all 10801 formats jumpy, 720p formats work wonderful. Has nothing to do with skew?

R

retohalme

Member
This is my first fully professional camcorder. I gave up sony hvr-a1u, as online footage was "jumping", like in Charlie Chaplin films.
HPX 301 did not bring me any relieve, as the same jumping continued, both with moving people and with still scenario panning.
I thought, this is "skew" issue, although skew does not excactly translate to jumps or chakes. I beliewed that there is nothing to do about it, that I have to live with this, as there is no money to another global shutter camcorder.
Thinking through everything possible, starting from tripode fluid head, ending to sata speed of the mac book pro, with no help, I decided to try the 720p formats, and all problems are gone.
So, if the problems is caused by shutter, why does it go away with a "software' solution?

I got inspired of a codex article in studiodaily, and wrote down this memo of an experiment panning handhold using a rolling chair in my white work room, illuminated by a 800w redhead:

these are my working notes. Any comments to the above main question?

cheers

Reto

www.studiodaily.com
There are laptop editing software packages available from Apple, Avid, Grass Valley and others that do support AVC-Intra material, but the bit rate is lower than 50 Mbps and the resulting picture quality is lacking. Ott says he expects clients will have issues with the quality, especially as a project goes through multiple iterations during editing and transmission.
this could be tested by trying to use avcintra50 and to see, if it makes any difference?
tested formats:
1080:
avcintra100: shaky
avcintra50: shaky
dvcpro: shaky
720p (this p, progressive, might be the key issue!!!)
-avcintra50: fantastic, all shake gone like magic
-dvcpro: same fantastic quality
to test more on 720p:
- avcintra100: good and fluent.
- avcintra100 at 25pn: not quite so jumpy,but jumpy, but more unclear, like motion blur.
Then see if there is a similar 1080 format with the P:
- 1080/25pN jumps on viewfinder. Do not jump so much as export, but gets close to the original problem files.
- 1080-501/avcintra100/25pn: totally jumpy
how would the american formats do? as N might be north, as nobody there is complaining.
- 108059i/avcintra100/60i: shakes exactly like the european version
- 108059i/avcintra100/30pn: shaky and blurry, gets one extra stop light
- 1080/59i/avcintra100/24pn: shaky and blurry
 
I think you're just saying that your computer isn't fast enough to play the footage back, aren't you?

Play the footage from your camcorder directly to the television -- do you notice any of this jumping/stuttering? If not, then it has nothing to do with the camera, and everything to do with how fast your computer is.
 
Thanks Barry,

will try, need to find a cable. My idea was to take half off the computer load by using avcintra50 instead of 100. Is the 720p format much less computer intensive?
Have Lacie 4bih quadra raid (configured for speed) on a sata card on the slot. The mac book pro runs on 2.33 core duo.
Can the computer actually CORRUPT the footage for lack of speed. I mean, are we talking about speed of FCP on transcoding, rendering and exporting, or generally about spped of let's say quicktime player when playing exported and compressed footage?

cheers

Reto
 
I am using a 301 with FCP studio and have none of the problems you mention.

I have a mac pro 8-core 2.8g with 8g ram plus a 3tb raid 0 sata array and a macbook pro 2.16g with 2g ram with firewire 800 drive and both handle all formats with no problems.

I am importing AVC intra 100 native at 1080i 25np with FCP ver 7 and I do not see any playback problems.

All my graphics cards are ATI radeon and I shoot at a shutter speed of 50 for 25np.

Have a look at some of the examples here: http://www.vimeo.com/4970462

They were all shot AVC intra 100 with ingest into FCP natively then exported as movies at full res with down conversion to H264 mpeg4 at 5mbs. The resulting vimeo streams are at around 1.5mbs.

Can you give us some more details of what your computer/software set-up is?
 
