2016-02-12, 16:36
Put succinctly for the background setup here, I have an Amazon Fire TV Stick in a room that was originally set up for high-end stereo sound only. I added a TV at some point for versatility and because I had some extra powered sub/sat speakers and an older Technics outboard Dolby Digital decoder not being used, I figured why not add a surround sound option since it only cost me the price of some long RCA cables for the powered speakers. The system sends out the HDMI connection from the FireTV Stick to a JD Tech HDMI Switch that can extract a Toslink/Spdif signal from up to three remote switched inputs and send it to the outboard decoder while the HDMI out of that box goes straight to the television (which does not decode Dolby Digital itself).
Thus, when the stereo is all on, I MUTE the TV and use the full outboard decoding and I basically get Dolby Digital "4.0" decoding from a 5.1 signal. It works with Amazon Prime's player. It works with Netflix. And it works with Kodi. Here's the kicker, though. If I turn off the front speakers (preamp and amps off) but leave the decoder on all the time, I can still get surround decoding from the self-powered surrounds (whether Pro Logic decoded or Dolby Digital). However, the TV is where the strange difference between Amazon Prim and Netflix and Kodi shows up.
1> If I play a show in Kodi with Dolby Digital and Passthrough disabled, I get "Pro Logic" type decoding at the surrounds and the main signal at the TV. This works well if I don't want the giant mains speakers running for some reason and I can simply turn off the decoder or change it to stereo if I don't want the surrounds running.
2> If I play a show in Kodi with Dolby Digital Passthrough enabled, I get the decoded Dolby Digital Surround at the rear speakers and I get a digital NOISE (undecoded Dolby Digital I assume) at the television. This means I cannot just watch any movie willy-nilly in Kodi without either changing the soundtrack to the Stereo one or turning off passthrough first. There is no way that I can see to get a usable signal at the TV (at least without running analog signals to it and changing the audio input in the menu) and have Dolby Digital discrete surround in the room. OK, this sounds logical to me that it would do that. However....
3> If I play Dolby Digital show from Amazon Prime or Netflix, I get the expected decoded surround signal at the rear speakers (and the RED Dolby Digital light comes on at the outboard decoder, so I can easily tell it's Dolby Digital and not a Pro Logic decoding) BUT instead of the Dolby Digital signal at the television making noise, I get PCM Audio and therefore it's listenable (with discrete surround at the same time!)
My question is why do I get PCM with Amazon Prime and Netflix on the same FireTV Stick setup at the TV while still getting Dolby Digital at the outboard box, but I get noise instead at the TV from Kodi when I play back Dolby Digital
What could those two apps be doing differently that the HDMI splitter sends a passthrough type signal to the decoder, but PCM to the TV? That's IDEAL since I no longer have to worry about changing the Dolby Digital setting in the FireTV settings menu. But with Kodi, I still have to change over to either PCM with the TV speakers or mute and turn on the main speakers to get fully Dolby Digital.
Is it possible the JDM switchbox is actually somehow detecting the signal in the case of Amazon Prime/Netflix but not for Kodi for some reason? I wonder because its manual claims it recognizes all sorts of signals and can respond automatically in most cases (it has its own issues of the input controls locking up sometimes, but otherwise seems to work well. It has its own settings of 2.0, 5.1 and 7.1 plus "AUTO" (detect) and ARC on/off. For Netflix to even offer 5.1, it has to be set to 5.1 on the JD box and not 2.0 (apparently the Netflix App polls it to see if 5.1 is available before it even offers it). Amazon Prime doesn't need that setting to offer Dolby Digital and neither does Kodi (since it's over SPDIF anyway), but they both work fine with it set to 5.1 or Auto regardless.
I'm going to GUESS that since the box has ARC and can respond correctly to a poll from Netflix whether it's connected to a 5.1 type receiver, that perhaps the switch box itself "asks" the TV if it can handle Dolby Digital and since it doesn't say yes, it assumes no and sends it PCM instead over HDMI, but sends the encoded signal out its SPDIF optical port. That would potentially explain why it works like that with Amazon Prime and Netflix, but what is "wrong" or "different" about the Kodi Dolby Digital signal that it doesn't do the same thing with it and instead sends the encoded signal to the TV anyway
Is there some sort of handshake or meta data protocol at work here that Kodi doesn't offer (and instead just expects the decoder to recognize the signal itself) that the JDM Switchbox sees its Dolby Digital signal differently? It would be nice if Kodi behaved the same way as Netflix and Amazon Prime since I wouldn't ever have to turn passthrough on/off depending on whether I'm using the TV speaker or front mains. I just find it strange that I get two such different results at the TV speaker when all three are Dolbly Digital sources.
