Trying to Understand Capture Card Choices

[Quin]

I've been reading through the guides and this forum trying to figure out what kind of analog capture card that I need. It appears that I have several options and I'm not sure that I fully grasp the ramifications of each option.

(1) I guess that some capture cards use hardware encoding and others software encoding. The hardware encoding is good if you don't have a fast machine. The downside is that you are limited to the formats supported by that card. Do I understand this correctly?

(2) Some cards are WDM and some are VFW. From my reading, it appears that VFW is the old way, while WDM is the new (MS-preferred) way of doing things. Should I really care or just go with WDM since it is the future?

(3) I keep seeing posts refering to the BT8xx chips and the btwincap drivers. To a lesser extent, I've seen folks refer to a conexant chipset. It would seem to me that the chipset would dictate hardware/software and WDM/VFW. Does it not? Is BT8xx the way to go?

(4) I've seen many posts that say if you want to do any editing of the captured video prior to burning, you would need a capture card that will output AVI rather than MPEG. Evidently, this would then require the use of software encoding. Will there be a loss of quality going from AVI to MPEG to DVD? Or is this a compression issue?

I really appreciate some clarifications on these points.

[lordsmurf]

1- Sort of. There are different kinds of hardware and software too. Some is DV only, some MPEG only, some AVI only, some can do several things. Hardware is generally better, period.

2- Don't worry about this. VFW is super-old, not used. It's all WDM now, has been for years.

3- BT8x8 chips are old and suck. CX chips replaced them, but those suck too.

4- You're reading too much into this. AVI is the means to acquire uncompressed. Hardware encoders are just for compression. Software compression done on-the-fly can often leave much to be desired. AVI to MPEG is fine, no loss aside from standard compression loss (unlike on-the-fly software compression, which can have standard loss plus more).

I doubt that "clarified" as what you ask is not super simply. But it's more info, hope you understand it.

[Quin]

Thanks for the quick response!

3- BT8x8 chips are old and suck. CX chips replaced them, but those suck too.

Should I assume that a CX chip is a conexant chip? And if they both suck, then what chip should I be looking for?

4- You're reading too much into this. AVI is the means to acquire uncompressed. Hardware encoders are just for compression. Software compression done on-the-fly can often leave much to be desired. AVI to MPEG is fine, no loss aside from standard compression loss (unlike on-the-fly software compression, which can have standard loss plus more).

Unfortunately, you lost me here. If hardware encoding is best, and the hardware encoder only supports MPEG (not AVI), then will I be able to do any editing of my home movies? The reason that I ask that, is that I have read that if you want to do editing, you pretty much need an AVI stream. But, like you say, maybe I am reading too much into this. To do editing, do you really just need an uncompressed stream? Is AVI, by definition, an uncompressed stream? Or can AVI be either compressed or uncompressed? Is MPEG, by definition, a compressed stream?

Also, can you give me an example (file type, app, etc) of "on-the-fly software compression". I am assuming, of course, that "on-the-fly software compression" is not the same as a capture card that employs sofware encoding.

Thanks for your help!

[lordsmurf]

Hardware best WHILE CAPTURING when using high compression (MPEG). Low compression or no compression (unc. AVI, MJPEG, HuffYUV) fine in software.

Low or no compression best for editing. But advanced editing. Just chopping off pieces of footage or merging files is not really "editing" in the same sense.

I am assuming, of course, that "on-the-fly software compression" is not the same as a capture card that employs sofware encoding.

You assume wrong. WinDVR, PowerVCR, NeoDVD, all samples of crap on-the-fly MPEG compression capture software.

As far as chips, go for specialty chips. ATI Theatre, Canopus DV, Matrox, Hauppauge's MPEG chip, etc

[reboot]

My opinions:

1 Yes.

2 The blue guy has this covered.

3 BT8x8 chips are cheap. Pick up a card for $20, and do some 320x240 uncompressed avi caps...IF you have the hard drive space.
Spend the next 2 days trying to get a decent quality mpeg encoded and authored to dvdr.
Find out it sucks anyhow.
Return card, spend more money, get a much better card, live happily ever after

4 With the state of "editors" today, editing (really EDITING, not just cutting out commercials) is almost easier than editing avi's.

