Intermittent black / green flicker problem

Hello All,

I have recorded video game footage captured from my Sega Genesis console (upscaled with an iScan VP30 and captured with a Hauppague HDPVR) in the 720p 60fps format. When I am editing this footage in Final Cut I notice an intermittent flicker which is sometimes green and sometimes black. The strange thing is that if I take two identical copies of the same piece of footage, the flicker does not happen in the same place for both of them, but yet seems to be repeatably consistent for each one. Furthermore, if I do a bunch of other things and then come back to a clip that was flickering, it will now flicker in different places, or maybe not at all.

First I thought that it might be a framerate issue, but no matter what frame rate I set my project too, the behavior persists (and I can verify that the changes to framerate are making a difference, because increased frame rate makes the animations look smoother etc.). Then I thought that perhaps it was because my computer was chugging, doing rendering or some such, so I bounced a small piece of the footage out in finalized form, and the output file still had the flicker.

Does anyone know how I can make this flicker disappear? The fact that an area where a black/green flicker frame was can be "fixed" by waiting or moving things around a bit makes me believe that I have no gaps in my captured footage, and its just some sort of framerate strangeness that can be ironed out somehow.

A few quick notes:

1. The framerate of the captured video should be stable (the iScan VP30's purpose is to upscale and time base correct, and it does this job well)

2. That being said, the flicker is unique to the Sega Genesis footage (other "live" footage I have in a picture in picture does not flicker, while the Sega footage underneath it does.


Does anyone have any ideas of how I can go about solving this issue? Thanks in advance!

What codec are the Sega clips? Sounds like they're some odd or non-standard codec. Also, what hardware are you running FCP on?

I had this exact same issue, except I only got green "flicker" or a single frames where green.
Reminds me of the green render issue when working with different codecs with ProRes in Motion 4 which I haven't noticed in Motion 5, anyways.

My footage was form the beginning (KiPro) ProRes 422.
Doing a replace edit with the identical footage from Event Browser did not fixed this... I can't really recall what I did but give removing the Render files from the Projects a try.
Also when I exported (Share) the footage it did not had this problem. Try exporting it and let use know if the issue still exists in the export. If that is the case it might be something else.

Thanks for the responses.

I'm running on an iMac with 8GB of ram and 2.8 Ghz i7 Core.
Exported footage does exhibit the problem.
The codec listed in the info tab for the Sega Clips is: AAC, H.264 (recorded via a Hauppague HDPVR using the HDPVRCapture software); as a comparison the codecs listed for the footage recorded with my video camera (live stuff, not sega) is H.264, Linear PCM

I suspect something with the way that H.264 from the Sega is being encoded. Does the HDPVR record QT files? Can it record ProRes files? There's something in the codec FCP is having to compensate for.

Frame size and frame rate would be import to know. Convert the media to get rid of that compressed audio. Make it AIFF 48k.

From Amazon's description:
"Records in AVCHD format for burning Blu-ray DVD discs"

Yeah, convert that to ProRes, AIFF audio, you'll be fine.

When the HDPVRCapture software records the gameplay it first records as .m2ts file which is then converted into a .mp4 file, which is the file I brought into FCP. If I do a "get info" on the .mp4 file the info listed is as follows:

Dimensions: 1280 x 720
Codes: H.264, AAC
Color Profile: HD (1 -1 -1)
Audio Channels: 2
Total bit rate: 5,411

When I highlight a Sega Clip in my event library it shows frame rate as 59.91 fps and dimensions as 1280 x 720, and I see the flickering when playing the movie in the event library, so the issue shouldn't have to do with project settings.

I just watched the .mp4 source material on my computer and it runs just fine, so the problem is definitely in how FCP is handling it, and not the raw footage itself.

How do I see the fort of the audio / convert it? I'm still new to this stuff so excuse my ignorance; thank you!

Okay BenB; do I do that to the source footage files in my Event Library? Also, will doing this not break anything in my project (i've already edited the material at great length, trimming it into pieces, rearranging it and fading etc. - hoping work won't get messed up!) Thanks.

This media needs to be converted to QuickTime. Best to use Compressor. For better quality convert to ProRes at 59.94fps, but you'd better have a good fast RAID. Or convert to QuickTime using H.264 59.94fps AIFF 48k. You could also try MPEG Streamclip.

OK, you must convert those files in to .mov files. You can let them keep the same name, just .mov, and relink the new files to your existing Event files.

Okay, so this is nothing that has to do with "transcoding media" then, but rather something I have to do outside of Final Cut?

Can you give me a step-by step; I'm pretty anxious about screwing thing up. Once again, I apologize for my greenness.

Select the files you already have inside your Event Browser, right click, select "Transcode Media".

Not sure what a fast RAID has to do with anything.

I was about to say, why bother with MPEG streamclip or co if the clips are already in Final Cut Pro X just transcode them there. Nothing will break.

As mentioned many post before in my case it was ProRes from birth. So I wouldn't blame the codec right away... but if transcoding fixes it cool to go. Could still be something under the hood of Final Cut Pro X.

Have you tried removing the Render files also you said it is visible in the export right?

Yes, this needs to be done outside of FCP. This media should never have been brought into the application. Which application are you going to use? Do you have Compressor? Which codec do you want to use? Is your system able to support large ProRes files?

How far into the edit ate you? Can you afford to start over? If not, you'll have to relink, which requires you to be more careful with the conversion. Also relinking may not be possible because of the non-standard frame rate of your original media. Project settings will also effect this.

Yes the problem is currently visible in export.
No I haven't tried to remove the render files (not sure how to do that yet).

So it seems like two different paths are being suggested here:

1. transcode the media inside FCP
2. do some conversions outside FCP, and relink the file

number 2 sounds definitely more daunting. is it possible for me to try #1 and if that doesn't work out try #2 with no harm done?

Transcode inside FCP X, no relinking needed, ProRes supports non-standard frame rates, so does FCP X. It just won't make timelines from scratch at non-standard frame rates. But if you tell it to adapt to the first video clip dropped in, it will do non-standard frame sizes and rates.

scotopia wrote: 1. transcode the media inside FCP
2. do some conversions outside FCP, and relink the file

number 2 sounds definitely more daunting. is it possible for me to try #1 and if that doesn't work out try #2 with no harm done?

Yes, do the transcode as I detailed inside FCP X first. At worse it will tell you it can't.

Okay I will try transcoding. Should I check both optimize media and create proxy media? I only care about final quality and not how long things take to process.

Don't bother with Proxy.