[noggin]

This is related, partially, to this : http://forum.kodi.tv/showthread.php?tid=306950 and http://forum.kodi.tv/showthread.php?tid=...pid2524203

Is there any likelihood of :

1. 2.0 matrix surround (i.e. Dolby Surround) encoded 2.0 AAC/AC3/E-AC3 audio AND correctly flagged in metadata to be properly decode to PCM multichannel being implemented. (ffmpeg currently doesn't have a suitable filter, but MythTV does) This would require a Dolby Surround 2.0 to 3.0/4.0 (i.e. 2.0 to 3.0 Stereo + Rear or 4.0 Stereo + Centre + Rear passive matrix decode) or a Dolby ProLogic/THX-style 2.0 to 4.0/5.0 (i.e. rear left and rear right plus centre) style active-steering decoding algorithm to be implemented.

2. 2.0 Matrix Surround AAC or AC3/E-AC3 audio being decoded AND re-encoded to Dolby Digital 2.0 (NOT DD5.1 and NOT PCM 2.0) with the correct metadata preserved/generated to trigger off-board AVRs to decode using ProLogic/THX etc.? (This would be a change to the current DD Transcode option which only triggers DD re-encoding in the presence of discrete >2.0 surround content and outputs DD/AAC 2.0 to PCM not DD 2.0)

Either or both would be amazing, though I realise 1. may require ffmpeg developer support?

[scarface_one]

1. If I'm not mistaken, Audio DSP has a plugin (freesurround) that decodes the Dolby Surround bits to PCM. I don't know about metadata though.
2. Again, Audio DSP has the required plugin - audiodsp basic.

Audio DSP, was unfortunately disabled in Kodi 17 Krypton because it was too buggy on some platforms.

@popcornmix,
I will disable it for the final release: https://github.com/xbmc/xbmc/pull/10756

@Melf11:
You could try my latest patches, they're fine under Windows. For more platforms I did not had time for testing. https://github.com/achimturan/xbmc/tree/...core_fixes

Linkto Audio DSP subforum on this forum

[noggin]

1. If I'm not mistaken, Audio DSP has a plugin (freesurround) that decodes the Dolby Surround bits to PCM. I don't know about metadata though.
2. Again, Audio DSP has the required plugin - audiodsp basic.

Audio DSP, was unfortunately disabled in Kodi 17 Krypton because it was too buggy on some platforms.

@popcornmix,
I will disable it for the final release: https://github.com/xbmc/xbmc/pull/10756

@Melf11:
You could try my latest patches, they're fine under Windows. For more platforms I did not had time for testing. https://github.com/achimturan/xbmc/tree/...core_fixes

Linkto Audio DSP subforum on this forum

Useful to know - that would potentially allow a route to get 2.0 AAC/DD with matrix surround content decoded to 5.1 PCM with surround. If metadata driven switching were available/implemented, that would be a solution for those with 5.1 PCM output.

Does AudioDSP work upstream of DD transcode? (I.e. Can you decode 2.0 matrix surround to 5.1 PCM and then re-encode the final result to DD 5.1?) That would also give those with a 2.0/SPDIF solution support.

[scarface_one]

Can you decode 2.0 matrix surround to 5.1 PCM

I believe this is the purpose of the freesurround addon for Audio DSP. It should handle Dobly Digital and DTS Neo.

and then re-encode the final result to DD 5.1?

Kodi already can do this. Go to Settings -> System -> Audio. Scroll down to Passthrough, then check Transcode to Dolby Digital.
The option might be named differently though. I don't think Audio DPS can be used in conjunction with passthough.
Also, if your AVR/Sound System supports Dolby Digital passthrough, there is a good chance that it can also decode the matrix encoded audio from a stereo stream, so there is no need for Audio DSP in that case.

[noggin]

Kodi already can do this. Go to Settings -> System -> Audio. Scroll down to Passthrough, then check Transcode to Dolby Digital.
The option might be named differently though. I don't think Audio DPS can be used in conjunction with passthough.
Also, if your AVR/Sound System supports Dolby Digital passthrough, there is a good chance that it can also decode the matrix encoded audio from a stereo stream, so there is no need for Audio DSP in that case.

Yep - the point is to see if it is possible to preserve 2.0+SUR vs 2.0 metadata (it's possible to flag the presence of matrix surround in DD/DD+ metadata - and initial tests of clips show that both DD+ 2.0 and DD+SUR 2.0 is broadcast in some cases)