Importance of Proper Tests for Reliable In-Cam Playback: Lessons from the Field

qwerty123

===NOTE: none of what I say below is meant belittle the fantastic and wonderful low gop patches that driftwood has produced (or any others with "extreme" patch settings). If anything, this is my fault for not testing thoroughly enough. But I think my experience is worth sharing===

==MY TEST==

I went on a shoot this weekend, and was using Sandisk Extreme 16gb 30mb/s cards. I wanted to ensure both spanning and playback in camera for the shoot, so I went with driftwoods "spanmybitchup" patch. I did just a few short preliminary tests: the test I did was to shoot the papasarts star chart (which I've attached--I also attached the more extreme codec test chart v2 2010), and let it run. I waved my hand around in the frame from time to time and also had some talking to get audio. Everything seemed good: I was getting spanning and smooth playback in camera with audio. (EDIT: also attaching Stray's death charts with color information!)

==MY SHOOT==

So during the shoot, after a few shots, I was getting the message "motion image cannot be played" for all my clips (or something like that I don't remember exactly)--my heart sunk! An actor asked me to check to see if we recorded something on a previous take, I had to say that "yes it was" without checking. I was worried about requests for playback--and this was only with one actor: imagine this on shoot with clients! For certain shots, I wanted to be sure that something was recorded since I wasn't at the camera, and I couldn't do this. The scene I was shooting was an actor in a car at night--he was lit and most everything else was dark. That's when I got the messages. I put in a new Sandisk card, and formatted it. Reshot the same scene and I was getting the same error.

==LESSONS==

1) In camera playback is important at least for some of us, and for some, like me, it is even more important than low gop. For me, I am willing to forego a very very high quality low GOP setting (awesome work driftwood!!) that doesn't have playback in camera on good SD cards for an improved long GOP with ultra reliable in camera playback. I'm NOT saying that everyone wants this or should want it (especially if you have the cash for more super high end SD cards or for extra harddrive space). But I'm guessing some people are in my situation as well.

2) It seems there's a relatively standard procedure for patch development (using streamparser, tweaking settings incrementally, etc etc). BUT there seems to be no standard procedure for testing spanning and in-camera playback. You might not think that makes a difference, but it seems that it does: it seems to matter what you shoot when you are testing things like spanning and in-camera playback. Or, at least the number of clips you shoot or the ISO you shoot at makes a difference: otherwise, I don't know how to explain the divergence between my pre-shoot tests and what happened on the shoot. I welcome some constructive thinking about standardizing spanning and camera playback tests.

==DESIRES==

The ideal for me would be to get a hack that improves quality over the stock settings, that has very very reliable spanning and in-camera playback with audio, and works on good quality cards like the Sandisck 30 mb/s (16gb). I know some people are getting the SandDisk extreme pro 64gb cards... but a lot of people (like me) already have a stash of good quality cards and don't want to fork over even more money to get these super high end cards.

I did test w/ @cbrandin 's (Chris's) 66M patch. We know that this doesn't span (but getting around 10 or 11 minutes is okay for me, although I'd love spanning). But what I did notice is that I couldn't get in camera playback with this either. I'm going to try the 44M patch.

Thoughts?

piotremanuel · vlcsnap-2012-01-01-14h34m29s0.png

@qwerty123 I am using Chris's 66M most of the time when I need spanning and longer than 30 mins times. I just ticked the relevant options in ptool before saving the patch. Just yesterday, for example, I was filming some long interviews with it, some going near 1 hour at a time. It all passed with flying colours and the quality is certainly satisfactory (Thanks @cbrandin so much!). Now, regarding the in-camera playback, all works until the recording starts spanning- from that point the clip becomes unplayable. Otherwise if there's is a problem switching the camera off and on cures the playback issue. Also, after long spanning I must record a short clip, otherwise the next time the power is turned on the camera refuses to record anything further. These are the only niggles I can think of with this patch. I like the quality of this patch and it became my all-rounder. You must remember about the ISO bug each time you power on. The noise macro blocking is there, sure, but you have to really put it under the loupe to notice it. In this respect of course it's not as good as the consistent grain you get from excellent @Driftwood patches which I admire, however when it comes to the quality versus reliability (spanning, cheaper cards, longer recording times) the choice is clear. I only wish not almost everyone here was so obsessed with short GOP (please don't flame me now, I fully understand and cherish the need for GOP1 and love the results); there is a clear need for some people for long GOP patches to be taken further. I attached a few snaps from the recent clips with Chris's 66M patch. Good luck!

driftwood

Quantum v9 playsback fine in camera on my 4 cams. The quality is way better now plus some great 720p/1080i. Give it a try.

piotremanuel

@Driftwood I am very intrigued by Quantum v9b. Believe me, I follow your brilliant developments very closely. I am certainly going to play with your latest one very soon.

Jspatz

Quantum v9. Unchecked 30. Shot a short clip after a 10 minuted spanned 24l would not play back. Then removed battery. The short clip plays fine but nothing gets the spanned clip to play. Driftwood, are you saying spanned clips playback fine for you. What could be the difference

driftwood

@piotremanuel, long time no see, must meet up sometime for a jar down the Lord Nelson.

