GH2 AVCHD spanning

sohus

Spanning is discussed a lot on these forums. It probably doesn't matter that much if you are a narrative filmmaker, but it is very problematic if you shoot events, documentaries, interviews, weddings where you can't have the camera stop recording. These people still want to shoot at the best possible settings, which is not really possible at this moment. I think the goal should be a 24H and 24L settings (in one set) with 24H not spanning but shooting higher quality and 24L spanning reliably (ideally all settings would span, but I don't think that is possible). Spanning is also very important if you shoot dual system audio as it safes a lot of time syncing clips.

What we know:

@KAE's 65M settings spanned (PTool 3.61)

After the release of PTool 3.62, spanning became more of an issue (at least it appeared to). Does this have something to do with the AQ settings that were opened up?

With PTool 3.62D, I have confirmed the following settings to be spanning:
@CBrandin 44M/32M at 24L setting (32M) --> GOP12, 32M, AQ4 (44M setting is not spanning)
Stock settings

Let me know if you know other settings with good quality and reliability that do span.

These two examples are extremes in terms of bitrate so I am pretty sure the bitrate alone is not the sole cause.

Driftwood's setting has no AQ set and the iFrames are smaller than most other settings (around 6MB instead of 8 - 11 MB) for most other settings. It also has no P & B frames (does the codec still need to work as hard?). Furthermore, it is GOP1 instead of GOP 3/6/12/ It would be nice if we could pin down what affects spanning: bitrate, AQ settings, GOP settings, memory card speed, scene detail (extreme: death chart). What makes that KAE's setting spanned with 3.61 but @CBrandin's 66M setting does not span? Is there someone who has an idea about this?

Ideally, I hope we can create a setting (ideally a 24L setting ) that spans at a decent bitrate (say 44M - 66M - 88M).

Looking forward to your thoughts and experiences on this matter.

arvidtp

I've not used Quantum Rocket, but sometimes with Sanity or Sanity X my spanned clips don't show up in FCPX's import. Not sure why this happens sometimes and not other times. You can get the clips out manually. If you're using OSX 10.8 or greater by right-clicking the AVCHD "file" (its actually a folder but the OS is annoyingly showing it as a package, trying to keep novice users from screwing things up) and choosing "Show Contents" like you would on a app package. Then so the same for BDMV and STREAM folders. If using an earlier OS X, they should just be folders.

Then take the .MTS files out and open them with quicktime X and save them as quicktime movies. You could try to use terminal to cat (concatenate) the .MTS files together first to get one continuous movie, but i find usually the resulting concatenated file fails to play properly in this situation (which is maybe why the software was failing to import the clip in the first place).

PS - Nothing about the hardware of your computer would influence this, just the software you have installed (unless of course the hardware is too old to run the new software you want). However, you will find a huge jump in performance for HD video editing between a 2008 macbook and a 2014, or even 2011 one (I have/use an early 2008, a late 2011 and a mid 2014 macbook and the later two are way way faster for video)

wrr53

I just installed the Quantum Rocket hack on my GH2 and shot some lovely footage. I can play it in the camera, however, when I go to import the videos into iPhoto or even in Premiere Pro CS6, the files aren't recognized. My hunch is this has to do with spanning. I'm a neophyte and could use some counsel re: successfully importing hacked GH2 into a Macbook late 2008. Do I need to upgrade my computer? Please advise. Thank you.

JuMo

I recently shot a TEDx event on Cake 2.3 (chosen for it's spanning reliability). It was a multi cam shoot (4 cams), with the cameras on all day for over 9 hours (using AC power). Not a SINGLE failure. Granted, I did use the SanDisk SD card formatter and formatted all the cards 3 times each with that software beforehand, then 2 times each in camera, which certainly helped keep the cards at their healthiest. Editing in Premiere Pro CS 5.5 has been a breeze, only have to drag the first file of the span onto the timeline.

For non-event stuff, I've been really enjoying Moon Trial 5, but for spanning reliability I can confidently recommend Cake 2.3

tinyrobot

I found what was going on. I batch renamed the files and I guess the metadata embedded within the files don't correspond with the new name. Without changing the name it spans fine. Too bad I'll have to stop renaming spanning files.

