Bug 4551 - Problem with playback of AC3 and DTS from DVD (48kHz) through SqueezeBox
: Problem with playback of AC3 and DTS from DVD (48kHz) through SqueezeBox
Status: RESOLVED WONTFIX
Product: SB 2/3
Classification: Unclassified
Component: Audio
: 69
: PC Other
: P2 enhancement (vote)
: Future
Assigned To: Chris Owens
:
Depends on:
Blocks:
  Show dependency treegraph
 
Reported: 2006-11-27 03:46 UTC by Erwin van den Berg
Modified: 2010-05-07 11:04 UTC (History)
1 user (show)

See Also:
Category: ---


Attachments
AC3 file in FLAC format (zipped) (5.77 MB, application/octet-stream)
2006-11-27 08:41 UTC, Erwin van den Berg
Details

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Description Erwin van den Berg 2006-11-27 03:46:32 UTC
The problem is that my surround processor (Meridian 565) looks for the 'non-audio' flag in the subchannel of the SPDIF signal. I checked with Meridian and they confirmed this is also true for the 561 and 568Mk1.

So actually you should check the PCM stream for the IEC61937 header and if it is available do the following:
1) Do not change volume (keep it at 100%).
2) Disable analog (will sound like white noise)
3) Set non-audio bit in subchannel of SPDIF.

Ofcourse point 1 and 2 from the above could also be done when DTS from CD is detected (not point 3 !!!!)
Comment 1 Erwin van den Berg 2006-11-27 08:41:15 UTC
Created attachment 1728 [details]
AC3 file in FLAC format (zipped)

I converted an AC3 file from DVD using the python script from a user of your forum, compressed it with FLAC and zipped it (3Mb less).
Comment 2 Chris Owens 2007-02-12 13:46:00 UTC
Currently we don't analyze the data at all, so this functionality would have to be added.  Therefore I have flagged this as an enhancement request.

A coworker points out there's another bug filed to also turn off the analog outputs when non-audio data is detected.

Since my last job before Slim Devices was working in this area, I have to point out that most receivers try to detect the bit stream despite the correctness of the non-audio flag, which is why few users have reported this problem.
Comment 3 Alan Young 2010-05-07 11:04:22 UTC
All new Squeezebox products are likely to be based on the SqueezePlay platform.
We do not plan to implement any further enhancements to the ip3k firmware or
which are targeted specifically at ip3k-based products.