Hardware

As only the Mac Pro has the ability to take an internal capture card, video capture options for Mac users are more limited.

The top options would be the Elgato Video Capture for composite video, the Intensity by Black Magic Designwhich accepts composite, component, or HDMI video (though it cannot decrypt streams using HDCP), and the EasyCAP (which is notorious for its inconsistency between models, but it can work).

Note that the first two tools will have trouble with certain older consoles, such as an NES. In this case it is useful to pass the NES signal through an additional piece of hardware. A VCR or upscaling DVD recorder are two options.

Elgato Video Capture

(Elgato users can explain their experiences here) It's really easy to set up and use but there is a slight video lag.

Intensity

Intensity users will likely capture their streams using Black Magic Media Express. This software comes with the Intensity, and supports Quicktime codecs. However by default it will only offer uncompressed video for maximum-quality recording. This is not optimal for space or disk performance, and so it is a good idea to install the ProRes codecs (using unpkg if necessary to get to the individual codecs) in order to have more options. Quoth CMiller:

There are several variations of Prores:

Prores 4444- Used primarily for 4K work or feature film finishing.
Prores 422 (HQ) - High quality used for HD finishing. Same as 422 but with higher datarate.
Prores 422 - Used for HD editing. broadcast quality.
Prores 422 LT - 2/3 the datarate of 422. Used for proxy work mostly.
Prores 422 (proxy) - 1/3 the datarate of 422. used for proxy work.

Capturing in 422 (HQ) and 422 both work wonderfully for 720p capture.

EasyCAP

There are 3 known apps that will capture video from this device: Norichan, EasyCapViewer, and VideoGlide. Norichan will only capture from the Stk1160 model (go to System Information -> USB. It should be called "USB 2.0 Video Capture Controller" and the manufacturer is Syntek Semiconducter). EasyCapViewer supports multiple models (check its site to see which ones), but its recording features are not on par with Norichan's (so no SDA submissions). VideoGlide also supports specific models only, and is supposedly harder to setup properly (users with more knowledge can elaborate on this).

Software

Capturing

The software used for capturing can vary with the capture hardware used. See above.

Quicktime Broadcaster is capable of recording from a video source, additionally.

CamTwist can be combined with Syphon Recorder to record a source as well.

For desktop capture of a game running on your computer, Kumari is a new option with great promise.

For older content (NES, Genesis, etc.), if you have the now-hard-to-find hardware it was written for, it is recommended you use Norichan to record raw uncompressed video, as it never drops frames and properly captures flicker commonly seen in old games.

Editing

On the software side you will need only iMovie (preinstalled on new Macs). From here it's pretty easy - just import whatever you want, then edit your clips so they start and end when you want them to.

(TODO: verify the following two paragraphs. I suspect a workflow of iMovie to Handbrake is more useful. Verify this.)

Once you have your clips ready to go, export them one at a time. If you want to, you can end your capturing adventures here by exporting to MPEG-4, the highest quality Internet-friendly format offered with QuickTime (choose "Expert Settings" when you go to Share your movie). I'd use 512 Kbps for the video track and 64 Kbps for the audio track. All of the encoders should be set on "Better" quality. Also make sure that "Hinting" is turned off. This will create a file that takes up about 4.3 MB for every minute of video it contains. Feel free to play around with the two bitrates to find a level of quality you feel is satisfactory.

If you want to create a 60 FPS file (double the framerate you will create by using MPEG-4), you will need to export your clips as full quality AVI files, using the either NTSC or PAL DV codec (not DVCPRO). By installing the MainConcept DV codec on an available Windows PC, you can use VirtualDub (which, for some reason, only runs under Windows at this time) to make full framerate videos out of your clips, even though you didn't capture them using VirtualDub. For more about this, please see the EDITING VIDEO section under the Editing in VirtualDub page.

Streaming while Recording

As streaming is so popular in the speed running community now, a note on streaming is useful. Quicktime Broadcaster is a great option for Mac users to broadcast a stream, though some use Adobe's FMLE. These tools can record while streaming.

These tools are great for a very basic stream direct from a video source, but for fancier stream effects, CamTwist is a great option. It cannot stream on its own, so it must be combined with either FMLE, QTB, or CocoaSplit (note that the 3.0 beta has abandoned the legacy capture that FMLE and QTB rely on in favor of CoreMediaIO; you'll need 2.4 to use them and 3.0 for CocoaSplit). An alternate tool like Blackmagic Media Express can be used to record the direct game feed, while CamTwist can capture the part of the screen featuring that feed, and then broadcast it with additional features, such as splits, live camera, text, and images.

The keys to getting good game audio in stream along with a microphone are Audio Hijack Pro plus Soundflower. The former is not free, though, so an alternative to it wold be Line In, however with that you can't control the levels of the audio components. Either way, use Audio Hijack Pro/Line In to route your microphone and your game audio both into one of the two Soundflower outputs, then have FMLE/Quicktime Broadcaster/CocoaSplit stream the Soundflower input.

If you're getting full framerate into Kumari, it is an option for streaming and recording.