Can I prevent transcoding of audio stream?

[GhostRider 49]

Hi

"I've read the Wiki on transcoding and understand that the 'auto' setting should determine if video and audio transcoding are necessary based on the client’s capabilities. However, I want to bypass this behaviour because I use passthrough audio on my smart TV, which sends the signal to my Yamaha receiver. My receiver can decode nearly any audio format, but I’ve noticed that the app on my smart TV is resulting in transcoding audio down to AC3, likely because the TV itself cannot decode the original audio stream.

As a result, I’m losing some audio quality, even though my receiver could handle the native audio stream. I’ve tried adjusting the transcoding settings, including setting it to the highest value, but the audio continues to be transcoded.

Is there a way to disable audio transcoding and send the native audio directly to my receiver for playback?"

[GrimReaper 4739]

2 minutes ago, GhostRider said:

Is there a way to disable audio transcoding and send the native audio directly to my receiver for playback?"

You can disable Audio transcoding in User settings (Settings>Users tab in the sibebar>edit desired user) - though if your TV doesn't "understand" the format you're trying to play, don't think it'd passthrough it either. Doesn't mean you can't check it, though. 

[GhostRider 49]

Many thanks I managed to find the disable Audio transcoding for my user account (only the one account at the moment, maybe I will need two one with and one without transcoding enabled). When I disable audio transcoding no sound is played at all. I checked the TV settings and it confirms that when in passthrough that Dolby TrueHD is passed over the eARC HDMI port. But I have no audio at all now. I double checked the HDMI cable to the receiver was plugged into the correct eARC enabled port on the TV.  So I am a bit puzzled is it possible to get the actual audio stream as the TV does suggest it passes Dolby TrueHD over the eARC HDMI port?

Edited September 24, 2024 by GhostRider
Update to Dolby TrueHD

[GrimReaper 4739]

4 minutes ago, GhostRider said:

Dolby HD is passed over the eARC HDMI port

Are you referring to Dolby TrueHD? 

5 minutes ago, GhostRider said:

I checked the TV settings

Which brand, which client app? As this topic belongs in client-specific section. 

[GhostRider 49]

Yes, apologies I am referring to Dolby TrueHD. For my sanity I double checked my Yamaha Receiver specifications and it does support playback of Dolby TrueHD. With audio transcoding disabled I can play back  DTS-HD MA so that must be being sent from the TV ok. So could this issue be specific to Dolby TrueHD? TV is an LG OLED and client is LG app latest version. 

[GrimReaper 4739]

Don't think any TV will passthrough Dolby TrueHD from native OS - only from external sources. But personally not using LG, maybe some fellow LG user might chime-in. 

[GhostRider 49]

Thanks for the advice GrimReaper. I am not an expert hence asking for help on this forum, but the TV help does say Dolby TrueHD is supported in passthrough mode. My HTPC plays Dolby TrueHD without issue, but that is direct connected to the Yamaha receiver. This thread is different to my earlier post where the LG app freezes with a TrueHD codec Intro, in that scenario audio transcoding is turned on. I was hoping to find a way to stop audio transcoding but with audio transcoding disabled I get no sound via the LG app. 

[Luke 42077]

Quote

but the TV help does say Dolby TrueHD is supported in passthrough mode.

Yes but we've seen evidence that they are not making this available to all third party apps.

Try temporarily using user permissions to restrict all access to transcoding. This will force the Emby app to try and direct play it. I think you'll end up with no audio being heard when the truehd track is selected.

[GrimReaper 4739]

3 minutes ago, Luke said:

Try temporarily using user permissions to restrict all access to transcoding.

 

2 hours ago, GrimReaper said:

You can disable Audio transcoding in User settings (Settings>Users tab in the sibebar>edit desired user)

 

2 hours ago, GhostRider said:

Many thanks I managed to find the disable Audio transcoding for my user account

 

5 minutes ago, Luke said:

I think you'll end up with no audio being heard when the truehd track is selected.

 

2 hours ago, GhostRider said:

When I disable audio transcoding no sound is played at all. I checked the TV settings and it confirms that when in passthrough that Dolby TrueHD is passed over the eARC HDMI port. But I have no audio at all now.

 

[GhostRider 49]

Thanks for replies. Sorry, I not sure I understand the conclusion. Summary of my results:

DTS-HD MA audio is played direct without transcoding even when audio transcoding is enabled, this shows Emby LG app and TV passthorough to receiver is working with DTS-HD MA audio.

Dolby TrueHD with audio transcoding enabled hangs the LG app if a TureHD audio Intro is selected, something goes wrong with the transcoding. Logs submitted in a separate thread, is this a bug in the app that can be resolved?

Dolby TrueHD with audio transcoding disabled gives no sound, @Lukedoes your post mean that LG are specifically prohibiting the Emby LG App from using the Dolby TrueHD audio stream?

 

Edited September 24, 2024 by GhostRider

[Luke 42077]

6 hours ago, GhostRider said:

 

Dolby TrueHD with audio transcoding disabled gives no sound, @Lukedoes your post mean that LG are specifically prohibiting the Emby LG App from using the Dolby TrueHD audio stream?

 

Well we don't know but that's what it looks like to us. If the TV supports it but the app can't utilize it, maybe they've only enabled it for their partners. Who knows, maybe if effects the cost of the license they have to pay for it.

[GhostRider 49]

Hi @Luke, I am using passthrough so the TV is not playing any sound just passing it to the eARC port and the TV help does state Dolby TrueHD is supported in passthrough. Direct play works fine with DTS-HD MA, but not Dolby TrueHD. I was hoping to dispose of my HTPC, but the LG App is not a suitable replacement if it cannot use passthrough for Dolby TrueHD so sadly it look like I will have to stop using the LG App and go back to my HTPC. 

[Luke 42077]

I understand the TV says it is supported. What I am telling you is that it appears lg is only activating it for their strategic partners.

[keemy 25]

Passthrough for Dolby truehd only works over HDMI to an external device like an Nvidia shield for example if plugged directly into 1 of the HDMI ports. I've tested this on my own LG TVs.

[GhostRider 49]

12 hours ago, Luke said:

I understand the TV says it is supported. What I am telling you is that it appears lg is only activating it for their strategic partners.

Ok, looks like selective marketing from LG. I will have to decide which to use: LG app or my HPTC, LG App would be fine for TV series. However, the Codec Intro issue in my other thread is important to get working for mvies, do you have an understadning what is causing the issue? Further testing today shows any of my Codec Intros that need trascoding freeze after 10 seconds, added a third example to the thread.