[FFmpeg-user] display size vs coded size

[Carl Eugen Hoyos]

Terry Bolands <tbolands <at> yahoo.com> writes:

> Is there anyway to specify a display size that differs 
> from the coded size with ffmpeg? So in other words if I
> want to tell a player to only show some of the coded 
> video, but keep that video in the file so it could be
> retrieved later, is there a way to do that?

I am not sure I understand your question:
Are you searching for -vf crop / -vf pad ?
Or do you want to know how to ask libavcodec 
programmatically (from within your video 
player application) to not decode the complete 
frame, but only a part of it (I don't think this 
is generally possible)?

Carl Eugen