ERROR: audio conversion failed: Unknown encoder 'libmp3lame'

Question

I'm trying to use youtube-dl on a Macbook (using Mojave). It used to work flawlessly but recently I am seeing the following error:

youtube-dl -x --audio-format mp3 https://youtu.be/somevidR4hhU
[youtube] somevidR4hhU: Downloading webpage
[youtube] somevidR4hhU: Downloading video info webpage
[youtube] somevidR4hhU: Downloading js player vflWnjS_n
[download] Destination: somevidR4hhU.webm
[download] 100% of 4.60MiB in 00:04
[ffmpeg] Destination: somevidR4hhU.mp3
ERROR: audio conversion failed: Unknown encoder 'libmp3lame'

I've tried to reinstall youtube-dl and lame with:

brew reinstall youtube-dl lame

but it makes no difference. Any idea what the problem may be? Thanks in advance!

Answer 1

Homebrew doesn't install the lame. Compile with libmp3lame:

git clone https://git.ffmpeg.org/ffmpeg.git ffmpeg
cd ffmpeg
./configure --enable-libmp3lame
make
make install
ffmpeg -version

That should fix it