Game capture and the variable frame rate abyss. Any video experts here?

[ProfessorProfessorson]

I imagine that anywhere it is supposedly doing it, it is going to be where there is minimal movement in the scene taking place on the video, like basically almost still shots, or in the case of gameplay footage, where your character and the scenery is not moving or very minimal animation is taking place. I mean, that would be the ideal spot to drop "un-needed" frames to save bandwidth and storage space, and I could see situations like that where duplicate frames could be added back and be unnoticed to the human eye. I'm just speculating mind you, so your guess would be as good as mine.

[mackdanger]

Yeah, that makes sense. If the variable frame rate mode is dropping the frame rate during times of little to no movement, I guess duplicate frames could be added at those same times in order to bump the frame rate up. I think next I am going to mess with a 60fps VFR clip and try to make it 60fps constant and see what happens.

[Bonknuts]

Late back to the thread. Ahh I see, so it's just the frame rate being variable in the format itself. I run a PC, and have a huge range of tools. But I tend to use avisynth, virtualdub, and After FX. Avisynth would probably handle everything you need, but it's not intuitive or gui friendly (though there use to exist GUI apps that would build out the scripts for you); avisynth is a script based language to used plugins to alter video in different ways. It's a frame server, which is realtime. I usually open the script files (frame serve files), in virtualdub and either re-encode or just do what I need there.

 Not that you probably need it, but I was able to make a 30fps video with an oscillating 'blend' mode, instead of the constant 50% frame or field blend mode. It would allow you to see the other frame, but wasn't as 'blurry' in motion. This is critical for stuffs like shmups IMO. Check out my Sapphire videos to see the result.

[mackdanger]

That was a very interesting clip. I noticed the transparency effects seemed to be preserved very well. So far my test clips have yielded mixed results with that. I am going to check out Avisynth later, thank you for the recommendation.

[mackdanger]

So here's a little update. I spent a number of hours messing around with various codecs and programs. I managed to get some fairly decent results. I still kept having various hangups with the conversion of a file from variable frame rate to constant frame rate. Mostly, I had trouble finding settings that would preserve transparency effects. I kept getting results where the flickering sprite would be solid for a little bit, then turn completely solid, then disappear altogether. Since I am still in the "just messing around" stage, a high powered capture card like the SC-512-N1 isn't on the menu yet. A card like that would necessitate a raft of upgrades that I don't want to deal with right now either.

I noticed that the new ElGato HD60 records in constant frame rate. I have one of the old Live Gamer Portables from Avermedia that I used to mess around with, which is okay. The PC free recording mode was kind of cool. The software is kind of crappy though. I had an Amazon gift card laying around so I went ahead and grabbed the HD60.

First, it does indeed record constant frame rate, which meant I no longer have any audio de-sync issues with Light Works. At first I was surprised that the files didn't seem to be too much larger, but the way the ElGato software handles the bitrate is different than the other software I was using.

So I wanted to make a test clip to see how well the transparencies are preserved. In the source clip, there is only one instance where the sprite of the old man flashes a little brightly, but other than that, the effect is preserved perfectly. After being rendered in Light Works and uploaded to YouTube however, things got a little messy. You can see what I am talking about during the cut scene. Be sure to watch in 60fps if you are on Chrome.

As you can see, there is quite a bit of flashing and drop out going on there. I haven't really done any tweaking of Light Works settings, so I am going to look at that next.