jediphoenix wrote:I have ONE of my 848x480 clips that needs to be cropped slightly off the top. Since I wish to do the LanczosResize(960,480) Crop(120,0,-120,0) option from above, and since it needs to be in multiples of 16, is it possible to do LanczosResize(960,496) Crop(120, 16, -120, -0)? This would give me 720x480 and get rid of that black bar on top that needs to be cropped, but I'm just curious if I'm thinking this through correctly or am totally off base with the multiples of 16 thing.
480 is a multiple of 16 (16x30=480). If you crop something slightly from 480, then just resize back to 480. For example:
Crop(120,2,-120,0).Lanczos4Resize(720,480)
The Crop would take it down to 478, the resize goes back to 480. If you took it up to 496, then the proper width would be approximately 992 (I think).
Basically, mod16 only requires the resolution to be a multiple of 16. It only gets more complex if you want to letterbox something, because you can save more bitrate on the compression step if the borders themselves fully occupy their own macroblocks (a macroblock can indeed be of varying sizes, especially with newer video compression formats, but the most established size is 16px x 16px, so if both borders and real video are multiples of 16, then the encoding app doesn't have to work as hard with the separation between the two). It's not
necessary to make sure everything adheres to multiples of 16, it's just a good habit to get into and provides a more optimal encode.