I am wondering if anyone on this list knows of an easy-to-understand
documentation of the ffmpeg -vf option.
I used to know how to crop a video and resize it, but have not figured out how
to do this with the new way of going about it. I will give an example of what
I would like to do, and perhaps someone could tell me how to do it, probably
with ffmpeg for LINUX.
I often have .mpg video (ntsc North America) that has video 720X480 (the DVD
standard) which has an aspect ration of 4:3. However, the part of interest is
16:9 centred vertically. I want to convert so that it is still 720X480, but
with an aspect ration of 16:9. This means that the top and bottom must be
cropped and then the resulting video expanded (or enlarged) to fill the entire
16:9 720X480 frame. I would like to do this with high quality so I would want
a bitrate of at least 6,000 (but 8,500 would probably be better).
I believe that my ffmpeg command would be something like:
ffmpeg -i INPUT.mpg -vf {something to do the cropping} -{something to make the
size 720X480 with aspect 16:9} -{something to set the bitrate} {perhaps -pass=2
if this would give higher quality results) OUTPUT.mpg
I find the explanations for how to do this to be verycryptic and difficult to
understand. I have not come across anything that really explains most of the
parameters very clearly. I am sure it is very simple, once you understand how
to do it, but I am still at a loss!
I find that most tutorials that I have found seem to be aimed at taking high
quality video and compressing it for posting on the web. I want to retain as
much quality as possible.
Thanks for any suggestions.
Murray
