DVB-T Autotune sometimes selects an incorrect frequency

Taipan · 2006-01-04, 23:44

Windows Version: XP Professional, SP2
CPU Type: AMD 2700+
Memory: 512 MB
Motherboard: Gigabyte 7VM400M-RZ
Motherboard Chipset: VIA KM400
Motherboard Bios: Award, F5
Video Card: ATI Radeon 9550
Video Card Driver: 5.9
Sound Card: VIA VT1617
Sound Card AC3: no AC3
Sound Card Driver: 6.14.1.4100
1. TV Card: Dvico Fusion HDTV DVB-T
1. TV Card Type: DVB-T
1. TV Card Driver: 3.11
2. TV Card: DNTVLive! LP
2. TV Card Type: DVB-T
2. TV Card Driver: 2.61.03
Video Render Type: VMR9
Video Codec: NVIDIA Pure video v1.02.150
Audio Codec: Dscaler
Satelite/CableTV Provider: n/a
HTPC Case: n/a, modified
Power Supply: n/a, 200W, modified
Remote: MCE 2005 (EU version)
TV: BENQ DLP Projector
TV - HTPC Connection: Sub-D

This is not a new bug - I first reported it in v0.1.3.0 - but I have verified that it still exists in CVS 12-30-2005--01-06 and it has not been added to Mantis.

I thought it should be reported again here, as it does potentially affect the overall stability of the final release version.

Details of the history of this bug are available here.

Briefly, it looks like DVB-T Autotune only records frequencies that look like xxx,625kHz.

For example, for me in Melbourne Australia:-

Channel 7 is actually on 177,500 - but MP Autotune sets it at 177,625

Channel 10 is actually on 219,500 - but MP Autotune sets it at 219,625

Channel 2 is actually on 226,500 - but MP Autotune sets it at 226,625

The other channels that are actually on a frequency of xxx,625 are all OK.

I believe that the effect of this "off-frequency" tuning is that channel changes are slower and jittery. Now that I have corrected the frequencies, channel changes are much quicker and smoother.

To workaround this issue, I have modified the dvbt.xml file to force Autotune to select the correct frequency:-

<country name="Australia - Melbourne" offset="0">
<carrier frequency="177500" bandwidth="7" />
<carrier frequency="191625" bandwidth="7" />
<carrier frequency="219500" bandwidth="7" />
<carrier frequency="226500" bandwidth="7" />
<carrier frequency="536625" bandwidth="7" />
</country>

Taipan · 2006-03-13, 04:48

I notice that this post has been marked "Bug confirmed", but I can't find it in Mantis anywhere?

As I consider this to be a critical bug to fix before the March 18 release of v0.2.0, could someone please add it to Mantis.....

EDIT:

Here is the link to ScanChannelsBDA and the sourcecode - maybe this could help to isolate the problem in MediaPortal Autotune?

samuel337 · 2006-03-15, 06:10

Windows Version: Windows XP SP2
CPU Type: AMD Athlon XP 2600+
Memory: 512MB
Motherboard: Gigabyte GA-N400L
Motherboard Chipset: Nvidia nForce2 Ultra
Motherboard Bios: F11
Video Card: Creative FX5200
Video Card Driver: Latest Forceware
Sound Card: on-board
Sound Card AC3: N/A
Sound Card Driver: nVidia nForce driver
1. TV Card: Dvico FusionHDTV DVBT Plus
1. TV Card Type: DVBT
1. TV Card Driver: 3.3
Video Codec: Mpeg2Dec Filter
Audio Codec: MPEG/AC3/DTS/LPCM Audio Decoder

Taipan...maybe its just me, but I can't confirm this bug report either...

I just did an autotune using CVS from 08032006 and it worked fine - it tuned in all the 500 frequencies, e.g. 177500.

Do I need to repeat it a few times?

Sam

Taipan · 2006-03-16, 01:30

Thanks for the confirmation Sam. In response to your findings, I ran Autotune with my other DVB-T card (a DNTVLive! LP) and I got the same as you - all the frequencies were spot on.....:confused:

Now I am really confused.

It now looks like the problem is in the BDA drivers for my particular Dvico FusionHDTV DVB-T card? Since you have the "Plus" version, it uses different BDA drivers. Strange thing is though, that when I use ScanChannelsBDA.exe against my Dvico card, it gets the correct frequencies.....

