* stv0298 signal issues on QAM256
@ 2012-06-10 12:20 Fredrik
0 siblings, 0 replies; 5+ messages in thread
From: Fredrik @ 2012-06-10 12:20 UTC (permalink / raw)
To: linux-media
Hi.
Unfortunatly my cable provider "Comhem" moved almost all channels to QAM256.
The results are terrible on my two cards. Blocky picture and skipping audio.
I've tried all suggestions i've found on mailing lists to change
different values in stv0297.c but without luck.
What i cannot see is, if those who reported problems since 2005, are
happy now or not. Perhaps this hardware is too obsolete.
On other devices QAM256 is ok.
Anyway im hoping for some help or some information to make me decide
about placing these card in the junkbox.
04:00.0 Multimedia controller: Philips Semiconductors SAA7146 (rev 01)
Subsystem: Technotrend Systemtechnik GmbH Octal/Technotrend
DVB-C for iTV
Kernel driver in use: av7110
Kernel modules: dvb-ttpci
dmsg snip..
[ 1.572820] DVB: registering new adapter (Technotrend/Hauppauge WinTV
Nexus-CA rev1.X)
[ 1.584677] DVB: registering adapter 0 frontend 0 (Philips TDA10023
DVB-C)...
[ 1.590877] adapter has MAC addr = 00:d0:5c:24:5c:71
[ 1.592807] IR keymap rc-anysee not found
[ 1.592809] Registered IR keymap rc-empty
[ 1.592852] input: IR-receiver inside an USB DVB receiver as
/devices/pci0000:00/0000:00:1d.7/usb1/1-6/rc/rc0/input0
[ 1.592869] rc0: IR-receiver inside an USB DVB receiver as
/devices/pci0000:00/0000:00:1d.7/usb1/1-6/rc/rc0
[ 1.592871] dvb-usb: schedule remote query interval to 250 msecs.
[ 1.592873] dvb-usb: Anysee DVB USB2.0 successfully initialized and
connected.
[ 1.594442] usbcore: registered new interface driver dvb_usb_anysee
[ 1.731015] usb 2-2: new full-speed USB device number 2 using uhci_hcd
[ 1.900088] usb 2-2: New USB device found, idVendor=046d, idProduct=0b04
[ 1.900092] usb 2-2: New USB device strings: Mfr=1, Product=2,
SerialNumber=0
[ 1.900095] usb 2-2: Product: Logitech BT Mini-Receiver
[ 1.900098] usb 2-2: Manufacturer: Logitech
[ 1.903118] hub 2-2:1.0: USB hub found
[ 1.905092] hub 2-2:1.0: 3 ports detected
[ 1.924098] dvb-ttpci: info @ card 1: firm f0240009, rtsl b0250018,
vid 71010068, app 80f12623
[ 1.924102] dvb-ttpci: firmware @ card 1 supports CI link layer interface
[ 1.998276] dvb_ttpci: DVB-C analog module @ card 1 detected,
initializing MSP3415
[ 2.101563] dvb_ttpci: saa7113 not accessible
[ 2.116015] usb 3-1: new full-speed USB device number 2 using uhci_hcd
[ 2.131523] saa7146_vv: saa7146 (0): registered device video0 [v4l2]
[ 2.131535] saa7146_vv: saa7146 (0): registered device vbi0 [v4l2]
[ 2.133473] DVB: registering adapter 1 frontend 0 (ST STV0297 DVB-C)...
[ 2.136094] input: DVB on-card IR receiver as
/devices/pci0000:00/0000:00:1e.0/0000:04:00.0/input/input1
[ 2.136119] dvb-ttpci: found av7110-0.
