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-   Sony HVR-V1 / HDR-FX7 (https://www.dvinfo.net/forum/sony-hvr-v1-hdr-fx7/)
-   -   High Action/Motion Video from HVR-V1U (https://www.dvinfo.net/forum/sony-hvr-v1-hdr-fx7/92806-high-action-motion-video-hvr-v1u.html)

Mike Gorski April 30th, 2007 02:09 PM

High Action/Motion Video from HVR-V1U
 
I know a lot of people on here second question the HDV format when it comes to a lot of motion and the ability of the camcorder to produce smooth flawless video. The GOP/HDV type compression makes it a difficult challenge but does anyone have some video they can share that shows the quality of the V1 with regard to a lot of motion or actions such as sports. I know finding a place to host is hard but if anyone has run across any links can you please post them here. Thanks for your time.

Gorski

Giroud Francois April 30th, 2007 02:29 PM

high action is a way to disturb an mpeg encoder, but it is not the only one.
the moving water of the surface of a lake is a difficult one too.
a vertical pan on ah highly detailled picture works also.
sudden light intensity (flashes) are good candidate too.

Mike Gorski April 30th, 2007 07:38 PM

Thanks for the extra info.

Marcus Marchesseault April 30th, 2007 10:15 PM

I find that the fast-action footage can look very good, but it is more difficult the more pixels change from one frame to the next. A camera tracking a motorcycle on brown dirt against a blue sky actually doesn't have too many pixels change. If the blue sky fills 25% of the screen in the upper left and right, that makes the compressors job a whole lot easier. A person running through a scene where the camera does not pan is not a problem at all. The background remaining static allows plenty of information for the runner. HDV really can make some great footage, but to be absolutely perfect in all situations the bitrate would need to be raised. The 25mbps of HDV is ALMOST there, but the 35mbps of XDCAM is where it could start to be perfect. Even with the odd compression error, HDV is far superior to DV. The images can be quite stunning on a big HDTV. Don't forget that broadcast HDTV signals are frequently 19mbps, so HDV is technically better than broadcast.

Giroud Francois May 1st, 2007 05:14 AM

yes the fast action picture has the advantage that even if the picture goes bad, it is not sure you will see it.
on the other hand some slow but difficult pictures can be more disturbing since the sudden degradation (most of time blockiness) is very visible.
if you know how mpeg is working , it is easier to create problematic shot (or avoid it).
basically, mpeg cuts a picture in small blocks, then calculate/predict between each picture the movement(direction) of each blocks.
if blocks are all moving as predicted or all to the same direction, the picture will look good. If blocks are moving too randomly, prediction will fail and the encoder will have to thrown out some info (bandwidth exceeded), so the loss in quality.
that is why a calm water surface with just small wave can be a nightmare for a mpeg encoder because the random behaviour of water.

Shaun Walker May 21st, 2007 10:15 PM

Hmmm ... Whitewater kayaking, handheld?
 
Wow ... I'm starting to worry a little about doing handheld HDV footage of fast-action whitewater kayaking, sometimes while I'm still floating in a kayak myself or am zoomed in fairly tight to a wildly churning/ splashing/ crashing rapid or waterfall.

Then again, what other choices do I have?

What are the least expensive higher-bitrate/less-artifacty camcorders and how much do they cost?

Marcus Marchesseault May 21st, 2007 11:38 PM

All HDV camcorders are typically the same bitrate. You really have nothing to fear. If you want something inexpensive, I would guess that the populous of these boards would recommend the Canon HV20 and the Sony HC series (HC1, HC3, HC5,...) for the very small cameras and maybe an FX7 if you don't mind your budget and size increasing. The smaller cameras are about $1300 and the FX7 is twice that. If your budget is creeping towards $3000 anyway, you will get a lot of recommendations to go up to the Canon A1 which is now under $3500. It is also another step larger than the FX7 but still a handheld.

Water isn't the problem. There is a particular issue with waves on the surface of water that can cause a minor problem but that shouldn't be present in your shots. Imagine a scene of a sunset over the ocean. The water would fill the bottom half of the scene. At this angle, several miles of ocean are in the shot. There are thousands of waves moving very quickly through the scene, but the apparent effect is a sort of flashing back-and-forth between a white and black pixel. As the waves go up-and-down, they oscillate quickly between a side that is lit and the other that is shadowed by the sun. When almost every other pixel on the screen is bouncing between black and white in a random pattern, there can be some macroblocking. It is a few scenes like this that can have a problem and even then it may very well not be noticeable. Keep your camera as stable as possible and you will probably never notice compression artifacts with HDV.

I can't post any footage from my V1 where there are apparent compression artifacts because I haven't noticed any. There may very well be technical flaws with some of my footage, but if it isn't noticeable while watching it doesn't matter. You will see far more compression artifacts watching big-budget movies on "professional" broadcast HD television every day. If "amateur" equipment originates footage better than the pros broadcast, I don't see a problem with HDV.

Piotr Wozniacki May 22nd, 2007 12:57 AM

Quote:

Originally Posted by Marcus Marchesseault (Post 683523)
You will see far more compression artifacts watching big-budget movies on "professional" broadcast HD television every day. If "amateur" equipment originates footage better than the pros broadcast, I don't see a problem with HDV.

