is the argument for hdv as opposed to the the more robust format of the hvx that hdv is recorable to tape? what are the other arguments for hdv? someone at creative cow seemed to suggest hdv actually had some advantage in terms of the image. anyway, what does hdv have on the hvx version?
arguments for hdv?
- Thread starter brianluce
- Start date
MovieSwede
Well-known member
think the image res is 1440*1080 is in hdv. But the chroma res is much lower on the HDV.
But other than that it just the cheap tape the hdv has as an advantage.
But other than that it just the cheap tape the hdv has as an advantage.
Jarek Zabczynski
Veteran
MovieSwede said:
"cheap tape" Some may call that a disadvantage, especially with HDV and mpeg compression.
Barry_Green
Moderator
There's nothing about HDV recording that is superior to DVCPRO-HD recording. The only argument that can be made is regarding luma sampling in 720p mode, because DVCPRO-HD's 720p mode downsamples by 25% (which totally ignores the fact that DVCPRO-HD's 720p mode records 50% more chroma, plus has *no* motion artifacts and is an overall much more robust compression system).
The arguments in favor of HDV are that a) it takes up less space on the disk, and b) it can be recorded on a $5 tape, and c) that it can record an hour's worth of footage to that tape. Also, with the 720p version, it can theoretically be directly broadcast without any recompression (something that is not true of the 1080 version).
The arguments in favor of HDV are that a) it takes up less space on the disk, and b) it can be recorded on a $5 tape, and c) that it can record an hour's worth of footage to that tape. Also, with the 720p version, it can theoretically be directly broadcast without any recompression (something that is not true of the 1080 version).
Barry, didn't you also say that in some situations 720p HDV displays less mosquito noise than DVCPROHD?
Regardless... HDV is designed to be CHEAP HD. It has plenty of resolution and is very cheap to shoot, but at the expense of heavy compression. If you are doing a lot of green/blue screen work in HD, I would spend the extra for DVCPROHD 4:2:2 compression OR capture uncompressed straight to a computer - I presume most green/blue screen work is in a studio. Canon's XLH1 would be ideal for that because of its HD-SDI output.
From what I have seen 720p HDV is pretty decent, and personally I am more worried about the capabilities of the camera than the codec in the majority of situations. I haven't seen so much footage on 1080i, but I hear it is more prone to artifacting, which makes sense.
Also remember that HDV is far cheaper to use when editing as it takes up 19-25Mbps instead of 40-100Mbps for DVCPROHD...or 1.5Gbps for 4:2:2 uncompressed. So you will be able to spend between 2 and 5 times less on hard drives. With DVCPROHD you also have the expense of backing your footage up after it is deleted from P2, this is built in with HDV.
At the end of the day I would take a good camera recording to HDV than a poor one recording to DVCPROHD any day of the week... As far as which camera is best, we won't know until they are released.
Regardless... HDV is designed to be CHEAP HD. It has plenty of resolution and is very cheap to shoot, but at the expense of heavy compression. If you are doing a lot of green/blue screen work in HD, I would spend the extra for DVCPROHD 4:2:2 compression OR capture uncompressed straight to a computer - I presume most green/blue screen work is in a studio. Canon's XLH1 would be ideal for that because of its HD-SDI output.
From what I have seen 720p HDV is pretty decent, and personally I am more worried about the capabilities of the camera than the codec in the majority of situations. I haven't seen so much footage on 1080i, but I hear it is more prone to artifacting, which makes sense.
Also remember that HDV is far cheaper to use when editing as it takes up 19-25Mbps instead of 40-100Mbps for DVCPROHD...or 1.5Gbps for 4:2:2 uncompressed. So you will be able to spend between 2 and 5 times less on hard drives. With DVCPROHD you also have the expense of backing your footage up after it is deleted from P2, this is built in with HDV.
