change the project size to one of the two resolutions I recommended in my last post, and encode a few minutes at 1/4 the bitrate you would normally use. Then, put the project resolution back up to 720x480 (assuming NTSC), and encode at the regular bitrate. See how it looks.

With VHS and SVHS sources, many people encode at these lower resolutions and swear they can't tell the difference. I'm not sure I'd go that far. Try it and see what you think.