[FFmpeg-user] Set audio level in aevalsrc audio filter

Massimo Battistel battistel at gmail.com
Tue Jul 1 18:45:03 CEST 2014

2014-07-01 12:12 GMT+02:00 Moritz Barsnick <barsnick at gmx.net>:

> On Tue, Jul 01, 2014 at 11:52:35 +0200, Massimo Battistel wrote:
> > I should obtain ~0.12589 for -18dB
> You do and you don't. :-)
> You must understand that the average level of a sine signal is -3.0dB:
> http://en.wikipedia.org/wiki/Crest_factor#Examples
Thanks Moritz, very useful informations. I solved my issue.

An additional hint:
"aevalsrc" generates a mono track by default: using "-ac 2" option causes
some kind of audio mixing and output level, when converted to stereo, is
3dB lower.
This can be solved setting "channel_layout=stereo" directly in "aevalsrc"
filter options.


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