Dolby Decoder Software
Sherlene Holloman
Yes, you read the title correctly. Here is a little background and all the information you'll need to decode and play lossless Dolby TrueHD with Atmos on a Windows or macOS computer, without the need for HDMI output.
Both DD+ and TrueHD carry the height channels in metadata. This makes the content on Blu-ray Discs appear like plain 7.1, but when decoded, the height channels are filled. It isn't practical to extract the height channels to a separate file, these are available at the time of decoding.
macOS has a built-in Dolby Digital Plus decoder using what's called DD+JOC. This is how Atmos / Spatial Audio content can be played and listened to on a Mac. However, this is the lossy version, not TrueHD lossless.
Why would someone want to decode and play Dolby TrueHD Atmos content on a computer rather than an AVR or processor? Mainly it's about cost, flexibility, and performance. The cost of a high end processor can set you back $10,000 or much more. The flexibility of a computer based system is endless (for better or worse). With respect to performance, a computer based system can use several types of room correction, 65,000+ taps, upsample to high rate PCM or DSD, and output to high end DACs with interfaces much better than HDMI.
Start by ripping the Dolby TrueHD content from a Blu-ray Disc. To do this, use a Blu-ray drive such as the Archgon BU40N that can also rip UHD 4K Blu-ray Discs (although a firmware adjustment is required to rip UHD).
Here you can see The Beatles Abbey Road Blu-ray. I have the TrueHD Surround 7.1 English track selected to rip. Again, it says 7.1, but the metadata will be used to create a 5.1.2, 7.1.4, 9.1.4 or greater mix.
Once you have both MKV and MKA files, you're ready to extract the lossless TrueHD files needed for decoding. Note: if you want to output the MKV or MKA files via HDMI into an AVR with Dolby Atmos decoding, then you don't need to go any further. However, if you want to decode TrueHD on a computer, keep reading.
Open MKVCleaver, then select the MKV file from within the app. Once open, select the audio track you wish. Here you can see I've selected what says MLP FBA 16-ch... on Abbey Road. Then click extract. This will extract the entire track into a TrueHD file with the TrueHD file extension.
Now for the good part. Purchase a license for the Dolby Media Encoder ($400 /yr). The Dolby Media Encoder comes with the Dolby Reference Player. The Dolby Reference Player is the app that's needed. Note: the Media Encoder is what's licensed for $400 per year, but only the Reference Player is what we need. The Reference Player will continue to work after one's Media Encoder license has expired, but updates will not be available.
Open the Dolby Reference Player and change the settings to match your audio needs. I disable Dynamic Range Control, set the presentation to 16 channels, speaker layout to 7.1.4, and audio device to my Merging Technologies Anubis. Then open one of the ripped MLP files and extracted earlier, and enjoy the glorious lossless Dolby TrueHD with Atmos content.
This was the quick and dirty how-to. There are many more items to cover, such as room correction and issues that may pop up with different audio interfaces. Right now, I can send audio from the Dolby Reference Player to HQPlayer for room correction and upsampling, then out to my Merging Technologies Anubis for playback. The decoding is all done by the Reference Player. Regular 12 channels of PCM is delivered to HQPlayer, so I can do whatever DSP I need. I also send Apple Music Atmos / Spatial Audio content through the same digital signal processing.
This is very, very cool. I bet some enterprising programmer could create a whole GUI application set that mimics a high-end pre/pro (like my Lyngdorf MP-40 that is brand new and unboxed currently! Hmmm....). Video switching, HDMI inputs for the ATV4Ks and Nividia Shields of the world. Net/net, this takes building an HTPC to new heights (pun intended). ?
If you can make them appear as a single device, you should be good. It's easier because the TrueHD content is almost always the same 48k sample rate. I've yet to see TrueHD Atmos anything other than 48k.
Not Ted but it may be possible to synch multiple DAC8 Pros by themselves by using the one of the outputs of the 1st DAC8 as a synch source to one of the inputs on the 2nd DAC8 which will get you 15 channels. Daisy-chain more and get 7 per DAC. Alternatively, you can use the U-DIO as just a synch source to each of the DAC8s.
In all cases, the DAC8s have to be in USB/AES mode and everything has to be at 24/48 since the Oktos require the same bitrate/depth on in and out in this mode. No upsampling or downsampling, at least in theory.
The bigger issue is having a way to send/distribute the channels to the DACs. In MAC, it is easy as MiDi setup lets you create virtual outputs from multiple real ones. In WinWorld, you may have to used something like ASIO4ALL.
First a a few reference points. I've been listening to the Beatles since I bought a 45rpm 7 inch "I want to hold your hand" when it first came out (not continuously) I've never heard any of their recordings I would call audiophile and some absolutely sucked, like the MoFi vinyl box set. Listening to the Apple Atmos mix has been a revelation. More full bodied, better fidelity than any other version I've heard. That said, I certainly haven't heard them all but definitely something you want to sit and listen to for the music and fidelity, not the effects. It is not gimmicky except the final little ditty where they pan the vocal from far right around the front of the room to far left Some of it is stunning. "Come Together" as you've never heard it.
I would love to hear the lossless version, I may buy the disc but they are at least $75 on Discogs at the moment for the 2019 set which is what the Apple mix is. Perhaps we need another thread to discuss the software (music) side of this.
@El Guapo, glad you are part of this discussion. I have the DRP up and running and am trying to get a 5.1.2 setup with sound coming out. The variations I have tried -- none of which produce any output to the Okto dac8pro -- are:
3. Output the DRP to VAC via ASIO4all. ASIO4all is then selected as the output in DRP (16 channels available). The VAC is selected as the in and out inside of the ASIO4all app. This appears as an 8 channel input backend in HQP under ASIO as ASIO4all, of course.
I've attached a bunch of screenshots so you can see my various settings. I'm open to ideas. I will advise that I can regularly stream digitized vinyl through my Benchmark ADC1 to a physical XLR input on the AES16e soundcard in my server, and that output is recognized by HQP by selecting ASIO Lynx as the input backend. To make it work, however, I have to start a 24/192 playback stream in HQP -- so there's not more than a second of latency against real-time, which for listening to vinyl works just fine. This is why I have been thinking that ASIO Lynx has to be the answer, but I just can't resolve it.
1. The process you describe after you extracted the mkv with makemkv, I understand you split the mkv file to get separate mka audiofiles for easier access to the individual songs. Yes, I would do the same with my concert and pure audio blurays. But in the case of a movie mkv, what would the process look like then? I assume the original ripped mkv is enough for Dolby Reference Player to play, or am I wrong?
2. As the DRP is required to decode the Atmos-tracks, what would the playback chain look like if the source is a movie-mkv..? You open the file in DRP to decode the Atmos-tracks, but what about the video..??
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