AVCHD high bitrate tests- MUD FREE footage

TO SVART:

I treid to record C settings on tripod with hidetail scene. I also had ticked 24p patch. And GOP 1080 24p set to 5. I didn't have any problems with recording( 1 min 15 sec and then I stoped gH1)
However my scene don't include trees and bushes, it will be good to try these settings in your environment.
Also setting GOP to 5, bitrate increase in low detail scenes ( due to larger number of I frames) and seems to image looks sharper...
It will be good to look at 'pulsing' problem with these settings also...
 
I wonder if its just me or there basically are no blacks on the GH1. I only shoot AVCHD, on MJPEG even with latest hack, resolution is much lower and I can rarerly finish a shot before it craps out.

So, Ive tried several re-encarnations of the hacked firmware, till now the last one, and honestly, dont see improvements. Color noise and rendition is horible and posterization artifacts on any greay to dark gery/bacl areas is horrible, no matter the bitrate hacks. Also, Ive notices true blacks dont exist, they are a mud of very dark blue. On low light situations or ISOs any higher than 100 ISO is simply unbearable.

So, since everyone is so happy, is this just my camera or anyone that trully looks at the black/shadow areas of their footage sees the same?

No motion, well lit, no shadows, all accpetably OK but other than that... its painful to look at... maybe its just my camera... Ive rolled back endless times bewteen stock ROMs and the higher bitrate ones, and see positively no improvement in the noise and color artifacts that are the worse of any camera Ive used in years...
 
HEAVEY Blocking in avchd 1080p/

HEAVEY Blocking in avchd 1080p/

I am enclosing a link to the mts file - you need vlc to play it on a mac. I set the camera looking at a fixed scene and waved my hand around the lens, kind a shutter. This was meant to stress the avchd algorithm. I got *HUGE* blocking and really low bitrates.
I tried 50, 52, 60 and 60, 62, 70. Using a Patriot LX Class 10 card.
Its a 32MB file so not too hard to download.
Has anyone seen this ? It really really terrible blocking.
The strange thing is that the encoder is not increasing the bitrate to compensate for the rapid changes in the scene.
This sample is from the 60, 62, 70. The camera is the orignal Made in China batch if that makes a difference.
BTW I have only checked the avchd options to try and isolate this problem. None of the mjpeg or 24p/25p options are checked.
Here is the filedropper link.

http://www.filedropper.com/00001_3
 
VeEuzUKY said:
I wonder if its just me or there basically are no blackson the GH1. I only shoot AVCHD, on MJPEG even with latest hack, resolution is much lower and I can rarerly finish a shot before it craps out.

----

all accpetably OK but other than that... its painful to look at... maybe its just my camera...
Click to expand...

My blacks are true black. Sounds like you have a dodgy unit or use a less than optimal transcode method. Have a .mts clip to check?
 
Svart said:
I've also done:

native 24p
Vid buffer
vid bitrate
overall bitrate
limiting bitrate

I'm starting to think maybe it's my cards. I'll probably end up getting a sandisk to compare.
Click to expand...
Vid Buffer and Vid Bitrate were in the old version of Ptool v3.36 it has then been revised several times without version change and these patches removed. Please make sure to download and test with the latest version, I think the were "code changes" as well.
 
zcream said:
I am enclosing a link to the mts file - you need vlc to play it on a mac. I set the camera looking at a fixed scene and waved my hand around the lens, kind a shutter. This was meant to stress the avchd algorithm. I got *HUGE* blocking and really low bitrates.

----

Has anyone seen this ? It really really terrible blocking.
The strange thing is that the encoder is not increasing the bitrate to compensate for the rapid changes in the scene.

----
Click to expand...

Downloaded the clip. Transcodes fine with Toast 10, plays back fine with Toast Video Player. Looks like utter crap in VLC which has never played GH1 .mts files particularly well. See attached example.
 

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Martti Ekstrand said:
My blacks are true black. Sounds like you have a dodgy unit or use a less than optimal transcode method. Have a .mts clip to check?
Click to expand...
I will shoot a quick clip and upload it. Honestly as I look at my footage, 2 things come to mind:
- The colors are so bad it looks Im looking at a monitor displaying 256 colors, there are no gradations, no intermediate tones, nothing.
- The camera is clearly recording with GAMMA set way to high. There is no way to control this. I can increase the contrast on the settings Menu but that crushes the Blacks and then blows all highlights making the image horrible... usually I prefer the opposite setting which is to use the -2 contrast as it preserves highlights more and reveals better shadow detail, but here, cannot do.

