extracting, cleaning and re merging audio

**marks_linux** · October 21st, 2012

I'm working on some videos with bad background noise. I'm using Openshot to edit the clips. I was hoping the audio track would be separate in the Openshot UI so I could extract it, clena it up in Audacity and then re-import.

Are there any tools that allow this to be done simply? I love commandline until I'm talking video, sound, codecs and bitrates!

thanks

**shantiq** · October 21st, 2012

ok simple [he says]

use ffmpeg to separate audio and video first check properties of videofile see if your audio is aac or mp3 and write in accordingly below

ffmpeg -i audiovideo.mp4 -vn -acodec copy audio.mp3 && ffmpeg -i audiovideo.mp4 -an -vcodec copy videomute.mp4

you now have both separated and the original still

take audio mp3 to audacity and play around until happy

save it as audio2.mp3

reassemble with ffmpeg too [ thank you FakeOutdoorsman !]

ffmpeg -i videomute.mp4 -i audio2.mp3 -c copy newvideowithnewsound.mkv

===================================

or use mencoder here thus

mencoder -ovc copy -audiofile audio2.mp3 -oac pcm videomute.mp4 -o newfinal.mp4

but not as good as audio has to be hiked to pcm better ffmpeg here the whole way

or reassemble in kdenlive [in synaptic]

**FakeOutdoorsman** · October 21st, 2012

Originally Posted by shantiq

probably can reassemble with ffmpeg too but not sure how so please add anyone if you do

Assuming video.mp4 has no audio streams. Newer syntax:

Code:

ffmpeg -i video.mp4 -i audio.mp3 -c copy output.mkv

Older syntax:

Code:

ffmpeg -i video.mp4 -i audio.mp3 -vcodec copy -acodec copy output.mkv

You can output to almost any container that supports your video and audio formats. If video.mp4 has audio, and you only want the video from it while adding the audio from audio.mp3, then you will have to use the -map option. It is explained here: FFmpeg mux video and audio from another video.