AppleTV 4 surround sound issue

LOL, but seriously, IMO if the atv4 can't passthrough the bitstream and let high end avr's do their job, then it doesn't get to be part of my home entertainment setup. Just a little shocked by Apple's take on this issue, I know I am not alone...

ROFLMFAO, if this is Apple's take on it, I guess I Am in possession of some pretty expensive hockey pucks.

Am not implying that the TV4 is little more than a brick paperweight, but I am stating there is an obvious difference of opinion as to which playback options should be available for DD+ and DD bitstreams. Like many users, I would prefer the Dolby bitstreams be passed through the TV4 to downstream devices for "proper" decoding and processing. Until the most recent tvOS release, the TV4—like previous TV models—had this capability. Unfortunately, some misguided Apple employee seems to have convinced "the powers that be" to change all that—contending that "Stereo" PCM output of a non-multichannel Dolby bitstream provides the same decoded/post-processed result as passing through the original Dolby bitstream. THIS IS NOT TRUE!

"Engineering has provided the following information regarding this issue:

"The attached Test-4.m4v contains two audio tracks, AAC 2.0ch and AC-3 2.0ch. Because both are the same 2.0ch, our current logic is to select AAC 2.0ch."

First of all, there is no "selection" process. A Dolby 1.0, 2.0, or 2.0 Active ProLogic II bitstream is now processed the same by the TV4 whether or not any AAC audio track is present—namely, the Dolby bitstream is output as 2-channel ("Stereo" mode) PCM audio in all cases. This means that, without further manual post-processing, a 1.0 Dolby center channel input signal will be played back as mono/mono (Left/Right) speaker audio instead of being played back through the center channel speaker as originally encoded. In a similar manner, by default a Dolby 2.0 Active ProLogic II bitstream plays back as stereo (Left/Right channel) PCM unless passive ProLogic II processing is manually activated by the user. True, manually applying such post-processing does "essentially" restore the PCM content to its original Dolby encoded channelization—but why bother? To me, this is like playing a 3D Blu-ray disc in 2D and then setting the TV to "simulate" 3D viewing.

Secondly, the current TV4 tvOS output process of creating a "pseudo" Dolby bitstream in the "Dolby Surround" mode prohibits proper "Quad" playback of a 2.1 Dolby Active ProLogic II bitstream. In this case, the active Left, Right, and LFE content is properly channeled to a DD 5.1 bitstream with the Center and Surround channels left empty. Since may AVR recognizes the TV4 output as a DD 5.1 bitstreams, it automatically deactivates my ability to post-process Active ProLogic II data leaving me with just Left/Right stereo speaker playback with LFE instead of the encoded Left, Right, Center, and Surround channelization with LFE. In short, the Apple engineering team has opted to NO LONGER FULLY SUPPORT DOLBY BITSTREAM CONTENT and, in the same breath, FAILS TO EVEN RECOGNIZE THE FACT THAT A PROBLEM EXISTS.

I had hoped/am still hoping, that a significant enough number of TV4 users will complain about this oversight and eventually prompt Apple to add an additional "Dolby Passthrough" audio output option as available in the Infuse Pro app and was previously available to TV devices (including the TV4) prior to the latest tvOS update.

Steve Waite wrote:

LOL, but seriously, IMO if the atv4 can't passthrough the bitstream

I haven't seen anyone with a deep understanding of tvOS development post about this. I'm sure the ATV4gen is capable of providing a bitstream but the API may not be public (yet). There are assertions that Infuse has licensed DTS and can provide a bitstream. I don't know if that's true.

Just a little shocked by Apple's take on this issue, I know I am not alone...

Exactly! It's not that Apple can't fix the issue but rather that they are currently choosing to ignore it. That is why I am so anxious to organize Product Feedback and/or Developer Bug Reports to underscore user dissatisfaction with the current TV4 Dolby Support limitations. If Infuse Pro properly supported my iTunes managed video library content metadata, I would be using it exclusively as my TV4 multimedia player. Unfortunately, it does not and I am unwilling to give up on all of the time and effort I have invested already over the last decade.

