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?

[Averdahl]

What Panasonic camera do you use?

I have no trouble with spanned clips from the Panasonic HMC-151 as long as i don't rename the PRIVATE folder or any of it's subfolders or it's content.

/Roger

[jefbak]

We have both an HMC-150 and HMC-40, I think with the latest firmware. I have had issues with the footage from both cameras, but the footage in this case is from the HMC-40. Both cameras are setup for 720P30 recording. Our workflow is to copy the entire directory structure form the SD card to the hard drive and then import to premiere. So the directory sturcture is not changed. It was working working for me in CS5.5, but I had problems with CS5 before that. So it was a surpise to see it crop up again.

[DearBrianTho]

I have two Panasonic TM300s and two SD900s and I use them regularly for concerts and plays etc. Clips are always between one and two hours each. I never even look into the AVCHD structure and I always use the Media Browser to import them. Then I always wait until all the Conforming etc progress bars in the bottom right disappear. Once I started editing before they'd finished and I lost half the sound on a clip. Nor more waveforms from that point to the end, total silence. Fortunately I had a backup as there was no other way to get the sound back for that clip.

[jefbak]

This is exactly what happeneds when the spanned clip is imported (no audio until the last 5 minutes). All the other clips on the card are fine.

Also as mentioned in my other post, the spanned clip does play correctly in quicktime and VLC players.

I did file a bug report with Adobe and got a reponse (holy cow!) from prembugs that said I should make sure I have logged with my adobe ID to activate the codecs (what?!?) Anyway I had done that. They also mentioned something about OS X 10.8 (mountain lion) but as indicated the Bug form, I am using 10.7.5 (Lion).

Anyway, I still think this is a Adobe issue.

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.

Our workflow is to copy the contents of the card to the hard drive before import, so any XML is written to the hard drive not the SD card.

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

[DearBrianTho]

I never thought of locking a card as I've only ever edited from a copy of the complete AVCHD structure stored on an external hard disk. I usually keep backup copies of that structure on other hard drives elsewhere.

[ECBowen · Accepted solution]

Take those Spanned clips into Media Encoder and re-encode them using Main Concept's AVCHD. Then import them into Premiere and see how they act. As long as you select the same codec settings as the original material then there wont be any generation loss as it will just re-write the file with a different file writer.

Eric

ADK

[Jim_Simon]

Umm....what makes you think that Eric?  To the best of my knowledge, AME will transcode any compressed footage, not simply rewrap it.

[ECBowen]

Jeff has already verified that Media Encoder will not re-encode the material and will just re-file write the media. You have to remember Main Concept's AVC codec is the most highly used in the industry today. You just have to make sure the Settings match the material.

Eric

ADK

[Jim_Simon]

I'm curious how he's verified that, especially with information to the contrary coming from Adobe.

[ECBowen]

Where is the information you mention contrary? Also if this was not the case then using this same system to change the format of MXF files which has also been verified by other editing applications would not be accurate as well. Sony also uses this system when changing Mpeg4 wrapped files to Mpeg2. Compression algorithms and Format writing are completely 2 different processes.

Eric

ADK

[Jim_Simon]

Adobe only recently added Smart Rendering (the ability to simply copy the content to a new format, rather than doing a full transcode) for limited MXF formats.  That's why I'm curious how Jeff has verified that it won't transcode in this case.

Also, maybe I'm being a dunce on this one but how exactly do you "re-encode them using Main Concept's AVCHD" so that no parameters have changed?

[ECBowen]

I would have to go looking to find one of Jeff's posts on this. However this system has been commonly used for years by different encoders or applications. Smart rendering was designed around using Preview Files for export and making the export times much faster. It was not designed to alleviate generation loss when you transcode the material to the same codec to another file format to prevent generation loss since that is not required. Think of it this way. Say I have a puzzle with the same number of rows and columns. I simply want to move that same data from that puzzle to a new puzzle format with the exact same data type. How do you have any loss of data when doing that? I am simply shuffling what rows and columns the data resides in. The original data never changed.

