What is "x24" in 1280x720x24

gogiants wrote on 10/12/2008, 3:30 PM

I am going to kick myself because I feel like I used to know this, but:

I have some MJPEG files from a camera that Vegas reports as being "1280x720x24" in resolution.

Is the "x24" part the frame rate?

Thanks!

Comments

gogiants wrote on 10/12/2008, 3:49 PM

OK, so I answered part of my own question... the video is 30 fps, so the x24 is not frame rate...

Tim L wrote on 10/12/2008, 4:06 PM

24 is the number of bits per pixel -- 8 bits per color x 3 colors (probably red, green, blue)

1280 pixels wide, by 720 pixels high, and each of those pixels has 3 bytes dedicated to describing the color of that specific pixel.

Now if you see 1280x720x32, the "extra" byte of color information is the "alpha" value -- the transparency of that pixel, from 0 (completely transparent) to 255 (completely opaque).

Video files typically do not have 32 bits (except maybe uncompressed files or some specialized Quicktime files, I think), but graphics like png's, etc., created in photoshop might have red/green/blue plus alpha in order to support the transparent (checkerboard) sections on the image.

Tim L