CS6.0.2 Update No Fix For AVCHD Spanned Clips - Workarounds?

[jefbak]

While I try to avoid Spanned Clips as much as possible due to a history with Premiere importing them, for event coverage we still get them and I just can't figure out how to make them work in Premeire CS6 on OS X. I see lots of posts about this and would like to know if there is a fix that does not require purchasing another product (like MTS Merge $35).

We are using AVCHD footage from Pansonic cameras and if it spanned, the sound will be missing for much or all or the clip.

I have tried using the Media Browser to import the entire AVCHD folder.

I have tried using Panasonics AVCHD Viewer application to import the footage (switches wrapper to .mt2s instead of .mts).

I have tried transcoding to new codec (Quicktime and VLC will play the MTS file correctly but output loses audio sync).

Ugh, this is terrible. Has anyone else found a workaround?

[ECBowen]

F4V is flash and using a different algorithm.

Eric

ADK

[excited_Genie16B8]

It said MainConcept H.264.  (Something even the H.264 presets don't say.)

But I'm still willing to admit defeat on a proper matching.  Once you get back to your work station, please post the proper method.

[ECBowen]

Main Concept has multiple algorithms which will change the data. I will check when I am at my Adobe system and give you the match sequence options. For now go under the H264 Presets and select match Source. Then run the export. Import the new file and check the quality. AVCHD and H264 are essentially the same thing with different flavors.

Also dont forget to go under the video tab in the reset options and check the codec/compression drop down for Main Concept.

Eric

ADK

[Guest]

Well, let's run some tests.

I have AVCHD 1080i25 (50i) clips from SONY camera.

I added one of them into AME render Queue, selected H.264 Blu-ray preset with Match Source Attributes settings and rendered M4V file.

Then I imported both original AVCHD footage and transcoded one into AE, set my project to 32 bits HDTV (Rec. 709) 16-235 linearised colour space, dropped footages into a comp and set upper layer blending mode to Difference. Here is the result:

I suppose there is some generation loss in quality...

[ECBowen]

Blue Ray will be a different algorithm So it will re-encode.

Eric

ADK

[Guest]

Will wait until you're on your machine with Adobe Suite to run next H.264 -> H.264 test...

[jefbak]

Okay, ECBowen's recommendation to transcode to using Main Concept seems to work with the following possible issues:

I had to choose MPEG2 .mpg output in order to select the Main Concept encoder.

The clips are no longer spanned of course, so I have 2 separate files imported now.

Playback quality of the resulting .mpg files in AVCHD 720P30 timeline shows some artifacts. But that may be due to the sequence setting and I have not actually exported the footage to see how it held up.

But this is progress and a workaround as I was hoping for!

THANKS!

**I had not seen the next posts suggesting Match Sequence in the transcode, so that may be the issue with the artifacts.

Looking at the SD card, I just don't see any files getting adjusted if unlocked. There are no hidden files or changes in time stamps, but my workflow is to copy the Private folder to the HDD before importing anyway. I guess the test would be to make another long spanned clip and then try to import it from a locked card right?

[Guest]

I have tried using Panasonics AVCHD Viewer application to import the footage (switches wrapper to .mt2s instead of .mts).

Jef, I'm curious, which difficulties you have with Panasonic utility?

As far as I understand, it should rewrap spanned MTS clips into a single M2TS file.

Never used it by myself. Just for the sake of getting to know.

[ECBowen]

That is the same thing the Sony Utility does and the Panasonic works as well. I have used both. It wraps the files in a Mpeg2 transport wrapper and will work fine if you don't want to use Media Encoder. I believe the 1080P HDTV presets under H264 should be the right presets if I remember correctly if you keep the files in Mpeg4 wrapper. I will look Monday.

Eric

ADK

[Guest]

Eric, H.264 HDTV 1080p can hardly be the right preset because it exports progressive media file, whereas original footage is interlaced, and the preset doesn't have 'Match Source Attributes' option, offering 32/40 Mbps bitrate by default, whereas this particular source file has of about 17 Mbps bitrate.

[ECBowen]

OK thanks for the heads up. Ill wait till Monday then and look.

Eric

ADK

[jefbak]

Yes the Panasonic utility created .m2ts files in the same folder structure as the sd card. But the spanned clips still did not import correctly.

[Guest]

But the spanned clips still did not import correctly

So, it doesn't rewrap spanned MTS clips into a single M2TS file?

[TradeWind]

I did just re-import the card (locked this time) and still have the same issue. Nothing appears to have been written to it ouside of the camera files.

Problem is if the OS has already written files ONCE to an unlocked card, locking the card does nothing to remove those files when you try the operation a 2nd time.

Trust me, whenever I browse a 2nd camera's SDHC cards in my PC after it has been plugged into a Mac OS, I can tell immediately if they locked the card or not, because I'll see 100+ files written to the SDHC directory by the Mac OS. These files would be hidden/invisible on a Mac. And they're not inherently bad...it's just how Mac works with storage devices, whether internal/external hard drive, SDHC media or any other non-copy-protected media. It causes a problem, however, with AVCHD, if the card isn't locked first.

