TO start out I have no idea if this is of any use or not. I started out replying to a comment on the GOTD download page, thinking the answer might apply or help out lots of folks -- once I started typing it grew to more of a mini-blog on what to consider if your video captures aren't happening like you'd want or need.
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#22: "For a screenshot software this program sure does use a lot of CPU power when recording video. Windows kept complaining that there was not enough CPU cycles to run Aero so it dropped to basic. Not a real biggy if I am doing a video review for a program. Should be more optimized for multi core processors."
Video is in a word: Complicated. In my experience Snap is not your problem. In case it helps anyone, here's some stuff to consider if everything doesn't go as you'd like when you try video capture...
Video gets stored via a codec [COder/DECoder] that translates all the pixels in the frame into color + lightness/darkness [luminance] data that's then put into that codec's storage scheme. And depending on the format, video frames may be processed further -- mpg2 for example looks ahead of the current frame, analyzing what changes, usually during the next 14 frames, & stores just that *change* data [often every 15th frame, the I frame, is a complete picture]. And there's more -- a good mpg2 encoder will also analyze the complexity of the picture along with the amount of movement [i.e. how much changes frame to frame], and then adjusts the amount of data stored accordingly, with more data discarded when you [hopefully] won't notice, so it can store more data when needed yet still maintain the overall bit rate you chose when you started recording/encoding. And mpg2 is one of the easier, faster codecs or video formats! Then of course all that data has to be written someplace, and the whole thing has to happen smoothly enough that the audio can be processed & stored or written along with it.
Video screen capture adds yet another dimension -- your PC/laptop has to do something to create the screen your capture software records -- if I'm recording the menu dropping down in an otherwise idle app, that's not a really big deal, but if I'm already using every available resource trying to maintain 60+ fps in a game, well that's another story entirely. :)
So, you should be able to [pretty accurately] predict the bottlenecks. Your PC/laptop should ideally be doing as little as possible so more resources are available for your video capture process. That very much includes other apps running in the background, since they not only use up resources, but they can help prevent the capture process from happening smoothly -- it's not uncommon to have a single interruption cause the audio to fall behind, then the capture app will try to store more in memory while it fights to catch up, then as it's working harder small errors will start to accumulate & it starts finding it can't write all this data fast enough, then you get a cascading failure that if you're lucky only means a few dropped frames. The smooth flow of data to your hard drive(s) is very often actually more important than anything else, matters more than the raw speed of any single component.
Next is the codec itself... it Has to be fast, & it Has to be efficient. Those qualities can be a bit rare -- Huffyuv is still popular, still often used, besides the fact it was written a surprisingly long time ago & never updated [December 22, 2003 -- http://www.videohelp.com/tools/HuffYUV ].
Your capture software itself has to be efficient & fast, but the codec's doing the most work, so it's more important. The best thing the capture software can do is tie into, let you use whatever codec you desire, & get out of the way. With analog video capture, e.g. recording from your VCR over a svhs or RCA cable, somehow tying the audio & video timing together is also important -- the speed of the audio &/or video recorded will often be changed *very slightly* to keep them synced. Now when it comes to leaving a codec alone to do its job, there's something else that comes into play -- other video related software you've installed.
In Windows lots of video stuff uses Direct X, particularly Direct Show. Video handling works by chaining together several DS [Direct Show] components or filters, e.g. 1 to open the file, one to split the audio & video, separate filters to decode each, often one or two more filters to alter the video's size &/or colorspace, additional filters to render & display the video & play the audio etc. Here's where it gets confusing -- you might have several filters installed that **tell Windows** they do the same things... they may or may not actually do what they say, & they may or may not play nice with other DS filter's that are installed. And now the icky part -- whenever Windows sees certain types of files or data, whenever an app calls or uses certain files related to media handling, Windows can start trying to put together one of these DS filter chains, & if it fails it'll try another combo of DS filters, & as necessary another, & another etc. It doesn't necessarily close those filters that failed. Long story short you can have something causing problems that you'd think was far removed from your screen capture app & the codec you want to use. And yes [sadly] it does get worse... your graphics hardware may similarly get involved whenever it sees something video related, & its drivers may open or call all sorts of DS filters too, so the potential for problems only expands.
The best cure or solution for DS problems is prevention -- Be Extremely Careful about adding video-related software, & backup, backup, backup, before adding/updating video software &/or graphics drivers. Finding the source of problems once you have them is incredibly tedious [if possible], often trial & error, & may even mean re-installing Windows, starting over.
Last comes your hardware... If you're recording 1080p AVC then CPU horsepower & GPU assist can both be extremely important, but if you're recording std. 720 x 480 or 576 mjpeg or mpg2, they hardly matter anymore. The mp4-type formats [DivX, wmv, Real etc.] fall in between. It used to take a special drive to record video -- I remember spending a small fortune for a SCSI AV drive that I still have in a box somewhere as I could never bring myself to part with it... it made that big a dent in the budget. Today if you're going to try to record near lossless 1080p [or better] you're gonna need a Very fast, probably RAID drive setup, but otherwise you're probably OK. Depending on your capture format you may need a lot of space, it shouldn't be terribly fragmented, & it's always best if the capture drive isn't the same one with Windows on it. You may also need to deal with audio hardware related DRM -- some audio hardware is pretty restrictive when it comes to recording. You may be able to find an easy solution [Google], or you may need a sound card or external hardware.