Question Will all devices output surround-sound through HDMI? Will an audio extractor preserve all channels?

eddielinton

Standard Member
I want to connect a cheap notebook (Medion MD62300) to an old AV receiver (Sony STR-DA1200ES) for multi-channel audio, and a projector (Infocus SP8600) for video. This would all begin by using the notebook’s mini-HDMI out.

The root of the problem: if I plug HDMI from notebook to AV receiver, then another HDMI from AV receiver to projector, the AV receiver simply passes through BOTH audio and video to the projector, instead of playing the audio through my lovely surround speakers. With any HDMI input, the receiver requires a separate optical cable to supply audio to its own speakers (insane, I know, but it’s in the manual… pages 25-26).

I will be loading films on to the notebook in MKV, AVI or whatever container format works, with surround audio. The output from the notebook is mini-HDMI, so I will be using an adapter, then a normal HDMI cable. As I understand, this shouldn’t affect the signal, but I thought worth mentioning.

So, my main question is: can I be certain that the notebook will output all 5.1 audio channels from (let’s say) an MKV video with its audio track encoded as Dolby Digital surround? Since it’s HDMI-out, surely the notebook just outputs the digital signals, without having to process or “understand” them. I am also hoping that, along those same lines, it’s all nothing to do with the device’s soundcard (which I am sure is terrible) or other capabilities of the cheap notebook itself?

The second and final hurdle is to split the HDMI signal into its audio and video parts.

Using an HDMI audio extractor with SPDIF output (and an extra HDMI + optical cable), I should get the HDMI video signal going in to the AV receiver, then on to the projector, but crucially capture the audio and input it to the AV receiver from the extractor’s SPDIF OUT.

I know the simple answer is “get a more modern AV receiver that deals with HDMI properly” but I don’t have the budget.

If I’d known it would be this hard, I wouldn’t have bothered - I feel like a donkey reading quantum theory – but I’ve come this far, I want to do everything I can to get it working! I’m sure some of you will know how that feels… but also the triumph of getting it working after a steep learning curve!

As ever, thanks in advance for any help.
 

Joe Fernand

Distinguished Member
AVForums Sponsor
AVR - in the early days of HDMI the HDMI Input/Output on many AVR was simply an HDMI switch added for convenience with no processing of video or audio on the way through the AVR.

Source device - hard to say what it will be doing, its is going to 'see' a 2.0 capable Projector on its Output so may list you Ito playing back 2.0 content or down-mix everything which is 5.1 to 2.0 unless you can manually override it within the PC settings.

HDMI Audio Extractor - will retain the separate channels, if you have a device with EDID Management which you can set to 5.1 that ought to trick the Source into Outputting video + 5.1 via HDMI.

Joe
 

eddielinton

Standard Member
Thanks very much Joe! The HDMI is just pass-through... I'm sure I'm not the only one buying that AV receiver and being pretty disappointed finding that out half way through the manual!

Source/extractor - The audio extractor has a 5.1 switch, so I'm hoping that will maintain the channels, but I see what you mean... if Windows sees a 2CH device, it may only output 2CH before the signal even gets to the extractor.

Fiddling about with EDID sounds like another rabbit hole, but at least I now know that's what it is - thanks!

I think I'll buy the switcher and will report back how I get on! Maybe some other poor numpty finding an old "HDMI switch only" AV receiver in the attic will benefit from it one day!
 

eddielinton

Standard Member
EDIT: I have edited this entire post because I pressed on with learning a bit more, effectively solved the problem (I will try to answer my own original question below), and realised that much of what I said I had "learned" in the previous iteration of this post was just plain wrong!

