List:       linux-video
Subject:    [video4linux] Video capture card advice
From:       Aaron Colwell <colwaar () charlie ! cns ! iit ! edu>
Date:       1998-08-05 23:55:23

Problem: Leaving work to go back to school. Want to continue contributing
to video4linux, but dont have a video capture card of my own. I am looking
for advice on what to buy. I'd prefer to have a card that not only does
capturing, but can also output video. I've been looking at the Iomega Buz
and the Matrox Rainbow runner, but I have a few questions that I wanted to
get some opinions on. The Buz seems pretty cool and I have seen a few
people on the list comment about it, but I am concerned about some
information I saw in the documentation for the Zoran chips that it uses.
According to what I read it appears that to do frame capturing you need a
contiguous block of memory to store the frame. This concerns me because I
am afraid that I am going to have to allocate huge blocks of contiguous
memory for my driver and as I pointed out in an earlier message to the
list I can only allocate 128k of contiguous space. This also may cause
difficulties in writing a driver for the newly proposed video4linux API.
Large amounts of contiguous buffers are going to be hard to come by. My
concern about getting the Matrox card is that I have been having a hard
time getting information about what chips the card uses and I have a
feeling that Matrox is not very forthright with its hardware information.
I remember how long it took to get X drivers for my Matrox card. Here at
work I've been using Intel Smart Video Recorder III cards, but they dont
have a video out. I've become relatively familiar with the bt848 driver
and wouldnt mind working on converting it to the new API proposal, but I
dont want to buy a bt848 card unless it has an output on it. Are there any
such cards that have an output and a bt848? Also please keep in mind that
I am a poor college student and that I cant really consider anything over
$250. Any suggestions about what I should buy or information about other
cards that I should consider would greatly be appreciated. I'm all anxious
to start contributing, but I need to get some hardware first. Thanks in
advance for any information that you might be able to give me.

Aaron 

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List:       linux-video
Subject:    Re: [video4linux] Video capture card advice
From:       Daniel Dunbar <ddunbar () diads ! com>
Date:       1998-08-06 1:35:56

Aaron Colwell wrote:
> 
> Problem: Leaving work to go back to school. Want to continue contributing
> to video4linux, but dont have a video capture card of my own. I am looking
> for advice on what to buy. I'd prefer to have a card that not only does
> capturing, but can also output video. I've been looking at the Iomega Buz
> and the Matrox Rainbow runner, but I have a few questions that I wanted to
> get some opinions on. The Buz seems pretty cool and I have seen a few
> people on the list comment about it, but I am concerned about some
> information I saw in the documentation for the Zoran chips that it uses.
> According to what I read it appears that to do frame capturing you need a
> contiguous block of memory to store the frame. This concerns me because I
> am afraid that I am going to have to allocate huge blocks of contiguous
> memory for my driver and as I pointed out in an earlier message to the
> list I can only allocate 128k of contiguous space. This also may cause
> difficulties in writing a driver for the newly proposed video4linux API.

actually no... when you want the iomega buz to dma to memory you send it
an address to a fragment table which is basically just a list of the
address and length of every segment that the iomega buz should write too and
tell it which fragment is the final one.....  you define four code (compressed
data stream) buffers this way and it will round-robin writing to them.

> Large amounts of contiguous buffers are going to be hard to come by. My
> concern about getting the Matrox card is that I have been having a hard
> time getting information about what chips the card uses and I have a
> feeling that Matrox is not very forthright with its hardware information.

the iomega buz people seem sorta middle ground.... one tech engineer said
he was going to refer me to some people in the company... the aren'y overtly
friendly, but it seems to me that their policy would be as long as you don't
want any official support theyll contribute informally.

also, all the info for the chips seems to be available on line.... the
onboard advansys card works out of the box with the linux drivers, and the
rest is the zoran 36057/16 chips some phillips chips, and an i2c bus... (all 
of which have pdfs available)

not only that, but the iomega buz card has video in & out at high
resolutions (though no tv tuner, etc., and sound is piped through the
sound card, but hey....) 720x480x30fps for me.

> I remember how long it took to get X drivers for my Matrox card. Here at
> work I've been using Intel Smart Video Recorder III cards, but they dont
> have a video out. I've become relatively familiar with the bt848 driver
> and wouldnt mind working on converting it to the new API proposal, but I
> dont want to buy a bt848 card unless it has an output on it. Are there any
> such cards that have an output and a bt848? Also please keep in mind that
> I am a poor college student and that I cant really consider anything over
> $250. Any suggestions about what I should buy or information about other

buycomp.com has the buz for 169.95 (or such) i think w/ shipping mine cost about
$180.

> cards that I should consider would greatly be appreciated. I'm all anxious
> to start contributing, but I need to get some hardware first. Thanks in
> advance for any information that you might be able to give me.
> 
> Aaron
> 
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> line "unsubscribe video4linux" without the quotes in the body of the
> message.

why am i so positive about the buz?

reason 1) i have one, and would love someone to write a driver. i am trying
myself, but i have some other projects at hand, and i am new to device
drivers.

reason 2) i think the buz pretty much rocks.

anyway....
-- 
daniel dunbar             Those who dream of tachyons are
ddunbar@diads.com           condemned to eternal sleep.
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