[dlcarrier]

There is a community of speed runners, who try to reach goals in video games as fast as possible, either with or without using glitches in the game, sometimes by hand and sometimes with tools, including tools that completely automate the entire process. The goals are usually related to completing the game or portions of the game, often as quickly as possible, as thoroughly as possible, or while doing as little as possible.

There's online forums for posting speed-running accomplishments and challenging others' accomplishments.

I'n this case, someone used the tools for automated speed running, to execute a glitch in SMB that allows for arbitrary code execution, then entered and ran a program that plays a Bad Apple music video, all with controller input. This is posted as a speed run with an accomplishment of playing the video.

A custom cartridge could be made to make a Bad Apple music video, but this is showing off a way to play the video using only SMB cartridges.

The data has to fit into RAM, which is much smaller than a tricky cartridge ROM. The music and graphic data is streamed as controller inputs, but the rest is done in RAM, using some data already in the SMB cartridge for video output, due to the low bitrate of controller input but also because the video processor can't display directly from RAM.

[dormento]

An important detail is that the TAS is tool-assisted (as the name says), but it could conceivably run on original, unmodified hardware (besides the input assistance that allows things that no human being could perform).