1080i/720p/shaking image question

1080i/720p/shaking image question

Ok,
so I did what Barry asked me to do, got a cable an run the video signal from video out to standard definition tv yellow video input. Recorded clips both 1080i and 720p separtely formatted p2 cards. Both clip types play well in tv. (In the same tv, the problems have been clearly visible, when burning problem footage on dvd's and playing them back with dvd player, so i dont think it is cause of standard def tv would be forgiving due to its lower resolution).

To make things sure and clear, I imported and transcoded and exported, then compressed the same, in TV good looking 1080i footage in fcp and uploaded to sorenson 360. Actually the sorenson compression has softened the skipping a bit, compared to quictime player playback of the original file.

http://videos.sorensonmedia.com/f89...res422hq/e1813511-9fdb-48a5-9bd5-13c2cd4aca88

The result can be seen here, definitely not stuff you want a commercial client to evaluate. Some pans sure are speedy, but actually with low span speeds the "special effects" would be even more dramatic, as there would be no motion blur, just sharper but as big "jumps". By the way, the same jumping appears when camera is on tirpode and somebody is walking on the street, or just a talking head making fast changes of his position.

Link:


As stated before, going through the same procedure in fcp with 720p/50/avcintra100 does not cause problems.

system:
-MacBook pro intel 2.33 core2 duo, 3 gig of memory, ati radeon x1600
-Lacie big4 quadra, sata configuration for speed and safety (4 gigs reduce to 2gb)
- Lacie sata card sticked to express card slot and other drives are disconnected during work.
- software: FCP pro studio FC 7.01, sorenson squeeze 6, all those P2 components and programs which do function with snow leopard.

workflow summary:
- copy contents of P2 cards unchanged 1 to 1 in P2 folders in a sata drive or other fast drive.
- disconnect all other firewire and usb drives during transcoder.
- fcp log and transfer: preferences: destination: apple prores 422 h.q.
- open timeline with one of these clips and let fcp change sequence settings for this material. Chceck that render settings are all at highest quality.
- edit as usual
- export master movie using export quictimemovie "current settings"
- use sorenson squeeze 6 web mpg4 hd settings for compression and upload (hd setting for mp4 only exists since january 2010).

So it is obvious, that system is not on the level it should be. Should I wait for the new mac pro's to arrive on the market, if 4 cores is considered as minimum of minimums.

Still, it is very interesting, that the 720p/avcintra100 is doing so well in my tiny system, as this footage takes the same place in P2 cards, 35 minutes for 32 gb card.

So, the other part of the conclusions could be, that this type of camera just works more "native" with 720p, as rolling shutter and interlacing are a bit dangerous combination?
 
Hi Reto, I think it's your machine and/or setup. With Final Cut (and other NLEs, I'm sure), you have to make sure everything is setup correctly regarding frame rate, codec, etc. This is especially true if you monitor your video on an external source.

I shoot almost all 1080p video at both 24 and 30 frame rates - no stuttering, jumping, etc. For hardware, I'm using a similar Mac Pro setup as Gary above (8-core, 2.8GHz, 8GB RAM) and all my video is on a separate internal 1TB 7200RPM Seagate drive. I have also played back the video on an external Lacie 500GB drive via firewire-800 with no problems. The video also plays back without stuttering/jumping on my MacBook Pro (2.53GHz, 4GB RAM).

Here are a couple videos I uploaded to Vimeo (shot at 1080p - one at 24 and one at 30fps): http://vimeo.com/8174880
http://vimeo.com/7561778

I think Barry is on the right track - take the camera out of the equation (which I'd bet a lot is not the problem) and you'll know where to look for the solution. Good luck and I hope you find the solution soon - I know over the years how frustrating a video quality issue can be!
 
Two things to check:

1: In log and transfer are you importing AVC 100 as native in the preferences settings?

2: I use quicktime to convert from my master movie in current settings res exported from FCP 7 to apple TV or Computer at 5mbs. It may be that sorrenson is causing the problems.
 
Tryed both native import and transcode to apple prores422 hq with same results.
Sorenson is not a key issue here, as the original exported quictime movie has same issue.
 
