[FFmpeg-user] FFMPEG loudnorm - linear normalization

[Paul B Mahol]

On 3/7/22, CMG DiGiTaL <cmarciog at gmail.com> wrote:
> hi,
>
> About loudnorm normalization: Normalization in Dual-pass mode.
>
> Rules for normalization to be linear:
>
> 1 - Values entry:
>     LUFS_TARGET (user entry)
>     LRA         (get input file - Pass 1 loudnorm)

where is measured_tp ?

>     TP_TARGET   (user entry)
>     THRESH      (get input file - Pass 1 loudnorm)
>     OFFSET      (get input file - Pass 1 loudnorm)

do not change offset option, but only measured_thresh

>
> 2 - The destination LRA must NOT BE LESS than the source LRA:
>     LRA_OUT >= LRA_IN
>
> 3 - The destination TP must NOT BE GREATER than the target TP:
>     TP_OUT <= TP_TARGET
>
> If these conditions are met, normalization will be done in linear mode
> and, if there is any divergence, normalization will be done in dynamic
> mode.
>
> These rules are never met... I normalized more than 20 audio files and
> in none of them the linear rule was executed, only the dynamic rule!
>
> In all my FLAC audios, the destination LRA's are always lower than the
> source LRA's!
>
> Has anyone managed to do the normalization in linear mode... what do I
> have to do to get linear normalization?
>

ffmpeg -i tom.wav -af
loudnorm=print_format=summary:measured_i=-17.8:measured_tp=-0.3:measured_lra=10.7:measured_thresh=-28.9:lra=50:i=-20
-f null -

You can not set output TP to much lower values and output I to much
higher values than measured and expect linear processing.

Post measured values of your flac files and target values you set?