JPEG on GH13 , never works, what am I doing wrong

T

truestory

Active member
Hello esteemed GH13 users, I have been trying for 6 months to get the JPEG side of things to work but no luck...
I have AVCHD working between 45-55mbps in different hacks on various GH13 cameras with 99% reliability..
Today I tried the Blackout-Powell native 24p patch and again the AVCHD side is 100% stable but the JPEG side freezes 95% of the time on very simple shots..
I am using PAL , I format the card before each try but never get to record anything...
All I want to do is record 1280x720 25fps in 4:2:2 for green screen work at a bit rate that is around 45-55 mbps or whatever rate gives good quality picture..

If anyone can shed some light on this I would be very grateful as I am pulling my hair out on this one....

cheers
Truestory
 
truestory said:
All I want to do is record 1280x720 25fps in 4:2:2 for green screen work at a bit rate that is around 45-55 mbps or whatever rate gives good quality picture..
Click to expand...
For both NTSC and PAL cameras, MJPEG video records properly only at the default frame rate of 30fps. If you use PTool to alter MJPEG frame rate to 25p, it will force the camera to simply discard every sixth frame in the 30p video stream.

With the Blackout-Powell Native 24p Patch, you can adjust the MJPEG 720p30 mode to any frame width (divisible by 8) from 1280 to 1920 pixels wide. This patch should record at an MJPEG bitrate of around 50Mbps in 4:2:2 color depth. If you're still having MJPEG reliability issues at 30fps, I'd suggest trying my Reliable In-Camera Playback Patch, which records MJPEG video at 35Mbps. For more details, check out this link:

http://www.dvxuser.com/V6/showthrea...aring-thread&p=2039780&viewfull=1#post2039780
 
ok, thanks so much Ipowell for taking the time to respond, this answers my question but raises another interesting one, I was not aware that the MJPEG was not valid for 25p.. So is there a patch to make the PAL side of things work for MJPEG or is this a fixed limitation for the GH13 hack..
Also if it discards frames causing lockup at 25fps how is it possible to use frame rates like 2fps for time lapse with out any issues. I have one gh13 hacked from long ago in early version of ptool and can record 2fps in MJPEG mode, I do not know what the setting are as I dont have the original Ptool version any more...

many thanks

Truestory
 
It's a limitation of the MJPEG encoder itself, it encodes only at 30fps. PTool cannot change the encoder's frame rate, it can only force it to drop frames from the 30p video stream.
 
Thanks for that, just one more thing just to clarify, does that mean the GH1 models that were manufactured for PAL countries and set from factory to record AVCHD at 720P50, 1080P25 etc were set to 30fps for MJPEG ???
 
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