From: Alan Cox <alan@redhat.com>
To: video4linux-list Mailing List <video4linux-list@redhat.com>
Subject: Re: V4L1: what's the meaning of video_window.chromakey?
Date: Wed, 24 Dec 2008 14:56:56 -0500 [thread overview]
Message-ID: <20081224195656.GA12626@shell.devel.redhat.com> (raw)
In-Reply-To: <20081224140706.GA475@geppetto>
On Wed, Dec 24, 2008 at 03:07:06PM +0100, Stefano Sabatini wrote:
> My guess is that V4L is using the simplest possible chromakeying
> algorithm, so that it copies each pixel from the capture buffer to
> the destination buffer with a value different from
> video_window.chromakey.
Chroma key is supported just for hardware that does it. Mostly old ISA hardware
could do chromakey overlay but nothing else. I think the PMS is the only card
with V4L1 one support that ever had chromakey in a production kernel.
Its also analogue side chromakey so "kind of the same shade as" rather than
24bit match.
Alan
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prev parent reply other threads:[~2008-12-24 19:56 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-24 14:07 V4L1: what's the meaning of video_window.chromakey? Stefano Sabatini
2008-12-24 19:56 ` Alan Cox [this message]
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