Thus, when the stereo is all on, I MUTE the TV and use the full outboard decoding and I basically get Dolby Digital "4.0" decoding from a 5.1 signal. It works with Amazon Prime's player. It works with Netflix. And it works with Kodi. Here's the kicker, though. If I turn off the front speakers (preamp and amps off) but leave the decoder on all the time, I can still get surround decoding from the self-powered surrounds (whether Pro Logic decoded or Dolby Digital). However, the TV is where the strange difference between Amazon Prim and Netflix and Kodi shows up.
1> If I play a show in Kodi with Dolby Digital and Passthrough disabled, I get "Pro Logic" type decoding at the surrounds and the main signal at the TV. This works well if I don't want the giant mains speakers running for some reason and I can simply turn off the decoder or change it to stereo if I don't want the surrounds running.
2> If I play a show in Kodi with Dolby Digital Passthrough enabled, I get the decoded Dolby Digital Surround at the rear speakers and I get a digital NOISE (undecoded Dolby Digital I assume) at the television. This means I cannot just watch any movie willy-nilly in Kodi without either changing the soundtrack to the Stereo one or turning off passthrough first. There is no way that I can see to get a usable signal at the TV (at least without running analog signals to it and changing the audio input in the menu) and have Dolby Digital discrete surround in the room. OK, this sounds logical to me that it would do that. However....
3> If I play Dolby Digital show from Amazon Prime or Netflix, I get the expected decoded surround signal at the rear speakers (and the RED Dolby Digital light comes on at the outboard decoder, so I can easily tell it's Dolby Digital and not a Pro Logic decoding) BUT instead of the Dolby Digital signal at the television making noise, I get PCM Audio and therefore it's listenable (with discrete surround at the same time!)
My question is why do I get PCM with Amazon Prime and Netflix on the same FireTV Stick setup at the TV while still getting Dolby Digital at the outboard box, but I get noise instead at the TV from Kodi when I play back Dolby Digital
What could those two apps be doing differently that the HDMI splitter sends a passthrough type signal to the decoder, but PCM to the TV? That's IDEAL since I no longer have to worry about changing the Dolby Digital setting in the FireTV settings menu. But with Kodi, I still have to change over to either PCM with the TV speakers or mute and turn on the main speakers to get fully Dolby Digital.Is it possible the JDM switchbox is actually somehow detecting the signal in the case of Amazon Prime/Netflix but not for Kodi for some reason? I wonder because its manual claims it recognizes all sorts of signals and can respond automatically in most cases (it has its own issues of the input controls locking up sometimes, but otherwise seems to work well. It has its own settings of 2.0, 5.1 and 7.1 plus "AUTO" (detect) and ARC on/off. For Netflix to even offer 5.1, it has to be set to 5.1 on the JD box and not 2.0 (apparently the Netflix App polls it to see if 5.1 is available before it even offers it). Amazon Prime doesn't need that setting to offer Dolby Digital and neither does Kodi (since it's over SPDIF anyway), but they both work fine with it set to 5.1 or Auto regardless.
I'm going to GUESS that since the box has ARC and can respond correctly to a poll from Netflix whether it's connected to a 5.1 type receiver, that perhaps the switch box itself "asks" the TV if it can handle Dolby Digital and since it doesn't say yes, it assumes no and sends it PCM instead over HDMI, but sends the encoded signal out its SPDIF optical port. That would potentially explain why it works like that with Amazon Prime and Netflix, but what is "wrong" or "different" about the Kodi Dolby Digital signal that it doesn't do the same thing with it and instead sends the encoded signal to the TV anyway
Is there some sort of handshake or meta data protocol at work here that Kodi doesn't offer (and instead just expects the decoder to recognize the signal itself) that the JDM Switchbox sees its Dolby Digital signal differently? It would be nice if Kodi behaved the same way as Netflix and Amazon Prime since I wouldn't ever have to turn passthrough on/off depending on whether I'm using the TV speaker or front mains. I just find it strange that I get two such different results at the TV speaker when all three are Dolbly Digital sources.