In the meantime, here's a very quick comparison (self portrait knackered Driftwood after a long day patching!) of the quality on a voit 0.95 lens. These are the the three modes (1080p, 1080i, 720p) with Quantum v9 straight from Windows Media Player - no editing! blown up to full screen on Paint ! All recs looking good. ;-)

driftwood

@Jspatz Ill do a span test now you bastard! Another 20 mins.... ;-)

piotremanuel

Yes @Driftwood, you look very sexy :o))) 720 seems to look great indeed. I'd love to meet up for some "jarry" conversations soon. BTW, VLC does a nice job with snapshots.

driftwood

Couldnt be arsed to do vlc, mpegstreamclip or whatever... these are simple 'Print Screen' grabs and pasted into Paint whilst playing the mts files!

qwerty123

@driftwood when you say you get playback on Quantum v9... I'm assuming this is on the very high end Sandisk 64gb 95/s cards?

I'm wondering if there are some easy and creative second best alternatives for getting playback on set. For example, having a laptop and loading up the card is one option. But this is less than ideal as it eats up too much time. Maybe some tablet option would be better...?

I'd be happy to use any driftwood patch as my go to for narrative filmmaking if I could somehow easily get playback--and I'm (begrudgingly) willing to get the highest end card. (grumble grumble)... I'd even get the higher end cards if I could get consistent playback in cam.

@piotremanuel Yeah... I recroded a 6 minute clip with chris's 66mb, and even then I was having problems: it plays back for one second, and then stops. Restarting doesn't help. So far 44mb seems ok. But I'd love to have the higher quality....

Meierhans

@qwerty123 You could try to connect a tablet or android phone (with usb host) via the usb cable that came with cam. Dunno if the cam can hold up with this datarate when acting as cardreader, but its worth a try.

proaudio4

fucking brilliant, thank you driftwood!

qwerty123

I think I'm starting to realize ****different modes for different work****

--many have said this all along (including Chirs) but I was stubborn in refusing to accept it.

It seems that above a certain bitrate level, in-camera playback is not going to be reliable irrespective of the card quality. It seems that it's a function of the camera's playback abilities.

So...if I really want to ensure in camera playback, then the low gop stuff is likely not my go to, then (something like) Chris's 44mb patch would be my go to for narratives in which I know I won't be running over say 10 minute clips. For spanning, I'd (reluctantly) drop to the L setting.

If I want absolute best quality with absolute best motion and noise rendering and don't need in camera playback, then low gop is the way to go with (most likely) an investment in higher quality cards.

Decisions, decisions.... I just want to shoot! Arg.

(EDIT: I was wrong. Playback works fine on Quantum 100 with my Sandisk Extreme 30 mb/s--Quantum 9vb requires the higher end cards; curiously SpanMyBitchUp gave me problems. Huh.)

proaudio4

Buy two camera bodies, problem solved ;)

LPowell

@qwerty123 Hold on, your pleas have not gone unheeded. Before you invest in a new set of high-priced cards, you may want to wait until my last round of tests are completed...

troyjason

Gotta shoot with 2-3 bodies (no excuse - they are cheap) and multiple firmwares loaded on 95mb/s cards.

Problem solved.

qwerty123

@proaudio4 @troyjason less than ideal solution...

@LPowell ...intriguing(!)... I'm holding on for the moment anyway due to lack of $... For now, I think I'm going back to the 44Mb patch.

troyjason

qwerty123 - not trying to nag, you typed a very worthwhile post. I enjoyed reading it and it should be a good reference for newbies to the GH2.

But a second GH2 can be rented for under $100 a week (borrowlenses, lensrentals.com) I don't shoot without 2 or 3 and don't know anyone that does either. If you can't buy, rent.

Also there is nothing wrong with saying to an actress/actor or crew "looks good, but lets improve xyz."

Read this article about David Fincher:

http://en.wikipedia.org/wiki/Zodiac_(film)#Principal_photography

He and directors like Ridley Scott are known for dozens and dozens and dozens of takes (if needed).

Best of luck in the future.

Mr_Moore

@driftwood Good teeth!

RRRR

There is one very simple and most reliable solution to the problem. Have several cards ready and bring a laptop (preferably one with a built in card reader). Always play back on your laptop, rather than in the camera. Obviously, it might not be an option all of the time (if you are out shooting with minimal gear somewhere remote) but for shoots where a lot of equipment is already used then it's no trouble to bring a laptop, really.

The better/bigger monitor will also help in terms of avoiding some mistakes that can happen with smaller monitoring..

driftwood

@qwerty123 Thats bollocks. In camera playsback fine on Quantum v9 and Quantum100 (min Quantum). Also there is going to be a mini version of Quantum INTRA for type 6 cards/slow type10s coming later today too. But please try out Quantum100 first to see if works for you on your cards.

quaresz

Hi Driftwood! I have a big problem with your's Q100 patch. On the settings of 1080i, 720p i can't take more videos than 10sec even on fsh, fh or sh and h (motion record was cancelled due the limitation of the writing speed of the card - or something like that). But on the highest setting of 24h and 24l is all fine. What is the problem? I have a 32Gb Sandisk extreme (30mb) card and tv out is ntsc.

Thanks!

driftwood

I'll take a look.

driftwood

@quaresz check Quantum v9b & see if the same happens and let me know. I'll take a look to see if 60 changed when I was doing 50 (which I did last) could be some correlation thing.

quaresz

HI! Thanks, but i have a similar problem with v9b to...:(

Strange. I checked fast v7, and exactly the same problems as above - 24L and H fine all other is bad...:( Maybe i have a "bad" card or "1080i or 720p resistant" GH2?:)

quaresz

There must be something wrong with the 30/60fps, becouse on pal settings all is fine...!:I

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