To cut:
Womble mpeg-vcr
VideoReDo
Cuttermaran
Whatever software comes with the card.
etc.
To edit:
Pinnacle
Vegas
Premiere
Mainconcept EVE
Whatever software comes with the card.
etc.

Best "bang-for-the-buck" would be the Hauppauge PVR-150 or the Sapphire Theatrix550.
Fortunately, there is also some excellent 3rd party software to run these, and make a real PVR out of your computer, instead of just a TV cap device.

[edDV]

You mentioned "home movies". There is a third way to proceed.

The if the camcorder is DV format then high quality results are obtained by transferring the DV stream to your hard drive (through IEEE-1394) then editing in DV format and then encoding the result to DVD MPeg.

If your DV camcorder (MiniDV or Digital8) has the analog pass through feature, then the camcorder can be used for analog capture to DV format as well.

If your camcorder isn't digital, DV capture devices (using hardware DV encoding) like the Canopus ADVC series can be used. These can also be used to analog capture from TV set top boxes and VHS to DV format.

You can also realtime encode a DV stream to DVD MPeg2 using some variations of the Mainconcept encoder V1.4. This takes a reasonably fast CPU (~2.4 GHz. Pentium). I've had best results with the ULead implementation of the Mainconcept encoder for real time MPeg2 encoding.

DV format is lightly compressed intraframe (~5x), but all frames are retained for serious editing. DV format material requires ~13GB per hour on the hard drive compared to considerably more for other light or uncompressed capture methods (e.g ~30GB/hr. huffyuv to ~75GB/hr YUY2)

[winifreid]

What do you want to do and how much do you want to spend? You also should put real values in your computer specs.

[lordsmurf]

DVD recorders are good too.

[junkmalle]

One of the best things about the hardware MPEG2 cards (like the Hauppauge PVR series and probably the ATI/Sapphire Theatrix 550) is that you can continue to use your computer while capturing with no fear of dropping frames or losing audio sync. You can even play games or defrag a drive while capturing.

A word of note: the Hauppauge PVR cards normally display the video while you're capturing. This means they decode the MPEG 2 stream that the card outputs and display it on the monitor. This display can get out of sync if you do a lot of stuff while capturing, but the MPEG file that's saved to the disk will have no problems.

On my 2.8 GHz P4 the decoding/display of the MPEG takes about 40 percent of the CPU. If I disable the decoding/display it drops down to about 3 percent.

[thecoalman]

One of the best things about the hardware MPEG2 cards (like the Hauppauge PVR series and probably the ATI/Sapphire Theatrix 550) is that you can continue to use your computer while capturing with no fear of dropping frames or losing audio sync. You can even play games or defrag a drive while capturing.

I can capture to my secondary drive and still use the comp when using my Canopus, I've never tried to stress it while playing a game or something similar but IE, e-mail, photo editing I have done. Since the Canopus eleiminates audio sync issues there's no issue there.

I would have thought that doing something as HD intensive as defragging would cause problems no matter what your capturing with.

[junkmalle]

I can capture to my secondary drive and still use the comp when using my Canopus, I've never tried to stress it while playing a game or something similar but IE, e-mail, photo editing I have done. Since the Canopus eleiminates audio sync issues there's no issue there.

Yes, DV can be pretty bulletproof too.

I would have thought that doing something as HD intensive as defragging would cause problems no matter what your capturing with.

Well, I don't routinely defrag while capturing! I've only done it as a stress test. Some people have multiple Hauppauge PVR cards and capture with two or three at the same time.

[lordsmurf]

you can continue to use your computer while capturing with no fear of dropping frames or losing audio sync. You can even play games or defrag a drive while capturing.

This is stupid. I cannot even begin to tell you how many crappy DVDs I have seen because people try to do two things at once. And yes, that includes pure hardware solutions, because they also use CPU, for preview and some other things. Defragging the hard drive has got to be the worst suggestion, that interrupts the data flow.

Some low use like e-mail or web surfing (no java! no plugins!) is generally okay, maybe even solitaire. Why do people have to use the computer that much? Get up, have a drink, do something else.

