Flickering playback of video at DVinfo.net

Jeff Harper · November 7th, 2011, 06:20 PM

I burned a wedding today. Flickering was pretty bad, and not sure what caused it. It only show up on my TV, not on PC or on internet. The flickering is of detailed areas like leaves and on the grooms detailed Pakistani-styled clothing, and the bride's veil, it's like a strobe effect. On the PC and on Vimeo there is no flickering.

I shot in 720p, and rendered to 720p, so not sure what is happening.

Jeff Harper · November 8th, 2011, 12:11 PM

Anyone? Am I not describing the problem properly?

Edward Troxel · November 8th, 2011, 02:00 PM

If you have fine lines, you will get flickering on a TV due to interlace issues. The way around that is to add blurring so that you don't have fine lines or make sure you have thicker lines.

Pan a brick wall and play it back on a TV, you'll get flickering like crazy!

Jeff Harper · November 8th, 2011, 02:17 PM

Thanks Edward. But this is Bluray 720 60p playing on a LCD. I've never seen this before. My camera the GH2 is famous for lack of moire. So is the TV interlacing the video?

I guess for the future, if this occurs again I'll add the blurring, just never expected to see nor have I seen this with progressive footage. I'm wondering if it had to do with the shutter speed of the camera.

Edward Troxel · November 8th, 2011, 04:05 PM

All older TVs are interlaced and your TV *may* be adding interlacing. Your DVD player *may* be adding interlacing. I'm guessing somewhere in the process interlacing is being added but I have no way of knowing where it is being added. Of course, I could be wrong too and it could be some other issue altogether.

Phil Lee · November 10th, 2011, 11:51 AM

Hi

Quote:

Originally Posted by Jeff Harper

Thanks Edward. But this is Bluray 720 60p playing on a LCD. I've never seen this before. My camera the GH2 is famous for lack of moire. So is the TV interlacing the video?

I guess for the future, if this occurs again I'll add the blurring, just never expected to see nor have I seen this with progressive footage. I'm wondering if it had to do with the shutter speed of the camera.

It is still possible to get moire/flicking over fine detail as there are no (as far as I know) native 720p panels in HD TVs, so some scaling takes place somewhere and fine detail can then pattern as you have two lots of patterns interacting with each other, interlaced or not unfortunately.

Regards

Phil

Jeff Harper · November 10th, 2011, 12:36 PM

There are 720p tvs, Phil, I had one (died on me last year) but that is of course, besides the point. I really think in this case it must be the fact I was shooting in program mode and likely was shooting at a high shutter speed. I was still very new to the GH2 at the time.

I think you're right regarding the detail issue and I'm sure the upscaling doesn't help.

Steven Thorsen · November 10th, 2011, 03:40 PM

Jeff,

I've had similar problems with a moire flickering/strobe effect in videos viewed on an LCD TV. To solve this annoyance I've done the following:

1. On the timeline select and right click the offending clip and choose "Properties".

2. In the "Video Event" tab check "Reduce interlace flicker" even though you're shooting 720P. I chose the "Disable resampling" option but maybe the smart or forced resampling options will give better results. Then that's it.

I've had this problem when there are many thin verticle lines, small, high and low contrast areas, such as tree leaves in bright sun light or any such similar shooting situations. I've never shot Pakistani-styled clothing, but if it's got a lot of fine lines, beware. Panning or any other camera motion will only exacerabate this strobing effect. Don't rely on the Vegas preview window or your computer monitor to see the results.

Why don't you test 1 short clip, render it and view it on the actual TV that you'll view it on.

Hope this was some help. Please let us know if this solves the problem. It did for me.

Jeff Harper · November 10th, 2011, 09:49 PM

Steve, I'll try that on next video. Only was problematic on three clips at the beginning, and this was a very low budget wedding in which I had invested too much time already.

I minimized the flickering a bit changing some settings, but I'll try your suggestions next time and try to eliminate it.

Rest of the video came out fine. If they complain, which I doubt they will, I'll just eliminate the clips.

Aaron Courtney · November 11th, 2011, 03:52 PM

which button on the GH2 did you press - the red one or the shutter trigger? There have been several points posted in various forums that pressing the red button will override your shooting mode and cause the camera to jump to something between full auto and partial auto. Seems no one has really drilled down the specifics on this but you can do various searches and read more about it.

Other than that, the extremely high rez of the GH2 relative to that of the Canon DSLRs has been attributed to the funky flickering in 24P (I know you were filming 720P60...) which has caused some to install filters to soften up the image. I know some lenses will exacerbate this problem because of their contrasty nature. My Oly Zuiko 14-35/2 can look just plain "bad" compared to an old sigma 70-210/2.8 in daylight with an ND-8 and polarizer setup about 15' away from the subject at 2.8 and ~135mm - talk about pure lovely bokeh.

There was an extensive thread about this 24P flickering problem in Vitaley's (tester13's) forum setup for the GH2 hack that continued this past summer.

