AVCHD file structure

T

the doc

Well-known member
Don't want to spam the boards - sorry, just thought this forum might have an answer for me...


There is a complex file structure for AVCHD. I have read many posts talking about the importance of copying the whole structure... not just the MTS files.

Since power director seems to let me edit MTS files without having any of the other bumf on the hard drive... do I still need them? If so for what? and if I dont need them... what the hell are they?

Cheers if anyone can clear this up for me before I format my memory card!

I notice that since I applied the hack the supplied panasonic software no longer aquires AVCH from the camera (though still works for photos.)
 
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You only have to copy the whole cards on macs....

because mac you see, is such a user friendly powerful computer, that it can't even seem to play avchd...
 
Ahhh - cheers for that... what is all that crap associated with the MTS files then? Surely it has some info on it?
 
AVCHD is basically a subset of Blu-ray and that's why the structure of AVCHD is like that. There are playlists (.mpl), title information (.bdm and such), clip info metadata (.cpl) and so on. There is also additional data which is not contained on Blu-ray discs like thumbnails for clips etc.

The playlists define the order of how clips are played and how clips are connected (seamless, non-seamless etc), the title information defines which playlists are contained in a title and the clip metadata describes useful information about the .mts file itself, like where the I-frames are (for easier seeking within the clip) and much more.

Hope this helps.
 
Blackout said:
You only have to copy the whole cards on macs....

because mac you see, is such a user friendly powerful computer, that it can't even seem to play avchd...
Click to expand...

Lol, my Windows system and my Mac system both can't seem to do what I want right. Too bad my linux system just doesn't keep up with video compatibility otherwise i'm sure that would rock.
 
pailes said:
AVCHD is basically a subset of Blu-ray and that's why the structure of AVCHD is like that. There are playlists (.mpl), title information (.bdm and such), clip info metadata (.cpl) and so on. There is also additional data which is not contained on Blu-ray discs like thumbnails for clips etc.

The playlists define the order of how clips are played and how clips are connected (seamless, non-seamless etc), the title information defines which playlists are contained in a title and the clip metadata describes useful information about the .mts file itself, like where the I-frames are (for easier seeking within the clip) and much more.

Hope this helps.
Click to expand...

That does help thankyou... and I can safely delete it all because it wont affect how I edit and use my MTS files? (rhetorical question - if that is right then no need to confirm!) :)
 
Well there is one exception, if you're recording clips which go beyond the allowed FAT32 file size limit (either 2 or 4gb) the recording will be distributed over several files and the only information that all these files belong to the same recording is stored in the playlist data. NLEs which properly import AVCHD do recognize this and transform the recording back into one single unit.
 
The stuff which isn't the actual video clips doesn't amount to much in terms of drive space used, so personally I copy the whole card contents across even though there's no apparent need. Who can tell in a couple of years' time what might suddenly turn out to be handy?
 
I have no personal experience of it, but I recall reading a number of posts here to the effect that VLC doesn't work well with GH1 footage.
 
Ozpeter said:
I have no personal experience of it, but I recall reading a number of posts here to the effect that VLC doesn't work well with GH1 footage.
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true, it doesnt work too well but for quick checking its ok.

there are several solutions to use AVCHD files but most of them require the whole "PRIVATE" folder to be copied so as a general rule: copy the entire folder and you wont have any problems.
 
the doc said:
Don't want to spam the boards - sorry, just thought this forum might have an answer for me...


There is a complex file structure for AVCHD. I have read many posts talking about the importance of copying the whole structure... not just the MTS files.
Click to expand...

As other have mentioned, there is the file structure that is defined for use with Bluray players. The structure is also used by Panasonic for the GH-1 camera. Some Bluray players can play 'sd/hc' properly formated 'cards' directly... so you could bypass any editing and play your home movies directly from the capture card.

Most people here are not wanting to play their movies directly... but rather 'ingest' them into a digital filmmaking work flow.

As such, they use one of Vegas, Final Cut {Pro, Express}, or Adobe Premiere {CS4,CS5}

All of these programs have some way to ingest the original capture files of the GH-1. Playing AVCHD encoded media has been problematic, whether one uses a Mac or PC. It has to do with the fact that the compression of the AVCHD and corresponding decompression, is really set up for 'cheap' but dedicated hardware engines. The several editing packages have only in the last year been improved such that play back of orginal AVCHD is 'possible'... and sometimes for some people has required a computer upgrade...

I had Premiere CS4 and while it was able to ingest the AVCHD media directly, playback was abysmal. CS5 has improved that, but still not ideal.

But what most people do is transcode AVCHD to a format that is more directed to pro/semipro editing.

In that regard, for Mac based systems, Apple's ProRes format comes into the discussion. In my case, once the material has been transcoded to a more edit/workflow oriented format, the 'playback' seems to fall into the background as an issue.

My procedure is to take the entire contents of a SD card, copy it to a hard disk archive, then point my editor, either Final Cut or Premiere, to that copy, and ingest the material. Very frequently these days, I don't use the SD card again, but place it in the 'archives'.
 
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