Apologies if this is not exactly the correct ng for this query; couldn't
find a more appropriate one.

I had been asked to source a digital recording device for a training
simulator that would capture from two thermal imaging cameras with
composite output. One of the requirements was that it needed to have the
ability to export footage in a format (mpeg, quicktime, windows media,
etc) to provide the trainee with the recorded footage on cd or dvd.

I thought that a DVR primarily designed for  CCTV use would be ideal,
and bought one of these:

http://www.iviewcameras.co.uk/IV_AVTECH_761ZCCTVSystemsdeals.htm

However, apart from the user interface and instructions being very poor,
where the system fell over was the ability to easily export footage in a
format that the trainees could view on a computer or DVD player. Despite
the pvr having a usb port and a network port, I was not successful in
getting this to work reliably. Now I think I may need to write off the
cost of this unit since it really doesn't seem suitable for what we want
it to do, despite the it looking ideal on paper/specs.

I am thinking that a computer based solution may be more flexible, but
while one can get capture cards (because of space constraints, a laptop
would be necessary so firewire or usb only) with one composite input, I
can't seem to find any with two. The usb capture cards can be bought
quite cheaply, but it's not clear whether I could have two installed at
the same time, or whether one firewire and one usb would be better.

Apart from the hardware, there is also the question of software. Apart
from MythTV I have had no experience with PC based PVR software. I
thought perhaps something like Windows Media Center could be adapted
since it is able to record two 'channels' simultaneously; or are there
other software packages at a reasonable price that would do a better
job.

"Mark Ingle"  wrote in 
message 
news:1i9r2a5.1t1hog18dhdtsN%markinglenospam@nospamfastmail.fm...
> Apologies if this is not exactly the correct ng for this 
> query; couldn't
> find a more appropriate one.
>
> I had been asked to source a digital recording device for a 
> training
> simulator that would capture from two thermal imaging cameras 
> with
> composite output. One of the requirements was that it needed 
> to have the
> ability to export footage in a format (mpeg, quicktime, 
> windows media,
> etc) to provide the trainee with the recorded footage on cd or 
> dvd.
>
> I thought that a DVR primarily designed for  CCTV use would be 
> ideal,
> and bought one of these:
>
> http://www.iviewcameras.co.uk/IV_AVTECH_761ZCCTVSystemsdeals.htm
>
> However, apart from the user interface and instructions being 
> very poor,
> where the system fell over was the ability to easily export 
> footage in a
> format that the trainees could view on a computer or DVD 
> player. Despite
> the pvr having a usb port and a network port, I was not 
> successful in
> getting this to work reliably. Now I think I may need to write 
> off the
> cost of this unit since it really doesn't seem suitable for 
> what we want
> it to do, despite the it looking ideal on paper/specs.
>

I've no idea whether the USB capture devices I use in the U.S. 
have the necessary options to work elsewhere, but they do have 
the ability to do otherwise as you wish. 
http://www.autumnwave.com/

They're not made in the U.S., so the likelihood is better than 
zero that they support other than just our standards.

The premium units are a tad pricey at US$250, but they are 
feature laden and one can attach as many as 4 USB devices for 
simultaneous capture.  They certainly accept composite inputs, 
as well as S-Vid, cable or OTA, and surprisingly - HD-VCRs!

The capture software generates a new instance of itself for each 
additional device plugged in, and the clones operate almost 
completely independent of the mother.  There are some recovery 
issues when a clone craps out but I believe they will address 
that in the next software release.

Until recently the documentation, as usual for new start 
companies, was absent - but that's now somewhat rectified. 
Despite that, the tech support here has been phenomenal, with an 
exceptional person at the helm.  I respect anyone who can not 
only tolerate my inane questions but answer them so that even I 
can understand;-0)


> I am thinking that a computer based solution may be more 
> flexible, but
> while one can get capture cards (because of space constraints, 
> a laptop
> would be necessary so firewire or usb only) with one composite 
> input, I
> can't seem to find any with two. The usb capture cards can be 
> bought
> quite cheaply, but it's not clear whether I could have two 
> installed at
> the same time, or whether one firewire and one usb would be 
> better.
>
> Apart from the hardware, there is also the question of 
> software. Apart
> from MythTV I have had no experience with PC based PVR 
> software. I
> thought perhaps something like Windows Media Center could be 
> adapted
> since it is able to record two 'channels' simultaneously; or 
> are there
> other software packages at a reasonable price that would do a 
> better
> job.

