Here are some of the connectors you should have on your system:
- Capture card coaxial input: A round, threaded connector with a small hole in the middle that accepts modulated signals with audio (multiple channels).
- Capture card composite input: A smooth, non-threaded (RCA) connector with a large hole in the middle. This connector accepts a single video input without audio. The composite video cable, or the composite video portion of an octopus cable, usually has a yellow connector.
- Capture card S-Video input: A rounded socket with four pin holes and a small rectangular slot (DIN-4). This connector accepts a single video input without audio, but with brightness and color information separated. The result is higher video quality than composite input. S-Video cables usually have a black connector.
- Capture card line input: A mini-mono or mini-stereo socket about 1/8" in size, this is the audio input for the composite video and S-Video inputs.
- Capture card line output: Also a mini-phone socket about 1/8" in size, this is the audio output from the capture card.
- Sound card line input: A third mini-phone socket, this is the input to the sound card for recording. On sound cards with color-coded inputs, this should be blue in color.
If you have an all-in-one style capture device that does both video and audio, especially one over USB, then hooking it up is a no-brainer: just connect everything to the capture device. You don't have a choice anyway. If you have a "TV tuner" style device, though, then some of the capture work is also being done by the sound card, and you have to hook up a couple of cables to get everything working.
Capturing from cable (coaxial input)
In this scenario, you have a TV tuner type capture card and want to capture from a TV channel.
- Connect the round coaxial cable to the capture card.
- Connect the line-out from the capture card to the sound card line-in.
The TV tuner card accepts the cable input, selects and decodes the desired channel, captures the video, and splits off the audio for your sound card to capture.
Capturing from audio/video outputs
In this scenario, you have a TV tuner type capture card and want to capture from another device that has separate audio and video outputs, such as a VCR or video game console.
- Connect the composite video or S-Video output to the same video input on the capture card.
- Connect the audio output from the output device to the capture card line-in.
- Connect the line-out from the capture card to the sound card line-in.
The problem you will often encounter here is that the output device will have a pair of round RCA connectors, one for each of the left/right stereo channels (red and white), while the capture and sound cards will have 1/8" mini-stereo inputs. A cable with a male 1/8" on one end with stereo RCA male connectors on the other end, along with a pair of RCA female-female adaptors, will help you hook everything up here.
This assumes that you have a capture card that has integrated audio capture. If your capture card simply passes through the audio, it's better just to connect the audio output directly to the sound card:
- Connect the composite video or S-Video output to the same video input on the capture card.
- Connect the audio output from the output device directly to the sound card line-in.
This shortens the audio path for better quality, and you won't have to worry about whether the capture card's audio mixer is set to the right level or the correct input.