ERROR: ffmpeg or avconv not found. Please install one.

[khinelay]

I am using Mac OS X 10.9.
youtube-dl --write-sub --embed-subs --sub-lang "my" -o "%(title)s.%(ext)s" https://www.youtube.com/watch?v=5ctsUsvIp8w

then I've got this message
[youtube] Setting language
[youtube] 5ctsUsvIp8w: Downloading webpage
[youtube] 5ctsUsvIp8w: Downloading video info webpage
[youtube] 5ctsUsvIp8w: Extracting video information
[info] Writing video subtitles to: Plot ordered pairs.my.srt
[download] Destination: Plot ordered pairs.mp4
[download] 100% of 6.27MiB in 00:02
[ffmpeg] Embedding subtitles in 'Plot ordered pairs.mp4'
ERROR: ffmpeg or avconv not found. Please install one.

[phihag]

Can you explain what you don't understand about the message, and how we can improve it?

youtube-dl focuses on the information extraction and downloading part. For --embed-subs (and almost all other post-processing options), we call ffmpeg (or avconv), which is a video editing toolkit. Simply install ffmpeg and it should work.

[khinelay]

Thank you. I'm sorry. I asked the question without googling the solution first. What I don't understand is how to install ffmpeg. Now I got it from your answer.
how we can improve it? Yes. if it is possible. add the solution like this "we call ffmpeg (or avconv), which is a video editing toolkit. Simply install ffmpeg and it should work.".

Thanks

[Reino17]

Instead of ERROR: ffmpeg or avconv not found. Please install one., I'd suggest ERROR: ffmpeg or avconv not found. Please put ffmpeg.exe or avconv.exe in the same directory as youtube-dl.exe..
I don't know about Max OS X, but here on WinXP,7,8.1 you don't have to 'install' ffmpeg. As long as the exe-file is in the same directory as youtube-dl.exe, it can use it.

[phihag]

Using in the same directory works only on Windows, and only because Windows is quite insecure in that regard. Instead, ffmpeg should be in any directory in your PATH.

[naarkhoo]

I believe I do have the ffmpeg inside the path - MacOS Mojve - but still is not found by youtube-dl