Hi Denis,

This sounds very interesting, and is a quite similar setup to what I would
like to use.

Denis McLaughlin wrote:
>  - While the USB 2 bus can support 8 streaming cams, there seems to be a
> fair bit of jitter in capture time.  The capture utility I wrote
> time-stamps each frame as it receives it, but while the frames are
> generally uniformly spaced 0.066s, there are occasional dropouts and
> periods where frames are snapped very quickly one after another.  I
> haven't done enough testing to know whether this jitter gets worse with
> more web cams or not.

That doesn't sound very good for my application, since I need synchronised
images (audio is not so important for me). Is the timestamp you recorded an
accurate indicator for the capture time, or is it independent from that?

>  - Likely as a consequence of the time jitter in the USB bus (or maybe a
> problem with the cams?  or maybe my capture program?), I'm having a lot
> of trouble trying to synchronize the video streams from the fusions with
> the audio I recorded.  I'm still working on a solution to this one... :(

If the timestamp itself is a reliable measure for the jitter, it might be
possible to leave out or duplicate some frames in post processing.

> My 640x480 MJPEG frames come in around 70k apiece.

Great. Sounds like a very managable amount of data.

ciao
  Pablo
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