HDMI Capture Problem SOLVED - AviSynth RULES!
- Thread starter Ralph B
- Start date
I plopped in your code and rendered out the night scene of the car. The red tail lights are perfection! Just a quick test, but it sure looks good.
One thing I noticed was that rendering times doubled. Do you think you could do a 'lite' version?
RE: After Effects - I rendered out RGB and 422 versions, and then brought them into After Effects. You're right, the red edges on the 422 version were starting to break up, although just slightly. I suppose if you're being an absolute perfectionist, you should render the intermediates as RGB.
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Does anyone think this thread should be a sticky? I sure do. There are going to be new GH2 owners in the future who are going to come here looking for information on how to record through the HDMI. It would be a shame if all the work we've done was buried in a mass of threads.
g.l
Well-known member
Sorry to hijack the thread temporarily, but this is significant for me - can you confirm that flipping the LCD definitely rotates the HDMI image? And is the footage merely turned upside down (ie. just rotated 180 degrees), or is it actually mirrored / flipped in some way?
I ask because I'm building a GH2-based stereo rig. I will preview 3D using two small HDMI monitors with a half-silvered mirror between them (viewed using polarized glasses). This only works if I can flip / mirror the image on one of the screens vertically or horizontally. Note I'm speaking about mirroring, not rotating.
If this can be done just by rotating the LCD screen, beautiful.
I just tested it. Yes, when the LCD is facing forward the image is flipped horizontally, the same as if you were looking in a mirror. And this flipped image is sent out over the HDMI.
One thing you need to be careful about, is that the HDMI port is directly in front of the LCD screen, so you need to rotate the screen before you plug in the cable. Once the cable's plugged in, you won't be able to rotate the screen, unless you unplug the cable.
Very intriguing project, by the way. Let us know how it goes.
g.l
Well-known member
Awesome, thanks! Some monitors can flip the image, and some that can't via their menus can be made to flip via a dip switch on the board. I'm seriously thinking of using some true 720p panel kits I found though, and the known compatible LCD controllers (there may be others) don't support flipping, so this is a really big deal.
Thanks for the headsup. I've actually found a right-angle cable that goes downwards along the body (also linked above), so hopefully it'll all work. Even nicer, the recorded footage itself won't be flipped, so doesn't need to be corrected in post (no big deal, but one less button to push
).Check the above link, it'll take you to our stereoscopic collaboration thread (lots of good info in there if you're interested in 3D).
Have you fully solved the chroma issue btw? I've been working a lot with luma & chroma recently, so if not maybe I can help out.
I'll see what can be scaled back safely.. maybe do an analysis of which steps take up how much time and so forth. I'll eventually retry to see if I can get something stable from using multithreading on a MT version of Avisynth. Like I said, I was at on point getting seemingly stable acceleration with maybe like a 30% improvement in speed, using one of the MT versions.. need to figure out which that was... threw out the results because those were among the slightly not perfect YUV clips.
I should probably also test with some other encoders to... if I can. I pretty much due all my encoding in TMPGEnc unless I need to spit something out CS4.
So does this mean the HDMI output is downstream of what is on the LCD screen. If so could this be the root of the odd cadence sent to the HDMI output.
Good point. Vitaliy should take note.
HKO
Well-known member
Ahem .....he he - this made me smile - you do realise that the beauty of the flip out LCD is that it can be rotated even with the HDMI cable plugged in? Just pull it out halfway so that it is at 90 degrees to the body and flip it any which way. I do it all the time when monitoring.
By jove, you're right!
You know Henry, you're the one who got me started on all this when you posted that HDMI clip of yourself. Thanks! Hope all is well.
Ralph are you keeping Vitaliy up to date on your progress?
I know it sounds strange that perhaps the signal from the LCD is causing all of the cadence problems. But if the HDMI output is effected by what is on the LCD maybe we need to understand what format the LCD is working at.
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Ian-T
Veteran
You know....if it wasn't for the "flipping" image on the LCD (literally) I wouldn't have given this idea a second thought. But now that you mention it (among others) it's all starting to make some sense.
Since the HDMI signal is exactly 60i, I think it's safe to assume the LCD is refreshing at an even 60 fps. The movement is very smooth. Of course, the LCD has much less resolution than the HDMI signal.
g.l
Well-known member
It does look like Panny are re-using the feed to the LCD, either to stay under their processing budget, or to deliberately make HDMI recording difficult. It's also possible that the LCD panel they use (or its controller) only supports exactly 60Hz (a common speed for panels until recently), so they may have been forced to butcher the stream to fit.
I haven't followed HDMI, does the GH2 never output true 24fps? This bit in the manual seems to suggest it can - or are they just talking about in-camera playback of 24p AVCHD files?:
"• During [24P CINEMA] and [VARIABLE MOVIE MODE] playback, please set [HDMI MODE] to [AUTO]. For settings other than [AUTO], it cannot output at 24 frames/second."
I suspect this is the case. For all we know, it may be a common practice to add in extra fields to make a video signal exactly 60P for display on camera monitors.
Here's a possible scenario. The exact same thing is being done on the GH1, but we never know, or even think about it. GH1 users clamor for HDMI output. Panasonic engineers listen. "Hmm, how can we do this without a major redisign of the circuitry? Aha, tap the feed going to the LCD! The reason people want HDMI output is to monitor the picture on a large display while shooting - perfect!"
This also explains why there isn't audio on the HDMI signal, because there's only picture going to the camera's LCD.
It really does start to make sense.
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Oh I hate when that happens!
That looks like it could be a pain to change with a frimware hack as it would effect the LCD monitor as well.
Either way it looks like you have solved the HDMI rec problem. Thanks for all your efforts Ralph.
The only faint glimmer of hope is that on playback, the camera outputs a correct HDMI signal, complete with audio... and simulataneously shows the picture on the LCD. So, the camera is capable of doing both simultaneously. But, whether you could use the output circuitry during recording is anybody's guess. I wouldn't hold my breath.
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