alignment1
Well-known member
alyn99- I got errors in both 1080p24 and 720p60...they all played back in cam- but just got a handful of card speed errors
50Mbps AVCHD Fast Action 3-Frame GOP Patch
- Thread starter Lpowell
- Start date
alyn99- I got errors in both 1080p24 and 720p60...they all played back in cam- but just got a handful of card speed errors
There's the problem -- there is no 720p60 mode with my settings. Did you check 720p59,94fps->29,97fp? If not, these settings won't work at all data rates will be way too high.
alignment1
Well-known member
That was the reason for trying "Worpig's mod"
http://www.dvxuser.com/V6/showthrea...me-GOP-Patch&p=2118374&viewfull=1#post2118374
The thought, was to dial back the '50Mbps patch' whilst leaving 720p60 intact to try to achieve those settings but leaving 60p for overcrank.
For what it's worth-I shot a lot.... filled an entire card even with the handful of errors.
I optimized the 50Mbps AVCHD 3-Frame GOP Patch specifically for AVCHD 720p30 mode, so it's probably not very stable when working at 720p60. My 40Mbps AVCHD High Reliability Patch is probably a better starting point for reducing GOP-length in 720p60 mode. If I find some free time, I'll see how short I can make it.
alignment1
Well-known member
I gotcha lpowell- already re-installed 40Mbps AVCHD High Reliability Patch.
But to reduce the GOPin the "40" patch is a good thought. I need RELIABILITY w-out question. I'm doing some work with auto racing series, sometimes(actually almost always) you get one shot to get it right...and RELIABILITY is a MUST. For me being able to shoot 720p60 at a constant is a plus--for slow-mo option.
Not shooting 'live' again until next friday so, hopefully some time to get some tests ironed out. Your help has been, and continues to be priceless, thank you again for your efforts.
Z
But to reduce the GOPin the "40" patch is a good thought. I need RELIABILITY w-out question. I'm doing some work with auto racing series, sometimes(actually almost always) you get one shot to get it right...and RELIABILITY is a MUST. For me being able to shoot 720p60 at a constant is a plus--for slow-mo option.
Not shooting 'live' again until next friday so, hopefully some time to get some tests ironed out. Your help has been, and continues to be priceless, thank you again for your efforts.
Z
Yeah, I find that with the right 'unstable' settings I'll just get intermittent 192s in some of the p frames but I can lay down footage that is 98% great all day long.. With the wrong 'unstable' settings I get intermittent longer GOP seqeunces as I surmise the codec is completely breaking down. In the first case, Avid will transcode the AVCHD streams fine and I might see a barely noticeable stutter where the 192 p frame was. But in the second case I will see a ton of glitchy noise in the transcoded clip and it will be unusable.
We're you able to test out the 40Mbps reliability patch in parallel with a lower GOP in 720/60p? I've been lurking these forums looking for the best combo of hack since I shoot a lot of 720/60p. Really looking forward to your results. I'm gonna give it a shot myself this weekend. Thanks
With the 40Mbps AVCHD High Reliability Patch, GOP-length for 720p50 mode can be set as short as 5, and GOP-length for 720p60 mode can be set as short as 6.
However...
Short GOP-length patches are not entirely reliable. Under extremely dim lighting levels, the AVCHD encoder's bitrate will drop below 5Mbps and it will generate empty P-frames. If this condition persists for as long as 7 seconds, the camera will stop recording, display a spurious SD card write-speed-limitation error message, and leave a zero-byte file. While this may be some sort of built-in auto-shut-off mechanism, it is dysfunctional and destructive. The only known way to prevent it is to insure that your subject is adequately lit at all times.
The original 40Mbps AVCHD High Reliability Patch is NOT afflicted by this malfunction. It only occurs when the GOP is set too low.
LPowell questions for patch
LPowell questions for patch
Using hack version 3.50, there is no place for:
#10: manual movie modes
#s 28-31: preset bitrates, and constants for 1080p & 720p
also
Is #12 E1 quality supposed to be 200 or 250?
I'm using a Mac and I can't open the ini file in the folder, so I have to do the patch manually.
Thank you.
LPowell questions for patch
Using hack version 3.50, there is no place for:
#10: manual movie modes
#s 28-31: preset bitrates, and constants for 1080p & 720p
also
Is #12 E1 quality supposed to be 200 or 250?
I'm using a Mac and I can't open the ini file in the folder, so I have to do the patch manually.
Thank you.
Manual Movie Modes is only for the GF1, you can ignore it for the GH1.
Preset Bitrate and Constant for 1080p are found in Patches for testers, AVCHD Movie Mode.
E1 - E4 Settings:
E1 Quality=280
E1 Table=4
E2 Quality=250
E2 Table=10
E3 Quality=225
E3 Table=24
E4 Quality=200
E4 Table=48
Preset Bitrate and Constant for 1080p are found in Patches for testers, AVCHD Movie Mode.
E1 - E4 Settings:
E1 Quality=280
E1 Table=4
E2 Quality=250
E2 Table=10
E3 Quality=225
E3 Table=24
E4 Quality=200
E4 Table=48
MJPEG at 60Mbps can only record about 3 minutes per clip. AVCHD 720p30 with a 3-frame GOP is about twice as efficient as MJPEG, and it can record a single take for as long as the SD card has space.
Thanks lpowell. My initial test with your 40Mbs reliability patch and 720/60p with a 6 GOP looks promising. I still want to do some more testing but so far I have not been able to make it fail with my 8gb class 10 scandisk. I've tested in various medium to low light conditions and even upped the shutter speed to 125 which is usually my max in 60p. I used a circular panning motion around a vase of flowers in low to medium light and achieved a avg bitrate of just a touch over 27. It's looks amazing on my 55" screen with no detectable artifacts. I will do some outdoor testing tomorrow or this weekend, but so far so good. Thanks for all your work!
the fast-action patch worked nearly flawlessly over the course of a 10-day documentary shoot. i had 2 clips that were cut short when played back in-camera and that my laptop could not even copy off of the memory card. don't remember getting any warning or error message from the camera at the time, but may have been when the stupid kit lens gave me 'lens not attached' warnings and not due to the patch at all.
otherwise, i'm totally stoked with this patch. loving 30p shot at 1/30th shutter; gives nice smooth creamy motion! very natural looking motion blur, especially when i scrub clips slowly.
otherwise, i'm totally stoked with this patch. loving 30p shot at 1/30th shutter; gives nice smooth creamy motion! very natural looking motion blur, especially when i scrub clips slowly.
Great to hear you're having good results with 720p30 AVCHD, especially at 1/30 sec shutter. The ability to scrub through the MTS files directly without need for transcoding is just what I was hoping the 3-frame GOP would deliver.
i can't scrub raw avchd in realtime on my system. i convert everything to Avid's DNxHD 720p 75mbps codec for editing. what i meant was that the recorded image motion looks great. no skipping. no weird strobe-like 24p! 
i just put this together for you, in honor of this upcoming Halloween, to show the motion blur:
i just put this together for you, in honor of this upcoming Halloween, to show the motion blur:
it took me a while to get a feel for the camera with the FaderND and to really really accept that i need to expose a little darker to protect the highlights!