Weird Symptom ~ No Audio on BBC/1 HD if Switching from Another Channel

I use my PC as the basis of a Home Theatre with all my TV, DVD watching being projected via HDMI cable and audio via Sony amp. I'm running Windows 7 Home Premium 64 bit and have just upgraded my TV card to a TBS6280 DVB T/T2 Freeview HD Twin Tuner Card. Yesterday my TV region completed the Digital Swtichover and so I can now receive BBC HD, BBC1 HD, ITV1 HD and 4HD.

All has gone fine after a re-scan but I have one weird problem. If I open WMC and then select BBC HD from the channel guide it opens OK and with audio. If, on the other hand, I choose another channel first and then switch to BBC HD the volume (on BBC HD only) stops (but the muted volume icon does not appear).

I have searched around for solutions and have tried the following, all without success:-

1. deselecting "Exclusive Mode" on the Advanced tab of my "Speakers' Properties" from the Sound section of the Control Panel.
2. configuring the speakers back to Stero (currently, I run 7:1)
3. selecting "languages" when watching BBC HD on WMC and trying either of the "English" options (in fact this might be a clue and might help because, when the audio is OK (because I have selected this channel first) but then try to select an alternative "language", the volume/audio stops and won't return, even if I switch back to "language" that was selected originally.

I hope my explanation is clear enough for someone to be able to resolve this problem. My soundcard is Creative SoundBlaster X-Fi Xtreme Audio 7.1 Soundcard PCI-Express.

I wondered if it could be down to signal strength but that wouldn't account for it being OK if I go to BBC HD first. Incidentally the problem also occurs on BBC1 HD, although infrequently, and very rarely on ITV1 HD.

I am also getting slight flickering on all the HD channels as well. I've tried updating my nVidia driver (GeForce GTX 260) but that created stuttering!

Oh dear, this is not going as smoothly as I'd hoped.

Many thanks in advance.

Hiyya and welcome Snakes mate I don't pretend to be any sort of expert but one thing I could suggest is a signal amp perhaps. If that doesn't work then I'd be looking at drivers for the new gear.
You mentioned too that the service had only just begun and I am wondering if that may have something to do with it as I had problems when we went all digital out here with the vid and audio being non synchronised.

Failing that ? dud card mate - by the way does it update the software when on line as it were cos my Panny PVR odes all the time.

Thanks for your suggestions all the way from NSW!

A signal amp implies a poor signal and I do think that is the route to take and I'm going to replace the aerial as a first step but logic doesn't account for why the audio always plays OK if I opt for that channel first?

Incidentally, I was playing around with Windows Media Centre last night (did I mention in my first post that I have no reception/audio problems on the two conventional TVs in the house) and once I'd got to the state where I was watching BBC HD with no audio I then tried editing channel source whilst having channel preview "On". As I selected one more of the 12 available sources I'd get sound. But I'd lose it if I saved that choice and then went back to the guide and selected that channel. Sorry that probably doesn't make much sense!

I think there is something in letting things settle down because from switchover I couldn't get those channels on multiplex Com6/ArqB which carries channels like Film4, ITV4, Yesterday, etc. but these all came back last night!

Definitely not a dud card because I had another issue (Jeez! This was with getting the remote to work with WMC! Still not resolved) and as part of that process the retailer have sent me a replacement card to try so I know that is not the cause.

Not sure about the software updating but I may try updating the drivers today.

Thanks mate!

No probs my friend let us know how you go and if you track it down - always helpful for someone else if they get similar glitches LOL!

(Ex pat Sussex)

OK, this just got even more weird!

I recorded a programme on Channel 4HD (Series 2 of Homeland which is excellent!).

Started watching it and audio fine. It came to the advert break and still OK but then as soon as the ads ended the audio went off! The workaround was to stop the programme and then choose resume from the options and the audio would be OK again.

This happened at every advert break - programme fine, ad's fine, ad's end and programme restarts with audio missing!?

Can anyone use logic to suggest what could be doing this? Could it be the transmission is in 5:1 and the ads in stereo and that triggers something?

HELP!

Hi,
This sounds like (sorry no pun intended) an HDMI issue. You may need updated firmware in the TV, the reciever (seriously happens all the time) and the latest computer audio, TV tuner and video drivers. Check you have the latest updates and codecs. This is a very annoying issue as it can happen any time and on any channel recorded or live. Get the model number of your TV and Hi Fi receiver and look on the manufacturers websites for firmware updates. Spent half my life over the last five years updating TV's firmware as HDTV took off here in Indiana. Channel surfing clients got annoyed very quickly when the audio dropped out.

Thanks for the suggestion but you'll see that the HDMI cable is going to a Sony amp (to provide the audio) then from there to the projector (for the video) so doubt whether this is a firmware issue for the amp.

Do you agree given the setup?

Google HDMI audio drop out. Start with firmware for your Sony receiver. I suspect the receiver is decoding the audio not the sound card. Sony equipment generally have an enormous issues with HDMI. I would look on Sony's website for updates.Or you can ignore me and look at other options

This could also be caused by the video card driver as the HDMI audio is often processed on the video card.