So then I'm wondering if anyone who works with spanning files ever successfully batch renamed their files while retaining the span.

arvidtp

@tinyrobot no - I should have been more clear. I don't get the glitches anymore only because I no longer use that method of importing. I just use final cut pro X now. @balazer is right - hacks don't change how spanned files are written, except that some make it just plain fail.

balazer

Different hacks don't change the way the GH2 writes spanned files. (among the hacks that support spanning. Not all do) The camera is splitting the transport stream on packet boundaries without regard to audio or video frame boundaries. It is one continuous stream, and needs to be treated as such when read if you want continuity across the files. Your editing software apparently doesn't know how to do that, so you will need to manually join the files before you open the stream in your editing software. Read the GH2 usage FAQ. http://www.personal-view.com/faqs/gh2-usage/gh2-usage

tinyrobot

@arvidtp So using Sanity 5.1, you don't get the glitche between two spanning files anymore so you no need to convert them to one file?

Since CBrandin 44M/32M is a spanning hack, I thought there wouldn't be any problems with the lower bit rate. If you successfully merge the two files, would that mean the frames are there "hidden" and by merging it's brought out? When I played the second file frame by frame, the reproduction is there and I wonder if merging would reveal the invisible frames.

arvidtp

I don't use any of the same software as you do, but I've seen similar things when using or converting raw .MTS files that have spanned. What I used to do in that case was concatenate the two (or more) .MTS files into one file before converting or using it and that would get rid of glitches at 4GB file boundaries. In the unix command line that is "cat 00001.MTS 00002.MTS > output.MTS". Dunno how you would do that on windows but obviously there is a way.

PS - if you're interested in spanning patches, I use Sanity 5.1 exclusively now for recording concerts that absolutely need to span and need to record for a long time.

tinyrobot

I shot about 20 minutes with CBrandin 44M/32M at 24L spanning setting which made two clips on my Sandisk 16gb 30MBPS class 10 card. Using PPro CS 6 on Windows 7, in the second clip, the audio seems to span fine. On the video side, on the second clip the first three frames are the same so by the forth frame there is a slight "jump cut". Can anyone tell me what I can expect with spanning GH2 hacks and if there is any way to fix this?

driftwood

@Brian_Siano A lot of its to do with timing and buffers. Cluster Slipstream atempts to match Clip duration to Transport Stream duration with precision measurement of timing & memory to obtain ideal buffer peaks that don't slip into low / poor QP. If the buffer slips to a very low setting on the chart (even though it may not underrun/overrun) then below average quant and even fallback mode may happen. Subsequently, if anyone uses Elecard buffer analysis to take a look at Slipstream they'll notice fewer cpb_delay errors than other settings & stock!

DrDave

My Patriot EP 64gb spans very well and makes the file transfer part fast as well. But I don't run the highest bitrates in shows where I need to span. I'm using Drew set to 60 right now and Flowmotion on the Lsetting. The one and only one time I was able to crash FM on the hedge of doom it saved the end of the file as well. In live shows, I always have some Camcorders running. SD cards are not 100 percent reliable, and there is nothing worse than having to tell a client that the event was not recorded.

I'll try the Slipstream soon but right now I'm patched out.

Brian_Siano

Spanning's also highly dependent on the memory card. Apparently, the only memory card that spans reliably is the Sandisk Extreme pro 64gig card: I've been experimenting the 32gig version, and even that fails to span for the higher bitrate patches.

I have found that the Cake patch spans reliably, even with my slower Transcend 32gig cards. So that's going to be my general-purpose patch.

Oh, one thing about patches that don't span. It's important to know how much time it can fit into a 4gig file. For example, if I'm using a patch that doesn't span, it'll record about 4 gig as 00000.MTS. and go on to appear to record more as 00001.mts... but when the camera shuts down, 00001.mts is lost. So, helpful hint: if you're using a high bitrate patch, find out how much time a 4 gig file holds. That is the longest take you can record, reliably.

driftwood

Try Slipstream v1 (Rev B) for reliability and spanning in all modes plus iA.

Driftwood Cluster X Series 'Slipstream #1 (Rev B)

72Mbps max IPB frame 1080p24 PLUS 68Mbps max IPB frame FSH/HBR/720p modes

All settings SPAN (SH/FSH/H) according to my tests (Ive had spanning on 720p60SH at 5 files with a datarate at 50Mbps). This is a great setting which appears to pass spanning, iA modes and death charts in all REC modes. Its a mix of 'Nebula' meets 'DREWnet' and is the first in a series of combi settings that attempts to offer decent IQ together with perfect timing and good bitrates to accomodate spanning.