Am not implying that the TV4 is little more than a brick paperweight

But that is exactly what you said, and with such an absurd viewpoint it is very hard to take you seriously.

Hockey Puck

There are assertions that Infuse has licensed DTS and can provide a bitstream. I don't know if that's true.

It's true. I'm watching The A-Team (extended MKV copy of my BD) in DTS while I writing this. That is, I copy most of my DVD and BD video disc library content to RAID (83 raw TBs providing 52.89 TBs of protected) storage. Unlike Plex, which performs live conversion of DTS audio, the Infuse Pro app can pass the source DTS audio stream to the AVR (or other downstream device) for decoding and playback. On the other hand, my iTunes managed videos are stored as M4V files with both AAC and AC3 audio tracks on a separate 18 TB RAID unit. In this way, I can access either the MKV source data or the iTunes compatible versions of the same content. Unfortunately, playing BD source content with DTS audio through the TV4 is nowhere as efficient as playing files converted for iTunes compatibility in the Apple "Computers" player and reaping the additional benefit of iTunes managed pre-programmed metadata listings/playlists.

But that is exactly what you said, and with such an absurd viewpoint it is very hard to take you seriously.

If this is your understanding, then you should probably read more of my posts and pay closer attention to the words. If you prefer having the more limited playback options provided by Apple's current logic that converts Dolby bitstream content to PCM, then you are welcome to it. I simply wish to retain the ability to pass Dolby bitstreams—whether AC-3, E-AC-3, or DTS—directly through to my receiver and let it automatically (or me manually) determine how the audio should be processed and played in terms of channelization and/or effects. I am not trying to take anything away from your preferred work flow but rather simply restore capabilities that have only recently been removed by the latest tvOS update.

Just installed Infuse on my ATV4. It has the setting to pass-through DTS and DD!

Tested streaming an DTS encoded movie and guess what. Receiver did receive a DTS 5.1 stream and did the decoding itself!

Don't know how they do it but someway Infuse is capable of actually making the ATV4 to pass-through DTS and DD bitstreams.

Question I have now is if it is possible to have Dolby Atmos being passed through when streaming. I am trying to have my BluRay 'man from U.N.C.L.E. streamed via Infuse. Don't know how to do this for now but if I do I will post the result here.

Sorry, dual post!

What about the terrible Dynamic Range of ATV in any mode. I've restored it and made sure full Dynamic Range is on. I also made sure the loud sound is not suppressed in the settings. I have a 7.1 system with dual Powered Subs at 110W each. I played a few movies with explosions and there is simply no full LFE sound. You can hear the rumble and explosion but its suppressed. No REAL BASS sound. Plugged in the old ATV3 and the Dynamic Range was real and full. I don't understand how Apple can release this thing with full 7.1 support and drop the ball on Dynamic Range. Now I read that Apple Engineers are not even going to try and look at this problem? Really?

SuperSizeIt wrote:

Now I read that Apple Engineers are not even going to try and look at this problem? Really?

Someone mistyped, you misread or it's simply a mistake. No one that knows what Apple plans with respect to the audio issues will be posting about it. And don't forget to test all video players. They're different.

I Have reverted to a 3rd gen Apple TV in order to restore quality sound.

I am surprised this issue is not more visible on the inter webs.

I just bought another ATV4 for my Bedroom and luckily it is running 9.0 which streams Apple Music and Youtube videos in Surround sound. Lost those features when I did the upgrade on my original ATV4. So I have now put the old one in my bedroom and the new one in my media room. I also shut off the automatic upgrade feature. I wish Apple would fix this !!!

I wish Apple would fix this !!!

Please post Product Feedback requesting restoration of the original tvOS v9.0 functionality.

How can I downgrade this to 9.0? Is it even possible?