[ 2.136157] saa7146: found saa7146 @ mem fa0b0000 (revision 1, irq
19) (0x13c2,0x000a)
[ 2.137704] DVB: registering new adapter (Technotrend/Hauppauge WinTV
Nexus-CA rev1.X)
[ 2.155901] adapter has MAC addr = 00:d0:5c:24:47:2a
[ 2.283286] usb 3-1: New USB device found, idVendor=08e6, idProduct=3437
[ 2.283290] usb 3-1: New USB device strings: Mfr=1, Product=2,
SerialNumber=0
[ 2.283293] usb 3-1: Product: USB SmartCard Reader
[ 2.283296] usb 3-1: Manufacturer: Gemplus
[ 2.485099] dvb-ttpci: info @ card 2: firm f0240009, rtsl b0250018,
vid 71010068, app 80f12623
[ 2.485102] dvb-ttpci: firmware @ card 2 supports CI link layer interface
[ 2.492128] usb 5-2: new full-speed USB device number 2 using uhci_hcd
[ 2.562280] dvb_ttpci: DVB-C analog module @ card 2 detected,
initializing MSP3415
[ 2.650542] usb 5-2: New USB device found, idVendor=0471, idProduct=0815
[ 2.650545] usb 5-2: New USB device strings: Mfr=1, Product=2,
SerialNumber=3
[ 2.650548] usb 5-2: Product: eHome Infrared Transceiver
[ 2.650551] usb 5-2: Manufacturer: Philips
[ 2.650553] usb 5-2: SerialNumber: PH00GEFN
[ 2.665560] dvb_ttpci: saa7113 not accessible
[ 2.695510] saa7146_vv: saa7146 (1): registered device video1 [v4l2]
[ 2.695522] saa7146_vv: saa7146 (1): registered device vbi1 [v4l2]
[ 2.695832] DVB: registering adapter 2 frontend 0 (ST STV0297 DVB-C)...
[ 2.695906] input: DVB on-card IR receiver as
/devices/pci0000:00/0000:00:1e.0/0000:04:01.0/input/input2
[ 2.695923] dvb-ttpci: found av7110-1.
Br Fredrik
^ permalink raw reply [flat|nested] 5+ messages in thread
* stv0298 signal issues on QAM256
@ 2012-06-10 12:25 Fredrik
2012-06-11 8:13 ` stv0297 " Fontana
0 siblings, 1 reply; 5+ messages in thread
From: Fredrik @ 2012-06-10 12:25 UTC (permalink / raw)
To: linux-media
Hi.
Unfortunatly my cable provider "Comhem" moved almost all channels to
QAM256.
The results are terrible on my two cards. Blocky picture and skipping
audio.
I've tried all suggestions i've found on mailing lists to change
different values in stv0297.c but without luck.
What i cannot see is, if those who reported problems since 2005, are
happy now or not. Perhaps this hardware is too obsolete.
On other devices QAM256 is ok.
Anyway im hoping for some help or some information to make me decide
about placing these card in the junkbox.
04:00.0 Multimedia controller: Philips Semiconductors SAA7146 (rev 01)
Subsystem: Technotrend Systemtechnik GmbH Octal/Technotrend
DVB-C for iTV
Kernel driver in use: av7110
Kernel modules: dvb-ttpci
dmsg snip..
[ 1.572820] DVB: registering new adapter (Technotrend/Hauppauge WinTV
Nexus-CA rev1.X)
[ 1.584677] DVB: registering adapter 0 frontend 0 (Philips TDA10023
DVB-C)...
[ 1.590877] adapter has MAC addr = 00:d0:5c:24:5c:71
[ 1.592807] IR keymap rc-anysee not found
[ 1.592809] Registered IR keymap rc-empty
[ 1.592852] input: IR-receiver inside an USB DVB receiver as
/devices/pci0000:00/0000:00:1d.7/usb1/1-6/rc/rc0/input0
[ 1.592869] rc0: IR-receiver inside an USB DVB receiver as
/devices/pci0000:00/0000:00:1d.7/usb1/1-6/rc/rc0
[ 1.592871] dvb-usb: schedule remote query interval to 250 msecs.
[ 1.592873] dvb-usb: Anysee DVB USB2.0 successfully initialized and
connected.
