Hot Ice Hilda wrote:when you shrink something, quality becomes better. so yes, resolution does play a part in quality.
Say What?
I'm sorry, you obviously have no idea what the word "quality" means.
First off - quality is a
subjective measure of how good something looks.
If you think shrinking resolution = higher "quality", why not distribute your video in 64 pixels by 48 pixels? Heck, I'm sure your filesizes would be tiny, and those 3072 pixels would all look just perfect!
I'll tell you why - because then you can't see what the hell is going on.
The way compression works when it's scaled over resolution is very complicated. If you took out the whole spatial compression factor it'd be simple - you wind up with a bits per pixel measure requirement depending on your bitrate and resoluiton. But when you throw spatial compression into the mix that all goes out the window because suddenly the bits are redistributed around the frame where they need to be.
Here's a very basic set of rules to go by:
As resolution increases, potential detail increases as well as bitrate required.
If you're trying to reach a desired filesize, removing detail from the picture can IMPROVE picture quality because they become easier to compress and thus the detail that is there is rendered very well, as opposed to the full detail being rendered poorly (i.e. causing MPEG artifacts because too many bits are required).
Thus the best way to achieved the highest "quality" is to find a balance between resolution, picture detail, and bitrate that gives you acceptable filesize and reasonable picture quality.
For me, this is around 480x352 (note that 360 is not a multiple of 16 and thus a no-no) for fullscreen and 512x272 for widescreen. at these resolutions, I can include a lot of detail in the pictures while still maintaining a reasonable bitrate after some prefiltering.
Unless I'm making a VCD (which I won't, because I hate them in terms of quality) I do not encode at resolutions smaller than 480 in the horizontal direction anymore.