75Mbps GH1 Peak Performance Patch

Version 4 of Peak Performance Patch available for download

Version 4 of Peak Performance Patch available for download

I've updated the 75Mbps Peak Performance Patch with a few minor refinements that may interest PAL users and event shooters. I've posted a new Version 4 INI patch settings file in the first post of this thread. Those familiar with selecting individual patches in PTool may prefer to update Version 3 of the patch with the following changes:

720p50 GOP Size=26

I've reverted this setting back to the default, so you can simply uncheck this patch. I had previously set the 50p GOP-length to 20, but found that it may occasionally produce empty P-frames at extremely high bitrates. 26 appears to provide an extra margin of reliability.

Video Bitrate H=29000000

From my testing, 29M is the highest bitrate setting that allows you to reliably shoot lengthy takes that require file spanning beyond a single 4GB MTS file. You can use this 720p50/60 video mode at any time by selecting "H" instead of "SH".

Video Bitrate L=17000000

This setting will produce an average bitrate of about 17Mbps, comparable to the camera's unhacked 720p50/60 video mode. You can use this video mode at any time by selecting "L" instead of "SH".
 
http://vimeo.com/19416689

This is still uploading/converting as I post, so have patience..
Shot yesterday using the peak performance patch, 1080p 25fps. Tried to break it but couldn't!

my first vimeo upload - hope I got it right
 
Great looking video. I am impressed with your smooth pans on that video. Please share how you did such smooth video: monopod? tripod? what lens, etc... Al
 
mr bill said:
Shot yesterday using the peak performance patch, 1080p 25fps. Tried to break it but couldn't!
Click to expand...
Nice shooting, mr bill! I downloaded the video file from Vimeo, but it has a ".h26" file extension instead of the GH1's ".mts" extension. Is this a transcoded version of the original AVCHD video?
 
Here are two test videos taken on a tripod from my apartment using version 4 of the patch with the kit lens zoomed to about 50mm or 70mm.
AVCHD
http://www.vimeo.com/19426652
MJPEG
http://www.vimeo.com/19427781

One specific question I have is that for the 1080 25fps video, there is subtle but annoying 'pulsing' in some static areas of the shot, ie, where the middle green light lamp intersects with the wall behind it on top of which there are trees. It's almost as though the codec can't resolve the detail and keeps changing its mind as to what it should be.

I've noticed this problem using other versions of the hack as well, usually in grassy areas that are in the background to my subject, and on a High Def TV, the 'pulsing' is actually quite noticeable and annoying. Maybe this is a limitation of the AVCHD codec as the second video I posted is the MJPEG version of the same shot, and the problem is gone, but note the MJPEG version totally misread the yellow wall in the background (showing it as yellow and white stripes when in fact it's entirely yellow as seen in the AVCHD version).

Any thoughts or comments would be appreciated.
 
Last edited:
lpowell said:
Nice shooting, mr bill! I downloaded the video file from Vimeo, but it has a ".h26" file extension instead of the GH1's ".mts" extension. Is this a transcoded version of the original AVCHD video?
Click to expand...

Afraid it is - I converted a sequence to 720p h.264 from the 1080p originals. Can I upload 'raw' avchd files to vimeo?
 
Last edited:
aljudy said:
Great looking video. I am impressed with your smooth pans on that video. Please share how you did such smooth video: monopod? tripod? what lens, etc... Al
Click to expand...

Thanks. Manfrotto 504 'fluid' head throughout, although obviously the last shot is using a tracking dolly..
 
had a good test of the version 4 of lpowell's 75Mbps Peak Performance Patch today (PAL GH1)... initially had no luck shooting FHD on high detailed scenes using the 1st release of the patch.

using version 4 i had no record errors, empty frames or any other issues, i have to say it handled perfectly on the exact same scenes that i had speed errors and other issues using the 1st version of the patch.

i was kind of expecting to see speed write errors but i was unable to get to to fail... and i was trying! :smile: lpowell does it again! thanks man!

can i ask does anyone know if the live bit rate readout (cmd+i) from VLC player is accurate?
 
Roderz said:
...note the MJPEG version totally misread the yellow wall in the background (showing it as yellow and white stripes when in fact it's entirely yellow as seen in the AVCHD version).
Click to expand...
This is not an MJPEG codec fault, it's a sensor resolution issue. The horizontal stripes in the MJPEG video are moire effects produced by the dense array of tiles on the wall. With 1080p, the AVCHD video has enough pixel resolution to reproduce the fine details without aliasing. The MJPEG resolution is not quite high enough and its vertical sampling interval at this level of zoom produces horizontal aliasing bands.
 
