I'm currently in the middle of that great "Should I get the HVX or the XH-A1 debate". And I was wondering if you can really tell a difference in quality between the DVCPROHD and HDV. I unfortunately haven't been able to compare raw footage and have only been able to see examples through already compressed media, so I wonder what the actual difference is and perhaps, if someone could point me to examples showing the faults of hdv, that'd be great too.
HDV Compression, Can you really tell?
- Thread starter ObiMcD
- Start date
t-h-e-w-h-o
Well-known member
Honestly, i have never been happier with a camera. The A1 is great. I have used the HVX200, but i cant tell you whats better since i dont own both. I havent done enough on the hvx to give good info.
BUT i will tell you this, for your money, an A1 and a firestore is a sure win. Or, dont need the firestore? Get 2 a1's.... There still cheaper than an HVX and its p2 card media....
BUT i will tell you this, for your money, an A1 and a firestore is a sure win. Or, dont need the firestore? Get 2 a1's.... There still cheaper than an HVX and its p2 card media....
I'll tell you this, there is ZERO difference in image quality. 99% of the time HDV is completely flawless. The 1% of the time is when you want to do heavy color correction or green screen, in which the extra color space might make a difference. Or you get lucky and get to see your work projected on a 1080p monitor.
There's a lot of hyperbole out there that might make you think HDV is useless and full of artifacts etc. but the honest truth is that it's a perfectly fine, although heavily compressed codec. People kept saying that it breaks up in extreme motion or coming out with outlandish scenario that most of us won't ever encounter in order to discredit HDV, but do a search either on here or on DVinfo and you'll find example of people deliberately taking their HDV cam to the limit, and see very few artifacts, if any.
There's a lot of hyperbole out there that might make you think HDV is useless and full of artifacts etc. but the honest truth is that it's a perfectly fine, although heavily compressed codec. People kept saying that it breaks up in extreme motion or coming out with outlandish scenario that most of us won't ever encounter in order to discredit HDV, but do a search either on here or on DVinfo and you'll find example of people deliberately taking their HDV cam to the limit, and see very few artifacts, if any.
t-h-e-w-h-o
Well-known member
jade8472 said:
This is very true, i think early "prosumer" HDV may have been like this (again dont quote me) probably the shitty sony hdv cams. But, hdv does not break up or artifact. I do heavy stuff with my camera, infact, i took it to its limit yesterday and filmed the band "Gym Class Heroes" live in San Francisco. It was a low light situation to the max, so i used the custom preset someone gave me here. It did well, but it had lots of grain (a1 gets grain when using 12+ Gain) and im doing some hardcore color correction right now and its still not giving up on me. Thats to say that it looks great even still
Barry_Green
Moderator
When used in ideal conditions HDV compares quite favorably. When used in less-than-ideal conditions HDV can suffer, and when used in extreme conditions HDV will turn to complete mush.ObiMcD said:
So it depends on what you intend to use it for. I can point to plenty of shots that show how HDV fails in extreme conditions, but those may not be relevant to your proposed usage.
To those who say it doesn't artifact, you just haven't put it in the right (or "wrong") set of circumstances. I'm pleased it's working out for you, but don't make a blanket statement about how suitable it is because it may very well not work properly for someone else.
Barry_Green
Moderator
It's not necessarily what you would think. Some things are obvious, yes, but other things may never occur to you. Here's a sampling of things that can cause problems:
Fire (flickering firelight), fireworks (especially not pointed at the fireworks, but shooting a scene that's indirectly lit by fireworks), flashing lights, strobelights, smoke, fog, dust, rippling water, zooming, rotating the camera, a 35mm adapter's vibrating ground glass, flashbulbs (like a "red carpet event" might do it), explosions, or fast-paced jittery events like mountain biking.
Not all of these will do it. It depends on how much of the frame is affected; if you were shooting a wide scene with a largely black background and a small campfire in the center you won't likely have any problem at all. But if you're doing a full-frame shot of your actor's face and it's lit entirely by flickering firelight, HDV might choke on that -- especially if you were dollying in during the shot, or shooting through a 35mm adapter at the same time, or somehow you combined various of these factors.
