Often sound for ‘voice over slides’ videos gets recorded badly (or at least needs some fixing up), so here are three approaches to enhancing the sound quality (and some reasonable settings for video).

### Method 2 : More complex ffmpeg filters

It would be nice if there was a ‘Noise Reduction’ option for ffmpeg - though perhaps there is good news :

FFmpeg now have 2 native filters to deal with noise background: afftdn and anlmdn. Also, for some time one has been able to use ladspa (look for noise-supressor) and/or lv2 (look for speech denoiser) filters with FFmpeg.

Ideas :

so (without the denoising, for now) :

### Method 3 : Treating the audio separately

• Take the audio from the combined file
• https://www.bugcodemaster.com/article/extract-audio-video-using-ffmpeg
• Process the audio (keep length the same)

• Recombine the audio into the video file
• https://superuser.com/a/1137613

HD 720p 25fps?

#### Process the audio (keep length the same)

Load SEER-01_audio_raw.wav manually into Audacity to do the following processing :

• Effect - Fade-in / out to smooth out the recording
• Effect - Noise Reduction (need to find a section of ‘silence’ for it to fingerprint first)
• Effect - Amplify (so that maxiumum amplitude is 0dB)
• File - Export as OGG (Quality=5 seems fine) &r_arr; SEER-01_audio_clean.ogg

#### Recombine the audio into the video file

Two versions of the same command (illustrating combinations tried) :

### Choices, choices…

Will be much easier to go with Method 2 (but need to wait for newer ffmpeg to arrive in the repos to get the denoising filter).