DVB-T Autotune sometimes selects an incorrect frequency (1 Viewer)

Taipan

Retired Team Member
  • Premium Supporter
  • February 23, 2005
    2,075
    44
    Melbourne
    Home Country
    Australia Australia
    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

    Retired Team Member
  • Premium Supporter
  • February 23, 2005
    2,075
    44
    Melbourne
    Home Country
    Australia Australia
    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.....:D

    EDIT:

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

    samuel337

    Portal Pro
    August 25, 2004
    772
    0
    Melbourne, Australia
    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

    Retired Team Member
  • Premium Supporter
  • February 23, 2005
    2,075
    44
    Melbourne
    Home Country
    Australia Australia
    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.....
     

    Users who are viewing this thread

    Top Bottom