[FFmpeg-user] Using Homebrew to install FFmpeg, But having wired problems.

[Kosei Seki]

(base) XXX-MacBook-Air ~ % brew install ffmpeg --HEAD
Updating Homebrew...
==> Installing ffmpeg from homebrew-ffmpeg/ffmpeg
==> Searching for similarly named formulae...
Error: No similarly named formulae found.
Error: No available formula with the name "nasm" (dependency of homebrew-ffmpeg/ffmpeg/ffmpeg).
==> Searching for a previously deleted formula (in the last month)...
Error: No previously deleted formula found.
==> Searching taps on GitHub...
Error: No formulae found in taps.
How can I solve this problem? Thx