[FFmpeg-user] HIGHPASS FILTER AND ID£ METADATA

[Michael Koch]

Am 01.10.2020 um 13:25 schrieb Marco Mircoli:
> Hello',
>      I'm a newbie.
> Just bought a php script that use ffmpeg.
> it converts to mp3/96Kbps all media uploaded in a unique format.
> this is the line, and now it normalizes to R128 (thanks Moritz)
>
> $shell     = shell_exec("$ffmpeg_b -i $audio_file_full_path -map 0:a:0 -af
> loudnorm -b:a 96k $audio_output_mp3 2>&1");
>
> I'm wondering if it is possible to include a simple hi-pass filter (highest
> db per octave @ 70Hz)

add  highpass=70,    before  loudnorm

This filter attenuated 6dB per octave. If you need higher attenuation, 
you can use several highpass filters, for example 
highpass=70,highpass=70,highpass=70,loudnorm

Michael