Possible breakthrough on Native 24p!

No, it's not true. However, it's a common way to hide information within images. When signatures are contained within images and video streams they aren't usually hidden. Well, they are from the image, but the metadata containing that data is typically accessable if you know how to retrieve it. Now you can identify specific sensors sometimes based on dead pixel mapping. Fortunately finding child porn is not part of my job, I'm more in the intellectual property and the anti-trust compliance fields.

Chris
 
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cbrandin said:
Actually, I might have it wrong. We may not be screwed after all - stay tuned. Many thanks to DaLiv for pointing out my error! I misread an address and went to the wrong places.

As for my day job, I do high tech forensics (processor architecture, encryption, hardware and software analysis, etc...) and testify at trials, etc... A big part of what I do is basically hacking. Also I'm chief scientist for Xpriori (nee NeoCore) - semi retired.

Chris
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keep us updated please! I got my finger on the trigger ready to pull the native 24p OFF if your conclusion is that we can have a STABLE high bitrate codec with 24p native unchecked.

by the way, quick question from a layman. you said possibly that biggest frame size the codec can deal with is 897,152. does this have any correlation or indication of how much resolution gh1 is actually doing? Is it doing true 1080 etc or how many pixels is it really doing or is there no way to know that?
 
Homunculus said:
by the way, quick question from a layman. you said possibly that biggest frame size the codec can deal with is 897,152. does this have any correlation or indication of how much resolution gh1 is actually doing? Is it doing true 1080 etc or how many pixels is it really doing or is there no way to know that?
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There should not be a correlation. Your question is explored in depth in the following article by Barry Green.
 
larryfine451 said:
So on a personal level Chris ,what is your interest in all this .....Is it the intellectual challenge ?
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Pretty much... Filmmaking and Photography are hobbies of mine. A long time ago I studied photography (the technical aspects of it) at RIT.

Chris
 
Nice! Hopin' for next amazing achievements around GH1 and 24pN guys! And take your time of course ... :)
 
As seems is impossible (actually) solve the 24p issue for buffer size problem, I suggest to wrap in a different wrapper: not 60i but some similar to a 48i.
In PAL, I can record at 50i instead 25p, and I have the same data to encode. Yes, there is some little difference in interlaced vs progressive encoding, but not so big at this point.
So, if we can record a 48i file, may be we have no more the buffer problem,and data to encode is the same than 24p but lesst than 60i with better quality.
If this is possible, this is not a solution but a workaround for reliablity. Or not?
 
Willyfan said:
As seems is impossible (actually) solve the 24p issue for buffer size problem, I suggest to wrap in a different wrapper: not 60i but some similar to a 48i.
In PAL, I can record at 50i instead 25p, and I have the same data to encode. Yes, there is some little difference in interlaced vs progressive encoding, but not so big at this point.
So, if we can record a 48i file, may be we have no more the buffer problem,and data to encode is the same than 24p but lesst than 60i with better quality.
If this is possible, this is not a solution but a workaround for reliablity. Or not?
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I've actually thought something like this also...However, I am not sure how hard it would be to create a type of frame rate in camera then program it to pulldown automatically.
 
Homunculus said:
well ****! with guys like this and vitaly, we're in good hands. we need you two to take a look at gh2 asap and start hacking that puppy! gh13 killed Canons, we want GH2.13 to kill Red! :thumbsup:
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Isn't this site owned by Jarred? I like a lot of things about the GHs and particularly the hacks, but killing RED isn't one of them!
 
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I might have stumbled upon something and thought it might be useful...I was thinking about modular's settings/cbrandin's double theory and it got me to playing around. With these settings I was able to record the papa chart-o-death and will supply the .mts files if needed. Both times I was able to record the chart for a minute with 24p checked.

FHD- 32xxxxx
Overall- 90xxxx
GOP- unchecked

FDH- 40xxxxx
overall- 80xxxx
GOP- 15

I tried dropping the GOP down to 10 but I received a card write error in 5 sec. I am using a sandisk 8gig class 10 30 MB/s...My thinking here (and not on a deep level) is if we shoot in FHD but keep the bits down but keep the overall bitrate very high. This might produce some higher quality images....Both were averaging around 25-35MB/s a second and I was using the media information on VLC to show me consistently updating stats.