If I try to decrease over all exposure by a 1/3 Fstop or so, things only get worse ans there is just more black that is never black and just patches of blocks and noise of very dark blue.

I look att he footage and it seems shot at super low bitrate actually, plus, positively no color space...

This is troubling...
 
Thanks Martti. That makes a lot of sense.

On another note, is there a way to force a higher bitrate ? I cannot seem to get more than 22 mbps no matter what settings I try.

Martti Ekstrand said:
Downloaded the clip. Transcodes fine with Toast 10, plays back fine with Toast Video Player. Looks like utter crap in VLC which has never played GH1 .mts files particularly well. See attached example.
Click to expand...
 
zcream said:
Thanks Martti. That makes a lot of sense.

On another note, is there a way to force a higher bitrate ? I cannot seem to get more than 22 mbps no matter what settings I try.
Click to expand...
VLC has problems playing back AVCHD files period, not just from GH1.

Now, as far as low bitrates are concerned, it seems that high bitrates (with appropriate settings) are mostly seen on "high detail" scenes. In that regard, AVCHD has an advantage (in my mind) over MJPEG, because it allocates extra bandwidth only when the extra detail in the scene make it necessary. Now, it still remains to be seen how intelligently does the encoder make those decisions in variety of situations, but early results seem to be pretty encouraging.
 
svecher said:
VLC has problems playing back AVCHD files period, not just from GH1.

Now, as far as low bitrates are concerned, it seems that high bitrates (with appropriate settings) are mostly seen on "high detail" scenes. In that regard, AVCHD has an advantage (in my mind) over MJPEG, because it allocates extra bandwidth only when the extra detail in the scene make it necessary. Now, it still remains to be seen how intelligently does the encoder make those decisions in variety of situations, but early results seem to be pretty encouraging.
Click to expand...
If you guys are on PCs, just use Splash Lite. Eats all AVCHDs and plays them like butter even on slow computers. VLC sucks and keeps on sucking to worse every verson upgrade. It used to be a great lightweight player when the project started but now, forget about it, junk. Splash Lite.
 
How does the 1080p 24 GOP setting affect image quality. I used to have it at 12 but now its back at 15 as I never saw in difference. Is a lower setting (supposedly) better and why?...
 
so let me make sure im reading right we can shoot 1080 24p ? and how long does it shoot ?
 
Last edited:
I did compare the original 1080 50i vs the 1080 25p using c settings (as defined in ptool)

see still image comparison using the 20mm 1.7 here: I did 2 footages within 5 minutes using the same camera settings and tripod.

1080 25p using c settings


Normal blur for 1/50s shutter speed

Uploaded with ImageShack.us

1080 50i using original firmware

muddy blur. This is not exactly this kind of muddy blur I had sometimes on some Mountain Bike footages. All the background and the Mountain Biker were muddy in this case.

see here:


Uploaded with ImageShack.us

Looking at this 1080 25p footage I can assume that for my future MTB footage I will get now a normal blur for the backgroung and a sharp MT Biker! (so a normal pan situation using 1/50s shutter speed)
 
VeEuzUKY said:
How does the 1080p 24 GOP setting affect image quality. I used to have it at 12 but now its back at 15 as I never saw in difference. Is a lower setting (supposedly) better and why?...
Click to expand...
A lower setting is NOT necessarily better, it makes the codec less efficient. Actually a higher GoP should potentially be able to squeeze the most out of the codec.

The lower the setting, the more like an intraframe-only codec it becomes. Which is fine and I'd prefer that, IF it had a corresponding increase in bitrate.

The higher the setting, the longer the group of pictures, and the more overall efficient the codec can become. However, if there's something abrupt that changes in the image, you might get muddy imagery until the codec "catches up".

There is no universal "better". Each setting is there for a reason. What we're trying to find is the best compromise for general shooting purposes.
 
Barry,

I'm using Cineform Neoscene, and I'm wondering isn't that tailored to 15Gop files from the GH1. If it's doing the reconstruction of the Mts to a quicktime, would that mix things up? Or does that not matter?

I notice that the first few frames of a cineform conversion have a mud look, then after that no more.


Here are my AVCHD settings that I'm trying today:
GOP - 12
52.000.000
55.000.000
65.000.000


Pappas
 
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