2006-01-04, 23:44	#1 (permalink)
Taipan Portal Tester Join Date: Feb 2005 Location: Melbourne Posts: 1,947 Thanks: 4 Thanked 15 Times in 15 Posts Country: My System	DVB-T Autotune sometimes selects an incorrect frequency Windows Version: XP Professional, SP2 CPU Type: AMD 2700+ Memory: 512 MB Motherboard: Gigabyte 7VM400M-RZ Motherboard Chipset: VIA KM400 Motherboard Bios: Award, F5 Video Card: ATI Radeon 9550 Video Card Driver: 5.9 Sound Card: VIA VT1617 Sound Card AC3: no AC3 Sound Card Driver: 6.14.1.4100 1. TV Card: Dvico Fusion HDTV DVB-T 1. TV Card Type: DVB-T 1. TV Card Driver: 3.11 2. TV Card: DNTVLive! LP 2. TV Card Type: DVB-T 2. TV Card Driver: 2.61.03 Video Render Type: VMR9 Video Codec: NVIDIA Pure video v1.02.150 Audio Codec: Dscaler Satelite/CableTV Provider: n/a HTPC Case: n/a, modified Power Supply: n/a, 200W, modified Remote: MCE 2005 (EU version) TV: BENQ DLP Projector TV - HTPC Connection: Sub-D This is not a new bug - I first reported it in v0.1.3.0 - but I have verified that it still exists in CVS 12-30-2005--01-06 and it has not been added to Mantis. I thought it should be reported again here, as it does potentially affect the overall stability of the final release version. Details of the history of this bug are available here. Briefly, it looks like DVB-T Autotune only records frequencies that look like xxx,625kHz. For example, for me in Melbourne Australia:- Channel 7 is actually on 177,500 - but MP Autotune sets it at 177,625 Channel 10 is actually on 219,500 - but MP Autotune sets it at 219,625 Channel 2 is actually on 226,500 - but MP Autotune sets it at 226,625 The other channels that are actually on a frequency of xxx,625 are all OK. I believe that the effect of this "off-frequency" tuning is that channel changes are slower and jittery. Now that I have corrected the frequencies, channel changes are much quicker and smoother. To workaround this issue, I have modified the dvbt.xml file to force Autotune to select the correct frequency:- <country name="Australia - Melbourne" offset="0"> <carrier frequency="177500" bandwidth="7" /> <carrier frequency="191625" bandwidth="7" /> <carrier frequency="219500" bandwidth="7" /> <carrier frequency="226500" bandwidth="7" /> <carrier frequency="536625" bandwidth="7" /> </country>

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2006-03-13, 04:48	#2 (permalink)
Taipan Portal Tester Join Date: Feb 2005 Location: Melbourne Posts: 1,947 Thanks: 4 Thanked 15 Times in 15 Posts Country: My System	I notice that this post has been marked "Bug confirmed", but I can't find it in Mantis anywhere? As I consider this to be a critical bug to fix before the March 18 release of v0.2.0, could someone please add it to Mantis..... EDIT: Here is the link to ScanChannelsBDA and the sourcecode - maybe this could help to isolate the problem in MediaPortal Autotune?

2006-03-15, 06:10	#3 (permalink)
samuel337 Portal Member Join Date: Aug 2004 Location: Melbourne, Australia Posts: 773 Thanks: 0 Thanked 0 Times in 0 Posts	Windows Version: Windows XP SP2 CPU Type: AMD Athlon XP 2600+ Memory: 512MB Motherboard: Gigabyte GA-N400L Motherboard Chipset: Nvidia nForce2 Ultra Motherboard Bios: F11 Video Card: Creative FX5200 Video Card Driver: Latest Forceware Sound Card: on-board Sound Card AC3: N/A Sound Card Driver: nVidia nForce driver 1. TV Card: Dvico FusionHDTV DVBT Plus 1. TV Card Type: DVBT 1. TV Card Driver: 3.3 Video Codec: Mpeg2Dec Filter Audio Codec: MPEG/AC3/DTS/LPCM Audio Decoder Taipan...maybe its just me, but I can't confirm this bug report either... I just did an autotune using CVS from 08032006 and it worked fine - it tuned in all the 500 frequencies, e.g. 177500. Do I need to repeat it a few times? Sam

2006-03-16, 01:30	#4 (permalink)
Taipan Portal Tester Join Date: Feb 2005 Location: Melbourne Posts: 1,947 Thanks: 4 Thanked 15 Times in 15 Posts Country: My System	Thanks for the confirmation Sam. In response to your findings, I ran Autotune with my other DVB-T card (a DNTVLive! LP) and I got the same as you - all the frequencies were spot on.....:confused: Now I am really confused. It now looks like the problem is in the BDA drivers for my particular Dvico FusionHDTV DVB-T card? Since you have the "Plus" version, it uses different BDA drivers. Strange thing is though, that when I use ScanChannelsBDA.exe against my Dvico card, it gets the correct frequencies.....