Why is that?
100% Quality Factor MJpeg Settings (very low compression - class 10 required!)
- Thread starter modulr
- Start date
Well I would say that the 100 mb/sec MJPEG 720p is better than any other form of 720p. Even the 720p @ 60 FPS on the GH1.
Now, I am not saying that the MJPEG 720p is better than the GH1 1080p AVC-HD. There is a clear difference in favor of the 1080p in that case.
Does anyone prefer 720p AVC-HD over ultra high bit rate 4:2:2 MJPEG?
Nitsuj
Well-known member
Very interesting.
Pappas,
Only 38/40/42 AVCHD setting can survive your chart right from the start (without "vision adjustment ").
I guess that's why some guys here are experiencing live recording interruption after the MTS file reaches the length of 4gb (I'm not sure how it works. I guess it should start a new file automatically)
It seems the camera's having hard time starting a new file due to some unknown processes (checking focus, codec, etc)
Only 38/40/42 AVCHD setting can survive your chart right from the start (without "vision adjustment ").
I guess that's why some guys here are experiencing live recording interruption after the MTS file reaches the length of 4gb (I'm not sure how it works. I guess it should start a new file automatically)
It seems the camera's having hard time starting a new file due to some unknown processes (checking focus, codec, etc)
I guess what I'm getting at: is what's your definition of "better?" MJPEG 720p is 30 fps vs AVCHD's 60 fps, so these are quite different beasts.
modulr - was wondering if your approach could be generalized as follows...
1. For each quality level L=1,2,3,4 define a reference frame with L=1 being the lowest detail (eg., headshot) and L=4 being the highest detail (as you have done). L=2 might be an indoor still life and L=3 might be an outdoor scene with modest detail.
2. Find the maximum value of Q4 that will safely encode all highest detail scenes (as you have done). Set Q1=Q2=Q3=Q4, shoot the highest detail L=4 scene and gradually increase Q4 until it breaks on your card and then back off.
3. Find the value of Q3 that maximizes the quality factor for the L=3 scene (or indeed any constant mixture of scenes). Set Q1=Q2=Q3, shoot the medium high detail L=3 scene (or any known mixture of scenes), and adjust Q3 to maximize the number of frames at 100% quality. Now you know Q3 and Q4.
4. Repeat for Q1-Q2 on medium detail scene and then Q1 alone for low detail scene.
Following this approach, it should be possible to optimize the four MJPEG quality settings for the card you're using and for the specific scenes that you're shooting. All you need to achieve the optimal values is a repeatable sequence of images with a representative distribution of image detail.
1. For each quality level L=1,2,3,4 define a reference frame with L=1 being the lowest detail (eg., headshot) and L=4 being the highest detail (as you have done). L=2 might be an indoor still life and L=3 might be an outdoor scene with modest detail.
2. Find the maximum value of Q4 that will safely encode all highest detail scenes (as you have done). Set Q1=Q2=Q3=Q4, shoot the highest detail L=4 scene and gradually increase Q4 until it breaks on your card and then back off.
3. Find the value of Q3 that maximizes the quality factor for the L=3 scene (or indeed any constant mixture of scenes). Set Q1=Q2=Q3, shoot the medium high detail L=3 scene (or any known mixture of scenes), and adjust Q3 to maximize the number of frames at 100% quality. Now you know Q3 and Q4.
4. Repeat for Q1-Q2 on medium detail scene and then Q1 alone for low detail scene.
Following this approach, it should be possible to optimize the four MJPEG quality settings for the card you're using and for the specific scenes that you're shooting. All you need to achieve the optimal values is a repeatable sequence of images with a representative distribution of image detail.
Since there isn’t really a great way to share 720p @ 60 FPS right now I can’t realize any of the benefits of the increased frame rate.
Right now, I would rather have higher bits per frame than a higher frame rate. 1080p @ 24 FPS is sounding better and better to me every day. I just wish my GF1 could shoot that so I wouldn’t have to buy a GH1 body or a GH2 when it comes out.
Motion looks very different at 60 fps than it does at 30 fps. Personally I would not "compromise" footage where such differences are critical, like action. Some things change -- Youtube now offers resolutions higher than 1080, but some things don't -- once you shoot something more often than not you can't go back and have another go at it.
You pretty much nailed it. I stops you from just throwing numbers in there, and just hoping it's better. By determining your max load with Q4 for your most complex scene, one can easily scale the quality factor upward for scenes that are less intensive.
It can easily be adapted to any class card. I just happen to only have class 10s.imho you are kinda over thinking this. MJPEG is a tool... it's just another option, and this one in particular yields very high quality results. There is absolutely nothing wrong with shooting 30fps.
Not to mention, the MJPEG codec is capable of very cool time lapse, when you set the framerate to something like 2fps with the ptool, record some stuff with an very slow shutter, then jump in dumpster (osx) and change the frame rate in the header to 24 or 30fps. Instant time lapse with no rendering.
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Martin Koch
Well-known member
This is a very cool trick. I didn't dare to change the frame rate so far but this is quite useful! Thanks.
How slow of shutter speed are you talking here?
Perhaps you are right on the over-thinking part. I believe in using the right tool for the right job :thumbsup: Which requires thorough understanding of both requirements of the job and the tool itself. By the way, I was reminded in another thread of something that pertains to this discussion. Since GF1 is not capable of shooting at 60 fps natively, those benefits I mentioned only pertain to GH1.
reggietelly
Active member
I have a PAL GH1 and it still shoots 30fps MJPG 1280 x 720. Is there a way to use these settings with 25 fps reliably. I have read that changed MJPG framerate is a no-no.
best
Richard
best
Richard
reggietelly
Active member
This is really cool. How do you do this. I thought you said changing the frame rate drops frames. Does this produce a smooth timelapse. If so this sounds like a brilliant solution. Which check box do you have to change? I don't ave Ptool on this computer so don't know which button I'd use.
I just loaded mpgxsvcd modulr settings 422 MJPEG high quality settings and they work great on my GH1 so far. Thanks modulr and mpgxsvcd!
Here's a sample screen grab from a test movie I shot. Smooth settings all -2
Here's a sample screen grab from a test movie I shot. Smooth settings all -2
Not to mention, the MJPEG codec is capable of very cool time lapse, when you set the framerate to something like 2fps with the ptool, record some stuff with an very slow shutter, then jump in dumpster (osx) and change the frame rate in the header to 24 or 30fps. Instant time lapse with no rendering.[/quote]
Thats sounds cool. Have you had any luck recording timelapse this way. It sounds like a neat option.
Thats sounds cool. Have you had any luck recording timelapse this way. It sounds like a neat option.