[matroska-general] Re: =[SPAM?]= Re: Dynamic Range Management

Christian HJ Wiesner chris at matroska.org
Mon May 26 09:25:03 CEST 2003

Pamel wrote:
> "Frank Klemm" <pfk at fuchs.offl.uni-jena.de> wrote..
>>The Dynamic Changes are not specific to an audio block.
>>A new setting can be choosen after 64, 256, 1024 or 4096 samples and this
>>new value is applied smoothly between the two props
> I am afraid that I am having a difficult time understanding the difference
> between this and the replay gain options that we have(other than the ability
> to limit to a specific number of samples).  But it sounds like something
> that would most likely occur at the codec level, which would place it inside
> of the block data.  But I just don't understand it well enough to make a
> good comment.
> Pamel

Replay gain is nothing but a constant factor that tells the player if a 
song has to be amplified ( factor > 1 ) or played with less volume ( 
factor < 1 ) to match with the average loudness of the complete 
album/song collection, to avoid that individual songs are louder or too 
silent. That way replay gain will not alter the dynamic range of a song 
( differnce between loudest and most silent parts of the song ).

DRC on the other hand will amplify the silent parts of a song or 
soundtrack and reduce volume on the louder sections, thus reducing the 
complete dynamic range of a song/soundtrack. If you ever listened to one 
of the crappy AC3 to MP3 conversions without DRC apllied, you'll notive 
that you can hardly hear the conversations, while on loud scenes your 
speakers will fall off the table. A flexible DRC control can allow the 
user to adapt the dynamics of the playback to the max dynamics of the 
playback chain ( cinema = high dynamics, walkman speakers = very low 
dynamic range ).

In short, Frank has plans to add DRC to MPC, using matroska ;) ....


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