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Guide on How to use FRAPS for Recording Stereoscopic 3D Movies

December 8th, 2009 · 17 Comments · Other S3D Tech


If you remember I’ve written when FRAPS version 3.0 was first introduced that among one of the exciting new features was the ability to record in-game stereoscopic 3D movies. This news was a very exciting one, with me hoping to see a lot of Stereoscopic 3D movies recorded and shared between the users of 3D Vision and possibly other stereoscopic 3D setups. Unfortunately this did not seem to happen as already a month has passed since and still the stereoscopic 3D in-game videos are kind of lacking or maybe nobody is sharing them…

One of the possible reasons that these videos are not appearing anywhere could be that they need some additional processing afterwards and then they need to be uploaded somewhere for everyone to have access to them. But more of an issue seems to be the fact that recording movies using FRAPS has always been a heavy task for the PC, especially if you don’t have a top-end system with a fast multicore CPU and a high-end video card. And with the increase of the resolution and the need to record video with double width the things are even harder for the computers, because you still need to be able to play the game while you are recording it. But when we add to the equation all the latest games that are quite demanding, especially if you want to play them with a lot of detail, then things become even more of a problem than before, so I’ve prepared some tips that might be useful for you should you decide to record such movie.

When you start FRAPS and go to the Movies tab you need to setup the program at first in order to get the best possible performance and quality, while still retaining playable framerate. First off you should use a second hard drive for saving the movies and not your system one where you probably also have the game you are playing installed. The video codec that FRAPS uses does not compress the video data a lot in order not to take up too much of the system’s resources and this is resulting in a larger file size, thus needing more free space and faster transfer speed. This is why you better use a second hard drive to avoid possible degradation of game performance if the game needs to read some data off the hard drive or the operating system needs some data accessed in the background.

AS for the Video Capture Settings you should select to record in 25 frames per second. This framerate is enough to have a smooth movement in most games while at the same time not requiring that much of resources as you get the in-game framerate synced to the chosen recording FPS when you activate it by pressing F9 (the default key). You should also record in the Full-size resolution instead of Half-size as the second needs to resample each frame to half the resolution in real time while you are recording and sometimes the resulting quality might not be what you expect. So instead of plying at a resolution of 1680×1050 pixels and recording the video in Half-size resolution you better lower the resolution to 1280×720 pixels and record in Full-size. This way what you see while playing the game will be recorded in the video an you won’t have to rely on the resampling to bring good enough results. Also playing in lower resolution lessens the burden on the video card and the CPU, though that when recording the video at Half-size resolution there is also less load on the system resources too. Another issue for when using Half-size is that you cannot achieve 720p output as the half resolution of 1680×1050 is actually 840×525 pixels, but you should also have in mind that recording at 25 frames per second on 720p resolution is still not an easy task for every PC, so you might even have to go to lower resolutions.

Sound capture is an option that you might not activate if you won’t be needing it, but that is ore like a personal preference and it does not bring a serious issue in terms of performance drop. Still it is recommended to use a Stereo mode for recording and not Multichanel one as the second choice might result in not being able to reach at least 25 fps. Not to mention that if you do some editing afterwards and not just recompress the video you migh have some trouble with the multichanel audio and most likely a lot of the people you share the video after that will be able to hear the audio in all its glory.

Regarding the CPU versus GPU requirements when playing games in stereoscopic 3D mode and want to record the game play in a movie things are quite interesting. The thing is that FRAPS need a lot of CPU power in order to compress the video in real time with the requested framerate, but at the same time the game also needs CPU power when you play it. This is why the faster the processor the better and having more cores is a good thing too especially if you share some of the cores exclusively for usage by the game and others by FRAPS using the Task Manager’s Affinity settings for the respective processes. The game on the other hand requires a lot of GPU power especially if being played in higher resolution and with maximum details and even more if you activate Anti-Aliasing mode. Also don’t forget that playing games in stereoscopic 3D introduces some additional load on the GPU and the resulting framerate is usually about 30-40% lower than what you can achieve normally without stereoscopic 3D mode active. You probably will notice that if you have lets say 60 frames while playing the game normally in Stereoscopic 3D when you activate the recording the framerate might drop to lets say 20 frames per second. This is not a problem for the video card, but is happening because of the big CPU load. And when you are playing in stereoscopic 3D at a resolution of 1280×720 pixels and recording the video your CPU will have to compress and record frames with the size of 2560×720 pixels as you actually get a side by side recording of a frame for the left and for the right eye. This can bring down to their knees even the top model processors, so yet again I’m reminding you that laying in lower resolution is better than using the Half-size video recording option. But because of this there is something you can do when playing the game at 1280×720 instead of 1680×1050… you can easily put the detail level to the maximum and even enable some AA filtering without noticing any framerate drop when recording the video as this usually increases significantly the load only on the GPU, but not on the CPU.

Feel free to share some tips that you might have, but I’ve missed mentioning above and of course you can post links to some of the stereoscopic 3D videos you’ve made with the help of FRAPS in the comments below…

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