Loss of Sound on HDMI

Black Hole

Black Hole

May contain traces of nut
Here's a bugger, not the HDR-FOX's fault as such, just reporting in case it helps.

I wanted to watch the Paralympics curling, only available on the Channel 4 YouTube channel, so I disconnected my HDR-FOX and plugged the iPad in (DVI output via an adapter). Fine, no problems, until... I plugged the 'FOX in again.

No sound. Picture, but no sound. Rebooted the 'FOX, rebooted the TV (LG), no sound. Broken HDR-FOX? Can't be, the sound goes over the same wires as the picture. Plugged the iPad in again... sound. Hmm.

Swap TV HDMI inputs, restored. Somehow the iPad has confused the HDMI input settings so now it won't work with the HDR-FOX audio! There must be a per-input setting on the TV, but it's not my telly and I haven't gone looking.
 
I could never get my TV to give sound to my AV amp via HDMI so had change the Audio setting on my TV to optical and use an optical lead. I would not be at all surprised if there is a setting on the TV that needs to be set back to HDMI audio for that input.
 
Many LG TVs have a feature called Deep Colour. Depending on model and software version this is activated in different ways. In my LG G2 if the TV detects an input device capable of supporting Deep Colour it automatically switches it on. If a different device is then connected the setting remains on regardless of compatibility. The Fox T2 will not output sound when Deep Colour is on (don’t know why) but an iPad will do so. Worth checking in LG settings, General, hdmi. If Deep Colour is on switch it off.
 
The 'new' TV here has come on a couple of times with no sound from the HDR on HDMI. Found switching it to a broadcast channel then back to the HDR sorts it.

(TV is a Loewe 40" from a charity shop for £30 that someone would have paid £2k for ten years ago. Came with matching Blu-ray player and two remotes.)
 
catnap said:
In my LG G2 if the TV detects an input device capable of supporting Deep Colour it automatically switches it on.
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Yes that explains it, Ultra Deep Colour has been enabled for that particular HDMI input and not the others.

The only other relevant thing I can find in the TV settings is HDMI audio (per input), either "bitstream" or "PCM". I would have thought "PCM" was the most appropriate, but all three HDMIs are set to bitstream (including the working input for the HDR-FOX).
 
Black Hole said:
Yes, but the HDR-FOX is outputting PCM. I suppose the TV falls back to PCM.
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If you have multi channel audio enabled in the HDR Fox T2 it will output Dolby Digital bitstream audio for all HD channels. This will be DD 2.0 for stereo audio and DD 5.1 for those programmes with multi channel audio.
 
Black Hole said:
Yes, but the HDR-FOX is outputting PCM. I suppose the TV falls back to PCM.
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Yes TV will do that... but then PCM is still a digital bit stream one could argue :dunno:

My Foxsat-HDR and HDR-Fox-T2 are both set to PCM to allow the Humax volume control to work rather than switching the remote <mode> to use the TV volume.

We switch either box output to Dolby(=bitstream) to allow TV surround speakers and/or bitstream pass through to our AVR on the HD programmes with full surround, which is fairly rarely implemented.
 
Rodders53 said:
We switch either box output to Dolby(=bitstream) to allow TV surround speakers and/or bitstream pass through to our AVR on the HD programmes with full surround, which is fairly rarely implemented.
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Depends what you watch. Multi channel sound is almost universal for films on BBC HD channels and C4 HD and very common on imported shows, whether US, Scandinavian, French or whatever. It's just UK made content that rarely has 5.1 sound.
 
Owen Smith said:
It's just UK made content that rarely has 5.1 sound.
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I have no need for 5.1 sound. I usually use headphones and only have 2 ears. Quite often I have problems with the mixdown from a 5.1 source to bog-standard stereo. So much so that if I have a 5.1 source file I use ffmpeg to get a reasonable stereo because a Humax and/or TV mucks it up.
Has anyone else noticed that sound on C4SD doesn't appear to be correct? Sound expected to be in the centre has a large right bias. (Very similar to the 5.1 mixdown I just described). C4HD seems okay.
 
