AppleTV 4 surround sound issue

While that is true E-AC-3 (Dolby Digital Plus) can carry Atmos information which gets lost when converted to 8 channel PCM. Keep the original encoded bitstream and have an AVR or pre-pro do the decoding. This would free the Apple TV 4 form doing the decoding which would free system resources for other tasks.

HAL9000.2 wrote:

While that is true E-AC-3 (Dolby Digital Plus) can carry Atmos information which gets lost when converted to 8 channel PCM. Keep the original encoded bitstream and have an AVR or pre-pro do the decoding. This would free the Apple TV 4 form doing the decoding which would free system resources for other tasks.

Now, if Apple could only make this happen, would be nice.

Jon, My files were encoded by Handbrake and first track is AAC and second track is AC3. You mentioned about re-enable the AC3 track as ATV3 had no problem with his but not sure how to re-enable the AC3 track as the default. I saw one earlier post about using Subler to adjust the tracks. Is that what you are referring to?

My files were encoded by Handbrake and first track is AAC and second track is AC3. You mentioned about re-enable the AC3 track as ATV3 had no problem with his but not sure how to re-enable the AC3 track as the default. I saw one earlier post about using Subler to adjust the tracks. Is that what you are referring to?

Yes. Here is an expanded description of my general workflow:

1. I currently store my source non-3D optical content as MKV files on 71 TBs of HHD configured as 4 protected RAID volumes—one each for SD Movies, SD TV Shows, HD Movies, and HD TV Shows. This content is used as the source file for Handbrake conversion and Plex server tests/use.
2. Handbrake is then used to create universal 720p24 M4V (H.264/AAC/AC3/Chapter) files for iTunes management and Air Video/Air Video HD streaming.
3. Universal M4V files are then added to my iTunes library for general storage and database management.
4. I then queue the newly added iTunes library files to iFlicks for assignment of metadata values and artwork.
5. My last step is to drag the metadata updated files from the iTunes library to Subler for re-flagging of the AC3 audio track for default playback on the TV4. (Multiple files can be opened in Subler simultaneously so I typically process a day's run of movies or an entire TV season at a time.)

This workflow:

1. Allows unchanged TV2, TV3, and mobile device playback of content, as well as, auto-selection of AC3 audio tracks on the TV4.
2. Allows Plex "on-the-fly conversion" serving of default unlimited data rate (?16-18 mbps targeted?) 1080p24 content to computer, 8 mbps 1080p24 data rate content over local network, and 4 mbps data rate 720p24 content over the internet—the settings for which can be overridden if desired.
3. Avoids the loss of metadata as reported by some users when re-flagging default AC3 track playback.

Since it is unsure whether or not Apple will update the TV4 tvOS software in the near future to accommodate Auto-selection of the AC3 track, I am only updating new files added to my iTunes library and old files which are routinely being upgraded to High Profile, Level 4.0 conversions to save library storage space.

I tried the Subler fix, and it did fix the issue for the Apple TV's default track selection, but it also broke my ability to sync any modified videos to an iPad or an iPhone. When I try iTunes says the video file isn't compatible and refuses to copy it to the device.

I tried the Subler fix, and it did fix the issue for the Apple TV's default track selection, but it also broke my ability to sync any modified videos to an iPad or an iPhone. When I try iTunes says the video file isn't compatible and refuses to copy it to the device.

Interesting. It has been so long since I last physically sync'd a video file with a mobile device that I, for one, had forgotten that some might still use this workflow.

If you prefer to keep the files modified for TV4, then you might consider using an IOS media player that automatically uses the AAC audio track (DropBox, Air Video, or Air Video HD) or one that allows the user to manually select the AAC track (VLC for IOS). I normally use the Air Video/Air Video HD apps for streaming playback of iTunes managed library video content via my local home networks or via the Internet but only Air Video HD allows download of such content for offline playback on mobile devices within the app itself. VLC allows cable file transfers between iTunes and mobile devices but requires the mobile device user to change the default audio track manually after the file is sync'd to your device. DropBox is easy to use and does not require a dedicated "server" app to be installed, but may offer the least "transfer space" allocation if using only the "free" initial storage space. If you have an iCloud account with sufficient space available, you can also email videos to your mobile device and then copy them to the VLC for IOS app but this is probably the slowest method for transferring content wirelessly. Plex may also be an option for some but my personal experience is currently limited to TV4 player testing and I have yet to invest in an IOS player app.