[reboot]

With a second drive, being ONLY used for capture, I can play Doom 3, while capturing 3 programs at once using my pvr-500 and 250.
I can surf, check email (yes, with java and plugins working) encode an avi in Mainconcept, frameserve from virtualdub, and build a dvd in DVDLab...simultaneously!
Absolutely NO problems with the finished mpg.
I also have comskip running on all mpg's, as well as a command line editor (mpgtx), run via postprocessing.bat after every recording.
I haven't had a glitch, or missed recording yet, and Doom still plays nice and smooth.
The key is to have a large, fast, second drive, ONLY for capturing, and TURN OFF any anti-virus programs you have, specifically on that drive, so NOTHING else is accessing it but your capture app.

[Quin]

Putting the defrag issue aside ...

What do you want to do and how much do you want to spend?

Well, at the moment I am trying to understand the concepts behind video capture/encoding/burning. Specifically in this thread, I was trying to clarify my understanding of the key factors in chosing a capture card. What do I want to do with all of this knowledge? Well, I thought I might start with copying some of my VHS tapes to DVD. After that, I would probably want to do some home movie editing. I have no idea if I am talking about "real editing" or "cut-n-paste editing" because I have not researched that topic, yet. And, I am sure that something else will tickle my fancy at some point down the road. As for a budget, well, as cheap as possible, I guess. Most definitely, something under 10K, and more than likely not even close to that.

Hardware best WHILE CAPTURING when using high compression (MPEG). Low compression or no compression (unc. AVI ... fine in software.... Low or no compression best for editing.

If I understand you correctly, MPEG is alway compressed (high compression, in fact), while AVI can be either compressed or uncompressed. Now, can a hardware-based capture card output a low/no compression stream, or are they all MPEG?

BT8x8 chips are cheap [and] ... it sucks anyhow.

Do you also put the Conexant chips into this category, as well. Maybe I am being a bit naive at this point, but they seem rather popular to be as bad as you folks are saying. At some point, cheap is not enough of an advantage to overcome a poor product. Just how bad are these two chips?

I am also not clear whether these two chips are used in hardware or software based capture cards. I assume that since they are cheap that they are more than likely to use software based encoding. If these chips were combined with low compression or no compression capture software, would that be enough to overcome the quality limitations of the chips? What would be some examples of such software?

Thanks!

[winifreid]

If by 10k you mean $10,000, then you are looking at some expensive stuff. But if you are just doing home movies and your not a rich guy who just has to have the best even if it isn't that much better, then you can get a card for $50 that will do the trick. I have the Leadtek 2000XP and a reasonable computer, and with the software that came with card I can capture home movies from a vhs camera and burn to DVD and they look great. I capture to avi (picvideo) since I add titles and fades and sound. I can capture to mpeg2 at full resolution, but when I want to edit the files, I find that I almost always have sound sync problems. I am sure there are programs that can edit mpeg without theseproblems, but they are not cheap and it is easy to edit and then convert avi. You can get the Leadtek expert for $45 and it is supposed to be little bit better than the 20000XP.

[lordsmurf]

ATI AIW cards are great for AVI or MPEG
Canopus ADVC okay for DV AVI
Hauppauge PVR for MPEG

if you have lots of money:
Matrox RT.X100 cards are supposed to be nice, does AVI and MPEG in hardware

[junkmalle]

Quin, there are basically two classes of video capture cards. Those that send "raw" uncompressed video to the computer, and those with hardware compression that send compressed video to the computer.

The raw class can give the best picture quality because the data is very close to the actual analog signal. Raw capture cards usually capture in the YUV colorspace with colors at half the resolution of the grey scale image (this is the way NTSC video is transmitted). This results in 2 bytes for each pixel. About 75 GB/hr for a 720x480, 30fps capture. (You can usually capture at lower resolutions if you want but I will use this frame size as a reference.) The computer can then save the data uncompressed, losslessly compressed (~2:1 compression with HuffYUV for example), or with a lossy compression like MPEG 1/2/4, MJPEG, etc. But since a new frame of video is arriving every 1/30 second the computer only has 1/30 of a second to perform the compression. If the computer isn't finished compressing a frame by the time the next one arrives the new one may be lost (dropped). So software compressers take shortcuts (less compression and/or less image quality) to make sure they don't take too long. And you may not be able to use your computer for much else while capturing. Raw capture cards have been around for a long time and there is lots of software that knows how to capture from them.