On 26/12/2007, Mark Ingle wrote in
message
<1i9r2a5.1t1hog18dhdtsN%markinglenospam@nospamfastmail.fm>:
 
>
Apologies if this is not exactly the correct ng for this query; couldn't
>
find a more appropriate one.
> 
> I had been asked to source a digital
recording device for a training
> simulator that would capture from two
thermal imaging cameras with
> composite output. One of the requirements
was that it needed to have the
> ability to export footage in a format
(mpeg, quicktime, windows media,
> etc) to provide the trainee with the
recorded footage on cd or dvd.

> I
> thought perhaps something like Windows Media Center could be adapted
> since it is able to record two 'channels' simultaneously

No.  Don't forget that software like that is processing data as fast as
it can just for /one/ channel.  It's designed to hog processor bandwidth
when it needs to.  Trying to process two video feeds at once both in
realtime is going to cause problems.

You need specialist advice and won't
find it on usenet.  Your requirements are too unusual.  CCTV recorders
don't generally have great output because almost no CCTV recordings need
to be preserved.

Consult a professional security company, or a
professional media processing company and be prepared to pay for the
equipment you need, and possibly for the advice.

Simon.
-- 
http://www.hearsay.demon.co.uk

Simon Slavin 
wrote:
> 
> No.  Don't forget that software like that is processing data as fast as
> it can just for /one/ channel.  It's designed to hog processor bandwidth
> when it needs to.  Trying to process two video feeds at once both in
> realtime is going to cause problems.

Thanks for your reply.

It's not a really good comparison, but I set up an  old computer
(Pentium 4, 1.8) for use with Ubuntu and MythTV and it manages to record
and playback at the same time, so I would  imagine a dual core processor
could  handle the recording of two mono streams of video, even allowing
for the overheads of Windows???. My ancient TiVo only has a PowerPC 601
chip, though that too runs a version of Lunux.
> 
> You need specialist advice and won't
> find it on usenet.  Your requirements are too unusual.  CCTV recorders
> don't generally have great output because almost no CCTV recordings need
> to be preserved.

Yes, that's true, although great output isn't really required, as long
as it's better than VHS. In actual fact, the DVR I purchased would have
been adequate if it was easy to use. When I was looking at alternatives
Bosch did a similar model that was about double the price; however I
couldn't find any reviews on it.

> 
> Consult a professional security company, or a
> professional media processing company and be prepared to pay for the
> equipment you need, and possibly for the advice.
> 
Well, that's just it; there isn't a huge budget for this. At the moment
they are using a time lapse recorder which just records the output of
one camera (mono composite). Because they provide the recording to the
student, it means they need one videocassette for each. With VHS
becoming obsolete, a replacement is required.

I suppose another alternative, while not ideal, is running two HD/DVD
recorders that will take composite input, but again the user interface
can be an issue. I bought one of the Tevion ones from Aldi before
Christmas and ended up returning it because the interface was so awful.

On 30/12/2007, Mark Ingle wrote in message
<1i9y6m0.tn33puparlf4N%markinglenospam@nospamfastmail.fm>:
 
> Simon Slavin 
>
> > No.  Don't forget that software like that is processing data as fast as
> > it can just for /one/ channel.  It's designed to hog processor
> > bandwidth when it needs to.  Trying to process two video feeds at once
> > both in realtime is going to cause problems.
> 
> Thanks for your reply.

You're welcome.

> It's not a really good comparison, but I set up an  old computer
> (Pentium 4, 1.8) for use with Ubuntu and MythTV and it manages to record
> and playback at the same time, so I would  imagine a dual core processor
> could  handle the recording of two mono streams of video, even allowing
> for the overheads of Windows?

