Re: [libdc] libdc1394 error: packet size is zero

[David M. <dcm@MIT.EDU>]

On Fri, 2008-02-22 at 14:25 +0100, Maarten Vergauwen wrote:
> This is remarkable!
> I changed grab_partial_image such that set_roi was replaced by the
> four functions you mention without any sleep in between. From that
> moment on I never experienced any problem with this executable
> anymore! How can this be if set_roi is simply a convenience function?
> I changed it back and the errors appeared once more...
> 

I have just committed a change to SVN that will do a usleep(500) between
retry attempts of read or write commands.  This only applies to juju.

I believe this may fix the instability you were seeing with set_roi().
Could you try again and let me know?

> When I performed this change in my own code, the bad initialization
> problem also disappeared. Contrary to the grab_partial_image example,
> however, I occasionally still encounter the problem that the camera
> initializes just fine but returns a size of 0x0 or 0x2 pixels when
> asked for its size with dc1394_format7_get_image_size.
> 

I'm curious to know if my change will improve this behavior or not.

Thanks,

David