If you want to see some of the worst of what can happen in the worst possible cases, I can show you that, but if you're just shooting generic-case footage you may find that HDV is plenty adequate. I went out to find out how bad it could get, and I shot the "Sirens of T.I." show outside the Treasure Island hotel, because it combines many of those elements -- there are explosions, strobelights, fire, smoke, and rippling water, all combined with handheld footage. The results were absolutely disastrous for HDV. But again, that's an extreme case; it was pretty much the worst case scenario I could think of (even though it is a totally legit shooting scenario someone might end up in; it's not like I manufactured an unrealistic scenario, I went and shot that show because I figured that the elements in the show would probably push the codec to the extremes, but it's a regularly-occurring show right there in the public.)
I keep meaning to do an article that shows what HDV can handle and what it can't, so people would know whether they were asking too much from the format. When it's within its limits it can be amazing; and it can be hideous when it's pushed too far.
Fire (flickering firelight), fireworks (especially not pointed at the fireworks, but shooting a scene that's indirectly lit by fireworks), flashing lights, strobelights, smoke, fog, dust, rippling water, zooming, rotating the camera, a 35mm adapter's vibrating ground glass, flashbulbs (like a "red carpet event" might do it), explosions, or fast-paced jittery events like mountain biking.
Not all of these will do it. It depends on how much of the frame is affected; if you were shooting a wide scene with a largely black background and a small campfire in the center you won't likely have any problem at all. But if you're doing a full-frame shot of your actor's face and it's lit entirely by flickering firelight, HDV might choke on that -- especially if you were dollying in during the shot, or shooting through a 35mm adapter at the same time, or somehow you combined various of these factors.
If you want to see some of the worst of what can happen in the worst possible cases, I can show you that, but if you're just shooting generic-case footage you may find that HDV is plenty adequate. I went out to find out how bad it could get, and I shot the "Sirens of T.I." show outside the Treasure Island hotel, because it combines many of those elements -- there are explosions, strobelights, fire, smoke, and rippling water, all combined with handheld footage. The results were absolutely disastrous for HDV. But again, that's an extreme case; it was pretty much the worst case scenario I could think of (even though it is a totally legit shooting scenario someone might end up in; it's not like I manufactured an unrealistic scenario, I went and shot that show because I figured that the elements in the show would probably push the codec to the extremes, but it's a regularly-occurring show right there in the public.)
I keep meaning to do an article that shows what HDV can handle and what it can't, so people would know whether they were asking too much from the format. When it's within its limits it can be amazing; and it can be hideous when it's pushed too far.
Elton
Veteran
Something else to consider is the reality that not all HDV is created equal. Each manufacturer's approach to encoding MPEG2 is slightly different and their chips have differing levels of actual encoding power. Look at the new JVC HD250; they're squeezing 60p into the same 19 mbs bandwidth but getting good results because their encoding effiiciency has improved. HDV isn't like DV or even DVCPRO HD. It's actually evolving in subtle ways because the more processing power you throw at it, the more it can make slight improvements. As the camera heads get better, so too does the encoding.
If you're shooting for the film look using 24F from the A1 you won't likely find too many problems because it uses progressive encoding on only 24 fps, which are both favorable factors when dealing with MPEG2 interframe encoding. More bandwidth per frame and progressive encoding help the more modern MPEG2 algorithms do a better job.
If you're shooting for the film look using 24F from the A1 you won't likely find too many problems because it uses progressive encoding on only 24 fps, which are both favorable factors when dealing with MPEG2 interframe encoding. More bandwidth per frame and progressive encoding help the more modern MPEG2 algorithms do a better job.
i only shoot 24f and you couldn't trade me an hvx for my cheaper canon a1.not to knock the users of the other but my work flow reqires me to shoot alot of tape and if i can get the same result as the hvx at a fraction of the price in terms of image then hdv is just fine.i've had no dropouts in 24f and a heavy color corection on one of my scenes held uo vey nice.if i had the money i'd buy two more of these because the a1 to me will be to canon what the first generation dvx was to panasonic.
Barry_Green
Moderator
Here's an example of when HDV is pushed too far. Here's extractions of two shots from the same HD100 that were taken only a few frames apart; both were extracted from the same clip, as you can tell by the position of the guy on the ropes they're very close together. The top shot is from when HDV was able to handle the shot, i.e., it's "within its capabilities", a shot before everything "hits the fan" as it were; the bottom shot just a few frames later is when HDV was seriously taxed too far so it just turned to complete crap.
