HDMI Capture Problem SOLVED - AviSynth RULES!

mambomobil said:
finally i found the problem with the AJA IO express - with the PAL GH2 it does not work because there is no 50i input... - but i made a test with the NINJA and it works perfectly!
Since the camera outputs 50i at the HDMI and i would love to convert it to 25p instead of 24p but keep the advantages of this great scripts. I was trying around with the "Assume(24000,1001)" line, changing it to "Assume(25,1)" - without result. So i guess i will have to get rid of the pulldown??
Thanks for your help -
Click to expand...

Did you record at 24p?

If you've applied Ralph's script, and changed the line to AssumeFPS(25), this will do a simple PAL speedup (i.e keep same number of frames, just speed it up from 23.976)

If you are recording analog audio , add "true" to speedup the audio as well
AssumeFPS(25, true)

If you were feeding that .avs script into ffmpeg to encode to DNxHD , you have to modify those parameters also (the parameters in the earlier post are only valid for 1080p23.976)

For 1080p25 ffmpeg DNxHD encoding , use -b 185M , -b 120M , or -b 36M (for 185Mb/s, 120Mb/s and 36Mb/s respectively) . And to pass uncompressed audio through, use "-acodec copy" instead of "-an" in the ffmpeg commandline

Note it's "AssumeFPS" not "Assume", and check for the latest script, he's added some recent improvements
 
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IMPORTANT ALERT

If you downloaded the Advanced script in the last two days, be aware there is a formating error in it.

DO NOT USE IT!

The corrected script is now available in the first post.
 
This may be an obvious question, but I'm new here and really curious about getting a Ninja or some other external HDMI recorder for my GH2. Is the only workaround for the pulldown issue achievable through Windows? Is there no OS X solution?
Also, is the image quality produced through this process that noticeably superior to its AVCHD counterpart--especially given the intense workflow?
Thank you for your time.
Best,
Marcelo
 
Marcelo though the answer to your question is subjective I think the positives far outweigh the negatives. The image to me is sharper (though the GH-2 doesn't seem to need a lot of help in that area) and you get what looks to be more detail in the dark areas (which means no more smearing). And....absolutely no more compression artifacts (including the blocking). There will be certain things that remain due to its 8 bit nature....but..
 
thank you for your help

thank you for your help

PDR said:
Did you record at 24p?

If you've applied Ralph's script, and changed the line to AssumeFPS(25), this will do a simple PAL speedup (i.e keep same number of frames, just speed it up from 23.976)

If you are recording analog audio , add "true" to speedup the audio as well
AssumeFPS(25, true)

If you were feeding that .avs script into ffmpeg to encode to DNxHD , you have to modify those parameters also (the parameters in the earlier post are only valid for 1080p23.976)

For 1080p25 ffmpeg DNxHD encoding , use -b 185M , -b 120M , or -b 36M (for 185Mb/s, 120Mb/s and 36Mb/s respectively) . And to pass uncompressed audio through, use "-acodec copy" instead of "-an" in the ffmpeg commandline

Note it's "AssumeFPS" not "Assume", and check for the latest script, he's added some recent improvements
Click to expand...

thanks PDR! as far as i can see that should work. but i have another question concerning the readout of the chip: do you know if this is also with the "pal - model" 23,976fps? panasonic says in a flyer the chip "Produces" 50p - which is interlaced in the camera. in my opinion that would change something in the "remove pulldown" section (?). the output at the hdmi is anyway 50i. running or not running the camera.
the ninja i was capturing with sees only this 50i signal - and also records 50i.
another thing: after running the avisynth script with virtual dub i imported the avi to premiere - and i have some doubled frames again (which seemed solved in virtual dub...).

sorry for bothering you people so much with maybe stupid questions - but i got the feeling we are almost there...

thanks again -

tobias
 
mambomobil said:
after running the avisynth script with virtual dub i imported the avi to premiere - and i have some doubled frames again (which seemed solved in virtual dub...).
Click to expand...

When working with Premiere (or any video editing program), be sure the frame rate for your footage matches the frame rate of your project. If not, the program will conform the footage to match the project's frame rate, and may produce either duplicate or blended frames.

In this case, the frame rate of the Premiere project should be 23.976 because that's the frame rate of the clips after they emerge from Avisynth.
 
thanks ralph, that was it! Any suggestions with this "readout - issue"? is there a difference on the hdmi output when i change from 24p to 50i in the camera setup (concerning readout)?
 
