How do I hide an encrypted VeraCrypt volume as a playable video file?
You can't. Or, at least not out of the box.
What you're asking for is termed steganography, or hiding data within data, without revealing that there's a second, embedded message.
Steganography is completely feasible, even in video. But Veracrypt does not support this. It supports hidden volumes, which will not show up as files, but rather as random noise on the drives unallocated parts. It's not perfect, and has severe drawbacks. And it does not allow storing data inside a video file.
What you're asking is feasible. How feasible depends on how well you want to hide it. You want to hide against cursory searches? Appending a TC container to the end of a video will probably work - but this will fail the instant anyone probes the video bit rate and size of the file. To achieve real steganography you want the signal embedded in a way that looks like random noise - and with video that is likely to need some heavy lifting CPU-wise.