The second class of cards capture raw data internally, compress it, then sends the compressed data to the computer. This compression generally involves throwing away some of the details. These devices can take the form of external boxes or internal cards. Since the device is doing the compression, all the computer really has to do is receive the compressed data and save it. So the computer is less likely to drop frames when capturing with this type of device. Typically the computer also decomrpesses the incoming data and displays it on the screen so you can see what you're capturing. Hardware compression generally gives better picture quality than realtime software compression because of the dedicated hardware. But not as good quality as you can get with raw captures followed by time consuming software compression later on.

There are two main camps in the hardware compression class: DV and MPEG (there are others but these are the main two).

DV has a fixed bitrate, ~13 GB/hr and is usually saved in an AVI container. Each frame is saved in its entirety -- you can reconstruct any frame from just the information for that frame. This makes the video easy for programs to handle. DV is usually received via the firewire (IEEE 1394) port. Many programs can capture from DV devices. Some software allows you to convert DV to other compression schemes (MPEG for example) while capturing. But you will run into the same speed limitations as with raw capture, and you will be starting with an already degraded image from DV compression. In practice, DV capture followed by MPEG compression for DVD later isn't bad.

MPEG can vary the bitrate at which video is saved. The more bitrate you use the better the quality and the larger the file. Typically you will use somewhere between 2 and 4 GB/hr for DVD compatibility. (Some cards, Hauppauge PVR series for example, can capture at higher bitrates for even better quality -- but you won't be able to use the files directly on DVD.) MPEG uses inter-frame compression techniques. Some frames contain the entire picture (key frames) but others contain only the differences between the current frame and the last one. This is the major method by which high compression is obtained by MPEG. To reconstruct a non key frame you have to search for the previous key frame and then decode each intermediate frame until you reach the one of interest. As you might imagine, this makes handling MPEG harder for editing software. Some editors only allow you to cut on key frames. Some allow you to cut anywhere but then reencode the entire video (every decompress/recompress cycle will lose some quality). Some allow you to cut anywhere and only reencode the portion from the cut to the next key frame. There are fewer choices of capture programs for hardware MPEG cards.

Generally, hardware compression devices only send compressed video to the computer. The latest ATI card, the TV Wonder Elite appears to have a hardware MPEG chip and the ability to send uncompressed raw data. The Sapphire Theatrix 550 appears to be based on the same chip. Software support for raw captures appears to be nearly non-existent at this time.

ATI's All In Wonder series receive raw video from the capture chips but have some hardware assist to compress to MPEG. This makes them less prone to dropping frames than many other raw capture cards.

This doesn't mean that every raw capture card gives better results than every hardware compression card. Many other factors of the design can effect image quality. Noise from the digital section leaking into the analog section can be a problem. Some cards are just better at converting the analog video to a digital format in the first place. Some cards come with crappy drivers.

You also have the issue of Macrovision copy protection. Some capture devices will refuse to capture Macrovision protected signals. Some cards incorrectly detect Macrovision with weak signals (like from old VHS tapes). Some cards don't care about Macrovision and let you capture anything.

And lastly, image quality is to some extent in the eye of the beholder.

[thecoalman]

If you have that kind of money you can get quite setup for even half that including the computer, card and software., as LS sugeested you may want to look at something from the Matrox line or simialr ones like the DVStorm etc., they do more than just capture such as real time editing. Whether it's AVI or MPEG capture you still have to encode parts that you change such as tansitions. Depending on the type of transition or filter that can take quite a while, cards such as the ones from Martox do it in realtime.

concepts behind video capture/encoding/burning. Specifically in this thread, I was trying to clarify my understanding of the key factors in chosing a capture card.

One other thing to consider is your other hardware because the capture card is only one of the pieces to the puzzle. A good VCR, TBC.... try the restoration forum for examples of what I mean. The hardware you use before it gets converted to digital can make quite a difference.