Owen Smith said:
Depends what you watch. Multi channel sound is almost universal for films on BBC HD channels and C4 HD and very common on imported shows, whether US, Scandinavian, French or whatever. It's just UK made content that rarely has 5.1 sound.
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But many of those the surround is poorly mixed... IMHO. Nothing to hear there thanks. Stereo is adequate. We'll watch the first ep and hear/see then revert to 'normal' unless it adds something to the immersivity.
The War Between the Land and the Sea was a disappointment in 5.1 -- a disappointment all round (only watched the first episode; probably should delete).
We watched the film Dead Calm via HiFi VHS in surround on an early analogue system we had many years ago... sound of water lapping all around one... so we know what we like.

Some of the films we'll have streamed in 4k rather than wait for the TV release anyway.

SWMBO often finds the sound in stereo through our TV clearer for speech etc.,. clearer than via the AVR and I can agree. (It is a Technics Atmos soundbar system inside the Panny OLED so does sound good most of the time).
 
EEPhil said:
I have no need for 5.1 sound. I usually use headphones and only have 2 ears. Quite often I have problems with the mixdown from a 5.1 source to bog-standard stereo. So much so that if I have a 5.1 source file I use ffmpeg to get a reasonable stereo because a Humax and/or TV mucks it up.
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The stereo mixdown is broadcast, it's not the Humax or any other Freeview device doing it. On Freeview HD (note Freesat is NOT the same) audio is sent as AAC. For 5.1 this sends a stereo signal and difference signals to remove from left and right stereo and to generate the rears, centre and LFE channel. If you select stereo the Humax just ignores all the 5.1 difference information and just plays the stereo AAC as broadcast. Then the Humax (using Dolby Pulse firmware) converts the AAC to Dolby Digital 2.0 or 5.1 at 640kbps (the absolute max bit rate for Dolby Digital).

So if you're doing your own stereo mixdown it's because you don't like how the broadcasters or maybe content creators do that job, not how your Humax does it.
 
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Owen Smith said:
So if you're doing your own stereo mixdown it's because you don't like how the broadcasters or maybe content creators do that job, not how
your Humax does it.
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Should have made it clearer. The 5.1 content has been created, usually by US media companies (CBS) and downloaded. If there has been 5.1 content on Freeview I haven't noticed a problem. To be fair, I rarely watch the HiDef channels.
 
To the above: do you really think I don't know that?!! :rolleyes: When I said the HDR-FOX is outputting PCM, that is exactly what I meant.
 
Black Hole said:
To the above: do you really think I don't know that?!! :rolleyes: When I said the HDR-FOX is outputting PCM, that is exactly what I meant.
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Surprisingly few people know that Freeview HD sound is sent as AAC, they assume it's sent as Dolby Digital like Freesat HD and also because DD that is what the box outputs. Even fewer know that the AAC is sent as stereo plus differences to make 5.1 since that is not how Dolby Digital works. I've seen a number of rants online about stereo fold down of 5.1 sound on Freeview HD boxes blaming the boxes for doing a poor job when it's actually what is broadcast.
 
...unless the HDR-FOX is set to Menu >> Settings >> Preferences >> Audio >> Digital Audio Output = Stereo, or it's not a HiDef service (both of which were the case here).

Are you by any chance including me in the "surprisingly few people"? Don't be so bloody stupid.
 
Black Hole said:
Are you by any chance including me in the "surprisingly few people"? Don't be so bloody stupid.
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You, no. I assume you know everything about everything :-).

But I was primarily talking to EEPhil on this subject and I have no idea of the depth of his knowledge on this.
 
Owen Smith said:
But I was primarily talking to EEPhil on this subject and I have no idea of the depth of his knowledge on this.
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Next to nothing. I don't think I've managed to save a HiDef file that contains a 5.1 audio stream. However, I'm certainly aware that the sound is AAC from the files I've managed to analyse.
 
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