Question about movie resolutions

How come in posts for movies or any videos, the author might say 720 or 1080, but the actual resolution of the file is lower than that. Is it a mistake by them or is it just because the source was the indicated resolution?
Thanks.
Answer #1
http://en.wikipedia.org/wiki/Aspect_ratio_%28image%29
Answer #2
720 or 1080
some refer to the source and others refer to the file
if “refer to the file” is what you mean
720 res is actually 1280 as all 720 rips are 1280 wide but may not be 720 high
1080 res is actually 1920 as all 1080 rips are 1920 wide but may not be 1080 high
and aspect ratios that are over 16×9 (1.77:1) will have a lower/smaller height (1.85:1- 691 high for 720 , 2.39:1 – 535 high for 720)
Answer #3
Yeah edwoodweb is correct. Many topics show it to be 720p but it turns out to be 720 * 488 and not 1280 * 720. All those with odd resolution are re-encoded, and not the original quality.
Sometimes some people re-encode to settings of those to get accurate size, so there is different quality and resolution at times.
Answer #4
If it’s a TV show or TV Movie then the video will be full resolution 720p or 1080p but if it’s a studio Movie the vertical resolution will be lower due to the Movie aspect ratio. Encoders remove the black bars because it wastes bitrate and/or increases file size/lowers quality. That is why a studio Movie is unlikely to be full 720p or 1080p resolution.