[FFmpeg-user] Erroneous volume level shifts using ffmpeg to convert AC3 in M2TS to WAV

Andy Furniss adf.lists at gmail.com
Sun Mar 1 01:20:27 CET 2015

Andy Furniss wrote:

> WRT dialnorm - I am not familiar with Dolby s/w, but I think it's
> possible that some decoders would scale up to a target higher than
> -31 depending on how they are set - so just because the stream is -31
> I am not sure that excludes the possibility that a decoder will
> adjust - target level is a decoder setting.

On this I was mixing up a bit with DVB AAC which does allow for s/w
scaling up.

I accept that Dolby says -31 is no correction and higher is scaled down
- though ffmpeg and I guess other "kit" may cheat a bit and let target
levels be set higher and do it in s/w rather than controlling amps.

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