[ 1.594442] usbcore: registered new interface driver dvb_usb_anysee
[ 1.731015] usb 2-2: new full-speed USB device number 2 using uhci_hcd
[ 1.900088] usb 2-2: New USB device found, idVendor=046d, idProduct=0b04
[ 1.900092] usb 2-2: New USB device strings: Mfr=1, Product=2,
SerialNumber=0
[ 1.900095] usb 2-2: Product: Logitech BT Mini-Receiver
[ 1.900098] usb 2-2: Manufacturer: Logitech
[ 1.903118] hub 2-2:1.0: USB hub found
[ 1.905092] hub 2-2:1.0: 3 ports detected
[ 1.924098] dvb-ttpci: info @ card 1: firm f0240009, rtsl b0250018,
vid 71010068, app 80f12623
[ 1.924102] dvb-ttpci: firmware @ card 1 supports CI link layer
interface
[ 1.998276] dvb_ttpci: DVB-C analog module @ card 1 detected,
initializing MSP3415
[ 2.101563] dvb_ttpci: saa7113 not accessible
[ 2.116015] usb 3-1: new full-speed USB device number 2 using uhci_hcd
[ 2.131523] saa7146_vv: saa7146 (0): registered device video0 [v4l2]
[ 2.131535] saa7146_vv: saa7146 (0): registered device vbi0 [v4l2]
[ 2.133473] DVB: registering adapter 1 frontend 0 (ST STV0297 DVB-C)...
[ 2.136094] input: DVB on-card IR receiver as
/devices/pci0000:00/0000:00:1e.0/0000:04:00.0/input/input1
[ 2.136119] dvb-ttpci: found av7110-0.
[ 2.136157] saa7146: found saa7146 @ mem fa0b0000 (revision 1, irq
19) (0x13c2,0x000a)
[ 2.137704] DVB: registering new adapter (Technotrend/Hauppauge WinTV
Nexus-CA rev1.X)
[ 2.155901] adapter has MAC addr = 00:d0:5c:24:47:2a
[ 2.283286] usb 3-1: New USB device found, idVendor=08e6, idProduct=3437
[ 2.283290] usb 3-1: New USB device strings: Mfr=1, Product=2,
SerialNumber=0
[ 2.283293] usb 3-1: Product: USB SmartCard Reader
[ 2.283296] usb 3-1: Manufacturer: Gemplus
[ 2.485099] dvb-ttpci: info @ card 2: firm f0240009, rtsl b0250018,
vid 71010068, app 80f12623
[ 2.485102] dvb-ttpci: firmware @ card 2 supports CI link layer
interface
[ 2.492128] usb 5-2: new full-speed USB device number 2 using uhci_hcd
[ 2.562280] dvb_ttpci: DVB-C analog module @ card 2 detected,
initializing MSP3415
[ 2.650542] usb 5-2: New USB device found, idVendor=0471, idProduct=0815
[ 2.650545] usb 5-2: New USB device strings: Mfr=1, Product=2,
SerialNumber=3
[ 2.650548] usb 5-2: Product: eHome Infrared Transceiver
[ 2.650551] usb 5-2: Manufacturer: Philips
[ 2.650553] usb 5-2: SerialNumber: PH00GEFN
[ 2.665560] dvb_ttpci: saa7113 not accessible
[ 2.695510] saa7146_vv: saa7146 (1): registered device video1 [v4l2]
[ 2.695522] saa7146_vv: saa7146 (1): registered device vbi1 [v4l2]
[ 2.695832] DVB: registering adapter 2 frontend 0 (ST STV0297 DVB-C)...
[ 2.695906] input: DVB on-card IR receiver as
/devices/pci0000:00/0000:00:1e.0/0000:04:01.0/input/input2
[ 2.695923] dvb-ttpci: found av7110-1.
Br Fredrik
^ permalink raw reply [flat|nested] 5+ messages in thread
* stv0297 signal issues on QAM256
2012-06-10 12:25 stv0298 signal issues on QAM256 Fredrik
@ 2012-06-11 8:13 ` Fontana
2012-06-13 8:46 ` SV: " Fontana
0 siblings, 1 reply; 5+ messages in thread
From: Fontana @ 2012-06-11 8:13 UTC (permalink / raw)
To: Fredrik, linux-media
typo in subject
-----Ursprungligt meddelande-----
Från: linux-media-owner@vger.kernel.org
[mailto:linux-media-owner@vger.kernel.org]För Fredrik
Skickat: den 10 juni 2012 14:25
Till: linux-media@vger.kernel.org
Ämne: stv0298 signal issues on QAM256
Hi.
Unfortunatly my cable provider "Comhem" moved almost all channels to
QAM256.
The results are terrible on my two cards. Blocky picture and skipping
audio.
I've tried all suggestions i've found on mailing lists to change
different values in stv0297.c but without luck.
What i cannot see is, if those who reported problems since 2005, are
happy now or not. Perhaps this hardware is too obsolete.
On other devices QAM256 is ok.
