Made volume control more linear

CONTRIBUTORS

@@ -630,6 +630,7 @@ Emil Naepflein <Emil.Naepflein@philosys.de>
  for fixing selecting the device, because sometimes an FTA recording terminated a
  CA recording
  for suggesting to never delete edited recordings automatically if the disk runs full
+ for making volume control more linear
 
 Gerald Berwolf <genka@genka.de>
  for suggesting to deactivate some templates in tools.h in case some plugin needs to

HISTORY

@@ -3022,3 +3022,4 @@ Video Disk Recorder Revision History
 - Avoiding unnecessary section filter start/stops (thanks to Marco Schlüßler).
 - Made the "Channel not available!" message and mtInfo instead of mtError (suggested
   by Wayne Keer).
+- Made volume control more linear (thanks to Emil Naepflein).

dvbdevice.c

@@ -4,7 +4,7 @@
  * See the main source file 'vdr.c' for copyright information and
  * how to reach the author.
  *
- * $Id: dvbdevice.c 1.95 2004/10/16 12:51:56 kls Exp $
+ * $Id: dvbdevice.c 1.96 2004/10/16 14:38:24 kls Exp $
  */
 
 #include "dvbdevice.h"
@@ -785,7 +785,11 @@ void cDvbDevice::SetVolumeDevice(int Volume)
 {
   if (HasDecoder()) {
      audio_mixer_t am;
-     am.volume_left = am.volume_right = Volume;
+     // conversion for linear volume response:
+     int i, Vol;
+     for (i = 1, Vol = 0; i < Volume; i++)
+         Vol += (256 - i) * (256 - i);
+     am.volume_left = am.volume_right = Vol / 21718;
      CHECK(ioctl(fd_audio, AUDIO_SET_MIXER, &am));
      }
 }