When you select the export settings simply select the option to match source material.

eric

ADK

[Jim_Simon]

Smart Rendering and using Previews are two entirely different things.  If your Previews are MPEG2 based, and you go out to another MPEG 2 format (even one matching the preview specs) the preview will be decompressed and restranscoded.  What saves time with using Previews in that case is that you don't have to render any effects from the sequence, as they're already baked into the Preview.  The exception to this is, as stated, the newly added Smart Rendering for limited MXF presets (and of course non-GOP formats like Uncompressed or DV).

Match Source Material in what format?  MP4, F4V, something else?  (My duncness shows though. )

[ECBowen]

The Mpeg 2 point you mention is because you are using 2 different compression algorithms which changes the data in the puzzle. That of course introduces changes that can be construed as generation loss. The point I am making is when you use the same algorithm the data never changes. There is no decompression so the data never changes. Only the puzzle format changes. That is the concept to understand. That is how I can change Log based DPX to Linear Based format and still retail all of the data up to the color data ability of that format bit depth wise. Match format which for AVCHD in Adobe I believe is under the H264 preset options. I am not at my Adobe system right now to verify. All reading I have done on Smart Rendering points to using Preview files on export and speeding the process up. If you have links otherwise, please post them.

Eric

ADK

[Jim_Simon]

The Mpeg 2 point you mention is because you are using 2 different compression algorithms which changes the data in the puzzle.

How so?

If you have links otherwise, please post them.

https://blogs.adobe.com/premiereprotraining/2012/05/premiere-pro-cs6-6-0-1-update-bug-fixes-and-impr...

"Enabled “smart rendering” and added Enable Smart Rendering Codec setting to the Video tab of the MXF OP1a exporters for XDCAM HD and XDCAM EX to enable or disable smart rendering for these formats."

This is the very first Smart Rendering capability that Adobe has had without installing a plug-in.

[ECBowen]

The Mpeg 2 you referenced is using the Iframe algorithm which is as you said decompressing the data. Then when you are using another Mpeg2 codec the algorithm is once again different. Keep in mind there are as many flavors of Mpeg 2 algorithms as there are Mpeg4. AVCHD and H264 are completely different from AVCIntra but they are both Mpeg 4 algorithms.

The link just states smart rendering was added for MXF to OP1A. Once again the codecs/algorithms for these 2 formats are the same ie file writers but the format is different MXF and OP1A are just 2 different format types.

Eric

ADK

[Jim_Simon]

The link just states smart rendering was added for MXF to OP1A.

Correct.  Previous to that, Adobe had no Smart Rendering capabilities without the use of a plug-in, meaning everything got transcoded.

I still can't find any method to avoid transcoding of AVCHD upon export.

[ECBowen]

Well evidently I was incorrect in my memory of options with media encoder. I had to select the H264 Preset and then manually match attributes to the source file includes changing to a set bit rate and audio bit rate. This outputs the media to MP4. In every comparison my editor can view, the quality is exactly the same as the original and the file size is basically identical. There is however no match source option. The settings have to be manually from the file attributes.

Eric

ADK

[Guest]

The test above with matching bitrate settings manually (MP4 file size is 39 850 kb while original AVCHD file size is 38 688 kb):

NB: True rewrapping with SONY PMB produces complete matching MTS and M2TS file size and the 'Difference' test in linearised colour space results in completely black plate with no a single artifact.

[ECBowen]

Well there were zero artifacts that we could find between the 2 images using the media encoder. We checked with WMP, Quicktime, and VLC.

Eric

ADK

[Guest]

Those tests are not precise enough. Even in case of the 'Difference' test in After Effects if you untick Linearize Working Space checkbox in 32 bit colour space settings, you get solid black screen. However, that just means there are no visible loss, but they are still here.

[ECBowen]

Yes I repeated your test with my files and the results were the same as yours. Very nice comparison test for material. I will have to remember this one.

Eric

ADK

[Jim_Simon]

In every comparison my editor can view, the quality is exactly the same as the original and the file size is basically identical.

Yeah, but was the CPU running at high cycles?  My guess is yes.  That's a sure sign it's being transcoded, not just copied.

[Jim_Simon]

Match format which for AVCHD in Adobe I believe is under the H264 preset options.

I was unable to find one there, but I did find that under F4V, which did transcode and not just copy.