dialnorm is unchanged with AC3 copy

[Mista_D]

dialnorm value change is not working when using -c copy.
1) ffmpeg -i source.ts -c copy -dialnorm -24 -vf c.copy.ts
2) ffmpeg -i source.ts -c ac3 -dialnorm -24 -vf c.ac3.ts

Audio tool used to show dilanorm was eac3to (Win/Wine)

eac3to.exe source.ts
TS, 1 audio track, 0:05:00
1: AC3, English, 5.1 channels, 384kbps, 48kHz, dialnorm: -31dB

eac3to.exe c.copy.ts
TS, 1 audio track, 0:05:00
1: AC3, English, 5.1 channels, 384kbps, 48kHz, dialnorm: -31dB

eac3to.exe c.copy.ts
TS, 1 audio track, 0:05:00
1: AC3, English, 5.1 channels, 384kbps, 48kHz, dialnorm: -24dB

Can dialnorm value be modified by FFmpeg without re-encoding of the AC3 stream please? Or an error message which would indicate that header changes can be only done during re-encoding

Thank you

[Mista_D]

AC3 Dial Norm editor

[Mista_D]

Found utility that changes Dial Norm on AC3 container level (changes DN value and rewrites CRC)