Game:

Super Metroid (1994)

Duration: 1:41:38

1,113 views

17

This marks the first published run of my favorite speed game!

--Nerd Stuff--

(Before 60 FPS conversion)
Real-time segment: 1:37:20.479
Number of Unique Frames Captured: 350995
Frame rate: 60.09696 FPS

--Hardware--
Console: "2 Chip" SNES SNS-CPU-GPM-02 (voltage regulator and some bypass caps replaced)
Cart: SD2SNES
Digitizer: Open Source Scan Converter (OSSC)
Capture: Elgato Cam Link

This is more of a video capture/post-processing tech demo coinciding with my personal best of this game and category. There are more factors involved than just the sharpness of the pixels. Frame rates, color/levels, and pixel geometry are often overlooked when considering capture quality.

I devised a simple method to capture as many SNES frames as possible in order to produce the theoretical native frame rate. The frames are later dropped in post-processing to a flat 60 FPS, so the drops should be at even intervals. The rate captured in this video was actually a little bit slower than what I usually get from test footage (around 60.098x FPS; the theoretical native rate is about 60.09848 FPS). This recording was about 9 frames less than the theoretical rate, but for a segment of 350k frames, it's not a big loss. Excessive loss of real SNES frames would result in noticeable desyncing with respect to the audio channel, but everything seemed perfectly synced in this recording (there are a few instances where the sound looks desynced, so it's not a perfect solution at the moment). It's possible that the game just ran slightly slower than usual at the time of the recording, or perhaps a recording of ~1.5 hours isn't sufficient to get that precise of an average.

Color was adjusted via the OSSC's fine gain controls. The 240p test suite is a good place to find some balance between the whites, blacks, and mid-greys. The RGB offsets have been raised slightly in order avoid clipping of the blacks and thus, capture all the real SNES frames. Theoretical reference values I chose were (0,0,0) black, (132,132,132) grey, and (255,255,255) white. I adjusted to (2,2,2), (133,133,133), and (254,254,254) respectively, so it is slightly brighter overall and there is no clipping in the blacks or whites. Clean separation of the colors removes any impression of a "color cast" and improves overall visual fidelity. Levels are also very close to the proper range, so it doesn't appear too dark and contrasty in one extreme or too washed out in the other.

The pixel aspect ratio (PAR) chosen was the SNES's native 8:7. The SNES was not meant to display square pixels. In the age of modern displays, that's all we have, so we have to do some scaling to compensate. With these considerations, the SNES's display aspect ratio is scaled to 64:49 DAR, slightly thinner than the standard 4:3 DAR for standard definition television.

The video was integer-scaled vertically by 10x (2240p) and then cropped down to 2160p, so a total of 8 SNES lines were cropped. The decision to do this was due to the inevitable 4:2:0 sub-sampling of the video; chroma resolution is halved to 5x the native resolution. If I chose an odd integer multiplier like 9x, the chroma resolution is halved to a non-integer 4.5x, which is not ideal. The chroma resample method chosen in AVISynth was "point". The result should be very clean horizontal lines when viewed in 4k. Horizontal scaling is a simple bicubic resize. This gives the smoothest result with minimal ringing, and at 4k the blur is not so offensive.

With these considerations in mind, the overall resolution of the video is 2928x2160. This may seem weird at first, but this is due to the fact that some of the active area was cropped. The video was originally ~2926x2240 for the proper 8:7 PAR, but 80 lines were cropped and the horizontal resolution was padded to a mod16 value.

No other post-processing effects, like denoising, was applied. This is a fairly decent representation of the raw capture quality. Noise is easily visible at 4k in some areas of the game, and vertical jailbars are present too. Places to look out for this is the Crateria grey sky and the dull green rooms of Kraid's lair. The purple background of Elevator rooms also exhibit the vertical lines. I have not yet found a way to deal with them, but this might be approaching the limits of the 2chip at the moment.

Other Statistics