[vdr] Low volume on Pro7 ?

Dr. Werner Fink werner at suse.de
Thu Jun 9 11:32:49 CEST 2005

On Thu, Jun 09, 2005 at 08:25:36AM +0200, Harald Milz wrote:
> Hi,
> is it just my setup or does Pro7 actually have a far lower volume than
> all other channels? I'm using Werner's 261d firmware with AC3overDVB
> from a FF 1.3 card over an optical SPDIF link into a home cinema system. 

Most AC3 channels do have a lower volume due to the fact that
the dynanic range of AC3 is much more than 100dB. This is much
more than you can do with Mpeg Audio and raw PCM at 16bit[1].

OK, in most cases at the most time for DD 2.0 this is not
relevant, but for DD 5.1 you could lose the friendship
of your neighbours on an explosion within a movie.
Nevertheless, even for DD 2.0 the possible upper loudness
is much higher than for Mpeg Audio or raw 16 bit PCM.


[1] PCM 44.1kHz/16bit includes a dynamic range of 96dB, but
    most mass markt audio CDs do not use them and any
    enhancement for a larger dynamic range and super bits
    is only marketing, which violates the shannon theorem.

AC3 loop through sound card http://bitstreamout.sourceforge.net/
Howto http://www.vdr-portal.de/board/thread.php?threadid=1958
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