Boon said:
does AviSynth runs on the mac?
Click to expand...
Not directly. Some mac users were using virtualbox I think ; scroll back a few pages

I think martin set up a blog page for mac users with more clear instructions


mambomobil said:
but i have another question concerning the readout of the chip: do you know if this is also with the "pal - model" 23,976fps? panasonic says in a flyer the chip "Produces" 50p - which is interlaced in the camera. in my opinion that would change something in the "remove pulldown" section (?). the output at the hdmi is anyway 50i. running or not running the camera.
the ninja i was capturing with sees only this 50i signal - and also records 50i.
Click to expand...



This works when you record using 24p in camera, not the liveview which is 50i , low resolution, and lower DR

If you go back a few pages the setup was used for testing on PAL GH2 examples with Ninja (Martin) ; there might be some differences with your setup with IO express

I don't know if it works for any other configurations. You would have to test it or provide samples

is there a difference on the hdmi output when i change from 24p to 50i in the camera setup (concerning readout)?
Click to expand...

If it's like the NTSC model, there are extra fields inserted. (instead of 60i + extra fields, you probably have 50i + extra fields) . I think Ralph put up a 60i script


another thing: after running the avisynth script with virtual dub i imported the avi to premiere - and i have some doubled frames again (which seemed solved in virtual dub...).
Click to expand...

If you were using the modified script for PAL speedup - AssumeFPS(25) , then you have to interpret the footage in premiere as 25fps (if it already isnt identified as 25p) , and use 25fps squence settings

Otherwise it's as Ralph said above (23.976)
 
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martinbeek said:
Is there any gain from using convertToYUY2 instead of YV12 ?

Martin
Click to expand...

No. ConverttoYV12 is part of the Chroma Fix and should be used for optimum performance. It's also essential for the filldrops function to work in the Advanced Script.
 
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Hello All.

An update for MAC/ProRes users who render to DNxHD MOV files.
I've found that the following addition to the script (placed before ConvertToYV12) results in a perfect match of the original HDMI footage and the converted DNxHD footage.

#Lower gamma to 0.825, keep other levels 0~255
Levels(0, 0.825, 0, 255)


Martin.
 
martinbeek said:
#Lower gamma to 0.825, keep other levels 0~255
Levels(0, 0.825, 0, 255)
Click to expand...

That's probably a typo

It should probably be

Levels(0, 0.825, 255, 0, 255, coring=false)

the "false" should be entered otherwise you clamp your footage Y'16-235 , CbCr 16-240
 
PDR said:
That's probably a typo

It should probably be

Levels(0, 0.825, 255, 0, 255, coring=false)

the "false" should be entered otherwise you clamp your footage Y'16-235 , CbCr 16-240
Click to expand...

Woops! Not even a typo, but sheer stupidity ;-)
Thanks!!

Martin.
 
Hi guys, (specially Ralph B. :) )

-I'm about starting a documentary film in which we'll going to use two GH2 (PAL version) with several lenses.

The thing is that I'm trying to decide a good workflow for the editing process as there's going to be a lot of material and the shooting is going to take several months.

-Most of the documentary involves interviews, that's why we decided for the GH2 (no time limit, no mirror, no heat etc..), also, quality is much better (to my eye). With the right lenses you can get a depth of field as small as with 5D, 7D etc..

-We want to use two Atomos.

-Boom microphone is going to be wired just to the "A" camera.

-Editing is going to be made in Media Composer in Mac Machines (both desktop and laptop)



-So, can you guys help me with the workflow?

Here's a first aproximation:

1. Record the HDMI out to the Atomos (prores at max. resolution. I think the out signal is 50i, right?)

2. Convert to 24fps DNxHD 185 with the script of Ralph B. BUT with which software in Mac OSX??? ffmpegx?? This is the point where I'm COMPLETELY LOST.

3. Import DNxHD files to Media Composer for editing.

4. Whe the edit is finished, export .DPX files from Media Composer for color correction in DaVinci Resolve.

5. Final export in .DPX for ArriLaser film recorder in Lab.

ALTERNATIVE:

2A. Convert to 24fps Prores 4:4:4 with the script.

3A. Link through AMA in Media Composer for editing

Last steps as in previous.


I've considered recording just in AVCHD in the cards, but I think that HDMI workflow delivers much more room for color correction (no blocks in shadows) and won't take much more time, as AVCHD workflow also involves transcoding from original files . Editing native files is a pain in the ass for all machines.



What do you think, guys?

Thanks for yout help.
 
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timetraveller said:
Here's a first aproximation:

1. Record the HDMI out to the Atomos (prores at max. resolution. I think the out signal is 50i, right?)
Click to expand...

We need to stop right here. Are you shooting 24P or 50i into the Ninja? If you're shooting 50i, then you need do no further processing, and can go staight to editing (if my understanding of the PAL GH2 is correct).

If you're shooting 24P, then you need to go the Avisynth route.

I have neither a PAL GH2 or a Mac, so I can't help you much beyond this.
 
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