George Lockwood
February 13th, 2010, 12:53 PM
we're capturing large images with an industrial camera used a lot for astronomical or
medical imaging. the images are 2048x1536. they capture directly to an avi file. the
software sets the file's frame rate at 10fps because that is the stream rate from the
camera. we are, however, not capturing the entire stream. we are capturing triggered
images, as in timelapse. we are also editing in a 24p environment and want our files to
match that with a frame rate of 24fps. we are editing on final cut.
i've tried using avifrate to change the files' frame rate and it works fine in windows.
the files are not correctly read at the new rate on the mac by qt player or final cut,
though. they both see the original 10fps rate. it doesn't appear to be an os level issue as
mpeg streamclip sees the new 24fps rate on the mac.
i tried making a ref movie and opening it in dumpster to view and edit the mov file
header info but have no idea, at this point, what to change. the relevant info seems
to be:
mvhd/timeScale 600
mvhd/duration 408000
edts/elst/Track Dur 408000
edts/elst/Media Rate 1.0
mdia/mdhd/timeScale 600
mdia/mdhd/duration 408000
mdia/minf/stbl/stts/sampCnt 6800
mdia/minf/stbl/stts/sampDur 60
the test file here has 6800 frames in it. it should run about 00:04:43:00. it currently
displays in qt player as 10fps with a duration of, something like, 00:11:20:00. i have
not found a combination of changes i could make to the info here that yields
24fps with the correct media length, data rate, and running time.
i'm posting here because i found a similar post here, although, it did not address
my issue closely enough to get me past this problem. seems like when i change one
thing, two or three change, and in differing ways. if i make a series of changes, it
might not do anything at all. very confusing.
can anyone here offer a formula as to how qt derives such info? i will have a lot of
this to do and it will save huge amounts of time to be able to make the necessary
changes in this manner instead of rerendering the files. many will be 400+gb.
thanks
medical imaging. the images are 2048x1536. they capture directly to an avi file. the
software sets the file's frame rate at 10fps because that is the stream rate from the
camera. we are, however, not capturing the entire stream. we are capturing triggered
images, as in timelapse. we are also editing in a 24p environment and want our files to
match that with a frame rate of 24fps. we are editing on final cut.
i've tried using avifrate to change the files' frame rate and it works fine in windows.
the files are not correctly read at the new rate on the mac by qt player or final cut,
though. they both see the original 10fps rate. it doesn't appear to be an os level issue as
mpeg streamclip sees the new 24fps rate on the mac.
i tried making a ref movie and opening it in dumpster to view and edit the mov file
header info but have no idea, at this point, what to change. the relevant info seems
to be:
mvhd/timeScale 600
mvhd/duration 408000
edts/elst/Track Dur 408000
edts/elst/Media Rate 1.0
mdia/mdhd/timeScale 600
mdia/mdhd/duration 408000
mdia/minf/stbl/stts/sampCnt 6800
mdia/minf/stbl/stts/sampDur 60
the test file here has 6800 frames in it. it should run about 00:04:43:00. it currently
displays in qt player as 10fps with a duration of, something like, 00:11:20:00. i have
not found a combination of changes i could make to the info here that yields
24fps with the correct media length, data rate, and running time.
i'm posting here because i found a similar post here, although, it did not address
my issue closely enough to get me past this problem. seems like when i change one
thing, two or three change, and in differing ways. if i make a series of changes, it
might not do anything at all. very confusing.
can anyone here offer a formula as to how qt derives such info? i will have a lot of
this to do and it will save huge amounts of time to be able to make the necessary
changes in this manner instead of rerendering the files. many will be 400+gb.
thanks