Firstly: massive thanks again to Joe Fernand, whose reply above was bang on! I bought an audio extractor with EDID capabilities (Pass/2.0/5.1) but the source (laptop running Windows 10) still understood the projector (HDMI endpoint) to receive only two channels. I am now pinning all hope on an EDID override and have started a new thread asking about that specifically: "EDID override: send 6 audio channels to "stereo" device (Windows 10)"

EDIT: Still massive thanks to Joe, the consummate pro! I did need to download an EDID manager (EnTech Taiwan's "Monitor Asset Manager"), but unexpectedly it told me that, when connected to the projector (i.e. Windows 10 reading the EEPROM rather than registry ID), it actually was happy to be sent six audio channels. This initially surprised me, until I realised I was an idiot...

I hadn't set up my media player correctly (Media Player Classic - Home Cinema... VLC works well, too). In MPC-HC, all I needed to do all along was go to View/Options/Internal Filters/Audio Decoder, then enable the bitstreaming formats supported by the optical cable I was using (i.e. AC3 and DTS... optical will not support multi-channel PCM or any means of compression more advanced than AC3/DTS).

In the original version of this post, I then went on to tell anyone reading not to even bother trying using old AV receivers, because it's not worth the bother. I totally retract that statement. I got it all working in the end, and the only extra cost was the audio extractor. I spent far too much time on it, but if you're reading this, you hopefully won't have to.


Some general tips on the project:

You can check how many channels, and compression type (audio and video) a particular file has, with some free software I found handy, called Tencoder.

It's possible my fairly cheap audio extractor (which the source doesn't recognise as a device, even if there's no output connected) could be the problem. Maybe a better extractor would better trick the source into outputting 5.1. I don't intend to find out as I've spent all the money I'm going to spend on this.

I don't think the cheap audio extractor was ever the problem. It's now working like a charm. If you're buying one, though, do make sure it has an EDID switch (e.g. pass-through/2.0/5.1).

I originally tried with a cheaper laptop, which I had even more problems with (e.g. not recognising projector as audio device). If one source doesn't work for you, try another (if you have one). It could eliminate at least one problem.

Well, I think I was at least right about this. The original (absolute junk) laptop I was trying to use doesn't output multi-channel audio. This has nothing to do with the sound card, because if you output via HDMI to an external device, it's the audio driver associated with the source graphics device that is being used, not the audio device. If it doesn't do 5.1 surround, you'll need an external sound card (e.g. SoundBlaster).

If you have a reasonably modern/decent laptop, though, it may well be capable of putting out multi-channel audio over HDMI.

I literally jumped for joy when I played a film on my laptop and the blue light ("multi-channel decoding") lit up on my old AV receiver, while I heard the immersive surround-sound of the opening scenes of Baby Driver and watched it in full HD on the projector. Success at last!

I can't thank everyone enough, who helped me out on AVForums, which is why I'm trying to share everything I've learned on this project (out of guilt for getting expert help at no cost!).

So, in answer to my own questions:


Will all devices output surround-sound through HDMI?

A pretty vague question in retrospect, but by "device" I pretty much mean "laptop", "Xbox" or anything else that you might expect to be able to use as a media source via HDMI, which may not have been designed specifically for that purpose.

No! Nor will your device's "tech specs" or user manual necessarily tell you the answer. My device (Lenovo V330) didn't advertise surround capability anywhere in its documentation - it's a business laptop - but it outputs six channels no problem, with no additional setup required in terms of drivers. In the end, I just needed to set up the software media player properly.

That said, my cheapo tablet-style laptop did not work at all, even with the same Windows 10 OS. It was definitely a hardware limitation, so you cannot assume that your 5.1CH AVI/MKV/x265 movie will be output over HDMI with multi-channel audio by any device, even if the receiving audio device is fully compatible with the number of channels contained in the source file, and the format that the audio is being delivered in (e.g AC3/DTS).



Will an audio extractor preserve all channels?

Yes, in my case anyway. I got a pretty cheap one (about £20) and it works fine. Get one with an EDID switch that includes a "5.1" setting and you shouldn't have any problems if your setup is like the one I've described in this thread.
 
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