From: Johann Schoonees <j.schoonees@ir...> - 2004-11-18 20:06:12
> I=92m trying to implement a system using 2 Digital cameras ( model Basl=
> 311fc ) synchronized via an external trigger.
> The Cameras are working fine in Mode0 however I have problems getting t=
> Mode7 ( scaleable Image) working right.
> When I switch to Mode7 the Framerate drops to 8 =96 12 fps and whenever=
> to adjust the packetsize the image becomes scrambled.
This is one of those libdc1394 gotchas. I assume you are using DMA=20
Changing the packet size also changes the total frame size because=20
some things (like packet size if I recall correctly) are rounded up to=20
page boundaries. There might be some other padding in the packet too.=20
Stuffing a differently-sized image into the same DMA buffers as=20
before obviously causes problems.
The only way I know to change frame rate in Format 7 is to=20
dc1394_dma_release_camera(), and start again with the right packet=20
size in dc1394_dma_setup_format7_capture().
You have reconnect the camera like this every time you change:
* the number of DMA buffers
* the image size
* the pixel colour coding
* the frame rate
Functions like dc1394_set_format7_image_size() and=20
dc1394_set_format7_color_coding_id() are unfortunately traps for the=20
Let us know how you get on.
Johann Schoonees Research engineer
Industrial Research Limited, PO Box 2225, Auckland, New Zealand
Phone +64 9 9203679 Fax +64 9 3028106 http://www.is.irl.cri.nz/
Camwire's home: http://kauri.auck.irl.cri.nz/~johanns/camwire/
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