This is not two cameras side-by-side or anything, this is all from one continuous shot. It's just that in the top section the compression was able to handle it all, and in the bottom shot it fell apart, but it's the exact same sequence from the same camera, just a few frames later.
This is not two cameras side-by-side or anything, this is all from one continuous shot. It's just that in the top section the compression was able to handle it all, and in the bottom shot it fell apart, but it's the exact same sequence from the same camera, just a few frames later.
90% of the time you wont notice the artifacts because they pass very quickly. That shot, barry posted would be gone and passed over in a few frames, and most people wont notice. Now, lets say you took that footage, Color corrected it. that CCed footage would now have to be Rerendered, and a small amount of additonal artifacts can be introduced. Then lets say, you reexport to Hd-DVD or Worse, you hand it over to a braodcaster for HD trandsmission. They then recompress it in to Mpeg2 again, but this time the Mpeg codec will try to recompress the footage WITH the artifacting as part of the image. It will think that the macro blocking is detial, and try to preserve it. But likely, the efect that causes the initial choke (looked like a flash bulb) will cause the second render to be pushed pretty hard. The artifacts kinda multiply as you pass from one Interframe codec to antoher. This is why many people trandscode their footage right away to Cineform, or Mov's. this way yo ucan keep as much information i nthe image as possible for as long as possible without encountering generational loss.
HDV IS GOOD. But thats it, its Good not great. Sorry to break it to you, guys. ( then again DV wasnt a bargain either.....)
HDV IS GOOD. But thats it, its Good not great. Sorry to break it to you, guys. ( then again DV wasnt a bargain either.....)
Barry_Green
Moderator
As Timur said, that degradation is going to fly by fairly quickly.
HDV works in groups of frames. For 1080 HDV, a group of frames is 1/2 of a second. If you get "hit" with degradation, a half a second will be degraded, and then you'll be on to the next "group" (which may be able to "right the problem" and look good again, or maybe it'll be stressed too... it all depends). For 720p HDV, a group of frames typically lasts somewhere between 1/5 and 1/4 of a second, depending on if it's 24p, 30p or 60p HDV.
You can see this type of artifacting happen in broadcast HDTV too. It uses the same basic compression, long-GOP MPEG-2, and it gets hit by the same issues.
It's just a fundamental compromise necessary to fit a 1,450 megabit data stream onto a 25-megabit tape. It can look fantastic, or it can be pushed too far and it can fall apart. And the worst thing is, you won't know until you play the footage back. You can't see the degradation happen on your viewfinder or LCD or even a live monitor while shooting; you can only see what's happened on playback (or, if you're monitoring through firewire on DV Rack HD, that'll also show it). That's why I say it's important to separate the truth from the myth from the hype, and understand what really causes the problem and what doesn't cause it, and to recognize the reality of the problem and make sure you understand what triggers it and how to avoid it.
The key for you to be aware of is: are the potential uses you're going to put the camera to, likely to cause the problems? If not, then HDV can be a great choice. But if you're planning on shooting horse racing (tons of action with clouds of dust flying) then HDV is probably a lousy choice for that. Nightclubs would be very difficult for HDV to handle. Use it where it's appropriate and it'll do just fine, but understand what its limitations are and you'll keep yourself out of trouble.
HDV works in groups of frames. For 1080 HDV, a group of frames is 1/2 of a second. If you get "hit" with degradation, a half a second will be degraded, and then you'll be on to the next "group" (which may be able to "right the problem" and look good again, or maybe it'll be stressed too... it all depends). For 720p HDV, a group of frames typically lasts somewhere between 1/5 and 1/4 of a second, depending on if it's 24p, 30p or 60p HDV.
You can see this type of artifacting happen in broadcast HDTV too. It uses the same basic compression, long-GOP MPEG-2, and it gets hit by the same issues.
It's just a fundamental compromise necessary to fit a 1,450 megabit data stream onto a 25-megabit tape. It can look fantastic, or it can be pushed too far and it can fall apart. And the worst thing is, you won't know until you play the footage back. You can't see the degradation happen on your viewfinder or LCD or even a live monitor while shooting; you can only see what's happened on playback (or, if you're monitoring through firewire on DV Rack HD, that'll also show it). That's why I say it's important to separate the truth from the myth from the hype, and understand what really causes the problem and what doesn't cause it, and to recognize the reality of the problem and make sure you understand what triggers it and how to avoid it.