Not a good test.  Encoding is the complicated side: analysing the three-
colour-plus-audio signal and producing a compact representation of it is
tremendously intensive in maths calculations.  Replay is simple by
comparison, taking something like (very vaguely) a fifth of the processing
power.

The other issue is the design of most consumer-level software: it's
designed on the principle that you'll be running just one copy at a time,
so each copy will hog all the processor time it wants.  And you can't have
that when you're analysing two real-time feeds at once, because if one
process hogs the processing power the other will miss part of its incoming
feed.

I don't really know enough about this to tell you how to do it properly. 
Sorry.

Simon.
-- 
http://www.hearsay.demon.co.uk

Mark Ingle wrote:
> I am thinking that a computer based solution may be more flexible,
> but while one can get capture cards (because of space constraints,
> a laptop would be necessary so firewire or usb only) with one
> composite input, I can't seem to find any with two.

Generally speaking, Firewire is better that USB for realtime transfer 
of large amounts of data.
http://en.wikipedia.org/wiki/Firewire#Comparison_to_USB

> The usb capture cards can be bought quite cheaply, but it's not clear
> whether I could have two installed at the same time, or whether
> one firewire and one usb would be better. 

An MPEG 2-stream suitable for direct burning to DVD must not exceed 10 
MBit/sec. Even with a poor USB 2 controller, having multiple capture 
cards at the same time should work fine in terms of bandwidth.
http://en.wikipedia.org/wiki/Mpeg_2#DVD

> Apart from the hardware, there is also the question of software.
> Apart from MythTV I have had no experience with PC based PVR
> software. I thought perhaps something like Windows Media Center
> could be adapted since it is able to record two 'channels'
> simultaneously; or are there other software packages at a
> reasonable price that would do a better job.

MediaPortal is for Windows and freeware. Might be worth looking into.

Do you need to see the signals as they are being recorded? If not and 
if you're familiar with Linux, you might consider a setup where you 
just pipe the output from the cards directly to the file system. If you 
don't do any post-processing, there's no real load on the CPU and if 
you want to do post-processing, such as transcoding to MPEG 4, it's 
easy to send it through mencoder or similar.

As for real-time transcoding of dual streams to MPEG 4, a fast dual-
core processor might be needed and even then it might not be enough. 
Not because of the dual streams, but simply because encoding is a CPU-
intensive operation. You can buy cards that can handle transcoding, but 
it would be a lot easier just to buy grabber-cards with the wanted 
output in the first place.
-- 
Toke Eskildsen - http://ekot.dk/

Simon Slavin 
wrote:
> 
> The other issue is the design of most consumer-level software: it's
> designed on the principle that you'll be running just one copy at a time,
> so each copy will hog all the processor time it wants.  And you can't have
> that when you're analysing two real-time feeds at once, because if one
> process hogs the processing power the other will miss part of its incoming
> feed.
> 
> I don't really know enough about this to tell you how to do it properly.
> Sorry.
> 
Thanks again for your  input, Simon.

With what you said in mind re the overheads of hardware encoding I've
done more searches, and for hardware the most promising product I've
seen so far is the EyeTV 250 plus as it has a built-in MPEG2 encoder.

'EyeTV 250 Plus incorporates a powerful hardware encoder that can record
high quality video from analogue sources, compressing audio and video
signals to small size MPEG-2 files and freeing up your processor for
other activities.'

It will export to QuickTime (among other formats), which willl do fine.

The refurb MacBooks can be had for 750 pounds, and the EyeTV 250 Plus
costs 120 pounds ex x 2, so not a cheap option.

Of course, that's assuming one can use two EyeTV 250 plus units
simultaneously; somehow I don't think so. Nevertheless, I'll enquire
just in case!

Toke Eskildsen  wrote:
> 
> MediaPortal is for Windows and freeware. Might be worth looking into.
> 
This might be exactly what I need! Thank you.

Although geared towards recording TV, Wikipedia says that 'With Windows
XP you are able to use MediaPortal with one DVB TVCard or multiple
Analog TVCards'; and some of the USB2 TV cards supported not only have
analogue capture but also MPEG2 encoders. At 70 pound each for something
like the Hauppauge WinTV USB 2 Personal Video Recorder, it is definitely
worth looking at.