I second that, Markus.

Shaun Walker May 22nd, 2007 04:25 AM

Quote:

Originally Posted by Marcus Marchesseault (Post 683523)
Water isn't the problem. There is a particular issue with waves on the surface of water that can cause a minor problem but that shouldn't be present in your shots. Imagine a scene of a sunset over the ocean. The water would fill the bottom half of the scene. At this angle, several miles of ocean are in the shot. There are thousands of waves moving very quickly through the scene, but the apparent effect is a sort of flashing back-and-forth between a white and black pixel. As the waves go up-and-down, they oscillate quickly between a side that is lit and the other that is shadowed by the sun.

I'm not too concerned, and the alternatives are very pricey, but the circumstances I'll be shooting in sometimes are quite different and can have nearly frame-filling, chaotic, splashing whitewater ... Like this:
http://www.dreamflows.com/Trinity/frank.trinity.lg.html

Piotr Wozniacki May 22nd, 2007 04:33 AM

Shaun,

My advice with content like this would be not to add "stress" to the HDV encoder with fast zooms, pans etc. If you keep your shots reasonably steady, the water itself should be handled just fine. Just MHO.

Steve Mullen May 22nd, 2007 05:26 AM

Quote:

Originally Posted by Piotr Wozniacki (Post 683591)
Shaun,

My advice with content like this would be not to add "stress" to the HDV encoder with fast zooms, pans etc. If you keep your shots reasonably steady, the water itself should be handled just fine. Just MHO.

I agree. The mpeg-2 blocking on 1080i60 hdtv channels are very painful. I've never seen anything from any hdv camcorder that is this bad. In fact, I just shot moving water with my old jvc hd1 -- zero blocking.

But, I expect CU of a bomb explosion would do it.

If you really want to be safe use xdcam hd or 720p24.

I really am getting tired of battling these endless myths about hdv. do folks realize that 720p24 is compressed less than dvcpro hd 24N? Yet, 24N is seen as fully acceptable.

and where is avid's support of 720p25 and fcp's support of the v1's 24p?

a good friend claims sony really doesn't care if the v1 flys because they have never supported shared standards like hdv. he claims they want to promote xdcam ex just like they do dvcam. i'm beginning to think he's right. after all, jvc long ago moved to ProHD.

i'm typing lower case because i have three new kittens and they are trying very hard to add their own keystrokes.

Bob Grant May 22nd, 2007 07:47 AM

Quote:

Originally Posted by Steve Mullen (Post 683605)
a good friend claims sony really doesn't care if the v1 flys because they have never supported shared standards like hdv. he claims they want to promote xdcam ex just like they do dvcam. i'm beginning to think he's right. after all, jvc long ago moved to ProHD.

i'm typing lower case because i have three new kittens and they are trying very hard to add their own keystrokes.

Never supported shared standards like HDV?

Well they didn't do too bad a job with DV, I wasn't in this game back then but I'm reliably told by just about anyone that was that DV came alive with Sony's VX1000.

HDV?, wasn't it Sony's Z1 that lit the fire under that format?

And who are the only ones that haven't caused compatibility problems by going outside that shared standard, Sony.

JVC 'moved' to ProHD? Well their first efforts at HDV wasn't exactly stellar but why did they move down to 720p?

XDCAM mightn't be a "shared" standard but at least you've got a choice of media vendors, if you wanted to pick on anything as being closed Panny's P2 would surely have to win that crown.

If you want to knock Sony for their closed and/or dodgy formats there's plenty of them but HDV isn't one of them.

Of course the reality is most things that look closed aren't, it's just that one vendor sees a hole in the market and finds a way to plug it. The rest realise the hole isn't big enough for two players and leave the market to one vender. IMX would be a good example. A pretty problematic format when it first rolled out but it still works well in many situations like Big Brother. It's never been a huge money earner for Sony but they still support it and even continue to develop for it.
I guess the reason mundane realities don't get much coverage is conspiracy theories sell more copy.

Congrats on the kittens, I'm a real sucker for them myself. Don't know how you stop them typing, our 8 year cat loves my noisy original IBM buckling spring keyboard.

Wendell Alvero May 22nd, 2007 09:49 AM

I just taped a hip-hop dance competition last week and I have to say that the V1 handled it great. It caught all the movements and looked very smooth and fluid. People who saw the footage was very impressed by it and love the hi-def look. Even I was taken back, because everyone has been talkin about a long GOP and was thinking the V1 wouldn't be good for sports, but it handled this test very well. I wish I can upload it it here by I have no online storage.

Piotr Wozniacki May 22nd, 2007 09:56 AM

Wendell, why don't you try this: www.rapidshare.com. Works great for me!

Marcus Marchesseault May 22nd, 2007 10:34 AM

Do you know what I see in that Trinity River shot? It's almost all white. There is some static black and a bunch of white that is going to swirl around. It's not going to flash from all black to all white every other frame. There will be plenty of data avialable to record the kayakers in all their HD glory. No, it won't be perfect, but it may very well be stunning.


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