Server Version#: 1.20.1.3252
Player Version#: 6.6.12.6662-64d4a08ac-Plex
I have just started ripping 4K movies from MakeMKV. I then transcode using Handbrake using HVEC Main 10 to reduce the file size. Since I don’t have any 7.1 capable devices, I transcode the 7.1 audio down to AC3 5.1 and AAC stereo.
When I play the movie, the audio and video transcode when I select the AAC stereo stream.
Stream info -
Playback Transcoding (pending)
Format mkv
Video H.264 - convert
Audio English (AAC Stereo) - convert
Subtitle none
When using the 5.1 AC3 audio stream, everything direct plays.
Stream info-
Playback Direct Play
Format mp4
Video 4K (HVEC Main 10 HDR)
Audio English (AC3 5.1)
Subtitle none
I have tried many different settings for the audio and the stereo audio stream always seems to cause the video and audio to transcode whether the original audio is TrueHD or DTS-HD 7.1.
Using AAC stereo with my 1080p HEVC version direct plays just fine.
I have tried to placing the mkv file from MakeMKV on Plex and all of the audio streams cause transcoding then. I have also tried searching in the forum, but all of the topics that I found involve either multi-channel AAC audio or subtitle files. Neither of these seemed to apply to my situation.
Your server logs might be more telling as that’s where Plex decides if it’ll transcode (and why).
Could be as simple as your Roku applying some limit to AAC streams (or Plex believing there is such a restriction).
This is one of those fun Roku edge cases, that is pretty nuanced. We are not able to select the audio track when direct played when it’s MP4. We are only able to specify the audio language to choose. We can however assume Roku will choose the best audio stream (5.1 AC3), so we can allow direct play when that stream is selected. When you choose the AAC stream, we have to defer to the PMS(transcode). That however should be a simple remux (copy all compatible streams), so it’s interesting that it’s choosing to convert the streams.
Here are a few things to check:
Open the Plex channel and go to settings.
Under the video section, verify:
Local and Remote quality are set high enough - try using original quality.
Direct Play: auto
Allow Direct Stream: checked
If this does not work, then we’ll have to view the logs which we handle if needed.
Another alternate option is to start using the MKV format instead of MP4. In that case, we should be able to select the stream during direct play.
@ljunkie
I did try those settings on the player. The video seems to always transcode unless original quality is selected. If I set Direct Play to force, it seems to work, but I would have to remember to change that setting on all the movies on all of my players. Allow Direct Stream is always checked.
I am reencoding the movie in a mkv container to see if that helps and will report later this afternoon when it is done.
@tom80H
I thought I included the server logs in the zip file, but looking back it seems I got the web client logs by mistake. I will grab the server logs later today if I still have the same problem with the movie in an mkv container.
Reencoded using an MKV container and it looks to be working now. I left the Handbrake audio settings the default which created two audio streams, one AAC stereo and one TrueHD 7.1 passthrough. Selecting the AAC stereo stream direct plays everything. When I select the 7.1 stream, the audio transcodes as I would expect, but the video direct plays now. I can happily live with this. I guess I should have gotten out my mp4 mindset earlier and use mkv containers.
