From: Lee Revell <rlrevell@joe-job.com>
To: Joel Jaeggli <joelja@darkwing.uoregon.edu>
Cc: Albert Cahalan <albert@users.sourceforge.net>,
linux-kernel mailing list <linux-kernel@vger.kernel.org>,
clemtaylor@comcast.net, qg@biodome.org, rogers@isi.edu
Subject: Re: reverse engineering pwcx
Date: Sat, 28 Aug 2004 14:08:51 -0400 [thread overview]
Message-ID: <1093716530.8611.47.camel@krustophenia.net> (raw)
In-Reply-To: <1093716249.8611.45.camel@krustophenia.net>
On Sat, 2004-08-28 at 14:04, Lee Revell wrote:
> On Sat, 2004-08-28 at 13:53, Joel Jaeggli wrote:
> > On Sat, 28 Aug 2004, Lee Revell wrote:
> > >
> > > How do you account for the Slashdot poster's assertion that it's
> > > physically impossible to cram 640 x 480 worth of data down a USB 1.1
> > > pipe?
> >
> > 640x480 = 307200 pixels
> > x 24 bits = 7372800 bits per frame (.9MB)
> > x 30 fps = 221184000
> >
> > so that's 221mb/s for uncompressed 640x480. dv with 16bit pcm is 25Mb/s
> > typically which is still a bit more than double what you can reasonably
> > push through a usb1.1 port. raw you can push about 1.6 fp/s at 640x480
> > through usb so your compression ratio needs to be order of 15 to 1 make
> > it fit reasonably with room for overhead.
>
> 15 to 1 is impossible without lossy compression.
Disregard, Vojtech's post clears things up.
Lee
next prev parent reply other threads:[~2004-08-28 18:08 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-08-28 16:17 reverse engineering pwcx Albert Cahalan
2004-08-28 16:25 ` Lee Revell
2004-08-28 16:56 ` Albert Cahalan
2004-08-28 17:11 ` Lee Revell
2004-08-28 18:05 ` Vojtech Pavlik
2004-08-28 17:53 ` Joel Jaeggli
2004-08-28 18:04 ` Lee Revell
2004-08-28 18:08 ` Lee Revell [this message]
2004-08-29 21:04 ` Helge Hafting
2004-08-30 7:42 ` Paul Jakma
2004-08-30 12:52 ` Albert Cahalan
2004-08-30 20:23 ` dulle
-- strict thread matches above, loose matches on Subject: below --
2004-08-28 0:52 QuantumG
[not found] ` <20040828012055.GL24018@isi.edu>
[not found] ` <20040828014931.GM24018@isi.edu>
2004-08-28 3:14 ` QuantumG
2004-08-28 3:35 ` Craig Milo Rogers
2004-08-28 3:49 ` Lee Revell
2004-08-28 12:23 ` Vojtech Pavlik
2004-08-28 19:20 ` Chris Meadors
2004-08-28 3:57 ` QuantumG
2004-08-28 12:07 ` Vojtech Pavlik
2004-08-28 6:47 ` Clem Taylor
2004-08-28 12:23 ` Wouter Van Hemel
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