we are working on a project where we capture live video from a DV
camcorder to a buffer.
From this buffer we play back the frames with some not-too-
We intend to go from DV to 720p or 1080p, budget permitting.
Playback starts before capturing has ended. So it is read-while-write.
The delay between capture and playback is 4 to 10 minutes.
So the buffer has to be disk based, not RAM based.
We chop the footage up into one minute segments, to deal with
and writing, and to deal with variable delay times.
No problem here.
We want to store the frames on disk in compressed form, to reduce
Ideally we capture a DV compressed frame from FireWire and store it
as-is on disk.
This we managed to do with WinDV. http://windv.mourek.cz/
In fact this is what most capture apps do, like the one you have in
iMovie or FCP.
The special thing about WinDV is that it does the chopping for us,
every N frames.
We did not manage to do this with [jit.dx.grab]. It is possible to
capture frames to disk
without decompressing and recompressing this way, but it is not
possible to chop up
the incoming stream. if we try to change the file captured to, by
first closing the current file,
and opening a new file, all within one frame as not to drop any, we get
"jit.qt.grab error -9402 setting bottlenecks"
The problem with the WinDV solution is that it is not possible to
into one idiot-proof max standalone.
Right now we have a very arcane solution to control WinDV from max,
which is easily broken.
Does anyone here have a solution to capture and chop a DV stream to
disk under max control?