[vdr] Linear volume response in VDR

[Emil Naepflein <Emil.Naepflein@philosys.de>]

Hi,

the volume control in vdr is not linear. The following patch makes the
volume control better:

--- dvbdevice.c.org	2004-09-25 14:15:45.000000000 +0200
+++ dvbdevice.c	2004-09-25 14:18:33.000000000 +0200
@@ -786,7 +820,12 @@
 {
   if (HasDecoder()) {
      audio_mixer_t am;
-     am.volume_left = am.volume_right = Volume;
+     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));
      }
 }

The line numbers may be wrong.

Enjoy,
Emil