Convert MKV to M4A
Settings
No file yet
Settings appear after you choose a file.
An MKV that often will not open on an iPhone or a Mac can still hold sound you want. Save the audio as an M4A that iPhones, iPads, and Macs play, with the picture left out.
MKV or M4A?
Keep MKV when
- You still need the picture. An M4A holds only the sound.
Pick M4A when
- You want only the sound of a video, as a small audio file.
- The sound goes to a player or app that takes M4A.
About MKV and M4A
MKV
A flexible video container that holds several audio tracks and subtitles in one file. Popular for films and screen captures.
M4A
AAC audio that plays in iTunes and Apple Music. Common for songs and voice recordings.
Questions
What does the copy line do?
It puts the sound in an M4A without encoding it again, so nothing is lost. It works only when the sound in the MKV is AAC; ffprobe clip.mkv shows the codec. For any other sound, use the lines that encode it.
Which bitrate should I pick?
The commands aim for 192 kbps, a common middle ground between size and sound. Change -b:a 192k to 128k for a smaller file or 256k for more detail.
What if the MKV has several audio tracks?
FFmpeg takes the first one. Add -map 0:a:1 after -vn to take the second.
What happens to the video?
It is left out. The M4A holds only the sound of the MKV, and the Terminal lines drop the picture with -vn.
Do the title and artist stay?
With the FFmpeg lines, yes: FFmpeg carries tags such as the title across to the M4A.