Do you want to buy a capture card? If you want to capture game consoles, you can skip the next question and read the next paragraph; if not, continue reading.
If you don't need to use a capture card in a dual PC environment, here are some things to know:
- Capture cards no longer provide a significant performance improvement over traditional capture methods.
- Capture cards can be used to solve some problems with traditional capture methods.
- Capture cards may increase the burden on the system compared to traditional capture methods.
- In fact, hardware encoders are not as capable as CPU encoding technology, and capture cards are not designed for live streaming, but mainly for recording.
That said, if you still want or need a capture card, let's start choosing. If you don't know the key factors to choose a capture card, even if you know why you need a capture card, it will be very troublesome to choose the best one from many products. However, all reasons for using a capture card revo-lve around one core question: What is the output interface of the device I want to capture, do I need to split the signal, or can I "clone/copy" the output to two different ports?
Device output interface type
- Game console: Common ones are HDMI, RCA, SCART, Composite (composite video), RGB.
- Computer: Including HDMI, VGA, DVI, DP, and older computers may be equipped with S-VHS/Composite interfaces.
- Camera/camcorder: Usually has interfaces such as HDMI, FireWire, RCA, etc.
From the above information, it can be seen that in some cases, a capture card equipped with an HDMI input interface allows you to capture signals output by a variety of different devices by switching switches or changing cables. However, the actual situation is not always the case. For example, the PS3 will protect the HDMI content, making it difficult for most capture cards to record its screen. However, the PS3 usually also provides an RGB/RCA output interface, in which case it is more appropriate to choose this interface for capture.
Capture card input interface and signal reading
After determining the input interface that the capture card should have, you also need to ensure that it can correctly "read" the signal output by the device. The output resolutions of devices from different eras are different:
- Old game consoles:
- Progressive: 256 × 224, 256 × 240, 512 × 224, 256 × 239, 512 × 239.
- Interlaced: 512 × 448, 512 × 478.
- Contemporary game consoles:
- Progressive: 1280 × 720 is common, 1920 × 1080 is less common.
- Although interlaced formats are supported, they are not recommended.
- Future game consoles:
- Progressive: 1280 × 720 will still be used, 1920 × 1080 is more common, and even 4K resolution may appear.
- Again, interlaced formats are supported but not recommended.
- Computer: Progressive scan supports a wide range of resolutions, 720p/1080p is a popular choice, interlaced formats are not recommended.
- Camera: Different models and aspect ratios of cameras have different output formats.
It should be noted that capture cards priced under $500 have certain limitations. Currently, USB/PCI-E x1 or Thunderbolt devices cannot capture 1080p 60fps at 60fps. Purplelec capture cards can downsample such images to 720p and maintain 60fps. If you want to record or live stream in 1080p, the frame rate can only reach 30fps because the bandwidth of the PCI-E x1 slot is not enough to support the capture card to output a full 1080p 60fps image.
In addition, some capture cards claim to receive 1080p 60fps input and output it as 1080p 30fps, but actually convert the signal to interlaced, which often significantly reduces the picture quality. You can confirm this by looking at product reviews or asking people who have used the device. In my capture card comparison list, I have collected this information as accurately as possible.
Some capture cards have hardware encoders that can reduce CPU usage when recording to zero in some scenarios. However, the disadvantage of such encoders is that higher bit rates are required to achieve the same picture quality as CPU encoding. Therefore, they are suitable for local recording, which does not require high bitrate and bandwidth; for live broadcasting, it is recommended to use CPU encoding.
Other considerations
At this point, we have clarified the ports required for the capture card and the resolutions that need to be supported. In general, the choice of port also ensures that the capture card receives the audio output of the device, but this may be different in some special settings, and due to limited space, it is not possible to cover all possible settings. If you have any related questions, please leave a comment below.
Finally, make sure your computer has an available PCI-E slot or USB port to connect the new capture card. Before buying, be sure to read product reviews, consult people who have used the device, look for known issues on the forums of the streaming or recording tool you want to use, confirm that the product supports no-questions-asked returns, and if you have no experience replacing hardware, consult someone who knows before proceeding.
