HD-PVR drops recording on channel change, Hauppauge says too bad.

[sgilani]

seeing if any of you guys can think of a creative solution...
Is there a way to (maybe with a device) have something act as a pass-thru for optical audio? meaning it sits between a STB's optical output and the HD-PVR's optical input, and ensure that there's always some output being sent out? that would solve the bug:

A lot of Dish Network's HD stbs (like the 211k) momentarily cut the audio stream on optical output during a channel change when set to DD5.1 mode.

Even though video is still there, the <1 second missing audio stream causes the HD-PVR to stop recording, and as a result, it's basically useless for scheduled recordings and timeshifting since the channel change ends the recording.

If I switch to PCM output from the stb, then the HD-PVR won't stop recording. Hauppauge tech support confirmed to me that this is how the HD-PVR behaves (the difference in the DD5.1 and PCM inputs), and that it's a hardware issue that can not be changed by drivers or firmware.

Soo basically, I'm stuck with only stereo sound.


any thoughts guys?

[mvallevand]

Did you try with Preview Mode off? This works for me.

Martin

[sgilani]

I always use timeshift mode only.. so no preview mode.

your STB probably is different since you're in Canada..unless you're on Bell maybe? it seems to be an incompatibility with Dish Network and Bell boxes according to Hauppauge.. which is absurd considering the huge customer base.

Can't help but feel misled into thinking I could use the HD-PVR to record in 5.1 mode.. of course, they point out it works fine in TME since there's no channel changing.. but that's not the point of using it in a PVR setup.

[mvallevand]

Ok, it still drops the audio on the change, so I use GraphRecoder to delay the recording. However the big difference for me is configuring the box to always output 720p since the HDPVR cannot handle changes in resolution, which is I think the biggest problem with the box.

Martin

[carpeVideo]

Well the simplest solution would be to have a setting in GBPVR with exe or ir tunings to tune a few seconds before recording, then the audio would have already been switched.

I have long noticed that tuning occurs after the recording starts, (which may make sense with sources that tune themselves) often I see a few seconds of a previous channel on a recording and then a new channel. This causes issues with different sound, frame rates and output sizes. Wishlist anyone??

[sub]

I have long noticed that tuning occurs after the recording starts, (which may make sense with sources that tune themselves) often I see a few seconds of a previous channel on a recording and then a new channel.

This has changed in the next release.

[mvallevand]

The delay won't solve the HDPVR problem though, because the graph always starts with the previous resolution settings and then after a period of sync'ing it transfer to a new resolution.

Martin

[sgilani]

Resolution is no problem; my stb locks output to whatever you choose. I've tried both 720p and 1080i.

The real problem is that the audio output stops for about 500ms, and that makes the HD-PVR stop recording (but only if it's DD5.1, with PCM it works fine).

I'm using GraphRecorder as well, how long of a delay do you put in (and which setting?). Not really good to wait 3-4 seconds for channel changing to occur before starting the recording, but it's better than nothing.

Seriously though, it's not like we're playing with a cheap toy, it's a pricey capture box and we shouldn't have to jump through these hoops. And very unprofessional for Hauppauge to coldly say that nothing can be done and I should use PCM sound only! Teetering on false advertising.

[mvallevand]

I don't think it's wrong, I'd say it's a flaw with your STB, with HDMI it might cause several seconds of silence, but the delay should work for you.

Not trying to defend Hauppauge (they have at least one good developer) I can understand the challenge. Typically the best sync timecode is the PTS in the audio stream and cutting it is a bad thing to do. AC3 audio is all crc checked and it would be very hard to inject a blank signal of unknown duration through SPDIF. Using PCM it's just a mater of sending no audio with the proper timecode Mine was pretty cheap $160 CDN

Martin

[sgilani]

Not trying to defend Hauppauge (they have at least one good developer) I can understand the challenge. Typically the best sync timecode is the PTS in the audio stream and cutting it is a bad thing to do. AC3 audio is all crc checked and it would be very hard to inject a blank signal of unknown duration through SPDIF. Using PCM it's just a mater of sending no audio with the proper timecode

hmm I don't see how AC3 encoding is a problem here because I have the HD-PVR pumping out AC3 audio no matter what.

So:

PCM over SPDIF --> HD-PVR --> AC3 (no problems, recording is not dropped)
DD5.1 over SPDIF --> HD-PVR --> AC3 (problem here, recording is dropped)

Obviously the HD-PVR is able to do the AC3 encoding just fine with silence, as long as it's looking at PCM input. Something about processing DD5.1 messes it up, and Hauppauge as much as admits it and tells me to just use stereo.. but that's not what they advertise.