The key for you to be aware of is: are the potential uses you're going to put the camera to, likely to cause the problems? If not, then HDV can be a great choice. But if you're planning on shooting horse racing (tons of action with clouds of dust flying) then HDV is probably a lousy choice for that. Nightclubs would be very difficult for HDV to handle. Use it where it's appropriate and it'll do just fine, but understand what its limitations are and you'll keep yourself out of trouble.
Elton
Veteran
HDV certainly isn't perfect, but I've shot at nightclubs with strobes, smoke etc. and been ok. You can't lump all HDV together, each manufacturer's codec is actually different in efficiency, even if, say, a Sony and Canon use the same GOP recording format. The Canon frame modes are noticeably better than regular 60i HDV under stressful conditions.
And HDV isn't necessarily the end of the road. Get an A1 and a MacBookPro with an AJA I/O or use a new PCI Express to Express Card adapter (for nearly the cost of an HVX with the latest 16 GB P2 cards) and take advantage of codec choice if you can deal with the tethered shooting. It's way better than trying to lug a workstation around, I can tell you that.
I mean, lots of folks are lugging their laptops around for set monitoring. (DVRack HD, etc.) With another 3 grand you could record superior ProRes 4:2:2 in full raster.
But of course it all depends on your needs. All I'm saying is if you're needing an A1 for its filmmaking potential, 99% of the time you will find that 24/25F will suffice. For that added need, there's always the uncompressed output if you're actually worried about how well the codec will hold up in a stressful scene.
With that said, how many complaints have you heard from A1 users about HDV artifacts?
And HDV isn't necessarily the end of the road. Get an A1 and a MacBookPro with an AJA I/O or use a new PCI Express to Express Card adapter (for nearly the cost of an HVX with the latest 16 GB P2 cards) and take advantage of codec choice if you can deal with the tethered shooting. It's way better than trying to lug a workstation around, I can tell you that.
I mean, lots of folks are lugging their laptops around for set monitoring. (DVRack HD, etc.) With another 3 grand you could record superior ProRes 4:2:2 in full raster.
But of course it all depends on your needs. All I'm saying is if you're needing an A1 for its filmmaking potential, 99% of the time you will find that 24/25F will suffice. For that added need, there's always the uncompressed output if you're actually worried about how well the codec will hold up in a stressful scene.
With that said, how many complaints have you heard from A1 users about HDV artifacts?
Barry_Green
Moderator
It's not any one easily-pinnable-down thing. It's a million different things, but they all add up to one consistent theme: too much change in the image.
That's what you have to avoid: too much change in the image.
See, HDV can be very efficient because it only encodes the changes between frames. It has a very, very tiny amount of bandwidth, but it functions because there is typically very little change from one frame to another, and actually over the course of a full group there's USUALLY not so much change. For example, imagine a typical interview shot: usually the background will be unchanged from shot to shot, and even largely the person's body will be unchanged; maybe their head moves a little, the mouth or eyes change, but for the most part, from frame to frame, everything stays the same. That's where HDV excels. It can duplicate those unchanged sections and not use up any of its precious bandwidth, except for the small areas that do change -- and if the changed bits are minor enough, HDV will have plenty of bandwidth available to handle those changes.
And it's not even predictable motion that causes problems. Like panning -- that doesn't really stress HDV too much, because MPEG-2 includes "motion prediction" -- it can see that an object has moved across the screen, while staying largely unchanged, so it knows how to just move the object from one position in one frame to another position in the next frame. That's something it was designed to deal with, and it can "predict" that.
But when you get into "unpredictable" territory, that's where MPEG chokes. And when you get into situations where large amounts of the frame change, it dies on that. Which is why strobelights are so bad, or flash photography -- it hates those, because in flash photography, or flickering firelight, *every* pixel in the frame changes! There's no way it has enough bandwidth to cope with that, so it craps out (like in the image above).
For simiilar reasons it hates smoke and fog and dust clouds; those are amorphous unpredictable changing objects and it usually just can't render all that detail accurately, so it goes soft and blocky.
Zooming is also fairly frowned upon -- because while it can handle a basic pan (just moving everything over to the left or right, conserving its bandwidth) the same doesn't happen for zooming! When zooming in (or out) objects are changing size, and that means that just about everything in the frame changes. Hence it chokes.