I've not quite figured out how it would export video to QuickTime, AVI
or mpeg, but I'll test it out.

> Do you need to see the signals as they are being recorded? If not and
> if you're familiar with Linux, you might consider a setup where you 
> just pipe the output from the cards directly to the file system. 

From my limited experience with setting up MythTV on Linux, I don't
think it is for me. It works great, but was a bu**er to set up.

Mark Ingle wrote:

[Mediaportal]

> Although geared towards recording TV, Wikipedia says that 'With
> Windows XP you are able to use MediaPortal with one DVB TVCard or
> multiple Analog TVCards'; and some of the USB2 TV cards supported
> not only have analogue capture but also MPEG2 encoders. At 70
> pound each for something like the Hauppauge WinTV USB 2 Personal
> Video Recorder, it is definitely worth looking at.
> 
> I've not quite figured out how it would export video to QuickTime,
> AVI or mpeg, but I'll test it out.

You really want to go for a card with hardware encoding and that 
normally means MPEG 2. MediaPortal supports plain MPEG 2 creation,
so it's easy to transfer to DVD for your trainees. No transcoding is 
needed, so repackaging to DVD format is very fast.

I've used MediaPortal myself with a DVB-T card and a dual analog 
grabber card at the same time. Both were Hauppauge PCI cards. It worked 
fine with multiple recordings and playback at the same time, provided I 
kept the drive fairly defragmented.

I'll recommend getting a 7200 RPM drive for dual recordings though. Or 
maybe an external Firewire-box? That would be needed anyway if you're 
planning on keeping the recording yourself.

[Linux?]

> From my limited experience with setting up MythTV on Linux, I
> don't think it is for me. It works great, but was a bu**er to set
> up. 

"bu**er"? Is that obfuscate for bugger?

Okay, sorry, I just find that such asterisks are... Well, a sign of 
some were strange social mechanisms. Something I used to write of as 
"That's what the fucked up americans do", until it began invading 
written danish internet communication as well.

(I'll step down from my soap box now)
-- 
Toke Eskildsen - http://ekot.dk/

Toke Eskildsen  wrote:

> You really want to go for a card with hardware encoding and that 
> normally means MPEG 2. MediaPortal supports plain MPEG 2 creation,
> so it's easy to transfer to DVD for your trainees. No transcoding is 
> needed, so repackaging to DVD format is very fast.
> 
Thanks Toke, I did think that would be the case, but it's good to get
confirmation.

The cards I was looking at did have MPEG 2 hardware encoding, so that's
good. I looked at the reviews of various cards on amazon.co.uk, and the
Hauppage ones seemed to be highly rated. Will try to order them tomorrow
> 
> I'll recommend getting a 7200 RPM drive for dual recordings though. Or
> maybe an external Firewire-box? That would be needed anyway if you're
> planning on keeping the recording yourself.
> 
I hadn't thought of using FireWire; yes, that's a very good idea.

> Okay, sorry, I just find that such asterisks are... Well, a sign of 
> some were strange social mechanisms. Something I used to write of as 
> "That's what the fucked up americans do", until it began invading 
> written danish internet communication as well.

I'm used to it because at work our Symantec email security 'compliance
policy' rejects all messages sent with such words that are in the
category of profanity :-)... not that I use words like that frequently.

Mark Ingle wrote:
Toke:
>> I'll recommend getting a 7200 RPM drive for dual recordings
>> though. Or maybe an external Firewire-box? That would be needed
>> anyway if you're planning on keeping the recording yourself.
>> 
> I hadn't thought of using FireWire; yes, that's a very good idea.

I don't know if it's necessary to use Firewire there, it's just me 
playing it safe. The total bandwidth for two MPEG 2 streams below 
10MBit from the grabbers and the same two streams to the external 
harddisk is well within the limits of USB 2. However, USB controllers 
and peripherals vary a great deal in performance.
-- 
Toke Eskildsen - http://ekot.dk/