Converting mp4 to mp3

I have a video I need to convert to mp3 (from the command line - not GUI): video.mp4

I tried:

ffmpeg -i -b 192 video.mp4 video.mp3

with no success. I get the following error:

WARNING: library configuration mismatch
Seems stream 0 codec frame rate differs from container frame rate: 59.83 (29917/500) -> 59.75 (239/4)
WARNING: The bitrate parameter is set too low. It takes bits/s as argument, not kbits/s 
Encoder (codec id 86017) not found for output stream #0.0

so I tried lame:

lame -h -b 192 video.mp4 video.mp3

I get:

Warning: unsupported audio format

Am I missing something?

For FFmpeg with Constant Bitrate Encoding (CBR):

ffmpeg -i video.mp4 -vn \
       -acodec libmp3lame -ac 2 -ab 160k -ar 48000 \
        audio.mp3

or if you want to use Variable Bitrate Encoding (VBR):

ffmpeg -i video.mp4 -vn \
       -acodec libmp3lame -ac 2 -qscale:a 4 -ar 48000 \
        audio.mp3

The VBR example has a target bitrate of 165 Kbit/s with a bitrate range of 140...185.

soundconverter

is the leading audio file converter for the GNOME Desktop. It reads anything GStreamer can read (Ogg Vorbis, AAC, MP3, FLAC, WAV, AVI, MPEG, MOV, M4A, AC3, DTS, ALAC, MPC, Shorten, APE, SID, MOD, XM, S3M, etc...), and writes to WAV, FLAC, MP3, AAC, and Ogg Vorbis files, or use a GNOME Audio Profile.

SoundConverter aims to be simple to use, and very fast. Thanks to its multithreaded design, it will use as many cores as possible to speed up the conversion. It can also extract the audio from videos.

How to Convert MP4 to MP3 with VLC

• Open VLC Media Player. Click "Media" > "Convert" to enter the "Open Media" window. Click the "Add" button on the right side of the screen to enter Windows Explorer. Locate the MP4 on your hard drive you want to convert. Click the "Convert" button at the bottom of the screen.

• Select the name of the Target file.

• Click the "Audio Codec" tab and select "MP3" from the "Codec" drop down box. Press the "Start" button to begin converting your MP4 to MP3 audio.

• Click Start