Anyway im hoping for some help or some information to make me decide
about placing these card in the junkbox.
04:00.0 Multimedia controller: Philips Semiconductors SAA7146 (rev 01)
Subsystem: Technotrend Systemtechnik GmbH Octal/Technotrend
DVB-C for iTV
Kernel driver in use: av7110
Kernel modules: dvb-ttpci
dmsg snip..
[ 1.572820] DVB: registering new adapter (Technotrend/Hauppauge WinTV
Nexus-CA rev1.X)
[ 1.584677] DVB: registering adapter 0 frontend 0 (Philips TDA10023
DVB-C)...
[ 1.590877] adapter has MAC addr = 00:d0:5c:24:5c:71
[ 1.592807] IR keymap rc-anysee not found
[ 1.592809] Registered IR keymap rc-empty
[ 1.592852] input: IR-receiver inside an USB DVB receiver as
/devices/pci0000:00/0000:00:1d.7/usb1/1-6/rc/rc0/input0
[ 1.592869] rc0: IR-receiver inside an USB DVB receiver as
/devices/pci0000:00/0000:00:1d.7/usb1/1-6/rc/rc0
[ 1.592871] dvb-usb: schedule remote query interval to 250 msecs.
[ 1.592873] dvb-usb: Anysee DVB USB2.0 successfully initialized and
connected.
[ 1.594442] usbcore: registered new interface driver dvb_usb_anysee
[ 1.731015] usb 2-2: new full-speed USB device number 2 using uhci_hcd
[ 1.900088] usb 2-2: New USB device found, idVendor=046d, idProduct=0b04
[ 1.900092] usb 2-2: New USB device strings: Mfr=1, Product=2,
SerialNumber=0
[ 1.900095] usb 2-2: Product: Logitech BT Mini-Receiver
[ 1.900098] usb 2-2: Manufacturer: Logitech
[ 1.903118] hub 2-2:1.0: USB hub found
[ 1.905092] hub 2-2:1.0: 3 ports detected
[ 1.924098] dvb-ttpci: info @ card 1: firm f0240009, rtsl b0250018,
vid 71010068, app 80f12623
[ 1.924102] dvb-ttpci: firmware @ card 1 supports CI link layer
interface
[ 1.998276] dvb_ttpci: DVB-C analog module @ card 1 detected,
initializing MSP3415
[ 2.101563] dvb_ttpci: saa7113 not accessible
[ 2.116015] usb 3-1: new full-speed USB device number 2 using uhci_hcd
[ 2.131523] saa7146_vv: saa7146 (0): registered device video0 [v4l2]
[ 2.131535] saa7146_vv: saa7146 (0): registered device vbi0 [v4l2]
[ 2.133473] DVB: registering adapter 1 frontend 0 (ST STV0297 DVB-C)...
[ 2.136094] input: DVB on-card IR receiver as
/devices/pci0000:00/0000:00:1e.0/0000:04:00.0/input/input1
[ 2.136119] dvb-ttpci: found av7110-0.
[ 2.136157] saa7146: found saa7146 @ mem fa0b0000 (revision 1, irq
19) (0x13c2,0x000a)
[ 2.137704] DVB: registering new adapter (Technotrend/Hauppauge WinTV
Nexus-CA rev1.X)
[ 2.155901] adapter has MAC addr = 00:d0:5c:24:47:2a
[ 2.283286] usb 3-1: New USB device found, idVendor=08e6, idProduct=3437
[ 2.283290] usb 3-1: New USB device strings: Mfr=1, Product=2,
SerialNumber=0
[ 2.283293] usb 3-1: Product: USB SmartCard Reader
[ 2.283296] usb 3-1: Manufacturer: Gemplus
[ 2.485099] dvb-ttpci: info @ card 2: firm f0240009, rtsl b0250018,
vid 71010068, app 80f12623
[ 2.485102] dvb-ttpci: firmware @ card 2 supports CI link layer
interface
[ 2.492128] usb 5-2: new full-speed USB device number 2 using uhci_hcd
[ 2.562280] dvb_ttpci: DVB-C analog module @ card 2 detected,
initializing MSP3415
[ 2.650542] usb 5-2: New USB device found, idVendor=0471, idProduct=0815
[ 2.650545] usb 5-2: New USB device strings: Mfr=1, Product=2,
SerialNumber=3
[ 2.650548] usb 5-2: Product: eHome Infrared Transceiver
[ 2.650551] usb 5-2: Manufacturer: Philips
[ 2.650553] usb 5-2: SerialNumber: PH00GEFN
[ 2.665560] dvb_ttpci: saa7113 not accessible
[ 2.695510] saa7146_vv: saa7146 (1): registered device video1 [v4l2]
[ 2.695522] saa7146_vv: saa7146 (1): registered device vbi1 [v4l2]
[ 2.695832] DVB: registering adapter 2 frontend 0 (ST STV0297 DVB-C)...