On a side note, when I used the star chart I was recording it off of my 28" 1920x1200 monitor so that might have effected the outcome as well. I dont have access to a high rez printer to get it off the computer so it was the best I could do. With these findings it makes me think the AVCHD codec has two points |-----------| and it will bounce its bitrate between those until it cant take it any more and write error but between those bookends is infinite. The MJPEG seems to work in steps where it will shoot for the high step and then go down to the next step if it cant handle it.

http://vimeo.com/16495828

For anyone who wants one of the files...this was filmed with: overall- 90xxx, FHD- 32xxx

Shutter: 1/60
ISO: 100
F-stop: 2

nostalgia: sat: -0, contrast: -2, sharpness: -2, red: 0
 
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Hi guys I am new to dvxuser, I have just brought GH1 yesterday with 1.2 firmware. I did hear about the hack with ptool and I tried doing it myself but it seems like the hack is not working? (Or I am not doing it right!!). Though it's my first time using DSLR I am a quick learner, I did search on the net for step by step instructions on how to hack GH1 (I did lots of forum reading too but still was unsucessful)....

I hope by posting my question, it will help me solve my problems as well as many others that may or are facing similar issues.....So can somone please be kind enough to help me/us out by posting clear instructions here (I guess everyone once went through this, so you know what it's like guys, so help would be very much appreciated)..

Ok i will explain what I've done so far, I went to the following link for instructions http://wiki.eoshd.com/index.php/Begi...Firmware_Guide I've followed and done exact steps that were mentioned in this page and few additionals. Additionals were ticking the "Thrid-party battery" box, ticking the "30min limit removal" box and ticking the "Video Bitrate H" and changing the value to 50,000,000 from 16,000,000 under it (Even though ticking and changing the value for "Video Bitrate H" wasn't mentioned in that page, I done it simply because of the image shown there had a tick in it and some forum reading done before)......By the way lots of forum i read talks about using ptool v3.35 and v3.36 but the ptool I used was v3.40d...not sure if that makes any differences?

Then I saved the firmware naming it GH1_133.BIN (yes with double underscore). Then I copied the saved GH1_133.BIN to empty Class 10 Transcend 16GB memory card and inserted into my GH1. After that I clicked "Playback button" in GH1 and it automatically asked me if I wanted to update to version 1.3 which I selected "Yes" then it started to load and after loading, GH1 restarted (Now at this point, I assume that the hack has been already applied).....Piece of cake!! (that's what I thought!! But how wrong was I?)

I then started to record some videos (without changing any setting in the menu, maybe i have should have? If yes, please let us know what settings to change).....Then I took the memory card out of my GH1 and inserted into my card reader and plugged into USB port and extracted the recorded videos (Can I extract the videos from my GH1 straight using the usb cable that came with GH1? instead of taking the memory card out? If yes, how? Because I tried doing it, but my PC didn't find any USB connection, maybe because I should have installed the software that came with my GH1? (which I didn't) I simply didn't do it because I thought it was going to update the firmware version automatically and I dind't wanted to take the risk of having the latest firmware updated in my GH1 where I wouldn't be able to apply the hack if I am right?? and I did make sure that I only buy GH1 with specific firmware so I can apply the hack).....

After looking at the video shot from my GH1 I was sad :(....(because it had very similar quality comparing to my £200 camcorder where as I spent £800 for GH1).....I also compard the videos which I shot earlier without trying to apply hack and the quality were very similar??.....So guys this is my sad story (LOL)....please help me/us out :(

Thank you very much for taking your time to read this. Help and answers to all questions asked above would be very very very much appreciated.....

Now I helplessly wait for a super man :P...hahaha good day :D
 
omnidecay said:
Testing some more I was able to get stable settings using my sandisk extreme class 10 30MB/s WITH 24p checked:

Overall bitrate: 90xxx
FHD: 40xxx
GOP: 15

I was able to film papas chart here: http://vimeo.com/16509731
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I really hope you're right, but the camera never seemed to be fully still. A lot of the problems came from a complex scene, a dead still camera, and a wide lens.
 
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