Over a month ago I reported a problem with a change that was made to
the Genpix driver which broke 8PSK. The change limited DVB-S streams
to QPSK and 8PSK to DVB-S2. There are a couple problems with this.
First of all, Genpix devices do NOT support DVB-S2 but pretends to for
access to 8PSK. Secondly, the 8PSK the Genpix provides is modified,
aka 8PSK turbo-fec. Two of the biggest North American DVB-S providers
use 8PSK turbo-fec for a lot of their content. Therefore, limiting
DVB-S to QPSK only is crippling reception of all those providers
transponders which use it.
Ideally 8PSK should be allowed for DVB-S in v4l so that a device like
the Genpix doesn't have to pretend to be something it's not to use it.
While I seriously doubt that will be fixed, this problem can still be
resolved by simply reverting back to the drivers original behavior
with the following patch:
diff -pruN v4l-dvb.orig/linux/drivers/media/dvb/dvb-usb/gp8psk-fe.c
v4l-dvb/linux/drivers/media/dvb/dvb-usb/gp8psk-fe.c
--- v4l-dvb.orig/linux/drivers/media/dvb/dvb-usb/gp8psk-fe.c
2009-08-14 19:17:43.000000000 -0700
+++ v4l-dvb/linux/drivers/media/dvb/dvb-usb/gp8psk-fe.c 2009-08-14
19:19:18.000000000 -0700
@@ -146,8 +146,8 @@ static int gp8psk_fe_set_frontend(struct
switch (c->delivery_system) {
case SYS_DVBS:
- /* Only QPSK is supported for DVB-S */
- if (c->modulation != QPSK) {
+ /* Allow QPSK and 8PSK */
+ if (c->modulation != QPSK && c->modulation != PSK_8) {
deb_fe("%s: unsupported modulation selected (%d)\n",
__func__, c->modulation);
return -EOPNOTSUPP;
--
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