Trouble mapping digital channels

[tjc]

I have been struggling with the digital side of my dual tv tuner. ATI TV Wonder HD 650. The analog side with my cable input works good, but I really want to get the HD over the air channels. During channel scan, 29 available channels are found, but only a few, when selected, appear in the preview box. None of the main network channels, 4.1, 6.1, 8.1, 13.1 appear although the audio is present. Sometimes selecting one of the channels crashes GB-PVR, "GB-PVR Configuration encountered a problem and needs to close" error message appears. Start GB-PVR and the channels that I did get mapped work ok. Suggested on one of the wiki was to ReRegisterFilters, which I did but did not seem to help. The Catalyst Media Center software that came with the tuner card scans and finds 23 HD channels, including all four of the network channels and displays them all, which I take to mean I just have to get GB-PVR configured correctly. GB-PVR has a much better GUI then the Catalyst software, and the Catalyst software has no EPG.
GB-PVR v1.3.11, VisionTek ATI Wonder HD 650 tuner, Winxp sp2, 4gig memory
I have attached the log files and one screenshot during mapping.
Thanks in advance

[johnsonx42]

My first guess is a decoder problem. What mpeg playback decoder do you have selected?

[tjc]

I have the ATI Mpeg Video Decoder selected. I think that was installed with the Catalyst software. Originally selected was "system default". Tried mapping with either decoder, no good.

[johnsonx42]

just for sanity's sake, try the mpv decoder from free-codecs.com. It's not the greatest decoder on the planet, but it does work. also, when you change decoders, make sure you exit the config utility, then go back in to the channel mapping util.

oh, sub, does the channel mapping util use the decoder selected in the playback tab, or does it just use system default? I suddenly realized I have no idea whether changing the selected decoder in config has any effect in channel mapping, so I don't know if I'm telling tjc the right thing...

[tjc]

Registered and selected the MVP encoder, that did the trick for mapping all the available channels. The channels can now be selected and tuned from the EPG. Thanks a million. Just one thing though, "not the greatest decoder on the planet", does that mean less video quality?

[johnsonx42]

It doesn't seem to do hardware acceleration at all, and sometimes doesn't de-interlace very well either. At least that's been my experience, it may work better for some than others. Sub often recommends trying it, because it always seems to work.

I've had the most success with the Cyberlink PowerDVD decoder; you can get that from any Cyberlink CD that comes with a DVD drive, or from the klite codec pack. You'll need a CSS capable DVD decoder if you want to play DVD's anyway...

You may also find that you can now select the ATI decoder and use that in the program; as I was asking sub, I'm not sure whether the decoder you have selected affects the tuning utility at all, it may just use the default decoder which may not have been the ATI decoder... installing MPV made it the default, so that may be why it worked.

[tjc]

Just made a test HD recording, video quality seems fine, but no audio. I can play the file with VLC and audio is there. I tried the other audio codecs from the setting menu but none work. Past recordings in mpg have no problem with the audio, it is the .ts file format of the HD recording?

[tiger66]

You might want to try installing the AC3Filter audio decoder. That might help with playing the audio for HD recordings. (It did for me...)

[johnsonx42]

no, it's the audio format of the broadcast signal. Some US digital channels use mpeg-1 layer-2 audio, others use AC3 audio. If you hit ctrl-o during playback (or livetv) it will tell you what the audio format is. If it's the AC3 format you can't hear, then you'll need another decoder. I use AC3Filter, no probs at all since 1.3.11 (occaisional slow-mo audio with 1.2.13 and 1.3.7, but sub fixed it this time around).

[tjc]

the AC3Filter fixed the audio problem. You guys are the greatest! Thanks!