It's unquestionably not the camera or the cards or the recording format. Since it plays back good from the camera, you know that the footage got recorded properly. So, follow the other people's advice, because the problem is in the way you're working with the footage in your computer.
 
fcp sequence settings

fcp sequence settings

Have spent another full day doing test transfers to fcp 7.
Indeed the problem has to be in fcp settings.
I have followed the Fcp "AVC intra workflow" quidelines of Apple (native quidelines).
Interesting point is, that if bring a cliean 1080i50 clip to a clean project and "allow" fcp to match the sequence settings to my clip, as recommended, the system forces the editing base frame rate to 25 for my 50 clip. Forcing it to 50 and re-importing and re-rendering dont bring any luck.
In case doing the same with 720p clip, the editing base rate stays voluntarly at 50, and everything works fine.
By mismatching 1080i sequence settings (pixel aspect ratio to square) I can get the movement to be clean and free of jumps, but then of course the aspect ratio is wrong.
I doubt if just adding horsepower to the computer would help, it looks really that something on the settings is wrong.
 
Ah we may have hit a problem here and you have said something that it doesnt seem right to me.

Are you expecting the system to run at 50 frames per sec if you record a 1080 50i clip?

That is not what is meant to happen in PAL land we run at 25fps not 50fps.

So a 1080i 50i clip will run at 25fps and a 1080i 25np clip will run at 25fps.

The 50i is interlaced and two fields per scan so once it is played back it will still be 25fps but with the two fields interlaced.

If you are playing back an exported 50i interlaced recording on some systems such as computers then it will look jerky and have jagged lines, also if you are exporting a 50fps file and then playing it back at 25fps but without interlacing then it will have problems.

I always record at native 1080i 25np and keep in this format all the way through to delivery and have no problems..

Hope this helps I am not a video engineer but I am sure other experts will add to what I think is wrong.
 
frame rates, interlacing

frame rates, interlacing

I am kind of selft taught (ingorant) in these questions, learning things the hard way.
Beeing in still photography 20 years, video only few.
Lived in L.A. with a NTCS camcoder (1080i only).
Then moved to Madrid and clients wanted to use my footage in PAL dvd's or eventually broadcast, alhtouhg most is for the web, which is global.
So I decided to get the 301 to be ok in all countries.
Usually I worked on 25fps timebase anyways, as FCP would bring me there based on the first clip on timeline. Only tested what happens if i force it to 50.
What you said about interlacing seems hitting the key, as If i take out a still of the problem footage (shot 10801, edited 25fps), the worst parts show interlacing lines at the area of the storngest movement, like 1/2 to 2/3 inch long in mac full screen, at that is about the same distance the reulting "jump" in the moving image will be.
 
As I said I tend to shoot 1080i 25np all the time now and have not seen any interlacing problems at all.

OK its the filmic look but as most of my material ends up on LCD screens I think it looks better that way. I adjust the contrast ratios using the scene files but tend to use the BBC video and BBC film settings most of the time.

Certainly I find that the workflow doing this from P2 to delivery is very quick and downscaling for you tube web delivery at 720p works well too.

So to summarise my workflow:

Shoot: 1080i 25np
Import: Native AVC to pro res (HQ)
Edit: Native AVC pro res (HQ)
Export Master: Settings as per edit
Master Mov file: 1920x1080i 25np
DVD Encode from the above.
H264/MP4 for streaming from master movie to: Apple TV 1280x720 @ 5mbs
Upload to you tube etc and let them re-scale it to suit themselves.
Resulting streaming example: http://www.youtube.com/watch?v=LoU1ghlp7Q8

Note I dont use compressor at all and do all my transcoding in quick time.

I also have a canon HF11 that I shoot holiday movies in 1920x1080i 50i and I import the AVCHD into FCP as pro res LT, I then export it as a pro res 1920x1080i 25p file.
Resulting steaming example:http://www.youtube.com/user/HDProdSolutions#p/u/0/kitieXZW_14

I also do broadcast but that is a totally different story as it involves HDCAM SR.
 