Hello and welcome Indiana yep you're right I was thinking maybe renewing th cable and / or checking the sockets too. I have had a few probs with cables dropping (physically) out or having lousy contacts.

Personally with my computers I always go DVI and audio differently as at least the plugs are fixable (screwed in) the HDMI too prone to sloppy fit for me.

Hi,

I appreciate the proposals but this cannot be a hardware issue (and in that I include cabling). The symptoms indicate a processing issue as the audio drop out occurs when either changing channel or whilst viewing a recording and the audio dropping on return to the transmitted programme after the ads (all within the recorded file).

I have already tried updating the nVidia video card driver.

Bit stumped really.

It must be something triggering the drop out that is contained within the recording that can also occur with live TV when switching between channels. Something to do with the audio data.

As I was writing this I thought I'd try to update the Creative soundcard drivers but their website stated that there is no more support for this card (due to its age). So I went to the Device Manager and right-clicked on the card and selected update driver and opted for it to automatically find the new driver. It located and installed and I restarted the PC.

Bingo! The recorded programme now plays audio before and after ads on that recorded programme (which I retained as a test vehicle). This, on its own, is not conclusive enough to demonstrate that the problem is fixed but it's a positive start.

I'll let you know and thanks for your interest and suggestions all .

Well, I still have the problem but am getting closer to finding the cause!

I noticed after the new driver install that all my settings had reverted to the default ones. It is this that caused me to believe that the problem was resolved.

The setting that is causing the problem is the speaker configuration (and I thought I'd tried this - see first post!). On any other setting than 2/2.1 (i.e. stereo) the problem persists. My preferred setting is 7.1 because that is my speaker setup but it also "fails" on 5.1 etc.

So we know it's a sound issue re 2.1 vs 7.1 but that doesn't explain the whole problem. Let me describe the scenario when testing above...

Watching recorded programme, an episode of Homeland on 4HD, with the speaker config set to 7.1 (or 5.1) and audio OK. Ad break starts and audio OK. Ad break ends and programme starts - no audio. Click programme back to the ads (audio returns) and then stop programme. Change speaker config to 2.1. Click "Resume" on WMC and ads play with audio, ads end and programme restarts and we have audio.

So far, pretty clear but this next bit is the confusing part (as described in an earlier post). Repeat the above sequence to be sure and recreate the problem by having the speaker config as 7.1 and the programme restarts after the ads with no audio. Now stop the programme without clicking back to the ads and the choose to "Resume" the programme and the audio returns even though the setting is still in 7.1 mode.

So, the cause, whatever it is, occurs when passing from advertisement break to a transmitted programme on an HD channel when not in 2.1 speaker config mode. I'm sure it does this at other times as explained in the first post but at least this condition is repeatable because I have the recorded programme to test with.

Ideas?

Check for updates to your receiver firmware. We have had the same issues as you have here in the USA since HDMI equipment took off. We had cable boxes and sat boxes that would lose sound on channel change, commercial breaks and so on. I personally had a Samsung TV that lost HDMI audio every time the wife wanted to watch something on Window Media Centre. I updated the firmware. I have updated firmware for many different devices and I would start at your receiver. Look at it this way.Program audio 5:1 Dolby Digital..Ch4 goes to regional commercial break, Advert is in stereo, audio bit stream format changes and audio drops out due to HDMI miscommunication. I spent many years repairing home theatre stuff in the UK and the USA and have seen exactly what you are experiencing myself and it is cured by firmware and software updates.

Yep sometimes it takes more than one or two goes at updating - well, just what I have experienced anyway with the usual stuff but I have to admit I ma not that well up on this stuff in any case but glad something ishappening for you Snakes

I'll try this when I get back home next Monday as I'm away until then.

However, the only "receiver" I have is the TV card in the PC. This is a brand new card and I think I have already tried updating the driver.

The other piece in the chain is the standalone amp. If it is that, how the hell do I update the firmware?

You guys are leading him in the wrong direction here! The reason your audio sometimes works on adverts and sometimes on certain program's on hd isn't anything to do with hdmi leads,
It's codecs and drivers.

You need to have a suitable hd audio driver installed have you got this?

What codec is processing your sound? I had the same issue
And took me ages to find out but is simple! Play HDTV and find out what audio processor is running, look in settings and you will probably find your answer!

neil123456 said:

You guys are leading him in the wrong direction here! The reason your audio sometimes works on adverts and sometimes on certain program's on hd isn't anything to do with hdmi leads,
It's codecs and drivers.

You need to have a suitable hd audio driver installed have you got this?

What codec is processing your sound? I had the same issue
And took me ages to find out but is simple! Play HDTV and find out what audio processor is running, look in settings and you will probably find your answer!

Click to expand...

Hum I didn't think we mentioned leads Neil even I who is not that savvy would know that a lead isn't the problem mate - unless it is a dud of course.

I was under the impression that the problem lay in that secondary amp Snakes was using.

Myself I prefer DVI and a dedicated audio line to quite honest am not a fan of HDMI unless I run from the PVR to the TV.