O/T Video Capture Board/Box advice...

[jscorse]

The MPEG compression routine will actually VARY it's compression on the fly to be able to maintain the real time throughput?

Thus, USB 2.0 (higher bandwidth) will 'allow' the compression routine to 'ease' up and not compress the video as much?

These are posed as questions - notice the ? at the end.

I understand what you are saying about lossless and lossy compression, I'm not clear on whether or not MPEG compression is 'variable' and whether or not the software smart enough to compress on the fly using the available bandwidth to set it level of compression.

This is getting interesting....

I've worked with various encoders and don't remember which features belonged to which. I know that mpeg-2 is tunable. I'm not sure if it's tunable on the fly or if the encoder is set for a specific ratio/bitrate. Some encoders reduce framerate, others reduce detail. A fractal encoder I worked on some years ago was completely dynamic and would maintain a steady framerate by reducing detail in high-motion areas of the frame for a few frames until it could catch up and fill in the detail. The static portion of the frame would stay clear though. We did this for a videophone. You could actuall hold a conversation at 8fps because it was consistent, not choppy. Since only the person's head was moving, it could keep up. If you waved your hand through the frame and stopped, the hand would be a blur that would come into focus when the motion stopped. The framerate never stuttered though. All this over 28.8 dialup lines, with audio.

I know that mpeg is tunable, but HOW tunable may depend on the encoder processor and how fast/smart it is.

In these times of cheap/commodity hardware, there's still a reason why some things are $80 and some others are $800.

As "AbdominalSnoman" said, your best results would probable be through a capture card rather than an external thing. The cheap guys know they're building for cheap and choose parts accordingly.

CJ

[jscorse]

The Dazzle 200 is $160 on the street which isn't cheap but still less than $800. I like the idea of the built in encoder and I don't like the idea of spending $800 so I may stick with that one.

I'm still looking though for the best performance available under $200.

Thanks for the info.

You sound like your having a great time compressing things...

Video and image compression is a much stranger process than it sounds.

Fractal encoders run through an image repetetively finding image bits that look similar enough to call the same and then recording one and remember all the places to put it to recreate something that looked a lot like the original. Then use a Huffman encoder to further compress this data.

The lossless we did would use a high quality variant of fractal, then decompress the frame and compare them and record the errors. It would then aggregate the fractal codes with the error codes and use a Huffman or Arithmetic encoder to further compress that. The decode would decompress the lossy frame, and apply the error corrections to it to get a perfect copy of the original.

It gets weirder from there.....

If the dazzle has the features you want, buy it. It's a comparatively small expense and then you'll find out if it's sufficient for your needs.

CJ

[jscorse]

My head hurts.. ) Next time I have a question about compression I'll know who to ask. My work is more around electromagnetics and the nice 'friendly' differential equations therein. Fractals are fascinating to me. Someday I will get some time to study them in more detail. They seem so simple, yet the math becomes so abstract.

I'm always the first to notice how the compression routines that my satellite Rx uses, stumbles on complex pictures like crowd scenes and forests.

My wife just looks at me like I have two heads and suggests that I just let it go and enjoy the movie.....

These days, the movies are usually compressed very well and pixelation isn't in the source material. If the sat rx or dvd uses a slightly slower chip, it can run out of time decoding more complex scenes. It will have to just show the pixelated frame and move on. A momentary pixelation is a lot less noticeable than completing the frame but stumbling on the timing. Video compression uses key frames (which are complete) and delta frames (which only contain the differences between this frame and the last one). Key frames are interspersed throughout so if things get out of sync it doesn't last long. The decode doesn't really happen in realtime, but close to it (depending on the memory in the decoder). I have 2 different DSS boxes which are about 1/2 second out of sync because one is older but a fast chip, while the other is a newer HDTV box that has more to do.

It's a good thing you put O/T in the title.

CJ

If that dazzle thing has a true mpeg 2 encoder on the chip than it will be able to squeeze about all the information through on the usb port that is needed for the highest quality dvd. DVDs are usually recorded at around 6 - 8 Mbits/Sec the sound is usually 384Kbits/Sec. This sounds like it would be fine over a 12 Mb pipe, but you have to consider the overhead of the communications between the dazzle and the computer, PLUS whatever other devices you have running via USB. I doubt that this would ever become a problem, just be aware that you can't be doing anything really more strenuous over the usb than using a keyboard and mouse. (no cable modem / DSL or anything else)

One advantage of using the dazzle thing is that it also captures and (hopefully) compresses the sound using the same standard as DVDs usually use. Lots of times if I use any capture program than the one that comes with my video card, I get little sync problems where the sounds will play about a fifth of a second before or after the same thing happens on the screen. This only develops over an extended period of time like 30 minutes and isn't easily noticable. Compressing DVDs takes a lot of time and if this can do it hardware based that would be pretty good as well. If it has a good software package (which I think they do) it could make lots of other things a lot easier.

