Bad Apple but it's inside the terminal (ANSI escape codes)
I recently discovered ANSI escape codes. By typing in your print statements \e or \x1b and a special code such as [31m or [41m, you can change the color of the displayed text or the background of the text in a terminal. This uses the latter.
By decoding the video with ffmpeg into bmp frames and an audio file, it was very easy to decode pixel data using C, and play the audio file directly with ffplay.
In the end I am very happy with my first C program (I usually use C++).