On Thu, 17 Feb 2022, Rich Shepard wrote:
Where do I look for codec mp3 and how do I put it where it should be for
ffmpeg to find? Or, is there another tool I can use to extract the audio
stream from an .mp4 I created so I can test my sound system with a file I
know has recorded audio?
libmp3lame is installed here:
$ locate libmp3lame
/usr/lib64/libmp3lame.so.0.0.0
/usr/lib64/libmp3lame.so.0
/usr/lib64/libmp3lame.so
/usr/lib64/libmp3lame.la
From <https://trac.ffmpeg.org/wiki/Encode/MP3>:
"This page describes how to use the external libmp3lame encoding library
within ffmpeg to create MP3 audio files (ffmpeg has no native MP3 encoder).
See also other codecs you could use, and FFmpeg AAC Encoding Guide if you
want AAC instead, and the official documentation."
Using the command on the ffmpeg mp3 encoding guide page I tried again:
$ ffmpeg -i regulatory-science-models.mp4 -codec:a libmp3lame -qscale:a 2
reg-models.mp3 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from
'regulatory-science-models.mp4':
Metadata:
major_brand : mp42
minor_version : 0
compatible_brands: mp42mp41isomiso2
creation_time : 2020-08-13T18:57:21.000000Z
encoder : x264
Duration: 00:43:56.93, start: 0.000000, bitrate: 214 kb/s
Stream #0:0(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661),
yuv420p, 960x542 [SAR 542:541 DAR 960:541], 109 kb/s, 30 fps, 30 tbr, 3k tbn,
60 tbc (default)
Metadata:
creation_time : 2020-08-13T18:57:21.000000Z
handler_name : VideoHandler
Stream #0:1(eng): Audio: mp3 (mp4a / 0x6134706D), 44100 Hz, stereo, s16p,
99 kb/s (default)
Metadata:
creation_time : 2020-08-13T18:57:21.000000Z
handler_name : SoundHandler
Unknown encoder 'libmp3lame'
Why?
Rich