[Quin]

there are basically two classes of video capture cards. Those that send "raw" uncompressed video to the computer, and those with hardware compression that send compressed video to the computer.

Wow! This is an excellent post. You should really consider putting this together in a guide.

Raw capture cards have been around for a long time and there is lots of software that knows how to capture from them.

[Some boards] have a hardware MPEG chip and the ability to send uncompressed raw data. Software support for raw captures [from these boards] appears to be nearly non-existent at this time.

I was a bit surprised by these statements. If the capture card can handle a raw feed, why would it care if that feed was coming from a raw capture card or an MPEG card that happens to support uncompressed raw data? My guess is it is a limitation of the device drivers for these "have it both ways" type of cards.

DV is usually received via the firewire (IEEE 1394) port. Many programs can capture from DV devices.

Until I read the earlier post by edDV, I had always assumed that DV was strictly for the digital camcorders. While I've done very little reading about DV, it seems to me that analog support is more of an afterthought. I would think this approach would make the most sense for the person that already has an investment (either time or money) in DV or those considering a DV camcorder where analog processing is a great feature, but not the primary focus. Or is it truly a viable alternative, in terms of quality, to a raw capture?

You also have the issue of Macrovision copy protection. Some capture devices will refuse to capture Macrovision protected signals. Some cards incorrectly detect Macrovision with weak signals (like from old VHS tapes). Some cards don't care about Macrovision and let you capture anything..

This is a whole other issue that I have, so far, only given cursory consideration. I think I read in one of the guides (don't recall exactly) that the higher quality boards tended to respect the copy protection, while the lower quality boards were the ones that ignored the signal. That, of course, wasn't exactly what I wanted to hear.

[edDV]

DV is usually received via the firewire (IEEE 1394) port. Many programs can capture from DV devices.

Until I read the earlier post by edDV, I had always assumed that DV was strictly for the digital camcorders. While I've done very little reading about DV, it seems to me that analog support is more of an afterthought. I would think this approach would make the most sense for the person that already has an investment (either time or money) in DV or those considering a DV camcorder where analog processing is a great feature, but not the primary focus. Or is it truly a viable alternative, in terms of quality, to a raw capture?

Well, you need to do some reading on the DV format. It's the consumer version of the way the pros do it for serious production (broadcast news, film transfer, studio production, post production, and now with HDTV, film production).

Leaving off HDTV for a moment, the core of high end video production is serial digital 4:2:2 (SMPTE 259M) which is uncompressed. Capital requirements are high and your $10K budget needs a 10x multiplier to get started on a system. A single Digital Betacam camcorder or editing deck will set you back >>$30K. There are no video sources available in the home that are near these bandwidths. Minimum entry point is for aquisition is a >$30K Digital Betacam camcorder or access to professional master tapes + $30K player*.

Workaday broadcast production is done in DV format (DVCAM, DVCPro). There is very little difference (none as far as image quality) between the consumer and pro versions of DV.

Analog I/O is readily supported from many sources although hardware codecs are required for acquisition to a PC and generally for quality playback. A PC will be stressed playing back DV with only a software codec but it can do it. Most people use the hardware codec in the camcorder for acquisition and playback of DV format video..

Start your reading here.
http://www.simplydv.co.uk/Formats/DVandD8.html
http://www.adamwilt.com/DV.html
http://www.videouniversity.com/dvformat.htm

* DVCPro50 is a DV 4:2:2 format extension. Players are available ~$19K.

[lordsmurf]

about DV, it seems to me that analog support is more of an afterthought.

That's exactly the case. It was developed as a shooting format, and the analog conversion stuff is an afterthought to use the tech. At least as it concerns DV25 consumer equipment. DV transfer methods are flawed and leave behind artifacts in the color, things you will not experience with other compression formats.

And, as has been pointed out to me several times, even 4:2:2 is not uncompressed.

[edDV]

about DV, it seems to me that analog support is more of an afterthought.

That's exactly the case. It was developed as a shooting format, and the analog conversion stuff is an afterthought to use the tech.

DV first showed up in the PC environment as a camcoder to IEEE-1394 self contained solution for home movie making.