In my camera the 1080i 25 pn has shaking in the viewfinder of the camera. Suppose this is caused by slower shutter speed? It doesnt appear in any other format, except 720/25pn.

Other side of the question might be, that maybe 720p/50 just matches my shooting style.
Coming from still photography (fashion, music etc) my trademark has been wide angle (35mm to 28 mm) but filmed from close of the model.
So if the model moves, the movements trhough the screen will be relatively as fast on the screen as a very fast moving subject filmed from more far away.
I like the abstraction of 24 compared to the ultra realistic look of 50, but have been sometimes getting there by slowing down the speed on post (there is no talki in most of my footage).

Here is a sample of that, filmed on my old 1080i sony at 60fps and then slowed down
http://videos.sorensonmedia.com/f89...Final_HD/355d3465-80e9-4389-8840-88de8db1db8f
 
Sounds like your reversing your fields when you are encoding for DVD...

If your shooting interlaced it's upper field for Mpeg encoding...

Cheers
 
It boiles down to the following (some already mentioned here)

-Interlaced footage and progressive (I and P) have both 25 frames per second (in PAL)
-However: the interlaced 'lines' of interlaced footage can be used by good old tv's (and also your camera's viewfinder / LCD playback) to give smoother motion. More specific: the odd and even fields from interlaced footage are being used for this purpose (just google 'interlaced' or 'odd even field')
-You will then also read that this is also called '50i' It's really just the same thing with another name.
-On laptops/computers, you DON'T get smooth motion and you will see those jaggies / miceteeth on moving shots, because computer / laptop screens don't use those lines from interlaced footage. Youtube and vimeo don't use those either! You don't get silky smooth motion, but are just presented with weird looking lines when the'res movement.

Interlaced is just an old school leftover from times where everybody had big old TV's and there wasn't enough bandwith to make it all 50 frames per second. It was just a smart way to get smoother motion with the same amount of bandwith. Since then everybody has moved on to newer technology, but interlaced just wouldn't leave the building :P

So:
-1080i means 1920x1080 interlaced. That means 25 frames per second, but with interlaced lines. Same goes for 576i en 720i
-1080p means 1920x1080 progressive. That also means 25 frames per second, but without the interlaced lines. Same for 576p and 720p

Either way, you alway set your project to 25 frames per second, but either progressive or interlaced depending on the footage. Don't get yourself fooled by terms like "Hey, I got some 50i footage" They just mean they have 25 frames per second footage interlaced. They call it 50i though because every frame is split into an even and odd field (2x 25 = 50 fields)


And last, but not least:
-25p footage is really just HALF as smooth as 25i footage (regardless of 720x576, 1280x1024 or 1920x1080)
-So don't throw you camcorder out of the window because you think the shutter is stuck or something. Every 25p mode is just not as smooth as the 25i mode.

Then why use the 25p mode? Because there are a quite some situations where interlaced footage isn't showing correctly (like I said, technology moves on, but interlaced just wouldn't leave - !) Youtube, vimeo and computerscreens in general work better with progressive modes. Also: some peeps just LIKE the 'not so smooth' property of 25p, because it looks like the 24p from the movies...

By the way, you can always make 25p from 25i in software. You will lose a little bit of sharpness. It's called 'deinterlacing'. But if you camcorder can just be set to '25p' thats better and a lot faster too!

Also you can make 50p (yes, real 50 progressive frames / sec) from 25i (or 50i depending what you name it) I'm not sure however where a outputfile like that can or can't be played / uploaded etc...

One more thing: if you get really weird choppy motion after you made a DVD that you play back on a TV, you probably switched the field order around! Source files in standard definition interlaced 720x576 are LOWER field first, but HDV and full HD is UPPER field first (in PAL) If you're finished editting and you make a DVD you should make sure the output settings are again LOWER field first. (even if you were editting upper field first) The editting program will do the conversion!
 
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