[ 2.695906] input: DVB on-card IR receiver as
/devices/pci0000:00/0000:00:1e.0/0000:04:01.0/input/input2
[ 2.695923] dvb-ttpci: found av7110-1.
Br Fredrik
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 5+ messages in thread
* SV: stv0297 signal issues on QAM256
2012-06-11 8:13 ` stv0297 " Fontana
@ 2012-06-13 8:46 ` Fontana
2013-06-10 10:15 ` Daniel Glöckner
0 siblings, 1 reply; 5+ messages in thread
From: Fontana @ 2012-06-13 8:46 UTC (permalink / raw)
To: linux-media
Hello,
After some further digging i found a post with attached patch.
http://www.linuxtv.org/pipermail/linux-dvb/attachments/20080731/de8768ed/att
achment.diff
Dunno why there were no followup on this one?
http://linuxtv.org/pipermail/linux-dvb/2008-July/027517.html
Applied cleanly to kernel 3.4.0 with the following change.
- (p->u.qam.modulation == QAM_256) ? 6718 : 7250);
+ (p->modulation == QAM_256) ? 6718 : 7250);
//Br Fredrik
-----Ursprungligt meddelande-----
Från: linux-media-owner@vger.kernel.org
[mailto:linux-media-owner@vger.kernel.org]För Fontana
Skickat: den 11 juni 2012 10:13
Till: Fredrik; linux-media@vger.kernel.org
Ämne: stv0297 signal issues on QAM256
typo in subject
-----Ursprungligt meddelande-----
Från: linux-media-owner@vger.kernel.org
[mailto:linux-media-owner@vger.kernel.org]För Fredrik
Skickat: den 10 juni 2012 14:25
Till: linux-media@vger.kernel.org
Ämne: stv0298 signal issues on QAM256
Hi.
Unfortunatly my cable provider "Comhem" moved almost all channels to
QAM256.
The results are terrible on my two cards. Blocky picture and skipping
audio.
I've tried all suggestions i've found on mailing lists to change
different values in stv0297.c but without luck.
What i cannot see is, if those who reported problems since 2005, are
happy now or not. Perhaps this hardware is too obsolete.
On other devices QAM256 is ok.
Anyway im hoping for some help or some information to make me decide
about placing these card in the junkbox.
04:00.0 Multimedia controller: Philips Semiconductors SAA7146 (rev 01)
Subsystem: Technotrend Systemtechnik GmbH Octal/Technotrend
DVB-C for iTV
Kernel driver in use: av7110
Kernel modules: dvb-ttpci
dmsg snip..
[ 1.572820] DVB: registering new adapter (Technotrend/Hauppauge WinTV
Nexus-CA rev1.X)
[ 1.584677] DVB: registering adapter 0 frontend 0 (Philips TDA10023
DVB-C)...
[ 1.590877] adapter has MAC addr = 00:d0:5c:24:5c:71
[ 1.592807] IR keymap rc-anysee not found
[ 1.592809] Registered IR keymap rc-empty
[ 1.592852] input: IR-receiver inside an USB DVB receiver as
/devices/pci0000:00/0000:00:1d.7/usb1/1-6/rc/rc0/input0
[ 1.592869] rc0: IR-receiver inside an USB DVB receiver as
/devices/pci0000:00/0000:00:1d.7/usb1/1-6/rc/rc0
[ 1.592871] dvb-usb: schedule remote query interval to 250 msecs.
[ 1.592873] dvb-usb: Anysee DVB USB2.0 successfully initialized and
connected.
