2.5.5 Black screen during Live TV (Analog)

[whyukon]

Since upgrading to 2.5.5, when I start Live TV, I see the video and hear the audio for about 1/2 second (this varies, but rarely longer then 1/2 second), then the screen goes black (but with progress bar), and the audio continues. If instead I choose to record the program using the TV guide, then immediately start playing it back (while still recording), then it works as normal, both video and audio.
I have two different TV tuners to choose from, a Dell Angel with built-in MPEG, and a Hauppauge 950Q with no built-in MPEG encoder. Regardless of which I choose to watch Live TV, I have the same problem... video but no audio.
I have gone to my settings and tried each one of my MPEG2 video decoders (ffdshow, Cyberllink, Microsoft MPEG2, Sonic Cinemaster, MPC, Intervideo, and CBVA DMO wrapper filter) and they all work, or rather don't work, the same way.
I tried installing the latest patch, but the problem remains the same.
I have checked the forum for a similar issue in the past, and I haven't found anything that helps me out.
I have attached a zip containing my NRecord.log and NPVR.log.
Thanks for helping me with this.
Glen

[sub]

2012-08-05 19:43:56.004 [DEBUG][1] adding audio renderer: DirectSound: Speakers / Headphones (IDT High Definition Audio CODEC)

Have you tried setting your audio renderer back to 'default'? Sometimes video can behave badly with other audio renderers.

[whyukon]

Thanks for the suggestion, sub, but changing the audio to default does not help.

[sub]

Nothing else stands out in your logs.

Does the live tv buffer file continue to grow? If you copy that file and play it in another player, like vlc, does it show video?

[whyukon]

yes, it grows, and yes, a copy of the buffer file does play properly (show video) with VLC.

I have a correction to make, though on my original problem report. The progress bar does NOT show on the screen. For a fraction of a second, I get video with progress bar, then both the video and progress bar disappear. However, the program information (channel number and program details) remain displayed on the screen.

[sub]

Based on that, it does sound like it's something to do with the decoders and/or renderers you're using.

[whyukon]

I've done a bit more experimentation. Sorry, I should have tried this before. If I run NPVR in a window, instead of full screen, I get the same problem. However, if I resize the window, the video appears, but then sometimes I lose text or menus from the screen. If I click to a different window, then back to NPVR, the video disappears again. I have a two-monitor setup, with NPVR on the second monitor, although I run into the same disappearing video issue regardless of which monitor NPVR is displayed on. Does this sound like a video (graphics card hardware) driver issue?

[Reddwarf]

I've done a bit more experimentation. Sorry, I should have tried this before. If I run NPVR in a window, instead of full screen, I get the same problem. However, if I resize the window, the video appears, but then sometimes I lose text or menus from the screen. If I click to a different window, then back to NPVR, the video disappears again. I have a two-monitor setup, with NPVR on the second monitor, although I run into the same disappearing video issue regardless of which monitor NPVR is displayed on. Does this sound like a video (graphics card hardware) driver issue?

Just tested analog here and I'm seeing the exact same behaviour. If I start a recording from the analog device and then play it while recording video is fine, else it shows video for about half a second and the black screen.

[whyukon]

I've done a bit more experimentation. Sorry, I should have tried this before. If I run NPVR in a window, instead of full screen, I get the same problem. However, if I resize the window, the video appears, but then sometimes I lose text or menus from the screen. If I click to a different window, then back to NPVR, the video disappears again. I have a two-monitor setup, with NPVR on the second monitor, although I run into the same disappearing video issue regardless of which monitor NPVR is displayed on. Does this sound like a video driver issue?

[whyukon]

Just tested analog here and I'm seeing the exact same behaviour. If I start a recording from the analog device and then play it while recording video is fine, else it shows video for about half a second and the black screen.

Thanks, Reddwarf. I was thinking it might just be something wonky with my own NPVR installation, or some problem specific to my machine. It's a relief to me (but maybe not sub) to hear that someone else can replicate the problem.