Hang when playing back DTS-HD variant using passthrough

In attempting to see how small I could make my audio tracks, I found out that DTS-HD MA does not require the DTS core. For Blu-Ray, yes, it does, but there is a variant for “digital distribution” (i.e., streaming) that doesn’t have a core.

This audio plays back correctly on the Vero 4K when passthrough of DTS-HD is disabled. Testing shows that ffmpeg seems to handle it fine on any platform. But, if passthrough is enabled, all I get is a frozen black screen (after a “buffering” message) that requires a restart of mediacenter through the shell.

The log file is too big to upload (even if I capture logs during playback right after a reboot).
The file that causes the error is only 320MB, so I could upload it somewhere for testing.

I know that this audio format is not something you are likely to see, but it is technically possible for a streaming service.

None of my rips have the DTS or DD core when there is a hi-res soundtrack, they all play fine on passthrough to my Marantz NR1603.

Does this actually make the audio track any smaller? I can’t see why it would, or why anyone would want to do that. Presumably, it stops players that can handle only core from outputting 5.1.

Can you upload kodi.log to collab?

I just checked a title that was around the 24GB size and omitting the DD core saved 500MB. Not much in context of overall file size, but as all my playback clients can handle hi-res audio, I’ve never bothered to keep the core. If I were starting from scratch I’d probably keep it as I’ve long-since stopped worrying about disk space.

Dramatically. For the short sample of 7.1 24-bit audio, it’s only 85% of the size of the version with a 1509Kbps core. For 5.1 or 2.0 (or 16-bit source), the reduction is even greater. A quick test with a 2-hour movie with a DTS-HD MA 2.0 soundtrack shows the following file sizes:

1,726,796,116: DTS-HD MA (1509 core)
  498,947,532: DTS-HD MA (no core)
  486,426,680: FLAC

You could see how this would benefit streaming/downloading.

DTS-HD suffers compared to FLAC or TrueHD in having an absolute minimum bitrate set by the fixed rate of the core. This means that even if the audio track is not complex, you still use bits that might not be needed. Overall, FLAC, TrueHD, DTS-HD (no core), DTS-HD (core) is the order from smallest to largest for any given audio track. If everything you play back on supports lossless audio, then why not use a format that takes up less space?

I don’t actually intend to use no-core DTS-HD in general, because FLAC is better, but in playing around with it, I was shocked to see that various players had no issue with it, so I tested on the Vero 4K.

For Aliens (Director’s Cut) 5.1, 24-bit:

4,616,166,216: DTS-HD MA (1509 core)
3,939,698,120: DTS-HD MA (no core)
2,252,767,777; FLAC

So, DTS still is pretty large, even with no core, but FLAC saves 2.3GB.

I know that disc space is cheap now, but saving 1-2GB per movie is going to be 3-10% savings even with a remux. Since you don’t lose any quality, and it doesn’t take any extra time (any processor can encode to FLAC faster than reading from a Blu-Ray drive), why not?

Where it really shines is transparent re-encodes using H.265, when you can get a movie down to less than 10GB from the original Blu-Ray, and retain all the video and audio quality.