avi file properties question

[pohm66]

Just trying to compute this?!?!

I have taken 2 short clips with the same camera hence same codec, one at VGA and the same image again in HD

Looking at the clips I can't see any clarity difference other than in HD there is more frame drops.

The properties are (using mediainfo)
VGA - 640 x 480 pixels, 8.7 seconds, frames 25 ps and file size 3.52mb
HD - 1280 x 720 pixels, 9 .2 seconds, frames 25 ps and file size 4.3mb

It strikes me odd that the HD has 3 times the pixels but only 22% more file size and again image quality seems the same bar frame drops.

Is this a case where some internal fudging of file properties goes on when the images are recorded?

Thanks.....

[mike_ie]

Just trying to compute this?!?!

I have taken 2 short clips with the same camera hence same codec, one at VGA and the same image again in HD

Looking at the clips I can't see any clarity difference other than in HD there is more frame drops.

The properties are (using mediainfo)
VGA - 640 x 480 pixels, 8.7 seconds, frames 25 ps and file size 3.52mb
HD - 1280 x 720 pixels, 9 .2 seconds, frames 25 ps and file size 4.3mb

It strikes me odd that the HD has 3 times the pixels but only 22% more file size and again image quality seems the same bar frame drops.

Is this a case where some internal fudging of file properties goes on when the images are recorded?

Thanks.....

Not necessarily the same codec - or at least, not necessarily the same codec settings with HD as with VGA. It's hard to give a definitive answer without knowing the exact camera used, or the codec it employs, but I would make an educated guess that the compression ratio is very different between both modes.

[pohm66]

Thanks Mike_ie,

That may go part of the way to solve the mystery but still leaves the question about no discernable difference in image quality. I'll have to fire up the PC to get the extra info, tableting at the mo...

The camera is a cudo special car dvr camcorder made by Gator, super cheap and I think repco are selling them.

[mike_ie]

I'd imagine if you played both files on a big hi-def screen, you'd notice a difference in quality. Comparing both on the tablet really isn't going to tell you much.

[Aussie]

That's not true HD either, it's only 720P true HD is 1920 x 1080 res, thats when you'll see a huge difference in size and quality, also as mike says watch them on a large screen that'll show you the difference