[musv]

Hi there,

I used all the years Live TV with Dolby Digital passthrough without big issues. From V18 the default behaviour have been changed. It's described quite good in those threads:
https://forum.kodi.tv/showthread.php?tid=284580
https://forum.kodi.tv/showthread.php?tid=359122

The summary:
I'm using an AVR on my Android Box. Comparing PCM Multichannel and Dolby Digital passthrough produce very noticeable differences in the sound quality. PCM gives a flat weak sound. In Dolby Digital the sound spots are far more distinct. The sound from behind is more present. Also the subwoofer is different. Reading the first thread, the differences could be a result of the lost metadata in the PCM stream. Probably the AVR makes a difference in processing the PCM signal and a DD signal.

The decision for preferring PCM over DD was probably made to guarantee a synchronous playback especially when using timeshift.

So we have a design conflict between a much better sound quality (DD) or a guaranteed synchronous playback (PCM).

The current workaround to re-enable DD in LiveTV is to set the speakers to 2.0 and activate DD transcoding in the system audio settings. This has the downside of a de- and re-encoding. Also the setting is not obviously understandable.

My proposal:

• Remove the "Enable Dolby Digital (AC3) Transcoding" setting in Settings -> System -> Audio, because the setting is only PVR related and does not have any impact on any other sound processing (Movies, Music).
  
• Put in Settings -> TV a setting: "Decode DD to PCM for accurate audio synchronisation in LiveTV."
  
• Drop the processing chain for Live-TV: DD -> PCM -> DD and passthrough the original DD track to the AVR, if no the setting one line above has been activated.

Would be nice, if the current behaviour could be corrected. At least according to the first link I'm not the only one with a better sound equipment, who suffers with PCM sound in Live TV.

And generally: Thanks a lot for you fantastic work on this wonderful project.

[noggin]

Remove the "Enable Dolby Digital (AC3) Transcoding" setting in Settings -> System -> Audio, because the setting is only PVR related and does not have any impact on any other sound processing (Movies, Music).

This option isn't just there for PVR use. It's used by a lot of people who have older AVRs or Surround speaker systems using SPDIF/TOSLINK (so only get DD, PCM 2.0 or in some cases DTS) or use first-generation ARC (again limited to SPDIF bitrate DD/PCM 2.0 and I some cases DTS) to carry audio from a TV to their AVR via HDMI and only have support for Dolby Digital (and in some cases also DTS)

If they playback PCM, FLAC or AAC multichannel audio, then without the transcode to AC3 option they will only get stereo. (Also DTS if their surround speaker solution doesn't support DTS bit streamed - which some TVs don't via ARC)