The broadcast enviroment was at the time mostly analog. Analog to DV format converters have been available in all quality levels for that market for over 8 years. Prosumer and consumer level transcoders have been around for 4 years.

Consumer DV camcorders soon added "analog pass thru" feature for analog acquisition through the existing camcorder hardware codec.

"At least as it concerns DV25 consumer equipment. DV transfer methods are flawed and leave behind artifacts in the color, things you will not experience with other compression formats."

Compared to what? DV 4:1:1 is perfectly acceptable for broadcast television.

And, as has been pointed out to me several times, even 4:2:2 is not uncompressed.

Color difference channels are sampled at half the rate of luminance. Otherwise it is uncompressed.

[TBoneit]

DVD recorders are good too.

I find myself using the DVD Recorder more than the ADVC 100 myself. Just saves time even with having to use DVD Decrypter (RIP) to rip to the computer to reauthor. Quality is good. Only problem I had was having to buy a TBC so that the recordings from tape wouldn't quit at every dropout in.the tape. Sort of a hidden time saver tax. By now I figure I'm covered with a TBC, Video Proc. ADVC 100 & DVD recorder and a few other trinkets.

Not cheap over all but then what hobby is?

Cheers

[edDV]

DVD recorders are good too.

I find myself using the DVD Recorder more than the ADVC 100 myself.
Cheers

I'm waiting for the ideal standalone DVD recorder optimized for home VHS transfer. Volume transfer is best done on a dedicated recorder.

The other missing link is a VHS VCR that will play tapes made on misalligned decks.

VHS transfer is mostly a mechanical problem.

[junkmalle]

Raw capture cards have been around for a long time and there is lots of software that knows how to capture from them.

[Some boards] have a hardware MPEG chip and the ability to send uncompressed raw data. Software support for raw captures [from these boards] appears to be nearly non-existent at this time.

I was a bit surprised by these statements. If the capture card can handle a raw feed, why would it care if that feed was coming from a raw capture card or an MPEG card that happens to support uncompressed raw data? My guess is it is a limitation of the device drivers for these "have it both ways" type of cards.

I don't have the cards in question, I only know what I've read about them -- mostly here at videohelp.com. The primary support appears to be for hardware MPEG capture. A few people claim to have successfully captured uncompressed with GraphEdt (a developer tool from Microsoft).

You also have the issue of Macrovision copy protection. Some capture devices will refuse to capture Macrovision protected signals. Some cards incorrectly detect Macrovision with weak signals (like from old VHS tapes). Some cards don't care about Macrovision and let you capture anything..

This is a whole other issue that I have, so far, only given cursory consideration. I think I read in one of the guides (don't recall exactly) that the higher quality boards tended to respect the copy protection, while the lower quality boards were the ones that ignored the signal. That, of course, wasn't exactly what I wanted to hear.

I don't know that that's true. In any case, if you're prepared to spend some money, you can use a full frame Time Base Corrector to eliminate the problem. You'll need a TBC to get the best results from video tape anyway.

[thecoalman]

You also have the issue of Macrovision copy protection. Some capture devices will refuse to capture Macrovision protected signals. Some cards incorrectly detect Macrovision with weak signals (like from old VHS tapes). Some cards don't care about Macrovision and let you capture anything..

This is a whole other issue that I have, so far, only given cursory consideration. I think I read in one of the guides (don't recall exactly) that the higher quality boards tended to respect the copy protection, while the lower quality boards were the ones that ignored the signal. That, of course, wasn't exactly what I wanted to hear.

I don't know that that's true. In any case, if you're prepared to spend some money, you can use a full frame Time Base Corrector to eliminate the problem. You'll need a TBC to get the best results from video tape anyway.

For the most part that is true, the only high-end card that I'm aware of that gets reccommenended a lot that doesn't look for the MV signal is the Hauppauge ones. There's ways around other protection such as the infamous Canopus 100 hack, you hold the input selector down for 20 seconds and it turns the protection off. I have a 110 which is the current version and I haven't tested it to see if it still works.