So fire, explosions, strobelights, flashes, etc -- those all change every pixel, and they do it over the course of several frames, and that's when HDV really chokes. It could maybe handle one superfast flash, if nothing else changed, but with firelight you're looking at slow changes in color and brightness throughout the image, and flash photography can ramp up and down over the course of a few frames... that just pushes HDV too far.
And again, it can sometimes handle one of these "catastrophe" events fine. But when they're combined, that's when your image is toast. Flashing explosions while zooming in? I bet even XDCAM-HD would choke and die on that. Or rotating the frame, like if you were some wild artistic music video shooter? HDV can't predict or handle a rotated frame, so if you have a lot of change and a lot of action and a lot of motion and color changes and rotation or zooming, you're paste.
On the other hand, a typical dramatic narrative scene probably isn't going to tax the codec hardly at all. Unless you combine a 35mm adapter (with a visible grain pattern). That can be a disaster too. If the grain of the ground glass is detected by the codec, that makes every pixel in the image change every frame, and HDV doesn't like that at all; we shot some stuff using the premium Mini35 on the JVC HD100 and it exhibits some of the most objectionable motion-trail artifacts I've ever seen. Now, we didn't know "the rules" for HDV at this time, so we foolishly combined the mini35 with a dolly shot, and that was too much for HDV. We might have gotten away with the mini35 by itself, and probably would have gotten away with the dolly by itself, but putting both together caused the footage to exhibit nasty motion-trailing artifacts with a weird red ghosting after-shadow effect. Look at the weird trailing effect on the buildings in this clip:
http://www.icexpo.com/HD100/HD100-weirdness.wmv
So -- back to the original question: how do you avoid it? You gotta know what causes it, and think ahead, and avoid those circumstances. Or, you have to use something like DV Rack 2.0 HD to monitor your footage while you're shooting it, to see if you're running into troubles. Or don't use a long-GOP compression system. Other than that, I don't know what to tell you. It happens, and when it happens your footage is permanently compromised. But it doesn't happen all the time (obviously), and I dare say many HDV shooters have never run into the issues.
That's what you have to avoid: too much change in the image.
See, HDV can be very efficient because it only encodes the changes between frames. It has a very, very tiny amount of bandwidth, but it functions because there is typically very little change from one frame to another, and actually over the course of a full group there's USUALLY not so much change. For example, imagine a typical interview shot: usually the background will be unchanged from shot to shot, and even largely the person's body will be unchanged; maybe their head moves a little, the mouth or eyes change, but for the most part, from frame to frame, everything stays the same. That's where HDV excels. It can duplicate those unchanged sections and not use up any of its precious bandwidth, except for the small areas that do change -- and if the changed bits are minor enough, HDV will have plenty of bandwidth available to handle those changes.
And it's not even predictable motion that causes problems. Like panning -- that doesn't really stress HDV too much, because MPEG-2 includes "motion prediction" -- it can see that an object has moved across the screen, while staying largely unchanged, so it knows how to just move the object from one position in one frame to another position in the next frame. That's something it was designed to deal with, and it can "predict" that.
But when you get into "unpredictable" territory, that's where MPEG chokes. And when you get into situations where large amounts of the frame change, it dies on that. Which is why strobelights are so bad, or flash photography -- it hates those, because in flash photography, or flickering firelight, *every* pixel in the frame changes! There's no way it has enough bandwidth to cope with that, so it craps out (like in the image above).
For simiilar reasons it hates smoke and fog and dust clouds; those are amorphous unpredictable changing objects and it usually just can't render all that detail accurately, so it goes soft and blocky.
Zooming is also fairly frowned upon -- because while it can handle a basic pan (just moving everything over to the left or right, conserving its bandwidth) the same doesn't happen for zooming! When zooming in (or out) objects are changing size, and that means that just about everything in the frame changes. Hence it chokes.
So fire, explosions, strobelights, flashes, etc -- those all change every pixel, and they do it over the course of several frames, and that's when HDV really chokes. It could maybe handle one superfast flash, if nothing else changed, but with firelight you're looking at slow changes in color and brightness throughout the image, and flash photography can ramp up and down over the course of a few frames... that just pushes HDV too far.
