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Full Version: multichannel wav/ flac -> no passthrough possible?!
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(2014-05-22, 11:14)Bluebuster83 Wrote: [ -> ]Actually, XBMC KNOWS playing a DTS file, because it is shown correctly in the fullscreen display of XBMC as "DTS 5.1".

Indeed it does, at least for the DTS WAV files. However mentioning what XBMC "sees" made me double check the codec OSD and this brings about another difference.

On x86 Gotham (OE 4.0.2, paplayer), the codec OSD shows only 2 channels for a DTS WAV file, yet the amp shows DTS and outputs surround sound to all 6 speakers:
Image
Whereas on Pi (OE Helix, paplayer), same DTS WAV file, the codec OSD shows 5 channels and the amp shows multichannel (PCM) and the audio sounds identical to how it was playbed by x86.
Image

Neither x86 or Pi seem to be agree on the bits/sample, which mediainfo claims to be 24 bits.

But as you can tell, I'm guessing about much of this stuff... certainly there seem to be differences between x86 and Pi where DTS WAV is concerned, but possibly just cosmetic differences.

The WAV-encoded DTS sample I uploaded on the other hand is "seen" by XBMC as a pure FLAC/WAV file both by the Pi and x86 - both see it as a 48kHz/16-bit/2-channel FLAC file, which is what it is to all intents and purposes, so unless your amp is able to detect the resulting digital audio as DTS all you'll get is white noise. Make sure your XBMC volume is set to 100% because if its any less the bitstream will be corrupted.
ufff.

Thanks for the hint of 100% volume! Now I am able to play your flac correctly. But as deaper i dig as less I understand Huh Why is your flac detected as 2 channel, but playing 5.1 DTSHuh

I noticed that it may depends on the sampling rate. All files recognised and correctly passedthrough DTS streams are in 48kHz! The files with 44.1kHz are transfered to PCM.
I don´t know how to resample a file, but I think this should be tracked next.
(2014-05-22, 13:31)Bluebuster83 Wrote: [ -> ]Thanks for the hint of 100% volume! Now I am able to play your flac correctly. But as deaper i dig as less I understand Huh Why is your flac detected as 2 channel, but playing 5.1 DTSHuh

The file I uploaded has WAV "headers" making it appear to be a 2-channel WAV file even though the digital data is 5.1 DTS.

XBMC (and my Squeezebox) thinks it is just a plain stereo WAV (compressed with FLAC) and sends the uncompressed digital data to the amp which interprets the "WAV" (PCM?) data - as long as its bit-perfect, ie. 100% volume - as DTS. See previous posts with links and explanation. That's why if you modify the volume of XBMC it mangles the PCM data (modulated by the volume) which is no longer interpreted as DTS data - the only way to send bit-perfect data from XBMC (or Squeezebox) to the amp is at 100% volume.

(2014-05-22, 13:31)Bluebuster83 Wrote: [ -> ]I noticed that it may depends on the sampling rate. All files recognised and correctly passedthrough DTS streams are in 48kHz! The files with 44.1kHz are transfered to PCM.
I don´t know how to resample a file, but I think this should be tracked next.

I guess it's possible that 44.1kHz isn't a valid DTS rate and maybe there's some re-sampling going on, but would this also explain the difference between x86 and Pi when a DTS WAV file will appear as "DTS" on the amp when played by x86, but PCM when played by the Pi? Also 2 channels on x86 but 5 channels on Pi?
I had this working perfectly two years ago, thanks to the nice guys in this forum. Check this thread: http://forum.xbmc.org/showthread.php?tid=131508

To sum up:

Add the following line to your playercorefactory.xml:

<rule filetypes="(dts|wav)" player="DVDPlayer" />

If you use .dts as the file extension, you should be able to add it by putting the following line in your advancedsettings.xml:

Code:
<musicextensions>
<add>.dts</add>
</musicextensions>

Plus I made a cue file for tagging.

I don't know what has changed in XBMC since then, so I have no idea if this still works. But it did then. It also had perfect gapless playback, which was broken in later versions. But it is back now?
After reading the posts, I don't think anybody answered the question:
Which of the both RPi/OE or AVR decodes DTS/.wav file?

As I said, I'd prefer AVR but I don't know.
In my setup it is the AVR that decodes the DTS file. I have a HDMI splitter, with an optical SPDIF out that goes to my receiver. I don't know how the RPi could be used for decoding multichannel files.
(2014-05-22, 22:02)trondis23 Wrote: [ -> ]In my setup it is the AVR that decodes the DTS file. I have a HDMI splitter, with an optical SPDIF out that goes to my receiver. I don't know how the RPi could be used for decoding multichannel files.
So, you AVR display "DTS file playing"?
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