[MPlayer-dev-eng] Software volume control

[Anders Johansson]

Hi,

I have added soft clipping (compressor) to the software volume
control. I decided to add it to volume instead of volnorn plugin
(sorry for the noise pl). I have also made the volume scale
exponential cause it sounds more natural for the ear than having it
linear. It is now also possible to amplify the volume (per user
request). The soft clipping is disabled per default and has to be
enabled using a switch. The documentation for the new switch is
attached to this document.

Has there been any progress on the Audio Filter Layer, Alex?



On the wish list: I would like to have lists as a configuration
argument. What I mean is for example this:

somefile.c:
char** list;

cfg-mplayer.h:
{"list", list, CONF_TYPE_STRING|CONF_TYPE_LIST, 0, 0, 0, NULL}

on the command line:
mplayer -list=ada,ede,ini movie.mpg

Would make 0==strcmp(list[1],"ede") true.

If someone who understands the config parser wants to add this feature
I would be happy.


Cheers,
//Anders
-------------- next part --------------
--- DOCS/sound.html	Tue Mar 12 13:08:51 2002
+++ ../main/DOCS/sound.html	Wed Mar 13 21:07:21 2002
@@ -228,14 +228,15 @@
   without changing the PCM volume setting in the mixer. It has one
   switch <CODE>volume</CODE> that is used for setting the initial
   sound level. The initial sound level can be set to values between 0
-  and 255 and defaults to 255. Use this plugin with caution since it
-  can reduce the signal to noise ratio of the sound. In most cases it
-  is best to set the level for the PCM sound to max, leave this plugin
-  out and control the output level to your speakers with the mixers
-  master volume control. If there is an external amplifier connected
-  to the computer (this is almost always the case), the noise level
-  can be minimized by adjusting the master level and the volume knob
-  on the amplifier until the hissing noise in the background is gone.
+  and 255 and defaults to 101 which equals 0dB amplification. Use this
+  plugin with caution since it can reduce the signal to noise ratio of
+  the sound. In most cases it is best to set the level for the PCM
+  sound to max, leave this plugin out and control the output level to
+  your speakers with the mixers master volume control. If there is an
+  external amplifier connected to the computer (this is almost always
+  the case), the noise level can be minimized by adjusting the master
+  level and the volume knob on the amplifier until the hissing noise
+  in the background is gone.
 </P>
 
 <P>Usage :<BR>
@@ -243,6 +244,17 @@
   list=volume:volume=&lt;0-255&gt;</CODE>
 </P>
 
+<P>This plugin also have a compressor or "soft-clipping" capabilities.
+  Compression can be used if the dynamic range of the sound is very
+  high or if the dynamic range of the loudspeakers is very
+  low. Observe that this feature creates distortion and should be
+  considered a last resort.
+</P>
+
+<P>Usage :<BR>
+  &nbsp;&nbsp;<CODE>mplayer media.avi -aop
+  list=volume:softclip</CODE>
+</P>
 
 <P><B><A NAME=2.3.2.2.5>2.3.2.2.5. Extrastereo</A></B></P>