You know that feeling when you start to look up something on WebMD and you start to panic because you think you have some terrible disease? That’s kind of what happened to me when I started looking up retro gaming video quality. My WebMD, in this case, was the My Life in Gaming RGB Master Class. I had been doing a lot of research on playing retro games on modern displays, but my only modern display was a Panasonic plasma TV, which is not ideal for retro games due to the risk of image retention and burn-in. As luck would have it my large CRT has started to act really strange when it first turns on and has only been getting worse. The replacement for my failing CRT handles retro games with surprising grace but still falls flat in a few areas. To address those issues I’ve purchased a video upscaler. Why not just plug in my consoles and let the TV do it’s thing? Well, that takes a lot of explaining. In part 1 we’ll address some of the technical information we need to know before diving head-first into what the scaler does.
Pixels, Sub-pixels, and Resolution
When an image is displayed on a screen you’re actually looking at small squares called pixels (short for ‘picture elements’) that, when viewed from a distance, make up an image. On top of that, each pixel is made up of three sub-pixels, each one displaying either red, green, or blue (RGB). Colors are created by changing the brightness of each red, green, and blue sub-pixel individually. For example, if red and green are at full brightness and blue is completely darkened you get a bright yellow.
Standard definition is 480i, or 480 lines (rows) of horizontal resolution with interlaced video. Interlacing displays only the odd lines of a video frame (1, 3, 5…), then the even lines of the next (2, 4, 6…). Modern displays are typically 1080p, with 1,080 lines of horizontal resolution with progressive scan. Progressive scan means the whole image is drawn in a single pass, on every line, rather than alternating the lines. The result is a much better quality video when there’s fast motion or scrolling test.
It should be noted that I’m only mentioning horizontal resolution. This is because the vertical resolution, or the vertical rows that made up the image, could vary wildly. Even the true resolution of standard-definition was much wider than what the TV was able to display, and some games ran at wider resolutions than other, even though the horizontal resolution was the same.
Retro game consoles only had the processing capability to generate 240p video, which, despite being a non-standard resolution, TVs were able to display without issue. It wasn’t until the Sega Dreamcast that consoles could display 480i and 480p images. Most modern TVs are able to accept and display a 240p image, but they see this non-standard resolution as 480i and attempt to deinterlace an image that is not interlaced to begin with, ironically making the image appear interlaced and introducing other potential issues. This can be as minimal as a blurry image, but can also interfere with flickering transparency effects, effectively making some sprites and characters disappear when taking damage. The process of upscaling this “480i” signal to 1080p can also introduce input lag, making time-sensitive games like MegaMan or Beatmania impossible to play.
So now we understand what makes up a picture, but how does that picture get from the console to the TV? When the console generates each frame of video it leaves the image processor and enters a digital-to-analog converter (DAC), which turns the video into a signal that the TV can display. The quality of the video that gets sent to your TV depends largely on two things: the quality of the DAC, which you can’t change, and the connection type used, which you usually can.
There was a time where many consumer TVs in the United States only had a single input for their video; the coaxial connection also called the antenna connection. This was used for both over-the-air TV signals as well as cable TV signals and was often the only way to plug in your video games. Internally the game system would convert the video signal, which is digital when it’s originally created, converts it to an analog signal, then sends it to an RF (radio frequency) adapter which converts the analog signal to another kind of analog signal that, to the TV, looks just like a TV broadcast. If you remember having to use radio adapters to listen to your iPhone in your car, it’s the exact same thing but with a physical connection. The signal was also susceptible to interference from other devices, like TV broadcasts, which would create distortions and ghost images. All this, combined with cramming all the audio and video information into a single cable, really took a toll on the image quality.
As a side note, even if you wanted to connect your console to your modern high-definition TV, many no longer come with analog TV tuners (since it’s no longer used in the US), so this may not work at all.
Where RF combines audio and video data into a single connection, composite only transmits video data; audio is transmitted over one or two separate RCA cables (white and red). Picture quality is greatly improved because there’s less information to transfer over a single connection, there one less signal conversion and the connection is not susceptible to the same interference as RF. A lot of newer TVs support composite, but not s-video, so for some situations, this may be the only connection type you can use.
This connection is also referred to as “AV” or “RCA”, though RCA the physical connection type and doesn’t refer specifically to composite video.
S-video, short for ‘separate video’, splits the video signal into two connections: one for color information and one for gamma (brightness) information. Composite video carries both of these signals on two separate frequencies. These signals can interfere with each other, causing blurriness in the image. Separating these into their own connections means they cannot interfere with each other, providing a higher quality image.
If your TV supports it, S-video is typically the way to go. Most consoles support it and it’s typically the best video quality you can get with a very minimal investment.
The correct name for this connection is YPbPr, but is known largely as ‘component’. It carries video over three separate RCA cables; one for gamma, (which is basically a combination of the red, green and blue color information), one for gamma minus red, and one for gamma minus blue. Green is created by subtracting red and blue from the gamma information. It’s also possible to carry an RGB connection over this connection, which the PlayStation 2 has the option to do, but most TVs don’t support this option.
For consoles with AV multi-ports it should be possible to get YPbPr video by using a SCART cable with an SCART-to-component adapter, though your results may vary depending on the console and TV used. You’ll also be getting 240p output, so you’ll end up with similar blurring, interlacing, and input lag issues that you would get with composite and s-video.
What’s the Result?
I took a screenshot of Super Mario World and did some Photoshop work on them to give you an example of the kinds of image quality differences you can expect with each connection. For a more real-life comparison check out the RGB Master Class series.
So What’s the Solution?
There’s a group of video products called scalers that take standard-definition and output them at 720p and 1080p. Most of these devices are expecting a 480i signal, so while you might have less input lag and other issues caused by the TV’s misinterpretation of the 240p signal, you might still end up with some distortion. Common issues are halos around sprites from heavy-handed sharpening and image stretching to fill the TV screen. While there are plenty of options out there, the best so far seems to be the Micomsoft XRGB Mini, also known as the Framemeister. This piece of hardware was designed specifically for 240p video, allowing for proper, distortion-free scaling. Mine was just delivered today, and I’ll be documenting my experience with it as soon as I’m back from Korea.
Another solution is console-style emulators like the Retron, but I’ve never liked that solution. Yes, it uses cartridges, but there’s nothing authentic about the feel of it, the controller is garbage, there’s apparently some amount of input lag, and I already have a PC to connect to the TV, so why pay for an emulator that you could legitimately download for free?
There’s also official emulation from Nintendo, Sony, and Microsoft, as well as backwards compatibility from newer consoles with higher quality output. Some consoles offer perfect compatibility, like playing PlayStation games on a PlayStation 2, but the Xbox 360’s emulation of original Xbox games hit hit-or-miss, but usually ‘miss’. Having a single solution that solves all my video issues, rather than a dozen bandaid solutions, is the better option for me, and the HDMI-out from the XRGB Mini also allows for easy capture of extremely high quality video for streaming or recording gameplay videos.