If you want to save money, you could get that video card that I mentioned earlier. For under 60 you can get something that will capture at 720 X something at 30 fps WITHOUT any compression. It will also compress it as it captures it too, which is what I would recommend for you. There have been times when I wanted something to look the best and I just used a lossless compression (like huffyYUV) and done all my editing with a file that didn't have any loss introduced into it. The final result is a product that looks a little bit better, but you also spend a lot more time doing it like that. If you go this route (either compressed or not), you will have to spend the 5 - 15 hours of recompressing the video using MPEG2 before it can be written to dvd. It may not be worth the hassle to you.

I doubt that either of these will look as good as what it would if you used a DV camera to convert it to digital for you. There wouldn't be much of a difference, but I believe that if you put them side by side you'd be able to make out a difference. For only about 200 more you could buy yourself a pretty nice camera. About a week ago, I saw one for about $270 w/shipping, so you may want to look around to see if you can find any good deals on cameras as well. I've had good luch using www.pricegrabber.com to look for electronics and www.pricewatch.com for computer parts. (you'd need a firewire card that will probably cost $25 w/shipping) hopefully this will take you straight to miniDV camcorders: http://www.pricegrabber.com/search_a...12b0483e1c55fe

In my opinion you have 3 options each with their own strengths:
1: If you want cheap, you can go with a video card that has capture capabilities. You won't lose any quality and may even gain some over the dazzle, but lose the convenience of their software package.
2: If you want convenience, go with the Dazzle, Since you say that it can compress to mpeg2 in the hardware, I believe that it can fully satisfy you as far as quality goes. It is also made for your purpose specifically instead of a broad range of uses so the software may have a narrower scope but be easier to use and faster.
3: For the best looking picture, I think that the DV camera would turn out the best. I also think that this may be the best value since for about $350 (if you're patient for a deal) you can get a good camera and a firewire card.

My recommendation is for a firewire card and a DV cam. I have a firewire port built into my powerbook, and the editing is fantastic in imovie2. Very easy, and very fast.

Mike

Originally posted by Green1995SVX
My recommendation is for a firewire card and a DV cam. I have a firewire port built into my powerbook, and the editing is fantastic in imovie2. Very easy, and very fast.

Mike

I'll second that. iMovie2 owns. Us mac guys sure have simple answers eh? Look at the size of the replies from the PC dudes. :P'`'`'

- Ca$h

I could never go to a PC after ownt a mac. It would be like going from a SVX to a... NEON!!! I'm just joking around, Rob.

Mike

Originally posted by Green1995SVX
I could never go to a PC after ownt a mac. It would be like going from a SVX to a... NEON!!! I'm just joking around, Rob.

Mike

But Macs never crash, never get a virus, never bottleneck, are way more upgradeable than a PC, and to top it off they never ever need a driver.

lol, if anyone could make a computer that does any of the above they would dominate the market.

Originally posted by I_Alcyone_I


But Macs never crash, never get a virus, never bottleneck, are way more upgradeable than a PC, and to top it off they never ever need a driver.

lol, if anyone could make a computer that does any of the above they would dominate the market.

Well, sorta.

They almost never crash (OSX anyway), its true that they NEVER get viruses, they don't bottleneck in all the times I've used them, but the are definitely not very upgradeable though. And yes, most of the time they don't need a driver. Plug something in and 90% of the time it just works instantly.

Macs own.

- Ca$h

[jscorse]

Very thorough answers. Thank you, thank you.

I understand the benefits of a digital camera, but right now my needs are more along the lines of capturing hours of existing analog video along with transfering our kiddy movies from VHS to DVD so I can take them on the road.

I've just installed a DVD video system into our Forester. With headrest monitors and IR headphones. LOTS of crawling around and removal of seats, seat covers, consoles, and trim,.....but it's all in and works....mostly.

I'm having a problem with the IR headphones that I need to call Clarion to work out. They don't want to work...and that's clearly a problem...but not for this thread.....

So from your post I gather that I'm still on the Dazzle route. I like simple and I like the idea of compression BEFORE it gets into my computer. I'm willing to live with 'mild' losses as long as the result if comfortably viewable.

As for the Mac...now your REALLY talking about spending money...that I don't have.

[AFBeefcake]

If you’re looking of a Dazzle I have one that I want to sell.
It is a USB one I don't know what model I can look when I get home. I only used it 3 times and I don't need it any more. I got a video card that has video in on it now.
I have the original box and everything that was in the box new

If you or any one else is interested let me know.

[jscorse]

Yup.

I'm interested. Let me know what model you have.

What kind of video card did you get?