The main problem here seems to be a change in how video files are now flagged for track selection. The QT 7 Pro "Properties" window insists that the "physical" enable/disabled track status remains unchanged by Subler, but all QT X based apps can see the change and either refuse to sync the content or simply do not play the AC3 audio track under IOS if sync'd to a mobile device using an alternative method of file transfer. This basically means that each user currently has to choose between TV4 support (re-flagging user encoded content) or mobile device support (alternative player app)—something that will likely spawn yet another round of user complaints.

Thanks for the options Jon.

I've used a number of those apps in the past, but my primary need when I sync video (which I do a lot) is to use it where streaming ins't available or reliable, so I need to be able to copy them locally. I've been a video collector sine the days of VHS and Laserdisc. We have a very large collection of discs which have all been encoded to mp4/m4v, and I have no intention or 'retrofitting' all those files to work correctly with the new Apple TV. I also don't want to do something that 'breaks' the video so it doesn't work across all of our devices using the native apps, which makes me reliant on a 3rd party app which may or may not be around/work in a few months. I've gone down that road before and the result was me switching apps every few months so that everything would continue to work correctly, which my family did not appreciate.

Manually selecting the track is annoying, but not my biggest issue. The fact that I can't get both Dolby Pro Logic and 5.1 to work on a single set of Apple TV TV / Amplifier settings is a significantly bigger issue. If the Apple TV is set to Dolby Surround all our 2 Channel Video plays as stereo, and won't decode into Dolby Pro logic correctly, so we actually have to change both Apple TV and Amplifier settings each time we switch from videos that have only 2 Channel AAC audio versus videos encoded with 5.1 (which is about half our library). That totally *****, especially since we didn't used to have to do a thing and it just worked correctly. It's broken, and Apple should fix it, I shouldn't have to 'fix' my library every time they release a new product.

The fact is, for anyone who encodes their own content, the Apple TV 4 is an incredible disappointment. I'm mad at myself for not returning ours (we bought 3) when I had a chance, instead of trying to fix all the issues. Broken audio, Siri not searching your own library, descriptions set via iTunes don't work, etc.. The list goes on. Not that I should really expect anything different by this time. Each generation of Apple TV has focused more on online content and broken or buried the features that who build their own content libraries really need or want ... but that's what you get from a company who doesn't believe in focus groups and whose employees think bandwidth is ubiquitous and that everything you'd ever want is stream-able ...

Manually selecting the track is annoying, but not my biggest issue. The fact that I can't get both Dolby Pro Logic and 5.1 to work on a single set of Apple TV TV / Amplifier settings is a significantly bigger issue. If the Apple TV is set to Dolby Surround all our 2 Channel Video plays as stereo, and won't decode into Dolby Pro logic correctly, so we actually have to change both Apple TV and Amplifier settings each time we switch from videos that have only 2 Channel AAC audio versus videos encoded with 5.1 (which is about half our library).

If I understand you correctly, I don't have this problem if the TV4 is set to the "Dolby Surround" mode, the AVR is set to "Auto-Surround" mode, and the Pro Logic II audio is encoded as 2.1 AC3 audio. Here is a sample file:

http://downloads.walker4.me/Temporary_files/Test-4.m4v

Basically, AAC 2.0 Surround or Pro Logic II content does not automatically trigger PL II processing on my AVR but AC3 2.1 does. You can download and test the above file to see if your receiver works the same way. I.e., using the stated TV4 and AVR settings on my receiver, an AC3 track is always passed to my receiver for decoding. I.e., 5.1 content is decoded and plays as 5.1 content while AC3 2.1 Pro Logic II file decodes as 2.1 content and automatically triggers PL II post-processing. On the other hand, AAC 2.0 Pro Logic II content must always be triggered manually on my receiver—even in the "Auto-Surround" mode—and is why I'm now slowly recoding files to automatically select the AC3 track on the TV4.

You understand correctly, and you are absolutely correct on the Pro Logic 2.1 ... I missed the .1 part in the previous posts. Your sample file did trigger both the Dolby Pro Logic playback and the Dolby digital 5.1 playback correctly on my AVR-2311CI when I had 'Dolby Surround' selected on the Apple TV. With 'Auto' selected on the Apple TV both tracks in your video sample show up as 2 Channel PCM - mine show up as 2 channel and 7 channel PCM.

