can't use audio device type 'optical' to its full potential anymore

[OttoKerner]

Previously, PMP could be configured optimally to drive soundbars and older AVRs with optical inputs. But now it appears it has lost:

• the ability to encode surround sound of any source format to AC3 5.1 @ 640 kbps (so it fits through a S/PDIF or TOSlink connection and remains compatible with even the most basic AC3 decoders)
• the ability to define the speaker configuration (2.0 or 5.1) when switched to output type 'Optical'

The speaker configuration cannot be determined automatically. If the S/PDIF or TOSlink port is built in to the computer (there are still lots and lots of mainboards out there with TOSlink outputs), you cannot know which speaker configuration is sitting at the other end of the link. Additionally, some users are using HDMI -> TV -> TOSlink -> soundbar Others are using a signal splitter, which extracts the audio signal to TOSlink from a HDMI connection. All of these solutions need the ability of PMP to encode surround sound to AC3, or all these users won't be able to get any surround sound at all. And additionally a way to tell PMP to not encode to AC3 (in cases where the sound system at the end of the optical link is only stereo).

PMP used to have this ability. But it appears to have regressed lately.

Test environment

PMS Version: 1.15.0.647 PMP Version: 2.27.0.949 Platform (Windows/macOS/Embedded RPi/Embedded Intel): Windows

Steps to reproduce

1. Set audio device type to 'optical'
2. play a video with surround (5.1) sound (audio format doesn't really matter)

Current behavior

1. audio plays in stereo if it can't passthrough the original audio stream

Expected behavior

1. PMP should transcode surround audio to AC3 5.1

• if it can't extract a suitable 'DTS core' audio from the audio stream and 'passthrough' that or if passthrough of DTS is disabled
• if the orignal audiostream is not already in AC3 5.1 format (or is above of 768 kbps bandwidth)

2. PMP should correctly downmix to stereo (which means including the center channel, where all the dialogue is) if the speaker configuration is set to 2.0