AVCHD high bitrate tests- MUD FREE footage

One thing I'd like to see, which I may or may not test myself, is seeing the difference between a *slightly* increased bitrate(like the 24-32mb range that Barry talked about) and the all-out 50+mb range that a lot of people are testing. I'd like to see if there is a perceivable difference once you start to max out the "normal" parameters of AVCHD.

My thoughts are that *maybe* the encoder will increase bitrate but true quality won't increase beyond the 24mb/s range even though the encoder is creating larger files?

I think this is purely circumstantial at this time but from what I've seen, the videos that were done with lower bitrate hacks seem to lack "mud" and have detail almost equal with those using extreme settings. Of course this is just watching videos that people have uploaded so it begs to be tested in a scientific way.

Is there any way of testing AVC like the guys are doing with the MJPEG testing programs?
 
A_K said:
Hi Everyone!

I would like 720p/60fps with reasonable bitrate that does not crash even with intensive movement, which settings should I use?
Click to expand...

Hi there. This is an excerpt from "Jobless," taken directly from page 1, first post of this thread.....


"For 720 MODE use the following settings that will work without problems:

Video bitrate adjustment 38000000
Overall bitrate adjustment 40000000
Limiting bitrate adjustment 42000000

For these settings avg. bitrate in 1080 MODE is 34.4 Mbps and for 720 34.5 Mbps.
There are no problems with recording of any kind either with 1080 or 720.
No MUD with this setting also.
I should say that these are stable settings and I would recommend them for normal users that want to shoot with 1080 and 720."

Much more information to be read in the first posts of this thread.

http://dvxuser.com/V6/showthread.php?t=213082

[Edit] Looks like Adventsam beat me to it! :)
 
I've been running with those settings (the stable jobless ones) the last couple days and I would agree they are for the most part very reliable, even with a class 6 card. However there is definitely some of the old GH1 compression visible in the frame, not mud so much, but just parts where the detail is too much and it looks a bit painterly. It's actually kind of a cool effect, and I could envision shooting something to deliberately use that - kind of a hybrid of hyperreal and painterly in a single frame, depending on the level of detail in objects. But I think now that I have a Sandisk Extreme Class 10, I will bump back up to the full "D" settings and see how it goes.

Edit: My comments refer exclusively to 1080p AVCHD, I didn't really do much at 720. So there's every possibility at 720 it just looks like regular solid footage, no compression artifacts.
 
motherly said:
how do u edit MTS file if not converted?
Click to expand...
For those on the Apple platform, ClipWrap 2.0 can convert the file into one that the Apple NLEs can edit, with no loss in quality at all. Performance may or may not be adequate depending on your hardware, but it's a way to get at the native raw footage if nothing else.
 
Barry_Green said:
For those on the Apple platform, ClipWrap 2.0 can convert the file into one that the Apple NLEs can edit, with no loss in quality at all. Performance may or may not be adequate depending on your hardware, but it's a way to get at the native raw footage if nothing else.
Click to expand...

Thanks alot for the software info! going to try it now.
 
Well, I should clarify by saying I haven't used ClipWrap, but pulled that from their site. So that issue may be fixed now, but I can't say without having used the software. I'll have my GH1 tomorrow, so I'll do a test then.
 
I've been testing Clipwrap and it works. Not sure what the issue was, perhaps with original footage with pulldown?
 
Isaac_Brody said:
I've been testing Clipwrap and it works. Not sure what the issue was, perhaps with original footage with pulldown?
Click to expand...

Do you use it with FCP? Right now I use log and transfer to get the mts files to proresLT, but maybe clipwrap is a better solution. Are there drawbacks to using quicktimes made by clipwrap?
 
I'm using cineform to convert to prores without removing pulldown and I'm not noticing a quality loss, or any of the timing issues mentioned here.

Another overall question...with the AVCHD 'c' settings, when I'm shooting something stationary, the bitrate often falls to 12 mpbs, sometimes even a bit lower. As soon as the camera moves, it jumps right up, and as Tester himself suggested, I'm concentrating on the footage, not the numbers.

However, what I'm curious about is...to me, even the static shots with the hack look sharper than the original firmware. Maybe I'm crazy, but I swear they're crisper. My question is, the did original firmware have such a variable bitrate as well? In other words it said 17mbs but maybe on static shots it would fall way lower?
 
I will be recording a live performance (around 1,5 hours) with two PAL GH1s
I want to use 1080/25p. I also have the 30 min. limit hack enabled so I can film the entire show in one clip.

My 32GB SanDisk 15MB/s Class 4 card handles the new bit rate just fine, but I'm afraid I could have problems (overheating?) if I shoot for a long period of time using these settings:

Video bitrate adjustment 38000000
Overall bitrate adjustment 40000000
Limiting bitrate adjustment 42000000

Do you think I will be able to record this event without any real issues?
 
i'm gonna add this to the FAQ, there's probably a .1% chance your camera will overheat, however, it doesn't guarantee the bitrate won't mess up or guarantee your card will sustain those speeds for long periods of time.
 
Oetam, I wouldn't shoot a live show with the firmware yet unless you're just enabling the 30 min hack and leaving the bitrates alone. AVCHD doesn't seem to handle write errors gracefully so the chances are good you'd lose everything up to that point if you did have a write error. I think this will be possible to do safely in the future but more testing needs to be done first to establish bitrates that are reliable, not hit-and-miss. Just my $0.02. Event videography is not the place to be on the cutting edge with this kind of stuff.
 
Do you think I will be able to record this event without any real issues?
Click to expand...
With event stuff, there is absolutely no alternative to testing your rig under identical conditions (and that applies whether it's the GH1 hack or any other new element in your rig) before doing the actual event.

So I'd suggest running the hacked cameras for at least the planned times back at base, ideally a couple of times over, and see what happens. However, the problem is that as what's in front of the camera, and how it and the camera moves, can make a difference (by pushing up the recorded bitrate) you need somehow to replicate that element too. Tricky to be quite sure!
 
Oedipax said:
Oetam, I wouldn't shoot a live show with the firmware yet unless you're just enabling the 30 min hack and leaving the bitrates alone. AVCHD doesn't seem to handle write errors gracefully so the chances are good you'd lose everything up to that point if you did have a write error. I think this will be possible to do safely in the future but more testing needs to be done first to establish bitrates that are reliable, not hit-and-miss. Just my $0.02. Event videography is not the place to be on the cutting edge with this kind of stuff.
Click to expand...
If you think to go to a live show with just one camera, you're asking trouble anyways :-)
 
You're probably right. It's just quite tempting to try and use these new bit rates especially because my camera has already been modded and tested (short clips) with AWESOME results.

Emanuel said:
If you think to go to a live show with just one camera, you're asking trouble anyways :-)
Click to expand...

Two cameras.
 


This is a quick wierdo edit of a fun night last weekend.

96% of the shot made using the el cheapo 12.5mm f 1.4 fujinon lens of doom.
Shot in 1080p24 with the C setting.

Avchd -> ProRes422(HQ) -> XDCam 720p24VBR -> Vimeo

I see the diffrence. Thanks Tester.
 
You must log in or register to reply here.
Back
Top