[FFmpeg-devel] [PATCH] AC3 volume options

Måns Rullgård mans
Sun Dec 16 23:40:17 CET 2007

Justin Ruggles <justinruggles at bellsouth.net> writes:

> Michael Niedermayer wrote:
>> On Sun, Dec 16, 2007 at 10:20:12AM -0500, Justin Ruggles wrote:
>> [...]
>>> I like Andreas' suggestion to make the dialog normalization value more
>>> universal.  I think a floating-point decibel value for the dialog level
>>> would be appropriate.
>> i think a simple float scale factor is a better choice, its more readily
>> useable than a value in decibel
>> that is 
>> sample[x] * factor 
>> vs.
>> sample[x] * pow(10, decibel/10)
> Personally, I think it's more intuitive in decibels because it's not a
> scale factor to be applied to output, but rather a comparison between
> dialog level and maximum level.  To say that the dialog level is the
> maximum level * 0.028 makes less sense to me than to say that the dialog
> level is 31 decibels below the maximum level.

I have to agree with Justin.  A logarithmic scale is more intuitive
when dealing with sound levels.  As decibels are commonly used, that
unit is a natural choice.

M?ns Rullg?rd
mans at mansr.com

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