[ 1.594442] usbcore: registered new interface driver dvb_usb_anysee
[ 1.731015] usb 2-2: new full-speed USB device number 2 using uhci_hcd
[ 1.900088] usb 2-2: New USB device found, idVendor=046d, idProduct=0b04
[ 1.900092] usb 2-2: New USB device strings: Mfr=1, Product=2,
SerialNumber=0
[ 1.900095] usb 2-2: Product: Logitech BT Mini-Receiver
[ 1.900098] usb 2-2: Manufacturer: Logitech
[ 1.903118] hub 2-2:1.0: USB hub found
[ 1.905092] hub 2-2:1.0: 3 ports detected
[ 1.924098] dvb-ttpci: info @ card 1: firm f0240009, rtsl b0250018,
vid 71010068, app 80f12623
[ 1.924102] dvb-ttpci: firmware @ card 1 supports CI link layer
interface
[ 1.998276] dvb_ttpci: DVB-C analog module @ card 1 detected,
initializing MSP3415
[ 2.101563] dvb_ttpci: saa7113 not accessible
[ 2.116015] usb 3-1: new full-speed USB device number 2 using uhci_hcd
[ 2.131523] saa7146_vv: saa7146 (0): registered device video0 [v4l2]
[ 2.131535] saa7146_vv: saa7146 (0): registered device vbi0 [v4l2]
[ 2.133473] DVB: registering adapter 1 frontend 0 (ST STV0297 DVB-C)...
[ 2.136094] input: DVB on-card IR receiver as
/devices/pci0000:00/0000:00:1e.0/0000:04:00.0/input/input1
[ 2.136119] dvb-ttpci: found av7110-0.
[ 2.136157] saa7146: found saa7146 @ mem fa0b0000 (revision 1, irq
19) (0x13c2,0x000a)
[ 2.137704] DVB: registering new adapter (Technotrend/Hauppauge WinTV
Nexus-CA rev1.X)
[ 2.155901] adapter has MAC addr = 00:d0:5c:24:47:2a
[ 2.283286] usb 3-1: New USB device found, idVendor=08e6, idProduct=3437
[ 2.283290] usb 3-1: New USB device strings: Mfr=1, Product=2,
SerialNumber=0
[ 2.283293] usb 3-1: Product: USB SmartCard Reader
[ 2.283296] usb 3-1: Manufacturer: Gemplus
[ 2.485099] dvb-ttpci: info @ card 2: firm f0240009, rtsl b0250018,
vid 71010068, app 80f12623
[ 2.485102] dvb-ttpci: firmware @ card 2 supports CI link layer
interface
[ 2.492128] usb 5-2: new full-speed USB device number 2 using uhci_hcd
[ 2.562280] dvb_ttpci: DVB-C analog module @ card 2 detected,
initializing MSP3415
[ 2.650542] usb 5-2: New USB device found, idVendor=0471, idProduct=0815
[ 2.650545] usb 5-2: New USB device strings: Mfr=1, Product=2,
SerialNumber=3
[ 2.650548] usb 5-2: Product: eHome Infrared Transceiver
[ 2.650551] usb 5-2: Manufacturer: Philips
[ 2.650553] usb 5-2: SerialNumber: PH00GEFN
[ 2.665560] dvb_ttpci: saa7113 not accessible
[ 2.695510] saa7146_vv: saa7146 (1): registered device video1 [v4l2]
[ 2.695522] saa7146_vv: saa7146 (1): registered device vbi1 [v4l2]
[ 2.695832] DVB: registering adapter 2 frontend 0 (ST STV0297 DVB-C)...
[ 2.695906] input: DVB on-card IR receiver as
/devices/pci0000:00/0000:00:1e.0/0000:04:01.0/input/input2
[ 2.695923] dvb-ttpci: found av7110-1.
Br Fredrik
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
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More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: stv0297 signal issues on QAM256
2012-06-13 8:46 ` SV: " Fontana
@ 2013-06-10 10:15 ` Daniel Glöckner
0 siblings, 0 replies; 5+ messages in thread
From: Daniel Glöckner @ 2013-06-10 10:15 UTC (permalink / raw)
To: Fontana; +Cc: linux-media
Hi,
sorry for resurrecting this thread after a year and for my lengthy mail.
On Sun, Jun 10, 2012 at 02:25:09PM +0200, Fredrik wrote:
> Unfortunatly my cable provider "Comhem" moved almost all channels to
> QAM256.