Give it a try and let me know how you get on. See page 1 for details about these new settings & to download Slipstream #1 (Rev B).

http://www.personal-view.com/talks/uploads/FileUpload/a8/3faed58f8c8f03711b2e7526ee3a5c.zip

http://www.personal-view.com/talks/discussion/5806/cluster-x-moon%D0%85r%D1%96zznebuladrewnetslipstream-/p1

All rec modes tested on a Sandisk 45MBPS SD card. 14-140mm sharp lens used in test.

balazer

Spanning is in the GH2 usage and tips FAQ.

eddietor

For the new users such as myself who do not see "spanning" in FAQ. I read the above posts. I have my GH2 on stock settings. Question is, are you saying that the goal with each hack is you want it to span? Is spanning a good thing? The stock settings don't span correct? What I'm asking is, if I upgrade my camera to another hack (still haven't decided which), will that be part of the sacrifice, that now 4gb files will be created as opposed to one continuous stream? Sorry I don't completely understand what is good or bad and which hack to use. I have one lens: 14-140 and one card (so far) - class 10 transcend 32gb, -which hack to get and is it worth doing before I get more cards and more lenses?

azza_act

Thanks guys, will try.

duartix

Well, you don't need Linux for that: http://support.microsoft.com/kb/69575 I'll have to give it a try.

arvidtp

weird things can happen between the spanned files if your editing software is not made for that because the previous keyframe will be in the previous file and the NLE doesn't know that they are basically one continuous file. It has no way of knowing. What i do when i'm managing imports manually is use the unix command cat (i'm on mac) on my spanned files to literally concatenate them into one big file. Then the NLE should be fine with it (ie Final Cut Express no longer has glitches). There should be a similar command in windows command prompt i think.

As far as high bitrate spanning, try the SpanMyBitchUp (sp?) setting found in the GH2 settings vault thread. Should span on most class 10 SD cards on 24H. (caution: Will often not span on 24H 80% speed)

Also, spanning often depends on complexity of the image. sometimes it'll span once if there is little motion in the frame at that time, then die on the 2nd file if there is more motion or more noise then.

But if you really really need it to just work and don't have time to test, save yourself the headache and use stock firmware then experiment later what you have time. Shooting trees blowing in the wind out the window for hours on end with an AC adapter is my method for determining if it will reliably span.

azza_act

Heh guys, I'm hack noob shooting a wedding soon and i need a patch that i can span with, so i went with crb 44/32 settings. Did i little span test of shooting myself on the tread mill (Shooting 1080 24L, with the Panny 20 .17 (Manual focus), Sandisk Class 10 32g), to see if everything is fine. Only issue with this test, is that the wind shut the fucking door where all the light was coming for. So its under exposed. If you look at the picture, below my knees, you'll see some crap. This is a the start of the second 4gig file, when its on the time line (Pre CS5) Is this the codec freaking out because its to dark, i'm i worrying about nothing or does this happen in 24L 32mbps when you join spanned files together? Don't have time to do another test to see... Cheers

arvidtp

If you don't have time to test yourself, use stock firmware this time - just my 2 cents.

cyfernoa

does spanning work for 1080 60i at 32mb/sec? I have not seen anyone talk about this yet. I have a gig in a couple of hours that I do not have time to test for but I do need spanning as it is a show.

mpgxsvcd

File spanning works with the settings I posted for 720p with a Class 6 card and 32 mb/sec. I need to do more testing with the 1080p setting to confirm that all cards will span with the 32 mb/sec setting.

arvidtp

I need to go down to 26M in 24p or 20M in 720p60 to get spanning to work 100% reliably on a what i think is a mediocre class 10 card (patriot) with current (3.62) ptool release. See this post: http://personal-view.com/talks/discussion/comment/14894#Comment_14894 Not sure about class 6.

mpgxsvcd

So if spanning is important to you, how important is amount of time you can record? For instance, even if we could get the 176 mb/sec settings to span you would only get 15-20 minutes on a 32 gb card. =

Some people complain about the 29 minute time restriction. I would think that 15-20 minutes would not be that beneficial even if it spans.

I think ideally we need to find a setting that spans for exactly the time the battery lasts. That ends up being 32 mb/sec. It will record for 2 hours and 9 minutes on a 32 GB card and it will span perfectly.

I have modified the “No adverse affects” settings to use 42 mb/sec for the high setting and 32 mb/sec for the Low setting for 1080p. These setting will have no write errors for any card. In addition the 1080p Low, 720p High, and 720p Low settings will all span.

Using an extremely high bit rate and worrying about file spanning will contradict each other because with high bit rates you will run out of storage before you reach the capacity of the card. Therefore, the 1080p High setting is for high bit rate. The 1080p Low setting is for Spanning.

raizman

Do the Ptools 3.62 recommended safe settings for 24H (I think it's 44M) have any issues with spanning on class 6 cards?

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