At the end of the day I would take a good camera recording to HDV than a poor one recording to DVCPROHD any day of the week... As far as which camera is best, we won't know until they are released.
Barry_Green
Moderator
Only in a theoretical "best-case" scenario; shooting a still scene, for example. If it's any sort of real-world situation, then no. But for a laboratory test scenario, yes 720p HDV can exhibit less mosquito noise than DVCPRO-HD does.mmm said:
mmm makes a good point about the built-in archive too, but to be fair, it also is a disadvantage (P2 is ready to edit immediately, HDV has to be logged and captured from tape). So that's not a clear-cut advantage, more of a tradeoff (because if you were to archive P2, you'd be spending a comparable amount of time as the HDV shooter will in capturing).
To be fair, the comparison in 720p is:
HDV:
Y: 1280x720
Cr: 640x360
Cb: 640x360
DVCPRO-HD
Y: 960x720
Cr: 480x720
Cb: 480x720
Per frame, HDV has 460800 chroma pixels, DVCPRO-HD has 691200 chroma pixels.
Or, total HDV has 1382400 pixels, DVCPRO-HD has 1382400 pixels.
So actually, per frame, each image has exactly the same amount of information. HDV has 33% more luma, DVCPRO 33% more chroma.
-Spiff
Barry_Green said:
It would be interesting to do some real world tests to compare 720p24 of HDV and DVCPROHD. DVCPROHD would obviously win on colour rez, HDV on luma res, but compression artifact wise, I would guess HDV would be better in most situations as interframe is around 2-5 times more effecient and at 19Mbps to 40Mbps...well ... any thoughts?
Barry_Green
Moderator
DOH! Yes, that is one that I always point out, and didn't do so this time -- thanks for bringing it up! :thumbsup:taubkin said:
Barry_Green
Moderator
Your math is off -- it's 50% more chroma. 460800 * 1.5 = 691200.Spiff_2 said:
If you want to be fair though, we should examine the whole spectrum. HDV's 720p currently doesn't support 60p, nor will it likely ever (even though it's in the standard) because of the extreme compression it would undergo. So assuming a max frame rate of 30P (as all 720p HDV products to date have been), vs. 60p on DVCPRO-HD, you're talking about 41.4 million pixels per second, vs. 27.6 mpps for HDV. Plus variable frame rates, something HDV has no provision for.
It really depends on what you're trying to compare. If you're trying to compare 720/24p HDV against 720/24p DVCPRO-HD, that unnecessarily limits DVCPRO-HD. HDV is limited to 720/24p and 720/30p, but DVCPRO-HD isn't -- it can go to 1080/24p, 1080/30p, 720/60p, 720/4p, 720/22p, 720/36p, etc.
So if you want to compare resolution at 24p, HDV can deliver 1280x720 with 640x360 chroma. But DVCPRO-HD is capable of 1280x1080 with 640x1080 chroma -- 50% more luma resolution, and three times as much chroma. So you really have to ask yourself: why limit DVCPRO-HD to 720/24p? Is it only to make the HDV comparison look better? Because if your limiting goal is 24p, DVCPRO-HD is capable of a whole lot more. And if your limiting factor is 720p, DVCPRO-HD is capable of a whole lot more.
HDV's advantages are what they are: it's available now, it records on cheap tape, etc. Image quality is not now, nor will it ever be, an advantage for HDV.
I am just saying that it would be interesting to compare the two. It wouldn't necessarily be useful for comparing DVCPROHD to HDV, but is a good example of interframe against intraframe. And if you were shooting 720p with no need for variable frame rates, it would be a useful comparison.
If they were pretty even, maybe Pany would implement 720p HDV on the HVX200A so that you could just keep one 4GB P2 card for your slow-mo, green screen and crazy handheld moments...:evil: :evil: :evil:
I find that a high bitrate (~7Mbps) DVD is comparable with DV at 25 Mbps.