Media Browser is in AVCHD mode when I import and sees the spanned clips as a single clip.

When you import this single file into PPro, it's still causing problems?

[TradeWind]

Unfortunately this is not a spanned clip problem with Adobe or Panasonic. This issue does come up from time to time.

Be sure when you pull the card from your camcorder, you LOCK IT immediately. Then it becomes impossible to change anything on the card purposely or inadvertantly (and as you are aware, changing anything - structure, file names, ANYTHING - on the card will blow the whole operation, so locking it is perfect). Also, sometimes Mac users have problems when they fail to lock their cards, because Mac OS immediately starts writing files to the card if it's not locked.

When you're using the Media Browser in PPro, be certain that you are viewing the clips in AVCHD mode (there's a dropdown option for this right there in the Media Browser). If you're importing individual clips from a single continuous recording, you're NOT in AVCHD mode, and this will always cause the problem you are describing.

I don't mean to lay this out as "you're doing it wrong" but unfortunately this is all very well documented at this point, and whenever there is a problem with spanned clips, it is 100% of the time due to a user that renamed something, moved files, or otherwise didn't follow the complete rules of AVCHD management. I don't normally use a term like 100% (tend to prefer 99.9%) but I say 100% because it is absolute in this case.

[jefbak]

I guess my counter arugment to the Lock idea/issue is that I have never ever had a problem importing clips that are not spanned. Ever. Wither either of the Panasonic cameras. It is always spanned clips that have trouble importing, but play fine in VLC or even quicktime player.

Locking your cards sounds like a good idea, but I don't see it as the reason for this especially when the clip plays correctly outside of premiere.

[ECBowen]

Regular players do not write XML files to associate the clips when you play them while editors do. When you import AVCHD files, Adobe will write associate files to the current location of the media files. That is why the suggestion to lock the cards is a valid one. Editors need to remember that standard players and Advanced players such as Editing applications are completely 2 different animals. You cannot compare them as a troubleshooting mechanism.

Eric

ADK

[TradeWind]

I guess my counter arugment to the Lock idea/issue is that I have never ever had a problem importing clips that are not spanned. Ever. Wither either of the Panasonic cameras. It is always spanned clips that have trouble importing, but play fine in VLC or even quicktime player.

That's just the thing...spanned clips reference a piece of metadata on the card to create the seamless continuation from one clip's A/V to the next. That metadata "can" be corrupted by any number of things if the card isn't locked. Non-spanned clips are not having that problem because even if the metadata is corrupted, it's not looking to the metadata to line two clips up together properly. Other issues, sure, but not the clip spanning issue.

[josephs51576386]

If you have access to a PC you can just use this program for free.

http://www.vontraining.net/download/

It will merge all your stuff together for, it works very quickly too. Plus no quality loss since it's only simply merging the video together.

[ns194]

I have a suggestion for you, jefbak. Until adobe patches PPro to behave consistently with spanned clips, there are a couple workarounds. If you're on a Mac, you can always use ClipWrap, which just rewraps your spanned clip into a .mov file for easier editing (FCP people tend to use this to transcode to Prores, but there is a simple rewrap functionality as well). This may at least solve your playback woes in Premiere.

Another alternative requires using the command line to rejoin the clips. I have a hacked GH2, and the man behind the hack has a very useful FAQ regarding AVCHD and all things GH2 related. The section on spanning is helpful: http://www.personal-view.com/faqs/gh2-usage/gh2-usage#spanning

This worked pretty well for me in most cases. You should be able to tell by the date/time/size of the clips which of them constitute a larger spanned clip.

[excited_Genie16B8]

Spanned clips from the GH2 don't seem to exhibit the bug.  You should be fine using them as is.

[ns194]

Well, I have one of my longer clips affected. It may be due to the hacked firmware and shooting at a high ISO. I've had no trouble in most cases. But one clip has suffered laggy playback, dropped frames, etc. I found that manually joining the clips, and if need be, rewrapping them, did help. 

[excited_Genie16B8]

Laggy playback and dropped frames aren't necessarily evidence of this specific bug.  Other things could cause that as well.

The bug in question causes the hard drive to work overtime trying to read the spanned files.  So far, even 90 Mb/s hacked spanned clips don't show that bug.  (ISO settings won't have any effect at all on this.)

[ns194]

Interesting. Rewrapping allowed me to playback the video, despite other spanned clips working just fine. However, a few frames appear to be missing, or there was a glitch in the recording (the conclusion I feel that I'm coming to). During a few seconds toward the end of the clip, the video flickers white. It's strange. This happened after rewrapping. Before rewrapping, the video simply wouldn't cooperate - it imported, but then wouldn't seek, playback, etc. Now it will, but with those missing frames. I figured that that's better than a clip that won't play at all, but maybe if I follow the instructions to encode to h.264 it will solve my issues?

I'm a recent convert to PPro from FCP7 since getting my GH2, so pardon my noobness. So far I'm blown away by its video quality, until this issue with the one spanned clip...

[excited_Genie16B8]

If it's only that one clip, then it does sound more like a possible corruption.

Make sure to use only the SanDisk Extreme Pro 64GB 95 MB/s card for your hacked footage.