If your looking to invest some money in this the $300 for a full frame TBC should be on you list. It removes the MV signal, TBC's correct errors on tapes. Believe it or not that's all MV is, to quote LS "....and they have it patented" A TBC takes the incoming signals and syncs them, and stores thenm until it has the entire frame then spits it out giving you a perfectly synced signal vertically and horizontally. Things that TBC can correct for example would be tapes that appear to skew or warp when played or appear jittery. It's not some magic wand but if you have tapes like this with even slightl errors it can be indespensable.

There's more here, once the page loads refresh it to go to the correct post. There's images above it and once they load it repositions the page.: https://www.videohelp.com/forum/viewtopic.php?p=1115672#1115672

[lordsmurf]

"At least as it concerns DV25 consumer equipment. DV transfer methods are flawed and leave behind artifacts in the color, things you will not experience with other compression formats."

Compared to what? DV 4:1:1 is perfectly acceptable for broadcast television.

We've discussed this many times. 4:2:2 source to 4:1:1 DV to 4:2:0 DVD is damaging. The picture quality never looks as good as it would, had you skipped the middle conversion. Use a 4:2:2 or 4:2:0 conversion device, and stop the horrid middleman step.

HuffYUV, MJPEG ... even MPEG. All better.

[edDV]

"At least as it concerns DV25 consumer equipment. DV transfer methods are flawed and leave behind artifacts in the color, things you will not experience with other compression formats."

Compared to what? DV 4:1:1 is perfectly acceptable for broadcast television.

We've discussed this many times. 4:2:2 source to 4:1:1 DV to 4:2:0 DVD is damaging. The picture quality never looks as good as it would, had you skipped the middle conversion. Use a 4:2:2 or 4:2:0 conversion device, and stop the horrid middleman step.

HuffYUV, MJPEG ... even MPEG. All better.

Hmm, and all this is going on in the chroma components where the eye can barely resolve 600KHz let alone 1.75MHz for 4:1:1 and 3.75MHz for 4:2:2.

I would argue that unless these conversions somehow crosstalk into luminance (where most detail is resolved by the eye), there is no observable effect.

The other disconnect is that 4:2:2 sampling a broadcast or VHS source somehow is higher quality than 4:1:1 sampling. The highest U and V input bandwidth you can expect is 600KHz with VHS and most NTSC decoders*. Oversampling 600KHz U and V by 6 times is not going to increase quality.

* even if your source is a Betacam SP deck, The best chroma component bandwidth is still 1.2MHz at maximum. 4:1:1 @ 1.75MHz Nyquist bandwidth is capable of handling Betacam SP chroma componets with ease and does every night on local and national news. Most local advertising and promos are also done in 4:1:1.

DVCPro now has >60% of the local TV station recording market. The remainder is DVCAM (also 4:1:1), Betacam IMX (MPeg2) and some Digital Betacam (4:2:2, 2x compressed). Digital Betacam is usually used for graphics intensive production and for network and syndicated program playback.

The main reason network and syndicated programs are distributed on Digital Betacam is because they need to be upscaled for HDTV feeds. Local stations are just beginning to buy true HD recording equipment. Today they are just retransmitting the feed coming in off satellite.

[vhelp]

Ok. Here we go

A few people claim to have successfully captured uncompressed
with GraphEdt (a developer tool from Microsoft).

I believe that this may be inacorrate info from that site.. more or less,
it is likely to be the following example theory:

<<source>> -> MPEG card -> -[encoded mpeg stream intercepted]- -> [YUV_to_RGB]

In other words, they intercept the encoded MPEG stream from the card
and convert it to RGB (or whatever format being theorized here) and this
is probably done in real-time of course. Just like the real-time encoder
apps for DV. It's all possible, just so long as you have the knowledge
and know-how to put it all together

@ edDV

The Absolute Capture Setup ...

If what you say is true, in your last two paragraphs, then that explains
a lot more (at least to me) You see, I'm under the impression that all
TV broadcasts are (at least these days) MPEG, which in my understanding
is 4:2:0 in the end. And this same 4:2:0 is YUV color space.