If they were pretty even, maybe Pany would implement 720p HDV on the HVX200A so that you could just keep one 4GB P2 card for your slow-mo, green screen and crazy handheld moments...:evil: :evil: :evil:
I find that a high bitrate (~7Mbps) DVD is comparable with DV at 25 Mbps.
1/1.5 = 0.666666 -> 33%
My math isn't off... it's just inverted. Percentage is meaningless unless you define which is "100"... which is why I took the care to point out the actual pixel counts - i.e., the number of 8 bit numbers.
As for the 19 Mbps HDV @ 24p with exactly the same amount of information as DVCPRO-HD 24p at 40 Mpbs... taking the GOP into account the two should be almost exactly comparible.
Well - everyone here seems to think 24p is the only way to shoot - so who cares about 720p60 or 720p30 - unless you're looking for gimmicky slo-mo? It's nice, and a real advantage - but hardly a "killer app" for most people. Furthermore, everyone seems to like real progressive data - pull-down reversal can be irritating. Also, because if you're comparing 1080 formats, you should consider 1440x1080 HDV going to 24p. In this instance, it's expected HDV will fare marginally worse. In this case, HDV has again more luma... and if we crunch the numbers:
HDV
Y: 1440x1080
Cr: 720x540
Cb: 720x540
total: 2332800
DVCPRO-HD
Y: 1280x1080
Cr: 640x1080
Cb: 640x1080
total: 2764800
We can see there's actually more information in the DVCPRO-HD stream.
HDV has a lot of positive features, not the least of which is that the perceived quality of the output in all cases will be very comparible to DVCPRO-HD. No one really seems to believe that, but there are very legitimate reasons to expect HDV 720p to be entirely equivalent at 24p to DVCPRO-HD at 24p for nearly all tasks. At 1080i DVCPRO-HD is a clear cut winner... but the difference in price and overhead for the format will be barely justifiable to the vast majority of people.
-Spiff
My math isn't off... it's just inverted. Percentage is meaningless unless you define which is "100"... which is why I took the care to point out the actual pixel counts - i.e., the number of 8 bit numbers.
As for the 19 Mbps HDV @ 24p with exactly the same amount of information as DVCPRO-HD 24p at 40 Mpbs... taking the GOP into account the two should be almost exactly comparible.
Well - everyone here seems to think 24p is the only way to shoot - so who cares about 720p60 or 720p30 - unless you're looking for gimmicky slo-mo? It's nice, and a real advantage - but hardly a "killer app" for most people. Furthermore, everyone seems to like real progressive data - pull-down reversal can be irritating. Also, because if you're comparing 1080 formats, you should consider 1440x1080 HDV going to 24p. In this instance, it's expected HDV will fare marginally worse. In this case, HDV has again more luma... and if we crunch the numbers:
HDV
Y: 1440x1080
Cr: 720x540
Cb: 720x540
total: 2332800
DVCPRO-HD
Y: 1280x1080
Cr: 640x1080
Cb: 640x1080
total: 2764800
We can see there's actually more information in the DVCPRO-HD stream.
HDV has a lot of positive features, not the least of which is that the perceived quality of the output in all cases will be very comparible to DVCPRO-HD. No one really seems to believe that, but there are very legitimate reasons to expect HDV 720p to be entirely equivalent at 24p to DVCPRO-HD at 24p for nearly all tasks. At 1080i DVCPRO-HD is a clear cut winner... but the difference in price and overhead for the format will be barely justifiable to the vast majority of people.
-Spiff
LearningVideo
Well-known member
IMHO, I do not believe that a tape is an advantage. In my thinking, a tape is a major disadvantage.
Luis Caffesse
Admin
"IMHO, I do not believe that a tape is an advantage. In my thinking, a tape is a major disadvantage."
I think most people are mentioned tape as an advantage in terms of the portability and recording times it offers. For example, for documentary location shooting, tape would be a pretty big advantage (all things being equal...which they never are).