I've updated the 75Mbps Peak Performance Patch with a few minor refinements that may interest PAL users and event shooters. I've posted a new Version 4 INI patch settings file in the first post of this thread. Those familiar with selecting individual patches in PTool may prefer to update Version 3 of the patch with the following changes:

720p50 GOP Size=26

I've reverted this setting back to the default, so you can simply uncheck this patch. I had previously set the 50p GOP-length to 20, but found that it may occasionally produce empty P-frames at extremely high bitrates. 26 appears to provide an extra margin of reliability.

Video Bitrate H=29000000

From my testing, 29M is the highest bitrate setting that allows you to reliably shoot lengthy takes that require file spanning beyond a single 4GB MTS file. You can use this 720p50/60 video mode at any time by selecting "H" instead of "SH".

Video Bitrate L=17000000

This setting will produce an average bitrate of about 17Mbps, comparable to the camera's unhacked 720p50/60 video mode. You can use this video mode at any time by selecting "L" instead of "SH".
 
No changes to 1080p video modes in Version 4, though you may notice in PTool that I explicitly patch the GOP-length to the specific value required by each video mode.
 
Queston to Ipowell...what do you consider is the most reliable 24p native setings for AVCHD and MJPEG
runing at about 50 Mbps ...i need native 24p at this bitrate using class 10 card...more intrested MJPEG
but would sill welcome info on AVCHD settings..yes you are sill my hero hacker
 
Baitron said:
Queston to Ipowell...what do you consider is the most reliable 24p native setings...
Click to expand...
I've lost count of how many times I've been asked this question, but the answer is still the same...

To my knowledge, no one has yet been able to produce a reliable non-interlaced 24p native patch.
 
Version 3 patch. SanDisk Extreme 8 GB Class 10 card 30MB/s
Bright overcast day. Test clips all under 2 minutes in duration. Lots of grass, moving dogs, trees, ferns and shrubs
Some failures in all three modes usually at between 5 & 9 seconds into the clip

Error message:
Motion recording was cancelled due to the limitation of the writing speed of the card.

Media Info application used to check bit rates

MJPEG--22 clips--1 failure--Average Mbps 56.9--High 64.3 Mbps--Low 50.4 Mbps
1080p--24 clips--4 failure--Average Mbps 42.4--High 48.4 Mbps--Low 29.2 Mbps
720p-- 11 clips--6 failure--50%!--Average Mbps 44.3--High 48.4 Mbps--Low 37.5 Mbps

Failed AVCHD video clips recorded Mbps from low of 40.3 Mbps (1080p) to high of 48.4 Mbps (720p)
Failed MJPEG recorded no video.

Not sure why the failures. Will be doing further testing this week. Suspect it may be a combination of subject matter, lighting and/or incorrect camera settings.

I'm new to all this.

Have been using the Fast Action 50 Mbps AVCHD 720p30 @ 3-Frame GOP and 60 Mbps MJPEG 729p30 in 4:2:2 color Patch (Many Many Thank Yous to lpowell and vitaliy)
It has worked flawlessly for me.

Will continue testing this Peak Performance Patch. Hopefully I will be able to see a pattern soon and make the necessary adjustments to make everything work right!

Any input/insights would be appreciated. Trying to learn and understand how this thing called video works! <smile>
 
Lpowell-

A great many of us have been quietly waiting in the wings while you more adventerous souls have done the hard footwork of dialing in the best settings for the GH1 hack. For us your work is not merely appreciated - it is indispensable. Is there anything we need to know about shutter speed, or other issues when using your 75mbps hack? Can you give your exact settings - or perhaps someone else that has applied the hack - for those of us who feel a little overwhelmed?

Thank you for your hard work - LittleSteve in Oakland
 
If you install the hack and you do get failures, nothing will happen to your camera and you can always go back to the original firmware. So... try it out yourself, it is really easy to do, takes only 1-2 minutes and you can test it straight away.


lpowell: Thanks again for all the selfless effort!
 
lpowell said:
This is not an MJPEG codec fault, it's a sensor resolution issue. The horizontal stripes in the MJPEG video are moire effects produced by the dense array of tiles on the wall. With 1080p, the AVCHD video has enough pixel resolution to reproduce the fine details without aliasing. The MJPEG resolution is not quite high enough and its vertical sampling interval at this level of zoom produces horizontal aliasing bands.
Click to expand...

Okay. Thanks. I always wondered what aliasing was but was too lazy to ask! I still find the pulsing more than a little annoying on some of my vids when hooked up to my TV though, but since no one else has raised the issue, I guess I'll have to live with it.

Thanks for the response lpowell and really appreciate your hard work with these amazing patches.
 
Thanks for the responce...i am working on a windos 7 pladform what woud be the best rute to go
if wanted to convert my GH13 footage 24p, i will be outputing to 35mm film
 
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