.. I have briefly argued that 411 and 420 are too similar to bother arguing
.. about, though few still continue in that stand. These two "sampling" formats
.. are just slight variations to the eye. Once encoded to MPEG, there is *NO*
.. difference - period)
..
.. You can't go on a rampage to compare 420 vs. 411 when (if you read below
.. and consider as followup to this note here) your capture device (say
.. a DV advc-100 device is 411 and you proceed to capture a 420 source.
.. Why ?
.. IMO, its because you do not have the 420 source to *captured* as 420,
.. later to capture the same source, but in 411, and finally, to compare both.
.. It's just not in one's reach.
..
.. With the exception of having in possesion, an Analog Capture card that
.. can capture in YUV 420, and be in the form of such AVI to process and
.. analise. At best, and in my experience, I am only able to capture as
.. either, Uncompress RGB 24/32, or a codec variation of YUV. I don't
.. consider Huffy a true YUV 420 codec. In fact, I do not recall ever
.. seeing any setting in Huffy to capture in YUV 420 format. If it does
.. capture in YUV, it is doing so in some strange Sampling Format that I
.. (at this time) am not able to detail.
.. Huffy does compress, aka.. is lossy.. even it's website says so.

And, our capture devices (all that I am aware of to this day) are YUV by
nature, but can capture in RGB (through built-in YUV_to_RGB conversion)
if so requested by user (through mechanism of software control) ..
.
Thus, if we want MAXIMUM *reproduced* quality from a (any) source, than
we most certainly want a *TRUE* YUV capture card, that will allow a
user to capture in *TRUE* YUV space, but that matching of the sources'
YUV space.. not YUV 422 or yuv 411 or other odd format.. but, rather
YUV 420 *because* that is what the source is, once inside our devices
such as Cable or Satalite boxes, or even Antenna sources.
.
The reason why I may sound doubtful (when you read my *TURE* clause)
is because I'm not sure of which setup to use, when I'm capturing from
an Analog Capture card, (ie, my Winfast card) and there are (besides
other options) [Uncompressed]; and [Full Frame]; (I forget the exact name)
as options to capture. This leads me to believe that one of them is
the *TRUE* "by nature" to capture in.
.
That means, that if all capture cards are YUV, (and anything else, is
Converted_To, and our source if YUV 420, then the obvious (and most
pricise) choise is choose the one that instructs the Analog Capture
card to capture in *TRUE* YUV 420, and proceed to encode this
source to MPEG which is YUV 420

Now, in considering what you commented in your last response, I would
say, that if the broadcasters are airing YUV 411 video, then the best
method to capture this video and process, would be through the devices
that capture in DV format.. (ie, our ADVC-100 devices) this would be
the magic ingrediant.
.
Somehow, I have reservations about this, but only because of the slight
artifacts that are present in DV, due to it's format detail.. most
commonly refered to as the "411 bug" and mostly seen in RED areas along
the edges of fine detail.. of which I have accepted.
.
However, I beleive that broadcasters *do* use DV in their video work,
but that in the end, it is processed to MPEG. And, if it *is* processed
to MPEG, then that means, YUV 420 is the format to capture in.
.
But, before we can be *sure* that YUV 420 is the format to capture in,
we must be sure that our *devices* (ie, VCR; Cable box; etc) are all
serving us a YUV 420 format (RCA/S-Video) source to begin with.
.
It is my opinion that the only devices that meat this precision, are
those of hardware MPEG boards. Because they encode data directly to
YUV 420 mpeg. All that has to be researched in this area, is the
trueth, weather or not, it is capturing in YUV 420 and *then*( processing
it to an YUV 420 MPEG, and no conversion or compressing other than the
final encoding to MPEG.

Either way, and in the end ...

This (above) looks to me to be the most effeciant and pricise way to
reproduce through the machanism of (DV) or Analog Capture devices.

- vhelp 3389

[junkmalle]

Ok. Here we go

A few people claim to have successfully captured uncompressed
with GraphEdt (a developer tool from Microsoft).

I believe that this may be inacorrate info from that site.. more or less,
it is likely to be the following example theory:

<<source>> -> MPEG card -> -[encoded mpeg stream intercepted]- -> [YUV_to_RGB]

In other words, they intercept the encoded MPEG stream from the card
and convert it to RGB

I thought that might be the case too. I just didn't feel like bringing it up. And the people that made the claim were very excited about it so I decided to take them at their word.