AVCHD vs. MJPEG debate

[PJF]

The more I compare GH1(3) and GH2 footage, I become more and more convinced to upgrade, and be done with this whole codec and hack setting tomfoolery. The GH2 is producing the nicest DSLR footage out there to my eyes, hack or no, AVCHD or MJPEG.

So if Vitaliy, lpowell & co produce hack setting tomfoolery for the GH2 you'll be giving it a miss then? :happy:

Seriously, even if GH2 improvements are limited to Panasonic firmware updates, you won't be done with the codec. That's the heart of the game and getting the best out of it by whatever means will be the key to success.

What amazes me when comparing GH13 and GH2 footage is that when both cameras are at their best (i.e. 1080 and lots of light) there's not a gnat's willy between them; the quality is simply mega on both. The GH2 quality survives better than GH13 in low light; the GH13 quality survives better than GH2 in movement and with the other settings.

This makes the GH2 difficult to justify for me. Without significant improvements to the output all round, either via hack or official firmware, I probably won't get one.

 

[aljudy]

I agree with you PJF. I can get outstanding video from my GH1, now that I know which hack to use with the event I am filming. Indoors, I use the very safe hack from the Perfect Project, which never fails and I get pretty good video indoors with it. I have a hard time justifying buying the GH2 unless we can also hack it... Al

 

[jaydil]

mjpeg 720p30 --> 720p24 conversion is not true 24p (since it drops frames)...Are there circumstances in which, to those that aren't looking hard for it, it will produce an unnatural or aesthetically unwanted result? Ptool simply says it drops every 4th frame. Is this really noticeable?

The whole point of 24p is to achieve the "filmic" frame rate of old-school film recording. Frame dropping does not achieve this.

If you can't see the difference between 30fps with all frames, and 30fps with every 4th frame dropped...I'd bet you can't see the difference between 30fps and 24fps in the first place. Which begs the question...why are you trying to downgrade your footage to 24p, anyway? IMO, anyone professional editor is going to see immediately that it isn't really 24p.

The more I compare GH1(3) and GH2 footage, I become more and more convinced to upgrade, and be done with this whole codec and hack setting tomfoolery. The GH2 is producing the nicest DSLR footage out there to my eyes, hack or no, AVCHD or MJPEG.

All else being equal, it seems unlikely to me that a GH2 recording at stock codec bitrates would beat a GH13 with maxed out codec bitrates. But I honestly don't know, and I'm willing to be educated. Can you point to any online footage showing better codec performance with the GH2?

J

 

[balazer]

Do you really think this video looks all that great? I personally love the Longshan temple stuff that apparently looks crap, but it's probably on account of the lovely photography and stirring music, not the codec.

Yeah, the Longshan People's Part II video looks great to me - except for the MJPEG segments, which have annoying judder and lower resolution. (though the resolution looks just fine when viewed at 720p) The images are very sharp, clean, and natural looking. When I saw that video, and saw the price of a GH1, I said "I gotta buy a GH1!". And so I did. And now I have it. And now I have a lot to learn about how to shoot good-looking videos.

 

[balazer]

I can't seem to find a thread or even post on this question: while TECHNICALLY (as lpowel has demonstrated), the mjpeg 720p30 --> 720p24 conversion is not true 24p (since it drops frames), has any one done tests as to when, if at all, it is VISUALLY noticeable? Are there circumstances in which, to those that aren't looking hard for it, it will produce an unnatural or aesthetically unwanted result?

If there is very little motion, you could get away with frame rate conversion by dropping frames. But as soon as you have more than a little bit of motion, those dropped frames will result in a very jerky appearance. Perhaps not everyone would notice it, but I certainly do, and I find it very objectionable. The more frames are dropped, the worse it gets. Dropping one frame in 30 is mildly annoying. Anything more than that is pretty bad.

 

[Fool4UAnyway]

How many frames are dropped to get from 30p to 24p? Does anyone do their maths?

How many frames are dropped to get from 30p to 24p? Does anyone do their maths?

If you can't see the difference between 30fps with all frames, and 30fps with every 4th frame dropped...I'd bet you can't see the difference between 30fps and 24fps in the first place. Which begs the question...why are you trying to downgrade your footage to 24p, anyway? IMO, anyone professional editor is going to see immediately that it isn't really 24p.

Let me put my comments here, because here anyone is just copying what is written elsewhere.

I think it will be very hard to notice 24 fps from original 30 fps with every 4th frame dropped.

If you have 30 fps and drop every 4th frame, you will be left with 3/4 times 30 frames = 22,7 frames...

To get from 30 fps to 24 fps, you would have to keep 24 / 30 = 4 / 5 of all your frames. So, dump 1 in 5 frames, that is dump 1 frame after every 4(th) frame(s), dump every 5th frame instead of every 4th.