From: "Daniel Glöckner" <daniel-gl@gmx.net>
To: Ming Liu <mliu@migmasys.com>
Cc: video4linux-list@redhat.com
Subject: Re: a multichannel capture problem
Date: Tue, 9 Sep 2008 21:07:27 +0200 [thread overview]
Message-ID: <20080909190727.GA2184@daniel.bse> (raw)
In-Reply-To: <48C5948D.5030504@migmasys.com>
On Mon, Sep 08, 2008 at 05:09:33PM -0400, Ming Liu wrote:
> 1. Is there any example codes that I can follow to estimate the frame
> rates using switch channel approach?
Motion (http://www.lavrsen.dk/twiki/bin/view/Motion/WebHome ) is said
to support multiple inputs of one card "at the same time".
I never tried it, though.
> Can I do this by using standard V4L2 APIs, or I will need to deal with
> the driver?
You can do this with V4L2.
Some time ago I made some experiments changing the input at random times
using direct hardware access while capturing. IIRC the chip will skip at
least one complete frame before it continues to capture.
> 2. If I choose a multi-chip PCI based video capture card, is there any
> limit from the bandwidth?
Of course. A few days ago we had a discussion about bandwidth issues when
using 5+ bt8xx cards to capture 640x480 in YUV 4:2:0. When there are
other chips using the PCI bus (f.ex. the harddisk controller), the limit
will be lower.
> Are there any sample codes available?
Motion can handle multiple devices at the same time as well.
> 3. In the program point of view, is there difference between using
> multi-chip card and several single chip cards?
No.
Daniel
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next prev parent reply other threads:[~2008-09-09 19:08 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20080908160012.574456184D5@hormel.redhat.com>
2008-09-08 21:09 ` a multichannel capture problem Ming Liu
2008-09-09 16:05 ` Ming Liu
2008-09-09 19:07 ` Daniel Glöckner [this message]
2008-09-09 19:51 ` Ming Liu
2008-09-30 8:25 ` Vinicius Kamakura
2008-09-30 12:12 ` Daniel Glöckner
2008-10-01 18:27 ` Vinicius Kamakura
2008-10-01 19:46 ` Daniel Glöckner
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