November 7th, 2011, 06:20 PM	#1
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Flickering playback of video I burned a wedding today. Flickering was pretty bad, and not sure what caused it. It only show up on my TV, not on PC or on internet. The flickering is of detailed areas like leaves and on the grooms detailed Pakistani-styled clothing, and the bride's veil, it's like a strobe effect. On the PC and on Vimeo there is no flickering. I shot in 720p, and rendered to 720p, so not sure what is happening. __________________ "The horror of what I saw on the timeline cannot be described."

November 8th, 2011, 12:11 PM	#2
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: Flickering playback of video Anyone? Am I not describing the problem properly? __________________ "The horror of what I saw on the timeline cannot be described."

November 8th, 2011, 02:00 PM	#3
Edward Troxel Sponsor: JET DV Join Date: Dec 2001 Location: Southern Illinois Posts: 7,953	Re: Flickering playback of video If you have fine lines, you will get flickering on a TV due to interlace issues. The way around that is to add blurring so that you don't have fine lines or make sure you have thicker lines. Pan a brick wall and play it back on a TV, you'll get flickering like crazy! __________________ Edward Troxel [SCVU] JETDV Scripts/Scripting Tutorials/Excalibur/Montage Magic/Newsletters

November 8th, 2011, 02:17 PM	#4
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: Flickering playback of video Thanks Edward. But this is Bluray 720 60p playing on a LCD. I've never seen this before. My camera the GH2 is famous for lack of moire. So is the TV interlacing the video? I guess for the future, if this occurs again I'll add the blurring, just never expected to see nor have I seen this with progressive footage. I'm wondering if it had to do with the shutter speed of the camera. __________________ "The horror of what I saw on the timeline cannot be described."

November 8th, 2011, 04:05 PM	#5
Edward Troxel Sponsor: JET DV Join Date: Dec 2001 Location: Southern Illinois Posts: 7,953	Re: Flickering playback of video All older TVs are interlaced and your TV may be adding interlacing. Your DVD player may be adding interlacing. I'm guessing somewhere in the process interlacing is being added but I have no way of knowing where it is being added. Of course, I could be wrong too and it could be some other issue altogether. __________________ Edward Troxel [SCVU] JETDV Scripts/Scripting Tutorials/Excalibur/Montage Magic/Newsletters

November 10th, 2011, 12:36 PM	#7
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: Flickering playback of video There are 720p tvs, Phil, I had one (died on me last year) but that is of course, besides the point. I really think in this case it must be the fact I was shooting in program mode and likely was shooting at a high shutter speed. I was still very new to the GH2 at the time. I think you're right regarding the detail issue and I'm sure the upscaling doesn't help. __________________ "The horror of what I saw on the timeline cannot be described."

November 10th, 2011, 03:40 PM	#8
Steven Thorsen Tourist Join Date: Dec 2006 Location: Istanbul, Turkey Posts: 4	Re: Flickering playback of video Jeff, I've had similar problems with a moire flickering/strobe effect in videos viewed on an LCD TV. To solve this annoyance I've done the following: 1. On the timeline select and right click the offending clip and choose "Properties". 2. In the "Video Event" tab check "Reduce interlace flicker" even though you're shooting 720P. I chose the "Disable resampling" option but maybe the smart or forced resampling options will give better results. Then that's it. I've had this problem when there are many thin verticle lines, small, high and low contrast areas, such as tree leaves in bright sun light or any such similar shooting situations. I've never shot Pakistani-styled clothing, but if it's got a lot of fine lines, beware. Panning or any other camera motion will only exacerabate this strobing effect. Don't rely on the Vegas preview window or your computer monitor to see the results. Why don't you test 1 short clip, render it and view it on the actual TV that you'll view it on. Hope this was some help. Please let us know if this solves the problem. It did for me.

November 10th, 2011, 09:49 PM	#9
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: Flickering playback of video Steve, I'll try that on next video. Only was problematic on three clips at the beginning, and this was a very low budget wedding in which I had invested too much time already. I minimized the flickering a bit changing some settings, but I'll try your suggestions next time and try to eliminate it. Rest of the video came out fine. If they complain, which I doubt they will, I'll just eliminate the clips. __________________ "The horror of what I saw on the timeline cannot be described."

November 11th, 2011, 03:52 PM	#10
Aaron Courtney Major Player Join Date: Feb 2006 Posts: 229	Re: Flickering playback of video which button on the GH2 did you press - the red one or the shutter trigger? There have been several points posted in various forums that pressing the red button will override your shooting mode and cause the camera to jump to something between full auto and partial auto. Seems no one has really drilled down the specifics on this but you can do various searches and read more about it. Other than that, the extremely high rez of the GH2 relative to that of the Canon DSLRs has been attributed to the funky flickering in 24P (I know you were filming 720P60...) which has caused some to install filters to soften up the image. I know some lenses will exacerbate this problem because of their contrasty nature. My Oly Zuiko 14-35/2 can look just plain "bad" compared to an old sigma 70-210/2.8 in daylight with an ND-8 and polarizer setup about 15' away from the subject at 2.8 and ~135mm - talk about pure lovely bokeh. There was an extensive thread about this 24P flickering problem in Vitaley's (tester13's) forum setup for the GH2 hack that continued this past summer.