Questions about AVCHD transcoding

CovenantPictures

CovenantPictures

Active member
Hey guys, just got an HMC150 camera...
I was wondering, do programs like Final Cut, that contain support for HMC150, display the long GOP footage natively, or are they required to first transcode the footage to an I frame format
 
Final Cut requires transcoding to ProRes which can be done via the Log & Transfer window. Some of the other NLEs allow you to edit the AVCHD natively.
 
One could argue that native AVCHD is the ideal delivery format, because it can be directly played on a blu-ray player or off an SD card or AVCHD DVD... :thumbsup:
 
I guess I am just a bit confused about the logistics/technicalities of editing LongGOP compressed footage.

I mean, DVCPRO HD I understand, every frames stands alone as a compressed image, and the footage plays back relatively smoothly on most platforms, but LongGOP ACVHD footage gets to me:

When people say an NLE has "native" support for AVCHD (as CS4 so recently does I hear) the does that indicate that whenever you make a cut or edit ANYTHING, the NLE is decompressing/recompressing the GOP in real time? Analyzing the footage for redundancies/details to compress into the GOP structure?
 
Yes. That's why it's so much slower. Although as hardware improves, or software taps into the graphics card for power, the task gets done in realtime and becomes less of an issue.
 
Covenant:

Unless you are going to deliver just as Barry has described, aren't you going to have to do a full render to another format anyway?


I use Sony Vegas Pro 8. In the Sonycreativesoftware forum I have heard of a few people thinking that Vegas 9 will smart render/not re-encode clips that have not been edited. I can't confirm that though.

Also, native support just means that you can drop the native AVCHD file directly on the timeline and edit from there. That's all.

I have been using Vegas 8.0c with HMC-150 footage since October 2008 and have completed many projects with no problems. Early on I also had the Canon XH-A1 and could drop both it's HDV footage and the HMC-150 footage natively on the timeline and also never had a problem.

To me, a lot of people seem to believe that AVCHD footage needs to be transcoded even though experts like Barry G regularly correct them. I don't believe AVCHD needs intermediates or transcoding any more than HDV (unless it's mandatory for your NLE).

If your computer hardware is too slow for AVCHD, I would consider the computer hardware upgrade a mandatory part of using AVCHD
 
Mr. Green said:
One could argue that native AVCHD is the ideal delivery format.
Click to expand...

Not if you are going to broadcast.

Also, how do you move from a timeline or sequence to blu ray or SD card?

I don't believe any NLE will export an edit to an AVCHD compliant hierarchy. Is there one?
 
Meaning?

I mean, if you're rendering to a different output format, then you're rendering to a different output format, sure. But the question of additional transcodes still remains. You're not going to deliver a ProRes file to broadcast, are you? So under a ProRes scenario you have to convert at least twice; with native editing you convert once (on the final render).
 
Ah. Well EDIUS will export an AVCHD DVD, and I think Encore can do it but I didn't really look.

As to whether it can do it from the unmodified source, or it has to do an HDV-style "conform", that I don't know.
 
David S. said:
I'm referring to delivering AVCHD as AVCHD.

I don't know of an editor that will do that.
Click to expand...


Vegas renders to AVCHD main profile.

What version of AVCHD are you talking about?

Playback devices don't need a heirarchy structure. Why would a NLE create one?
 
You must log in or register to reply here.
Back
Top