Make parts of audio track louder in MP4 image 138

Make parts of audio track louder in MP4

Crank up volume on parts of the audio track in a video: I have an MP4 of an interview and one of the two people talking was not caught well in the audio track and is far too soft spoken. My challenge now: increase the volume of only that speaker.

The steps:

  • save audio from MP4 in a separate MP3 file (using VLC)
  • identify the soft parts and amplify the sound in those sections (using Audacity)
  • add the edited MP3 audio track to the MP4 – replacing the original video track (using FFmpeg or with

Open VLC (open source software). Click on Media | Convert / Save


Add the mp4 file. Click on Convert/Save.


Select the Profile Audio – MP3. Define the name of the output file – using the extension .mp3.

Click on Start to commence processing. In a few seconds, the MP3 file is created with the audiotrack from the video.

Load this MP3 in Audacity – another open source tool:


Select the low volume parts and use Effects | Amplify to increase the sound level for each of these parts (one by one)


The result will be a cranked up wave – indicating more volume.


Export the thus improved audio file


The next challenge: combine this MP3 with MP4 – replacing the audio track in the MP4 file.

Several tools are available for this:

  • – free website, adding its own watermark and perform quite well
  • ClipChamp – Windows utility, also delivering good results in a simple manner
  • FFmpeg – open source command line utility for manipulating video and audio files; I did not get the perfect result thusfar; getting the command line exactly right seems a little bit tricky

The command used on the command line with FFmpeg to combine video and audio:

ffmpeg –i “C:\Users\lucas_j\Downloads\prijstrekkingAdventOfCode – Copy.mp4” -i “C:\Users\lucas_j\Downloads\AudioprijstrekkingAdventOfCodeAmplified.mp3” -c:v copy -c:a aac -strict experimental “C:\Users\lucas_j\Downloads\prijstrekkingAdventOfCodeWithAmplifiedAudio.mp4”

It seems like the video’s own audio is not reduced (enough). I probably have to explicitly suppress the video’s audio track.

With ClipChamp:

Create a project, import the MP4 and MP3 files. Add both files to the project – both starting at t=0. Mute the audio in the MP4 file, as shown in this screenshot (right mouse click on video, pick Audio | Mute).,


This completes the work in ClipChamp. Export the project – as shown.


This results in an MP4 file with much improved audio levels.


Article on How to Replace Audio in Video –

VLC at VideoLAN –

Audacity – – open source tool for audio editing

FFmpeg – homepage- – complete, open source cross-platform solution to record, convert and stream audio and video.

FFmpeg downloads for Windows –

How to Merge Audio and Video Using FFmpeg  –

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