Hi, I used a 1920x1080 sequence and mixed in the 1280x720 footage... I want to encode a version that is 1920x1080 but also one that is 1280x720 for the web... Now if I scale up my 1280x720 footage (scale to frame size) ... and then scale it down during the encoding, will I lose some quality or will Premiere recognize that its 1280x720 footage to begin with and never resize it in a destructive manner...?
Another question would be if I scale down 1920x1080 (scale to frame size) on a 1280x720 sequence, is the process destructive and affect color correcting or will I be color correcting the full 1920x1080 image even if it is scaled down..?
will I lose some quality or will Premiere recognize that its 1280x720 footage to begin with and never resize it in a destructive manner...?
No, you'll suffer a quality hit, but more from enlarging than shrinking the image.
If you need a 720p output from footage that is a mix of 1080p and 720p, you're probably better off copying and pasting the edits into a 720p sequence, and shrinking the 1080p clips to fit. That will preserve as much quality as possible.