Also,
wouldn't the resolution be an advantage in HDV's favor when talking about something like the XLH1? I point that camera out specifically due to it's high pixel count. Granted, pixel count isn't everything and we may see a decrease in dynamic range and low light capability due to this size of the pixels...but it is an advantage if you're seeking the highest resolution possible.
It seems difficult to compare the two formats without comparing the specific cameras themselves.
I think most people are mentioned tape as an advantage in terms of the portability and recording times it offers. For example, for documentary location shooting, tape would be a pretty big advantage (all things being equal...which they never are).
Also,
wouldn't the resolution be an advantage in HDV's favor when talking about something like the XLH1? I point that camera out specifically due to it's high pixel count. Granted, pixel count isn't everything and we may see a decrease in dynamic range and low light capability due to this size of the pixels...but it is an advantage if you're seeking the highest resolution possible.
It seems difficult to compare the two formats without comparing the specific cameras themselves.
LearningVideo said:
The advantage of tape is a slightly different arguement, but the same applies and it is far easier to argue. I suppose you could say:
The advantages of HDV:
• It fits on a MiniDV tape
• It has higher luma rez than DVCPROHD equivalents
• Requires fair less bandwidth for storage and editing
The advantages of MiniDV tape over P2 and Firestore:
• Dirt cheap to buy
• Built in backup/archiving
• Long recording times
• Very unlikely to have a complete data loss.
• Very fast change over - No offloading and deletion required.
• Easy to pass on to clients and employers - eg, when I hire a second cameraman, I don't need to borrow his P2/Firestore at the end of the day.
• Common place all over the world.
Over Firestore:
• Light and intergrated.
Now I am sure Barry will present the flip side of the coin, with at least twice as many points - but no double using of reasons Barry :laugh:
Lots of things said here, some of them based on questionable deduction...
Anyhow: HDV has some advantages: You can NOT rule out higher resolution (Y). It is very important. Obviously the compression makes is less interesting to some applications, but I can imagine there are applications where HDV might even be better then DVCPRO-HD, just because of resolution.
DVCPRO hasn't catched on here in Europe, because it was considered crap. I can't say all reasons for that were true, but not all of them were wrong.
DVCPRO-HD would be an ideal higher-end professional format, but the framesizes and the fact that it's anamorphic won't coöperate. DVCPRO-HD should have been 1280x720 and 1440x1080/1920x1080. That would make it a lot more interesting. If then something would be published to consumers in a HD format that would likely be something like HDV, it could be DOWNCONVERTED in all aspects. DVCPRO-HD needs to be UPCONVERTED for resolution alone. And that is an important factor, no matter how hard you stress other benefits DVCPRO-HD might have.
Anyhow: HDV has some advantages: You can NOT rule out higher resolution (Y). It is very important. Obviously the compression makes is less interesting to some applications, but I can imagine there are applications where HDV might even be better then DVCPRO-HD, just because of resolution.
DVCPRO hasn't catched on here in Europe, because it was considered crap. I can't say all reasons for that were true, but not all of them were wrong.
DVCPRO-HD would be an ideal higher-end professional format, but the framesizes and the fact that it's anamorphic won't coöperate. DVCPRO-HD should have been 1280x720 and 1440x1080/1920x1080. That would make it a lot more interesting. If then something would be published to consumers in a HD format that would likely be something like HDV, it could be DOWNCONVERTED in all aspects. DVCPRO-HD needs to be UPCONVERTED for resolution alone. And that is an important factor, no matter how hard you stress other benefits DVCPRO-HD might have.
Jarek Zabczynski
Veteran
mmm said:
Not when dealing with HDV on MiniDV.
Gimmicky? I think HDV when implemented well can certainly be useful - depening on the application. But gimmicky slow motion? It's entirely real and very useful for many, many shooters (weddings, indie films etc). I think, for most people, slow motion is a very important issue to consider.