Re: [Linux-uvc-devel] Maximum framerate with multiple USB 2 cameras?

[Martin Rubli]

Hey Pablo,

The YUV mode definitely leads to a huge amount of data in that case. (if 15 or 30 fps is desired). With a firewire camera at least the capture wouldn't be a problem (no copying involved, all data transfered via DMA)

How is Firewire different from USB in this case?

saving to disk probably is the killer there. At first I'm looking at dumping the

images right to disk.

Likely, but a RAID could certainly handle this.

So a camera with MJPEG output would be definitely a nice thing to have,
because it would probably lead to a manageable amount of data.

Unfortunately, I would like to know a bit more about the capabilities of the recent logitech webcams before I buy one, just to find that it doesn't do

the things I need.

MJPEG support is good news, but there is not information on the web for with resolution and framerates it is supported.

All information from logitech is just marketing bubbles, no hard facts
there, like which mode is available at what image size and frame rate.

I work for Logitech, so feel free to bring on criticism ... :-)

Yes, we know that it's not exactly easy to get detailed information, but
the good news is that we're working on it! We're currently setting up a
server that will host, among other things, a website with just this kind
of details. I've attached an extract. It's a list of supported frame
rates, I think that's what you're looking for. Please keep in mind that it
has some data that still needs to be checked.

The only thing I found out is that the Fusion doesn't support more than 7.5 fps in its highest resolution (in RGB24 mode?):

True, see attachment. Just to be clear: There is no RGB24 mode in the
camera. The camera only knows YUY2 (YUYV) and MJPEG. RGB24 is emulated by
the driver on Windows and so is I420.

Cheers,
Martin

Title: Frame format matrix

Frame format matrix The tables below contain a complete list of supported resolutions for different cameras. [edit] Logitech UVC cameras Note that the frame rate given is always the maximum frame rate. All multiples of 5 below that value are also supported. Cameras with an asterisk still need verification. [edit] Uncompressed YUYV (YUY2) Camera/ Frame rate 160x120 QSIF 176x144 QCIF 320x240 QVGA 352x288 CIF 640x360 640x480 VGA 960x720 1024x576 1280x960 SXGA (4:3) QuickCam Fusion - - - - - - - 10 7.5 QuickCam for Notebooks Pro - - - - - - - 10 7.5 *QuickCam Orbit MP/Sphere MP - - - - - - - 10 7.5 QuickCam Pro 5000 - - - - 30 30 - - - QuickCam Ultra Vision 30 30 30 30 - 30 10 - 7.5 QuickCam Fusion (2006 model) 30 30 30 30 - 30 10 - 7.5 *QuickCam for Notebooks Pro (2006 model) 30 30 30 30 - 30 10 - 7.5 QuickCam Orbit MP/Sphere MP (2006 model) 30 30 30 30 - 30 10 - 7.5 *QuickCam Pro 5000 (2006 model) 30 30 30 30 - 30 - - - [edit] Compressed MJPEG Camera/ Frame rate 160x120 QSIF 176x144 QCIF 320x240 QVGA 352x288 CIF 432x240 480x360 512x288 640x360 640x480 VGA 704x576 864x480 960x720 QuickCam Fusion 30 30 30 30 30 30 30 30 30 15 15 15 QuickCam for Notebooks Pro 30 30 30 30 30 30 30 30 30 15 15 15 *QuickCam Orbit MP/Sphere MP 30 30 30 30 30 30 30 30 30 15 15 15 QuickCam Pro 5000 30 30 30 30 30 30 30 30 30 - - - QuickCam Ultra Vision 30 30 30 30 - - - - 30 - - 15 QuickCam Fusion (2006 model) 30 30 30 30 - - - - 30 - - 15 *QuickCam for Notebooks Pro (2006 model) 30 30 30 30 - - - - 30 - - 15 QuickCam Orbit MP/Sphere MP (2006 model) 30 30 30 30 - - - - 30 - - 15 QuickCam Pro 5000 (2006 model) 30 30 30 30 - - - - 30 - - -

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