Screen Resolution

[Sakuya]

I was wondering if I were to encode a good quality AVI that has the size 416x304, would it be wise for you to encode it to size 352x240 or 480x480. I am trying to aim for the highest possible quality. Maybe a constant bitrate at 100%. :P Do you lose a lot of quality when you have it at 100% but you're encoding to 352x240?

[andkiich]

Well, the original files resolution is non-standard for something like a stand alone player. If you are going to be viewing the file on the PC, I'd leave it alone.

However, if stand alone player is the next step for you, then I'd say go with a standard res. The general rule of thumb is that the files will look OK going form a high res to a lower, but trying to stretch a low res into a higher res may not give you the quality that you want(referencing the 480x480). I'd say if you want to go VCD, then yeah, you should be fine, SVCD res, you might find the quality lacking.

[Dennis1968]

I would use SVCD 480x480, using TMPGEnc to add borders to keep the resoultion the same.

[Sakuya]

So I should use 352x240 at 100%? I hope the files won't be too large. Is 416x304 more suitable for widescreen or full screen? I'm not too experienced with widescreen and full screen, I'm wondering if the video will come out elongated. Guess I'll have to test.

[RayS]

I second Dennis 1968 with a few qualifications.
Its amazing on these forums how little people know about sampling and TV line resolution. It seems once the world went digital, people began thinking binary.
There is a very famous theorem called the Nyquist Sample Rate Criterion. It basically says that in order to preserve the bandwidth of an analog signal, one needs to sample at least two times the highest frequency component. In practice, one should sample more than 2X. We found in practice that 2.5X to 3X was generally acceptable.
Digital pixels complicate life, but the basic principal still holds. A pair of pixels (or line pair) is similar to a cycle -(cycles per second is frequency)
You generally want to sample at the highest rate possible unless you have precise control over the phase relationship.
So Dennis 1968 is correct so long as you can guarantee that your original pixels will be transferred one to one in phase. If you're off a little bit, then you can start to create aliasing (lets not go there right now). Unless you can insure precise registration, you are always better off sampling at the highest rate (number of pixels) possible. If this video was very important to preserve and I couldn't gaurantee phase, I'd try to transfer it at 720 x 480.
Experiment a little and let us know how you make out. If you own a flat panel TV set, then lets not go there either. Because you are once again re-sampling the sampled imagery. SINC^3

[Sakuya]

Um...I seriously don't get what you're saying... Wouldn't transferring to 720x480 a little too large...? I guess adding borders would work. But would 416x304 be considered widescreen or fullscreen

[Dennis1968]

416x304 if close to what is called Fullscreen

Fullscreen in DVD terms is 1.33:1, 4:3 also 640x480, 800x600x1024x768 etc. you have to keep the pixel aspect ration the same regardless of size. to see what ration it is alway divide the the second number by the first number. 640x480, 4:3, 1.33:1 and so farth is .75.
When 720x480 and 702x480 are stored on a DVD-Video, it is usually played back on NTSC TV set that is always 640x480

416x304 is .73

[Sakuya]

Ok, I did a test. I burned 2 test clips, one at 480x480 and one at 352x240, both at 100% quality. But it seems they both look the same! I can't decide! But 480x480 does have a bit more artifacts than the other one....