> The results are terrible on my two cards. Blocky picture and skipping
> audio.
On Wed, Jun 13, 2012 at 10:46:00AM +0200, Fontana wrote:
> After some further digging i found a post with attached patch.
>
> http://www.linuxtv.org/pipermail/linux-dvb/attachments/20080731/de8768ed/att
> achment.diff
>
> Dunno why there were no followup on this one?
>
> http://linuxtv.org/pipermail/linux-dvb/2008-July/027517.html
>
> Applied cleanly to kernel 3.4.0 with the following change.
>
> - (p->u.qam.modulation == QAM_256) ? 6718 : 7250);
> + (p->modulation == QAM_256) ? 6718 : 7250);
As I recently bought a TT premium C2300 suffering from the same
problem, I spent Saturday night analyzing in detail what causes
it.
To make sure there are no offsets introduces by my cable provider,
I mapped the complete spectrum with cxadc (and XC3028 switched to
DVB-T). Both QAM64 and QAM256 channels are centered exactly at the
frequencies mentioned in the NIT.
I then tried to measure the output of the tuner with my cheap
oscilloscope but failed, probably due to the low signal level.
I did succeed however at the output of the TDA9819 (pin 18).
There I could see that the center frequency is about 6.6MHz,
in contrast to the 7.25MHz configured in the STV0297. From
both adjacent channels there are remnants visible, attenuated
to about the same level, so the 36.15MHz IF is correct.
But why is it not centered around 7.25MHz? That second IF is
generated by a VCO that is controlled by pin 16 of the TDA9819.
If you look closely, you can see that pin 16 is directly connected
to pin 15, which controlls the DVB AGC. This only makes sense if
these pins are tied to a fixed voltage. My multimeter says 2.47V,
which is close to the typical input voltage mentioned in the
data sheet for pin 15. The diagram for the VCO frequency tells
us this should make the VCO run at about 86.3MHz, which is
halved before it is multiplied with the signal from the tuner.
If we lived in a perfect world, we would get a 2nd IF of
86.3/2-36.15=7MHz. If the VCO is off by 1%, we arrive at 6.6MHz.
What counts is that there is no calibrated quartz controlling
the frequency of the 2nd IF, so it may vary with each device
(and probably temperature, supply voltage, etc.).
But why does QAM64 work? The STV0297 contains two stages
that can compensate for IF offsets. The first one is controlled
by stv0297_set_initialdemodfreq the second one by
stv0297_set_carrieroffset. Both stages can automatically try
different frequencies during locking, but we only allow this
for the second stage. The first one we fix at 7.25MHz
or rather 7.266MHz due to rounding while calculating the
register value. On a tuned QAM64 channel stv0297_get_carrieroffset
reports an offset of about 680kHz.
By why does QAM256 not work? I also get a lock on QAM256 channels
and there stv0297_get_carrieroffset also reports the same offset
give or take 5 kHz. The STV0297 data sheet says:
"It is possible to optimize chip performance by
optimizing the respective uses of CRL and initial
derotator (for example if the CRL locks for a given
offset value, it is possible to transfer this offset
cancellation from CRL to initial derotator before
Nyquist filtering, the latter being then better
matched to the signal actually received)."
So while at QAM64 we get away with doing the correction in the CRL
(second stage), QAM256 requires this to be done in the first stage.
We once had code in the driver trying to move the offset from the
second stage to the first stage, but it didn't work correctly and
was removed in 2005 without trying to fix it:
http://linuxtv.org/mailinglists/linux-dvb/2005/01-2005/msg00165.html
I found an error in stv0297_get_carrieroffset for negative offsets.
Maybe that was the cause back then. Maybe we should not reuse
the offset for different channels. A module parameter for the IF
probably does not work for people wanting to use more than one card.
I am not sure what is the best way to solve the problem but I do
know that the 7.25MHz don't work for everyone and it does not
depend on the modulation as suggested by the patch above.
Daniel
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2013-06-10 10:22 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-06-10 12:25 stv0298 signal issues on QAM256 Fredrik
2012-06-11 8:13 ` stv0297 " Fontana
2012-06-13 8:46 ` SV: " Fontana
2013-06-10 10:15 ` Daniel Glöckner
-- strict thread matches above, loose matches on Subject: below --
2012-06-10 12:20 stv0298 " Fredrik
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