KD 55 AF9 - AC3 etc passthrough

[Murph7355]

Just bought a KD-55AF9 and mostly working fine...

The biggest annoyance is that audio passthrough isn't working properly with Kodi.

Setup:

AF9 connected to a Denon X2200 receiver via a fast HDMI cable between the ARC connections on both.  CEC also set up and working OK (TV remote controls the receiver volume, turns the receiver off etc etc).

I've had the "eARC mode" set to both "auto" and "off" on the TV (made no difference to the following results).

With "Digital Audio Out" set to "Auto 1" ("output compressed audio without change"):

- TV sound comes out via the surround set up as expected

- YouTube, Google Play etc will output full surround sound

- Kodi, however, does not passthrough the surround stream and only plays on the front stereo channel

With "Digital Audio Out" set to "Auto 2" ("output compressed audio for multi-channel content without change"):

- TV doesn't make a sound at all

- YouTube, Google Play etc won't play sound at all

- Kodi, however, does  passthrough the surround stream and  plays the surround sound beautifully, but only when the source is surround encoded (e.g. menus don't make a sound)

The second scenario is, to an extent, logical...it reads like it will only passthrough a genuine multichannel source.

The first, however, doesn't seem right.  I would have thought it would passthrough ALL sound regardless of whether multi-channel or not.

Kodi is set to passthrough all soundstream types (the receiver can handle them all).

Part of me thinks this may be a Kodi problem (as YouTube seems to work).  BUT why would Kodi work on "Auto 2" and not "Auto 1".  ie Kodi is capable of passing through multi-channel audio via the TV.

[Kuschelmonschter]

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@Murph7355  schrieb:
as YouTube seems to work

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I have never seen any multi-channel audio on YouTube. It only supports AAC, Vorbis and Opus as audio codecs. Can you point us to some videos?

Passthrough on BRAVIA has basically been broken forever. There is also a German thread about the issue, see here.

[Murph7355]

Thank you.

Your post made me think about what I'd heard   The YouTube content sounded very credible as surround sound, but it wasn't (I must try not to muck about with these things in the early hours :)).  Furthermore, Google Play Movies wasn't outputting surround either. As with Kodi, Google Play Movies did play surround sound if I switched to the "Auto 2" mode noted, but then the TV sound stopped (as not multichannel).

So I've tried an optical digital cable and have a set up that pretty much works now.  I've moved the TV<>Receiver HDMI port away from the ARC port (to HDMI2) as it seemed (early hours again!) the TV was still trying to send audio down the HDMI cable.

I'm now getting surround audio everywhere I should (not in YouTube :)).

I now have two "problems":

1) Each time I turn  the TV on, I get a grey box with "Audio system has been connected.  If there is no sound, connect to HDMI3 (ARC)" that pops up twice.

2) Whilst CEC/BraviaSync works (controls the power and volume on my receiver), I no longer get the on-screen volume indicator.

I think this is a better situation than I had yesterday, but it's still doing my OCD no good

[Andreas23152]

@Kuschelmonschter @Murph7355

hey guys,

i think that the passthrough is the same issue as shown in the atv2 bugtracker (https://github.com/CiNcH83/bravia_atv2/issues/57). Perhaps it will be fixed in the next version. What do you think?

[Murph7355]

I doubt this is at the root of my issue as mine is also doing it with straightforward AC3 surround streams (ie not DTS-HD).

I think the issues is with the way Sony's ARC implementation handles the surround stream. 

If I select "pass multi-channel audio only" ("Auto 2") it works.  BUT I then get no sound from broadcast TV or the menu sounds from the TV etc.  I think that is because they are all stereo and hence not multi-channel.

If I select "auto"/"pass everything" ("Auto 1"), it seems to pass everything as stereo only.

People using Sony equipment throughout may see different results (indicated by the poster above who uses a Sony headphone set up), but I have a Sony TV and Denon receiver.

Edited to add...just reading the descriptions, maybe "Auto 1" is intended to down-mix multi-channel to stereo.  Seems an odd thing to do (if you are using ARC, I would think it likely you have a surround set up, or a receiver that can do the down-mixing).  But may be what is mean to happen.

Doesn't really explain why "Auto 2" is incapable of passing both stereo and multi-channel streams though.

Would be nice to get an answer from Sony on this.  Do they monitor these forums?

[Murph7355]

Well, my predicament looks to be resolved.

Denon came back to me with various suggestions (their support is very good it seems) and the one that cured it was simply to press the "Pure" button on the Receiver's remote.  

This puts the receiver into "Auto", "Direct" or "Pure Direct" mode (you cycle through them) and ensures any stream is treated in the raw.  

All apps are now playing in surround sound when they should (Kodi, Netflix, Google Play etc).  I get no more spurious messages when switching the TV on ("TV now connected to the internet", "Audio system now connected") and the volume OSD works as expected in all apps.

Very pleased.

TV seems to be getting better with use.  I used picture settings from the 'net which work well.  SD broadcasts seem to be getting better somehow and 1080p and 4k movies look fantastic.

[Murph7355]

Situation has returned (though a little different).

I'm getting the sound cut outs every 3sec on 5.1 content again, but this time have a reliable "fix" - switch to "TV Speakers" and then back to "Audio System" and it all then works (until the content is changed).

Anyone else found the same?  Think it coincided with the update to the interface (and presumably the underlying system)...but not 100% sure...