GH2 24p hack causes artifacting, unusable at the 24L setting

T

tylerindo1

Carbonite Member
why is it fine at the 42mb/s but on 24L the image is full of artifacting and looks like sheet...it's like the 24h setting during the first second of recording only it is destroyed for the entire clip. wtf>?
 
It really depends which hack you are using: the "extreme" KAE hacks are made for 24L and he explains that they will not work with 24h. I am personally waiting for some AVCHD hacks with "the Powell stamp of approval".
 
Actually it is the other way around. The 24p High setting is all KAE appears to have tested. It is completely stable up to 90+ mb/sec with the 65 mb/sec setting. However, it does have the low bit rate first few frames issue. None of the other resolutions have that issue for KAE's GOP 3 settings though. There are intermittent playback issues as well with resolutions other than 1080p for KAE's GOP 3 settings.
 
tylerindo1 said:
why is it fine at the 42mb/s but on 24L the image is full of artifacting and looks like sheet...it's like the 24h setting during the first second of recording only it is destroyed for the entire clip. wtf>?
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I had the same concern when playing back footage using VLC on OSX, the whole image like you said looked horrible almost like an oil painting & I came close to posting about it with caps lock & lots of exclamation points but when I transcoded to ProRes using FCP the images came out perfectly normal. Before you panic like I almost did, it could be that whatever you're playing the clips back with isn't handling the footage properly.
 
ethan cooper said:
I had the same concern when playing back footage using VLC on OSX, the whole image like you said looked horrible almost like an oil painting & I came close to posting about it with caps lock & lots of exclamation points but when I transcoded to ProRes using FCP the images came out perfectly normal. Before you panic like I almost did, it could be that whatever you're playing the clips back with isn't handling the footage properly.
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The clip is messed up even in the camera playback. Trust me you can see where the first few GOPs are messed up with stream parser. Vitaliy said that he should have a fix for this by the end of the week.
 
tylerindo1 said:
why is it fine at the 42mb/s but on 24L the image is full of artifacting and looks like sheet...it's like the 24h setting during the first second of recording only it is destroyed for the entire clip. wtf>?
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What you are claiming is untrue, ALL of the higher bitrate hacks have the first few frames like that. So you have to wait a second before the fantastic footage kicks in for as long as you record the clip following those first ten or so frames. That little function of the hack is no reason to claim the whole clip is unusable when it in fact it is VASTLY improved and does not have artifacts like you clam it does... only in the first few frames, NOT a big deal and it is not present the rest of the clip at all. Like mpgxsvcd mentioned above kae is testing for highest quality in 24H NOT 24L and as a result you really should consider to use it correctly before creating a misinformed thread bashing it. I myself am working on that same thread to make the 24L a stable 42mbs and keeping the 65mbs quality all in the same ptools ini (which is going to be sweet).

If the whole clip looks like crap in your player than its YOUR player and YOUR computer that simply cant keep up, though most players will struggle with it but that's not the cameras fault in the least, consider better hardware to minimize having trouble working with and editing such demanding footage. It will help you greatly to recode it to something you can handle but make sure you preserve the quality using neocene and of the like. I for one don't need to and just dump it in a timeline and edit from the avchd directly without a single hiccup in my NLE so i can only say good things about the hack especially the 65mbs, it looks fantastic.
 
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The problem is that most of the people are not doing scientific tests on this. They simply see the higher bit rate and assume it must look better.

I have done the scientific tests on KAE’s GOP 3 and Gop 6 settings and here is exactly what happens.

GOP = 3 for 1080p 12 for everything else

  1. 1080p H is completely stable. I couldn’t get it to have a write error no matter what I did. I stressed tested it up over 90 mb/sec and it never had a write error.
  2. 1080p H will always have an extremely low bit rate for the first few GOPs with KAE's 65 mb/sec settings. You will be able to see it in the incamera playback and in the preview image that the camera displays for the video. If your video player doesn’t load up quick enough then it might not start displaying the video until after these first few images have already past. VLC does this for me but Windows Media Player will always show the artifacts.
  3. 1080p L, 1080i H, 1080i L, 720p H, and 720p L will NOT have the low bit rate first few frames no matter what you do with KAE’s GOP = 3 65 mb/sec settings. However, they will show intermittent signs of an uneven cadence in stream parser’s analyzer. This cadence may be good or bad. We haven’t been able to determine that yet.
  4. With KAE’s settings I have intermittently seen playback issues when going back and forth between recording formats. It will play the files just fine until all of a sudden it will say that it cannot play back any of the files.

For now the 32 mb/sec settings are the only ones that have zero adverse affects. It will simply record at a higher bit rate than the default if the scene requires it. Otherwise it will operate exactly as the camera did with the standard settings.
 
yeah, the entire clip is trashed, if i film for 30 seconds it's 30 seconds of unusable footage played back in the camera...if i film a minute it's the same issue. on the plus side i can film at 42 mb/s but thats a bit much for the amount of filming i need, and not enough cards to cover that for the moment.
 
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