Since people have been asking about it, here's a short guide to record real-time as you play in LFS.
The problem with mechanical harddrivesMechanical harddrives are cheap, so most computers have this type of harddrive these days. Solid State Drives (SSD) are still, sadely, quite expensive. When you record video in real-time, you want as little impact on the computers general performance as possible to reserve it for all the other work it has to do to run your game at decent frame rates. FRAPS is one of such program that will record video with a very CPU inexpensive compression, but at the cost of very high video bitrates. The bitrate of the video stream will in many cases exceed the speed at which a mechanical harddrive can store data. One way to help this is reducing the frame size, and FRAPS have an option to record half frames. Unfortunately this gives very low resolution video.
Trading HDD bandwidth for CPU timeThe other solution is to spend alot more CPU time to compress the video more, reducing the bitrate. If you have a modern 4 core CPU and a mechanical harddrive, this can be the best trade of for the available resources of your computer. First of all we have to ditch FRAPS, as you can not change the video codec it uses to compress the video. And besides, FRAPS doesn't come with alot of options.
DXtory is similar to FRAPS, but has significant more options. One of them is you can scale the size of the frames exactly, i.e exactly 1280x720 (HD 720p). And you can use any video codec you like, as long it can encode in real-time. H264 has become a defacto standard for HD video, and you can download h264 compliant codecs for free. For DXtory I highly recommend
x264vfw.
Setting up DXtoryBefore you get to the steps in the images below, you should off course setup your prefered overlay and storage space settings. Note that DXtory can benchmark you storage device, and 70 MB/s should be quite alot more than required.
Select x264vfw as your codec, and the framerate to your preference. I have enabled VSync in LFS to avoid LFS rendering more frames than what my display can show, and thus spend unnecessary GPU time that also just makes my laptop hotter. This means I allways get 60 FPS ingame, and I like to record in 60 FPS. Since I record at the same frame rate my game is running, I also have checked the option to synchronize the recording rate to the game. But if the video codec for some reason should not record at your given frame rate, your game framerate will not suffer, unlike what would be the case with FRAPS. To ensure there is no problem with the rate at which the codec compresses frames, I display the "Write File FPS" which can be set in the overlay settings. To limit the CPU usage and bandwidth requirements for my harddrive, I scale down my frames to exactly 720p. Don't use clipping unless you want to record just specific areas on the screen.
Please not that Youtube only supports video of a maximum of 30 frames per second. So if you intent to upload your recorded video material directly to Youtube without any post processing, you will have to choose at maximum 30 FPS. I record at 60 FPS to blend the video frames during post production for a motion blur effect in the final 30 FPS video I upload to Youtube.
Select which audio source to record, and I recommend using uncompressed PCM. The addition bandwith PCM uses at 44,1 KHz @ 16 bit is neglectable: (44100 x 16 x 2) / 8000000 = 0.1764 MB/s
You can off course install i.e the LAME mp3 encode to encode to mp3 in real-time, at the cost of more CPU time. But with the relatively low bandwidth of uncompressed PCM audio, I just go with the least CPU intensive solution.
Only check these options if you are having trouble with DXtory or your video codec. Select the number of threads DXtory can assign your video codec, and I allways use limitations of the video frame rate to keep it at a tight leash. No need to record more frames than needed.
Setting up x264vfwSet all the options exactly like this:
With the rate factor you can choose the bandwidth of the video stream. Lower the rate factor, the higher the bandwidth (and CPU usage). I find a setting around 18 to be good enough for video in 720p without using too much CPU time and making ridiculous file sizes. The sad part is Youtube. Once you've uploaded your video, Youtube will re-encode your video with really hard compression. You can probably use a rate factor up to 23 without the Youtube video quality getting degraded very much.
A little warningThe x264vfw can be quite CPU demanding, depending on the frame size for your videos, and rate factor. Your CPU will generate alot of extra heat doing all this work, and your CPU fan will probably be spinning at full. This will draw dust into your computer, fans and heatsink at a higher rate than it normally will when you are not recording. So you will have to be prepared to clean your fans and heatsinks a bit more often if you record alot. But don't worry about the computer catching fire. Modern CPUs have a few mechanisms to prevent it to get so hot it gets damaged, such as reducing its speed making the game completely unplayable.
Have fun!