No channels with VideoMate DVB-T300

[nickhoare]

I have scanned and updated with all sorts of settings but I get no channels and no EPG. Scanning my local region or All Regions (57) finds no channels. The SIGNAL/QUALITY sometimes show a value in QUALITY but always shows 0 in SIGNAL.

I notice that the GBPVRRecordingService does not seem to use any CPU, other than that on starting. Doesn't this do the comms with the TV card? Its logs show no errors though.

The ComproDTV 4.2 software has no trouble and I can receive all channels.

The attached log files are a sample set I created and do not represent all the things I have tried.

(ERROR [5] was clearly a red herring - not getting it now)

[sub]

2010-01-21 18:40:11.406 VERBOSE FindFilterByName failed to locate filter: GB-PVR PSI Parser

Try running ReRegisterFilters.bat

[nickhoare]

Tried running Re-registerfilters, restarting all a couple of times but I still see plenty of FindFilterByName in the log file. And I don't get any channels.

All the DLLs re-registered OK.

I am IT professional so I am not afraid of the registry. I have Visual Studio 2008 and .NET 3.5 on my machine (and I use it). Willing to investigate deeper if you think it worthwhile.

[sub]

From GB-PVR's perspect it all looks fine now. It manage to hookup the device, and start it, and it looks like it locked onto the signals, but unfortunately didnt deliver any data to GB-PVR. I'm not sure why though. I dont really know anything about VideoMate devices.

[clayt_d]

I am almost certain it is a driver issue with the compro T300 - it has a non-standard way of communicating signal lock, strength and quality.
It works fine with the bundled Compro software (but then again - it would).

The card's driver seems to invert the standard BDA signal indicator logic - ie telling GBPVR that it has a signal lock on an empty channel, and no signal on MUXes I know are there. It prevents the card from autotuning.

One of the other members (Whurlston I think) suggested that the issue only appeared after version 1.3ish of Compro's T300 driver, but downgrading to an earlier driver didn't work for me.

I've spent over 3 years struggling with this card in GBPVR, even after sub introduced GBPVR support for the T300. It works fine for viewing and recording - but refuses to tune in (it does sometimes - but not reliably).

I was thinking of asking Sub for a tweak for this Compro issue a long time back - but I think it is restricted to a handful of older Compro cards, so is probably not worth the trouble involved.

My fix for this is to use another card for tuning the T300.

The tuning and channel information is written to a plain text scan.cache file in GBPVR's BDA directory, which makes it reasonably straightforward (although time consuming) to "tune" a card in by hand.

It is also possible to alter the channel names to suit: ie changing the shopping channels to "The Pants Channel" etc although pointless because it breaks the EPG listings for that channel.

As a last resort, TSReaderLite can be used to copy the channel information into the cache file by hand - but expect to spend your entire weekend doing this.

If you have no spare tuner card, ask in the forums for a scan.cache file from a GBPVR user on the same transmitter and use that. The forum members are very helpful in this respect.

My workaround (it does not fix the tuning issue but allows the card to be used):
>Delete all of the scan.cache files in the BDA folder. This prevents old channel information appearing (important for UK users to do this because of the Freeview retune).
>If you have a spare card, do an autotune and copy this scan.cache file to somewhere safe.
>Delete all of your channels in the config.
>Close the config app.
>Copy your new scan.cache file in. You may need to rename this file to whatever the T300 was using last time you attempted to tune it in. If you don't know, try tuning the T300 and start again using the filename it produced.
>Launch the config app and map the new channels for the T300 to suit. Do Not retune at this point - it will only confuse matters and may overwrite your cache file (or start using a different filename for tuning).
>Save your changes and enjoy.

Hope this helps.

[clayt_d]

Sub,

To make life with these badly behaved DVB-T cards a little easier..

I've often wondered how to get this card to tune successfully in GBPVR without breaking it for the majority of tuners..

Is there any way of forcing GBPVR to ignore the signal strength indicator when scanning channels selected from the DVB-T .ini files? Or of tricking GBPVR into thinking it has 100% signal strength when scanning channels?

For example, TSReader for example will attempt to read the channel information on the any DVB-T card when scanning a selected frequency - regardless of signal strength. When TSReader is used with the Videomate T300 the signal and quality indicators show 100% on empty channels, and 0% when tuned in and receiving TV programmes.
Exactly the opposite of what it should be.

My reasoning is that the DVB channel frequencies are pre-defined in the DVB-T\xxxx.ini files, so signal strength should be mostly superfluous when the correct transmitter is selected (in my part of the UK at least) and needn't prevent GBPVR from reading the channel information when tuning these DVB-T cards with dodgy drivers - except of course when scanning for new broadcast frequencies.

Is there any way of achieving this?

Thanks for all of your hard work by the way.

[sub]

Is there any way of forcing GBPVR to ignore the signal strength indicator when scanning channels selected from the DVB-T .ini files? Or of tricking GBPVR into thinking it has 100% signal strength when scanning channels?

It already does precisely that. It pays no attention to the signal strength or lock status, it simply logs it for information's sake. Instead it relies on the data being delivered from the device.

Unfortunately, I'm not sure what would different about this card vs every other DVB-T card, so its hard to suggest changes that might help with this.

That said, there has been some significant changes to the way tuning happens in the next release, so fingers crossed this card likes the next release more.

[clayt_d]

Thanks for your scarily fast reply sub!

I didn't realise that was how GBPVR tunes, that's blown my theory out of the water!

There is something definitely screwy about the way the Compro T300 talks to GBPVR (and everything else).

Having learned my lesson with the T300 I bought another Compro which does tune in.

I'll test them both and see if I can find any differences to account for the behaviour.

Looking forward to the next version with the tuning changes - I hope that sorts the T300 issue.

Many thanks