v17 DTS music playback from WavPack (.wv) files
#42
When I realize I have made a mistake, I do not hesitate to admit it. So, I admit that I was wrong when I said that AVRs decode Dolby Digital/DTS audio sent as linear PCM by accident. I had raised this question before, but never followed up on it: http://forum.kodi.tv/showthread.php?tid=...id=2149413

@Soli’s comment that it has worked on AVRs since the LaserDisc era made me look into the standards from that time. Indeed, the pre-1997 IEC958 standard have references about this. It has also been described in Annex B of A/52 (1995). Reference to this has since been removed from A/52. There is still a short reference to this in IEC-61937-1 under sec. 6.3.3 Burst spacing (which I seem to have overlooked although I have gone through the standards several times).

In short, this works by looking for Dolby Digital/DTS sync codes (Pa and Pb which are now part of the burst-preamble of IEC 61937).
Dolby Digital sync code – 0xF872, 0x4E1F (32-bit)
DTS sync code – 0x7FFE8001 / 0x3F (32/38-bit)
You can reduce the false detection rate by including the four “0” subframes in the burst-spacing along with Pa and Pb to form an extended 96-bit sync code.

(2017-01-03, 00:56)Soli Wrote: It's not an accident AVRs decode bitstream content even though they stream is flagged as linear pcm.
If all modern day AVRs did this, how do you explain why these users are getting noise with this “PCM Passthrough”? Some of them could be user errors (volume control), but I don’t think all of them are user errors. As mentioned in Annex D of IEC 60958-1, this doesn’t conform to 60958 standards and it is up to the vendor to implement this “fail-safe” option for linear PCM vs non-linear PCM audio detection.

http://forum.kodi.tv/showthread.php?tid=...pid2419995
http://forum.kodi.tv/showthread.php?tid=...pid2457364
http://forum.kodi.tv/showthread.php?tid=...pid2420652
http://forum.kodi.tv/showthread.php?tid=...id=2248752
http://forum.kodi.tv/showthread.php?tid=...pid2242081
http://forum.kodi.tv/showthread.php?tid=...pid2233494
http://forum.kodi.tv/showthread.php?tid=...pid2234479
http://forum.kodi.tv/showthread.php?tid=...pid2203068
http://forum.kodi.tv/showthread.php?tid=...pid2202047
http://forum.kodi.tv/showthread.php?tid=...pid2189107
http://forum.kodi.tv/showthread.php?tid=...pid2189156
http://forum.kodi.tv/showthread.php?tid=...pid2184950
http://forum.kodi.tv/showthread.php?tid=...pid2182566
http://forum.kodi.tv/showthread.php?tid=...pid2170080
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RE: DTS music playback from WavPack (.wv) files - by wesk05 - 2017-01-12, 20:04


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