Soundblaster 1024 Live! bulk

Last modified: 03.08.2003

Adding a TTL CD-SPDIF input

The bluk version of the Soundblaster 1024 Live! has no SPDIF input for the CD-ROM drive. With an easy modification you can add this input. The only thing you need to do is making a solder bridge at the location marked as C95. You can now add a connector at location J9 (SPDIF-CD) or directly solder a cable to the two pins.

The input you get is a TTL input which does not comply to the SPDIF signal level standard, but it is very useful anyway, because many devices have a TTL SPDIF output. This input can be directly used for example with the SPDIF output of a Technotrend or Hauppauge DVB-S card (Pin 4 of the 10 pin extension connector). This picture shows the modifications.

Using the CD-SPDIF input

Load the ALSA driver with the following command, this will enable the new input: 
modprobe snd-card-emu10k1 snd_extin=0x000f snd_extout=0x1f0f

The volume of this input can be controlled with the following command, where the last number is the volume in percent: 

amixer set 'IEC958 TTL' 50

Using the CD-SPDIF input with VDR

To use this input with the SPDIF output of VDR, apply the following patch to VDR and compile with adding SPDIF=1 in the commandline. 
diff -uN /tmp/vdr-1.1.31/dvbdevice.c vdr-1.1.31/dvbdevice.c
--- /tmp/vdr-1.1.31/dvbdevice.c 2003-05-03 16:03:20.000000000 +0200
+++ vdr-1.1.31/dvbdevice.c      2003-05-13 20:14:52.000000000 +0200
@@ -701,6 +701,12 @@

 void cDvbDevice::SetVolumeDevice(int Volume)
 {
+#if defined(SPDIF) // RaBa
+     char *cmd = NULL;
+     asprintf(&cmd, "amixer set 'IEC958 TTL' %d >/dev/null 2>&1", (Volume * 100) / 255);
+     system(cmd);
+     delete cmd;
+#endif
   if (HasDecoder()) {
      audio_mixer_t am;
      am.volume_left = am.volume_right = Volume;
Common subdirectories: /tmp/vdr-1.1.31/libdtv and vdr-1.1.31/libdtv
diff -uN /tmp/vdr-1.1.31/Makefile vdr-1.1.31/Makefile
--- /tmp/vdr-1.1.31/Makefile    2003-01-06 13:28:09.000000000 +0100
+++ vdr-1.1.31/Makefile 2003-05-13 19:56:15.000000000 +0200
@@ -59,6 +59,10 @@
 DEFINES += -DVFAT
 endif

+ifdef SPDIF
+DEFINES += -DSPDIF
+endif
+
 all: vdr
 font: genfontfile fontfix.c fontosd.c
        @echo "font files created."

An alternative patch to VDR was sent to me by Manio. He is not using the amixer ALSA utility, but is directly accessing the ALSA API to change the volume which is faster and more elegant. You can download Manio's patch here.

Back to Homepage

Hosted by www.Geocities.ws

1