Getting 5.1-Channel Sound in Old Home Theater Systems

[monkeylove 8]

Here's something I found out recently, and others might find it helpful:

I'm using an old home theater system, a Samsung HT-Z220

https://www.samsung.com/ph/support/model/HT-Z220T/XTC/

which came very cheap with the 32" TV (also a Samsung) from around 2008. I haven't used the DVD player for some time, but it works as a sound system.

I connected a Xiaomi TV Box S:

https://www.mi.com/global/product/xiaomi-tv-box-s-2nd-gen/

to it and the TV. In the TV box, I set the audio to S/PDIF, with an optical cable from it to the theater system.

For the software, I used Kodi in an Android OS and the Emby add-on, and they access videos in a local Windows 10 i5 PC in the same network. The Kodi audio setting was set to 5.1-channel, with upmixing, and passthrough for everything that the player could handle.

Videos with 5.1-channel aac audio played fine but the audio was never that strong. When I tested the system using a 5.1-channel test video, sound from the, say, left sat speaker was loud when the sound test was played on it, but I could still hear the test sound slightly when the left inner speaker was tested.

I discovered that the Emby Android app could be set to transcode all audio to Dolby, so when I went to the Emby add-on in Kodi and configured it transcode all audio to ac3. the audio suddenly became louder and in the test video separation of sound per speaker much clearer.

You might want to try this if the audio isn't that clear and the server can handle transcoding.

 

 

 

[monkeylove 8]

OK, it's also because the S/PDIF cable can't handle aac and other uncompressed audio. That means if you're using an optical audio cable, you'll have to transcode various codecs other than ac3.

If you want to avoid that, I think you'll need a home theater system or soundbar that has HDMI ARC and a TV (with one HDMI ARC and one or more HDMI jacks) that has the same, i.e., if HDMI can pass multi-channel audio easily.

You'll connect the TV box and other devices to the HDMI jacks of the TV, then connect the TV to the soundbar using the HDMI ARC jacks. That means the TV will receive video and audio from the devices, then pass on the audio to the home theater system. That means audio from all devices will come out of the system.

Lastly, I read somewhere that Kodi is supposed to transcode all audio played in it to ac3. I think that happens if you turn off passthrough in the audio settings. I tried that and played around with the settings (e.g., set it to default) but I still encountered the same problem given earlier.

 

[monkeylove 8]

Sorry, I found out that the transcoding in Kodi only shows up if you set the number channels in the audio settings to 2.0. Do that and a new setting "Enable Dolby Digital (AC3) transcoding" will show up. Enable "Allow passthrough" and that, and Kodi will do the transcoding.

 

[quickmic 1352]

11 hours ago, monkeylove said:

Sorry, I found out that the transcoding in Kodi only shows up if you set the number channels in the audio settings to 2.0. Do that and a new setting "Enable Dolby Digital (AC3) transcoding" will show up. Enable "Allow passthrough" and that, and Kodi will do the transcoding.

 

Did you try the transcoding option of the plugin? plugin config menu -> playback -> transcode audio" section and "transcode output format"

Edited April 25 by quickmic

[monkeylove 8]

2 hours ago, quickmic said:

Did you try the transcoding option of the plugin? plugin config menu -> playback -> transcode audio" section and "transcode output format"

Yes, that's what I did initially. By switching from aac (the default) to ac3 I get the 5.1 sound. Apparently, the reason's the hardware: optical audio cables can only deal with two channels of uncompressed audio. To get more than those channels, the audio has to be compressed, or like ac3.

I only realized this after I saw the setting in the Emby Android app, and realized that I could do the same for the Emby addon.

Later, I was told about the hardware limitations, and then also found out that Kodi itself can transcode on the fly, but to do that you have to set the Kodi audio to default settings, which is 2.0. Then turn on passthrough, and you'll see the option to transcode to ac3. Activate that.

However, I notice that when I do audio transcoding through Emby, the video would sometimes freeze after around 15 min. I have to stop playback and then resume. I don't know if setting the bandwith limit for video to 1000 Mbps will help (the default's 100). I'll report what I experience. For now, AFAIK, the server should be powerful enough to do transcoding (it's an old i5 but with 16 GB RAM, SSD, etc.) and connections are gigabit (e.g., 400 Mbps DL/UL speed test in the Android TV box). And the problem doesn't happen if I don't transcode.

 

 

[quickmic 1352]

Actually, the server shouldn't transcode video at all, only audio if the transcode settings are correct.

two options, transcode by bandwith (100 / 1000) should never trigger the transcoding and second.

transcode by containerformat. That's the one you shoudl enable (for audio only).

Check Emby servers dashboard to see what's happening.

[monkeylove 8]

It just happened now: the video froze after 15m57s. The audio codec of the video is aac 2.0.

I set the plugin to transcode audio only, and all except for ac3 and dts.

Checked logs and not sure what to look for. Saw "Playback stopped reported by app Emby for Kodi Next Gen....".

Went to transcoding setting in server and will turn on hardware acceleration and turn off enable throttling to see what happens.

[quickmic 1352]

13 minutes ago, monkeylove said:

It just happened now: the video froze after 15m57s. The audio codec of the video is aac 2.0.

I set the plugin to transcode audio only, and all except for ac3 and dts.

Checked logs and not sure what to look for. Saw "Playback stopped reported by app Emby for Kodi Next Gen....".

Went to transcoding setting in server and will turn on hardware acceleration and turn off enable throttling to see what happens.

Please also check in the Emby's dashboard if really only audio is transcoding. There are infos available while you play content.

[monkeylove 8]

Thanks for the help. I checked the logs and everything appears to be fine.

The problem lies with the Android TV box: it no longer gets the correct date and time with the local network, and it persists even after I reset the box twice and use wi-fi instead of wired. It happened before for this box and another one in the same network, and then a day later disappeared; I'm guessing that it's some sort of problem with the ISP and accessing the NTP.

In any case, I think it works either way: transcode using the Emby server or using Kodi (by setting the audio to default, then activate passthrough and the option to transcode to ac3.

[monkeylove 8]

Sorry, a brief aside, and in case anyone encounters the same problem:

If you have an Android TV box and the date and time are not being set correctly, try setting the Internet connection to use a static IP address. That should solve the problem.

About my transcoding problem, what happened was that I was playing a video from an old Popcorn Hour which I'm using as an storage device. For some reason, if I play anything from it transcoded, the video hangs after a minute. OTOH, if I don't transcode, anything from it plays fine.

About the video hanging after 15 minutes, I think it was caused by the wrong date and time in the TV box and/or not using a static IP address, which causes an "no Internet" connection message to pop up.

 

 

[monkeylove 8]

One more thing I just noticed: I had one video with a 2.0 AAC-LC audio track, and the sound was soft using Kodi as the transcoder.

However, when I use the Emby add-on with all codec types other than AC3 and DTS transcoded, the audio was louder. I'm guessing that Kodi might not be transcoding all codec types.

Lastly, this only applies to those of still re-purposing older home theater systems, or those with only optical audio jacks. Newer systems usually have HDMI ARC jacks, so there's usually no reason to transcode except if you can only afford cheaper ones.

And about the Android TV box static IP address, for some reason you may need to accept the default settings for DNS, which is those of Google (8.8.8.8, etc.) if the device still doesn't see the network date and time, which I think is taken from time.android.com or something like that.