diff -Nru vdr-1.2.1/Makefile vdr-1.2.1-alsa_spdif/Makefile
--- vdr-1.2.1/Makefile	2003-01-06 13:28:09.000000000 +0100
+++ vdr-1.2.1-alsa_spdif/Makefile	2003-07-29 01:47:53.000000000 +0200
@@ -59,6 +59,11 @@
 DEFINES += -DVFAT
 endif
 
+ifdef SPDIF
+# volume control for SPDIF output
+DEFINES += -DSPDIF
+endif
+
 all: vdr
 font: genfontfile fontfix.c fontosd.c
 	@echo "font files created."
@@ -80,7 +85,11 @@
 # The main program:
 
 vdr: $(OBJS) $(DTVLIB)
+ifdef SPDIF
+	$(CXX) $(CXXFLAGS) -rdynamic $(OBJS) $(NCURSESLIB) -lasound -ljpeg -lpthread -ldl $(LIBDIRS) $(DTVLIB) -o vdr
+else
 	$(CXX) $(CXXFLAGS) -rdynamic $(OBJS) $(NCURSESLIB) -ljpeg -lpthread -ldl $(LIBDIRS) $(DTVLIB) -o vdr
+endif
 
 # The font files:
 
diff -Nru vdr-1.2.1/alsa_spdif.c vdr-1.2.1-alsa_spdif/alsa_spdif.c
--- vdr-1.2.1/alsa_spdif.c	1970-01-01 01:00:00.000000000 +0100
+++ vdr-1.2.1-alsa_spdif/alsa_spdif.c	2003-07-29 12:00:28.000000000 +0200
@@ -0,0 +1,56 @@
+#include <string.h>
+#include <alsa/asoundlib.h>
+
+class alsa_volume
+{
+    private:
+	char card[64];
+	int err;
+	bool blocked;
+	snd_ctl_t *handle;
+	snd_ctl_elem_id_t *id;
+	snd_ctl_elem_value_t *control;
+    public:
+	void set(int);
+	alsa_volume();
+	~alsa_volume();
+} alsa_vol;
+
+alsa_volume::alsa_volume()
+{
+	strcpy(card,"default");			// change it if you need
+	blocked=0;
+	snd_ctl_elem_id_alloca(&id);
+	snd_ctl_elem_value_alloca(&control);
+	snd_ctl_elem_id_set_interface(id, SND_CTL_ELEM_IFACE_MIXER);
+	/* below i am using numid 20 for 'IEC958 Optical Playback Volume'
+	   on my SBLive!, while numid 17 is for:
+	   'IEC958 TTL Playback Volume'
+	   you can obtain it all using 'amixer controls' */
+	snd_ctl_elem_id_set_numid(id, 20);
+	if ((err = snd_ctl_open(&handle, card, 0)) < 0)
+	{
+		esyslog("SetVolume(): ALSA %s card open error: %s\n", card, snd_strerror(err));
+		blocked=1;
+	}
+	if (!blocked)
+	    snd_ctl_elem_value_set_id(control, id);
+}
+
+alsa_volume::~alsa_volume()
+{
+	if (!blocked)
+	    snd_ctl_close(handle);
+}
+
+void alsa_volume::set(int Volume)
+{
+	if (blocked)
+	    return;
+	snd_ctl_elem_value_set_integer(control, 0, Volume);	//left channel
+	snd_ctl_elem_value_set_integer(control, 1, Volume);	//right channel
+	if ((err = snd_ctl_elem_write(handle, control)) < 0)
+	{
+		esyslog("SetVolume(): ALSA %s card element write error: %s\n", card, snd_strerror(err));
+	}
+}
diff -Nru vdr-1.2.1/dvbdevice.c vdr-1.2.1-alsa_spdif/dvbdevice.c
--- vdr-1.2.1/dvbdevice.c	2003-05-24 15:23:51.000000000 +0200
+++ vdr-1.2.1-alsa_spdif/dvbdevice.c	2003-07-29 12:00:52.000000000 +0200
@@ -33,6 +33,10 @@
 #include "status.h"
 #include "transfer.h"
 
+#if defined(SPDIF)
+#include "alsa_spdif.c"
+#endif
+
 #define DO_REC_AND_PLAY_ON_PRIMARY_DEVICE 1
 #define DO_MULTIPLE_RECORDINGS 1
 
@@ -708,9 +712,13 @@
 void cDvbDevice::SetVolumeDevice(int Volume)
 {
   if (HasDecoder()) {
+#if defined(SPDIF)
+     alsa_vol.set((Volume*100)/255);
+#else
      audio_mixer_t am;
      am.volume_left = am.volume_right = Volume;
      CHECK(ioctl(fd_audio, AUDIO_SET_MIXER, &am));
+#endif
      }
 }