I have a video file with two AC3 audio tracks (media info attached). When Plex on my PS4 has Dolby Digital turned on in settings, Plex tries to Direct Play the file (Now Playing reports this) but the audio is silent. When I turn off Dolby Digital in settings, this forces the server to transcode AC3 to AAC and it works fine.
I noticed in the patch notes for the newest Plex media server that this might have been fixed, but when I tested out the same file, there was still no audio.
I did discover that if I turned off Dolby Digital AC-3 in the settings for the PS4 app, the audio will play fine, but if I turn it on, there is no audio, even with the audio track being AC-3.
I have had the same with the PS3 app. I have found a workaround of sorts for me anyway don’t know about PS4 as that is a whole diff POS them mine, don’t have 3 - 400 to lay down to get one.
As for the workaround I have gone into the profiles and added ac3 to the front of all the audio setting and when It says it’s transcoding will it is to the TS file format but it’s a direct copy of the h.264 video and the ac3 audio streams. It’s just moving them to a TS file to stream why, I don’t know as I can play the mp4 files from it’s hard drive just fine guess it has to do with how sony does it streaming.?? Hope that helps if you need me to i can copy the profile files I have modded and post them here.
I encoded some new files today with AC-3 tracks and the audio simply doesn’t play on the PS4. I have to force a transcode by unchecking Dolby Digital AC-3 in the Plex PS4 app settings.
Did this ever get resolved? I’m running into the exact same issue today with this file:
Media
Video Resolution 1080p
Duration 3:02:33
Bitrate 9431 kbps
Width 1920
Height 800
Aspect Ratio 2.35
Container MP4
Video Frame Rate 24p
Web Optimized No
Has 64bit Offsets 1
Video Profile high
Part
Duration 3:02:33
Size 12.03 GB
Container MP4
Has 64bit Offsets 1
Has Chapter Text Stream 1
Has Chapter Video Stream 1
Web Optimized No
Video Profile high
Codec H264
Bitrate 8791 kbps
Language English
Bit Depth 8
CABAC true
Chroma Subsampling 4:2:0
Duration 3:02:33
Frame Rate 23.976 fps
Frame Rate Mode vfr
Height 800
Level 4.1
Pixel Format yuv420p
Profile high
Ref Frames 5
Scan Type progressive
Stream Identifier 1
Width 1920
Codec AC3
Channels 5.1
Bitrate 640 kbps
Language English
Audio Channel Layout 5.1(side)
Bit Depth 16
Bitrate Mode CBR
Dialog Norm -31 dB
Duration 3:02:33
Sampling Rate 48000 Hz
Stream Identifier 2I think this is the issue we found in https://forums.plex.tv/discussion/comment/1258993/#Comment_1258993 which should be fixed in the next release.
@kay.one said:
I think this is the issue we found in https://forums.plex.tv/discussion/comment/1258993/#Comment_1258993 which should be fixed in the next release.
When will it be released and does it support PS4 DLNA? 
Just now I was having the issue where I wasn’t getting sound with any video on my Plex with AC3 audio. It now works now after disabling Dolby Digital AC-3 in the settings.
Still seems to be an issue that Plex hasn’t fixed
