Is anyone having problems with ATV outputting Dolby Digital Plus?

LOL. I found the answer to my question, but still welcome a reply relating to Dolby Digital Plu. Dolby Labs itself recognizes PCM 5.1 to be “Best Available.” See this:

http://developer.dolby.com/News/Dolby_Audio_Support_on_Apple_TV.aspx

If you are connected to a stereo device it will send stereo PCM audio; but if you are connected to a multichannel device, it will send multichannel PCM audio, including 5.1 or 7.1, depending on the capabilities of the connected HDMI device.

I respectfully disagree with your suggestion that Apple should dispense with PCM 5.1 support. My hat is actually off to Apple for being ahead of the curve and at the front of what I hope will become standard fare: PCM 5.1.

I DO agree Apple should support the higher bit, better sounding and richer DD Plus. That said, The digital world will always suffer some lack of uniformity. An interesting example is that I’m watching Wonder Woman in 3D streaming from Vudu via my LG OLED. When I pause I clearly see that Vudu is outputting in DD Plus. However, my Krell tells me that the LG OLED streaming this movie is outputting Dolby 5.1. So this is a function of what my TV is outputting via Optical Toslink cable to my Krell. No prepro or receiver can upscale D 5.1 to DD Plus.

Anyway, when I watch any movie or show on my Roku device, from most ANY app, I pull DD Plus. How is this possible? Well, it’s simply the difference between how the LG chooses to process Dolby and how Roku is designed to process the Dolby signal offered by the source content. I rather suspect that a master Dolby surround track is provided and left up to the device maker to decide how to express the Dolby surround. Obviously, if my Krell can support PCM 5.1, ALL Dolby except Atmos, the variable is the device.

So for me, what’s known is my LG outputs nothing greater than Dolby 5.1.

My ATV outputs PCM 5.1 as Best Available. If Apple engineers are reading this, please fix “Best Available” from FIXED to VARIABLE and output Dolby Digital Plus RATHER THAN Dolby 5.1.

This remedy I believe would satisfy virtually anyone. We’d have “best” in the way of PCM 5.1, “better” in DD Plus, and “good” in Stereo for those with no option other than two channel.

Finally, in support of Apple I think they’ve addressed iTunes properly. ATV used to output iTunes music in simulated PCM multichannel and music sounded terrible. I changed it to the way it was INTENDED to be heard: Stereo 2.0. Kind of mute issue for me now as I use my Mac mini for streaming all of my music, using the benefit of an excellent DAC and unique music playing software, Pure Music. Point here is that Apple did the right thing with iTunes here. They just need some work fixing up the audio outputs. I believe this can easily be done via firmware. After all, recall their spec page where they point to support for Dolby DD Plus 7.1. Just wondering if somehow DD Plus is only output for 7.1 systems as that’s how it reads. I have a 5.2 system so would be weird if that should be the case but I suppose anything is possible. Ha ha. Thanks!

Thanks for your reply, much of which is helpful. I’d respectfully disagree with your comment that “Apple engineers decided not to support Dolby Digital Plus.” See link to their specs on their own web site. It would be gross misrepresenta of fact for Apple to state that it DOES offer DD Plus support and not actually offer it. I believe it to be a glitch which I understand they are aware of. Apple TV 4K - Technical Specifications - Apple

With respect to PCM 5.1, it clearly sounds significantly better than any Dolby or DTS Surround mode I’ve tested. I confess I was largely unaware of how incredibly more dynamic PCM 5.1 sounds V Dolby or DTS. REMARKABLE. That said problems exist with the “Best Available” feature. The ATV not presently “smart enough” to switch to Dolby when it encounters a show not supported in native PCM 5.1. NO processor can output a source not native to the disc or streaming content. As a result I get no audio on some shows and have to exit out, back to settings/audio and change to Dolby Digital 5.1. It’s a pain. You’ll find very few Blu-Ray support PCM 5.1 for two reasons. 1) There’s so much video data in a Blu-Ray, adding an uncompressed audio track like PCM might challenge the limits of space on disk. 2) Not many receivers can support 5.1 PCM. This requires a specific circuit board and or firmware to support. Fortunately my Foundation supports PCM multichannel and it is GLORIOUS.

As for your issue with not getting PCM 5.1 pass through via ARC HDMI, that doesn’t surprise me. HDMI via ARC is known to be VERY finicky It may be that your TV lacks ability to pass PCM 5.1 and could explain why it reverts to what it can do - pass Dolby Digital.

Fingers crossed that Apple resolves the “Best Available” issue to make it a VARIABLE setting that can switch from PCM 5.1 when no PCM support detected. Also hoping Apple supports DD Plus as stated in their official spec page

I'm not surprised as I had understood that PCM 5.1 and higher required HDMI support. I actually rented a movie from iTunes and it streamed in PCM 7.1 which was great! Apple getting ready to release ATMOS no doubt. I hope engineers will listen and output DD+ rather than DD 5.1 Plus SO much better!

Per your other reply it’s great your TV supports PCM 5.1 Even if my LG OLED supported it I could not get it delivered via my toslink or optical cable which is limited to 2.0 or Dolby. I only use that cable for Smart TV (streaming). Everything runs through my preamp and it processes what it gets. Period. Only limitation is Atmos. The LG for video is great but suffers from intermittent audio pathways falling out.

I believe you stated you connected your ATV directly to your TV; if so, this will explain why you receive any mage at all; if you have video settings on ATV to 4K by all rights your receiver would output a black screen. The work around of course would be to set video to 1080P. But if connected via HDMI to TV, you will of course enjoy a 4K experience as there exists no video relationship between your ATV and your receiver.

Yes, makes perfect sense re: your receiver. If there Is anything in the chain that lacks the HDCP chip you’ll get nothing (4k). And you’ve nailed it with your observation in how your TV seems to handle processing HDR content better than ATV. The ATV needs dynamic video processing as it needs dynamic audio processing. I’m referring back to my issue while watching some content that doesn’t support PCM 5.1. The “Best Available” is fixed and should be variable or “dynamic.”