Android Smart TV - AC3 - Passthrough - Noise

[thelonew0lf]

Hi,

I have an android smart tv and I have connected to receiver via S/PDIF Coaxial cable. Whenever I play any ac3 files, if passthrough enabled, I am getting noise in my receiver. If passthrough disabled, I get the sound but it's in stereo.

I have set the TV audio settings to RAW for coaxial output. Even tried with PCM output. Nothing is working. Only noise if passthrough enabled. Am I missing something?

[heymoe]

Did you try using IEC instead of RAW for your passthrough output device?

[thelonew0lf]

My TV audio settings has PCM and RAW. in SPMC, I had even tried with IEC Passthrough but without any luck. Same issue.

[heymoe]

Hmmm.. I'm assuming the noise you are getting when set to pass-through sounds like static / white noise?

If so, then this likely a similar issue I was having with my previous receiver where it would not auto-detect the AC3 bit-stream correctly and tried to decode it as PCM thus static / white noise.

The work around I used was to force my receiver into assuming everything coming into its input was AC3 instead of setting the input to auto-detect.

Here is a link to the bug report that addressed this issue:

https://github.com/koying/SPMC/issues/114

It has been closed at this point and marked as fixed. I don't know if it actually fixed the problem in my previous setup since I'm no longer using the receiver having the problem though.

Another thing I would check is to make sure you're running the latest version of SPMC which is v16.2.0 right now, just to make sure you are running the version with all the current fixes in it.

If you're running the latest version and things are still not working for you, @koying is going to have to step in and see what can be done to fix this for you.

[thelonew0lf]

Thanks for the detailed info. Yes, its static/white noise.

I am running the latest version of SPMC(16.2) and I am not sure whether my receiver supports the forcing to receive only AC3. But, when I play the same audio through my laptop connected via hdmi to the receiver, I can hear all discrete channel sounds.

Thanks for the bug reference. Although, I could just see koying closed this some days back but is this really fixed? Some configuration needs to be changed? or any beta version?

[heymoe]

The person that reported the problem in that bug report seems to feel the fix solved the problem for them and the hardware they are using. As I mentioned earlier, I don't know if this fix for that bug report actually fixed the issue with my receiver since I'm no longer using that receiver any more.

This could be a new hardware related issue that has a similar symptom in which case Koying will need to see if he can do anything about it.

I see in the code submission that 16.2.1 is being worked on but I don't know if there is a download (beta) of that version available yet.

[roberthr74]

I also have the same problem with MXV plus box with Amlogic S905 chip. SPDIF passthrough works perfectly ok with MX Player, but with Kodi/SPMC I get static noise or decoding error message on amplifier. I have tried many combinations but only stereo works ok.

[thelonew0lf]

Thanks. I confirmed that my default player in my TV is able to play the ac3 files fine. I am able to hear the test sounds clearly in individual speakers. But, the same played through spmc is only coming as stereo. And if passthrough is enabled, same white noise.

Also, I am sorry that I just noticed that my version is 16.1.2 and not 16.2. Anyways, I will test the newer version tonight and will let you know the results.

[thelonew0lf]

Hi, I just installed 16.2 and its the same. Getting white noise when enabling passthrough.

@koying, is this something u can look into??

[Gazoo]

Same problem with my NEO X8-H Plus and SPDIF. Passthrough doesn't work with SPMC 16.2 but works fine using MX player.

Edit: 16.2.1 fixed AAC just no dolby digital . At least its partially working now :)

[thelonew0lf]

Well, I installed 16.2.1 and the issue is same with me. Same white noise.

@koying Can you please look into this?

[thelonew0lf]

@koying I don't know how to get your attention. But is it something you can look into? or Can I stop expecting your time on this? Can you atleast guide me if I am wrong in any configuration?

@heymoe any suggestions on getting @koying 's attention on this issue? :-)

[koying]

Currently, I don't even know which TV brand/model nor android version you have and I never used S/PDIF Coaxial cable. Bottom-line: I have no clue.

[thelonew0lf]

TV : Noble TV 42 inch smart TV(relatively new in market and lesser known) CPU : ARM Cortex A9 1.5 GHz quad core processor GPU : MaLi-450 Android Version : 4.3

The TV doesn't have HDMI out and the one HDMI input doesn't support ARC. So, the only audio output from TV are L/R stereo out and Coaxial output. I am using a normal Coaxial cable to connect my TV to my sony HT-IV300 Home theatre and yeah, the Sony HT supports DD and DTS.

When I play multimedia(video with DD/DTS or AC3 audio) through the default software of TV(which I am unsure which application but comes by default with the TV), I am getting the desired output in HT(All distinct 5 channels- tested with sample audios). When I play the same with SPMC, I am getting Stereo when passthrough is disabled(which is obvious). But, when I play with passthrough enabled, I am getting only white/static noise.

@koying If you need more info, I am happy to provide.

[Gazoo]

@koying Here is my info also:

Receiver: Cambridge soundworks playworks 2500 (Yes I know its old). Box: NEO X8-H Plus - Firmware Official X8-H PLUS version 009 - Android 4.4

SPDIF plugged directly from minix to receiver. With passthrough enabled AAC 5.1 works but dolby digital does not. Dolby digital does work when using MX player but not when using SPMC 16.2.1.

I understand that its probably going to be hard to fix this without access to the hardware. I wonder what MX player is doing that SPMC is not ?