Unfortunately for me, all of my files are encoded with AAC 2 Channel Audio mixed down to Dolby Pro Logic II (the default mixdown in Handbrake), and I have no intention of re-encoding years worth of work.

I called Apple to initiate a return, and they were gracious enough to approve it based on the sound issues, even though I'm more than two weeks past the return period. I was on the phone documenting the issue with support when you replied, so I added the bit about 2.1 working and 2.0 not working. They had actually passed me off to a 2nd or 3rd level support person to document the case, and she said she has had other cases opened for the same issue, so maybe they will actually address it.

At this point I plan on taking Apple up on their return offer. I don't have a lot of faith they will address this any time soon, if ever, given this seems to be an issue only for some user-encoded content. Since iTunes video (and thus sales) aren't affected I'm guessing this won't get much of a priority. If past history is any indication, users that encode their own video aren't a big enough group to bother with.

... and I forgot ...

Thank you for helping me identify the correct issue Jon. I really appreciate your time. I am only able to return 2 of my 3 Apple TVs, so at least I can get the one I have to keep (not bought from Apple) working correctly.

Jon Walker wrote:

My last step is to drag the metadata updated files from the iTunes library to Subler for re-flagging of the AC3 audio track for default playback on the TV4. (Multiple files can be opened in Subler simultaneously so I typically process a day's run of movies or an entire TV season at a time.)

...

It turns out that Subler is the answer to the default track problem, but using a different method (not the method laid out by Gino_Cerullo in this post:

Re: AppleTV 4 surround sound issue )

According to this post over on the HandBrake forums, the correct method is to leave the AAC 2.0 track enabled (as the default) and leave the AC3 track disabled (not checked), and then to change the 'Fallback' field on the AC3 track to the AAC track. This links the track, and makes the Apple TV 4 select the 'better' track when playing like it did in previous versions. If you do this you will only see a single track in the Audio field, just like you do when you look at iTunes Store tracks. Also, using this method still allows the video file to be synced to other Apple devices through iTunes.

Thanks PurpoiseHork and Jon for your great feedback and insight. This fixed my problem with the ATV4. Using Subler to leave the AAC 2.0 enabled and AC-3 disabled but with the fallback option of the AAC 2.0 track it allowed the ATV4 to play the Dolby Digital surround track just like the ATV3 use to through the AVR and sync perfectly to my mobile iOS devices through iTunes without any issue in playback. I tried a few different files and got the same results. Now I just need to run my library through this entire process. It is too bad that Apple took this step back after this was working with their previous products. Hopefully they will fix it so people don't have to jump through hoops to make things work that worked without issues before.

Thanks again.

According to this post over on the HandBrake forums, the correct method is to leave the AAC 2.0 track enabled (as the default) and leave the AC3 track disabled (not checked), and then to change the 'Fallback' field on the AC3 track to the AAC track. This links the track, and makes the Apple TV 4 select the 'better' track when playing like it did in previous versions.

Thanks for the expanded information. Had "toyed" with this setting previously but considered the inability to thereafter access the AAC track to be problematic in view of fact that we seem to be performing "public beta testing" of the TV4 device more than anything else. However, in view of your comments and additional research, I agree it might be better to adopt Apple's apparent workflow now rather than take the chance of running into further complications later.

If you do this you will only see a single track in the Audio field, just like you do when you look at iTunes Store tracks. Also, using this method still allows the video file to be synced to other Apple devices through iTunes.

Sorry, this comment was initially lost on me. Only iTunes Store download I have was a June 2006 freebie that appears to be targeted for the 5th Generation iPod (320x184, MPEG-4 AVC Baseline@L1.3, AAC). While I don't normally sync videos to my mobile devices, I do like the fact that this "Fallback" setting workflow does retain/restore previous device compatibility workflows should I choose to employ them.

Nice catch... my complements to you and your efforts. Looks like we are finally cracking some of the knowledge base issues here.

It looks like today's update fixed part of our issues.

It now output 5.1 when set Audio to Auto.

For Apple Music, still only two channels

Unless your amp can force at artificial surround sound then music will always be two channel as its recorded in stereo.