And again, it can sometimes handle one of these "catastrophe" events fine. But when they're combined, that's when your image is toast. Flashing explosions while zooming in? I bet even XDCAM-HD would choke and die on that. Or rotating the frame, like if you were some wild artistic music video shooter? HDV can't predict or handle a rotated frame, so if you have a lot of change and a lot of action and a lot of motion and color changes and rotation or zooming, you're paste.
On the other hand, a typical dramatic narrative scene probably isn't going to tax the codec hardly at all. Unless you combine a 35mm adapter (with a visible grain pattern). That can be a disaster too. If the grain of the ground glass is detected by the codec, that makes every pixel in the image change every frame, and HDV doesn't like that at all; we shot some stuff using the premium Mini35 on the JVC HD100 and it exhibits some of the most objectionable motion-trail artifacts I've ever seen. Now, we didn't know "the rules" for HDV at this time, so we foolishly combined the mini35 with a dolly shot, and that was too much for HDV. We might have gotten away with the mini35 by itself, and probably would have gotten away with the dolly by itself, but putting both together caused the footage to exhibit nasty motion-trailing artifacts with a weird red ghosting after-shadow effect. Look at the weird trailing effect on the buildings in this clip:
http://www.icexpo.com/HD100/HD100-weirdness.wmv
So -- back to the original question: how do you avoid it? You gotta know what causes it, and think ahead, and avoid those circumstances. Or, you have to use something like DV Rack 2.0 HD to monitor your footage while you're shooting it, to see if you're running into troubles. Or don't use a long-GOP compression system. Other than that, I don't know what to tell you. It happens, and when it happens your footage is permanently compromised. But it doesn't happen all the time (obviously), and I dare say many HDV shooters have never run into the issues.
disjecta
Lucky Duck
The HDV artifacts in the HD100 have been well documented on different sites on the Web. It makes my skin crawl when we get into these kinds of debates. As Barlow has said, the HDV codec(s) is developing all the time. The Canon codec is extremely robust and much better than what is illustrated in this thread.
I have shot about 200 hours of footage using a Canon XLH1 and XHA1 in all kinds of situations from fast moving animals to fast paced sports to rippling water to fireworks to flickering fire to falling snow to pounding rain, etc. etc, and I have not once seen anything that bothers me.
My biggest concern on these forums is that there are a lot of impressionable individuals that are quite vulnerable to these limited examples as being gospel.
HDV has been much maligned over the past couple of years and there are many who are still stuck in that old way of thinking. I think posting examples (whether asked for or not) should be reserved for an article that puts all of this in the proper context.
I don't mean any disrespect to you Barry because I know your heart is in the right place but many people skim over things you write, look at the huge pictures in your post, and draw their own sometimes distorted conclusions based on the the reputation of the person posting it. In some ways, I am in the position to influence others myself so I am constantly aware of trying to keep things in perspective.
Does any of what I'm saying make sense? I may be rambling.
I have shot about 200 hours of footage using a Canon XLH1 and XHA1 in all kinds of situations from fast moving animals to fast paced sports to rippling water to fireworks to flickering fire to falling snow to pounding rain, etc. etc, and I have not once seen anything that bothers me.
My biggest concern on these forums is that there are a lot of impressionable individuals that are quite vulnerable to these limited examples as being gospel.
HDV has been much maligned over the past couple of years and there are many who are still stuck in that old way of thinking. I think posting examples (whether asked for or not) should be reserved for an article that puts all of this in the proper context.
I don't mean any disrespect to you Barry because I know your heart is in the right place but many people skim over things you write, look at the huge pictures in your post, and draw their own sometimes distorted conclusions based on the the reputation of the person posting it. In some ways, I am in the position to influence others myself so I am constantly aware of trying to keep things in perspective.
Does any of what I'm saying make sense? I may be rambling.
Gotta say I disagree disjecta. Most of the advice in this thread, even if against HDV, simply seems to be suggesting ways in which one must compensate for potential faults in the compression system. And while the canon system may be more advanced, it is good to know what sort of things could strain the compression and so maybe under what circumstances you should be careful or quickly review your footage. I, for one, am still fairly set on the XH-A1 mainly because of the HD space I'll save on top of the fact that while the p2 workflow may be more efficient, I prefer having a hard copy backup that I can refer to if all hell breaks loose on my hard drives. But it is nice to know how to deal with the potential limitations of HDV, even if it's not as bad as some people claim it is.