I’m trying to find out how to prevent plex from transcoding my Flac collection to MP3. I’d like it to just passthrough to the shield which should then passthrough to my receiver which is fully capable of playing flac files. Is there a workaround for this?
Thanks!
Additional info: I’m trying to play stereo FLAC files that I’ve ripped from my cd collection. Both my shield tv and desktop PC are hardwired to the same network. Receiver is a Denon AVR-X4000 which can play flac files.
This is a huge issue. The Nvidia Shield is capable of passing FLAC files through natively. Why do the FLAC files get transcoded and why to MP3 of all things?
Check your settings in the Plex app on the Shield. Another user I was helping in the DVR area found he had disabled Surround Sound on the Shield which was forcing a Transcode of all of his Live TV and recordings. Once he turned that back on everything is now Direct Play to the Shield from Plex. You might have a similar issue. The Client device when communicating with PMS tells PMS what audio/video it can handle and Plex will transcode based on the client requirements.
@NINaudio and @dgmelvin
I am very sure that the HMDI standard is not able to carry FLAC (your Shield to AVR connection) as bitstream. That’s why Plex is transcoding to a format the Shield is able to convert to something supported by HDMI (e.g. PCM or DD).
Not true. When I run the same music through my ROKU 3 they go right through without transcoding. I use HDMI for the ROKU as well as the Shield. ROKU broke their machines (software) so I have moved on but this is a big problem for all my Plex FLAC music files that are 92 or higher. They seem to want to transcode to MP3 with a several second delay before they start. I imagine the transcoding from lossless down to the very lossy MP3 format is where the time is being spent.
Is there a setting on the Sheild Plex client for music files to force direct play?
@dgmelvin said:
Not true. When I run the same music through my ROKU 3 they go right through without transcoding.
Then I suppose your Roku decoded the audio to LPCM. HDMI does not support FLAC. But you are right, in theory the Shield TV should also be able to transcode FLAC to LPCM (lossless). Let’s see what my Shield does 
@dgmelvin 192000 Hz with 5 Mbps FLAC is direct playing in Plex on my Shield TV 2015. Of course, FLAC is decoded to LPCM (lossless) by the Shield TV and that’s what my receiver is displaying. So it’s just a settings issue I suppose.
Have you set Passthrough to “Auto” and “Audio Quality” to “Original” in the Shield TV Plex client settings? In the global settings of the Shield TV I have “Surround Sound” set to “Auto” and “Stereo Upmix” disabled.
Yes, I have all those settings the same as what you mentioned. Most of my Flac files work, but here is an example of one that sits silently for a number of seconds before finally changing from direct to transcoding to MP3.
@dgmelvin said:
Yes, I have all those settings the same as what you mentioned. Most of my Flac files work, but here is an example of one that sits silently for a number of seconds before finally changing from direct to transcoding to MP3.
Ha. Completely different scenario. That’s the fallback in case of a client error. I suppose Exoplayer2 is unable to decode some of your files so Plex is falling back to decode at the server.
I need at least this “broken” file and your Client logs (remote logging) would be nice. If I am able to reproduce your problem with this specific file I can create relevant logs myself.
https://support.plex.tv/articles/201573117-android-android-tv-fire-tv-logs/
The file is from an album I bought and downloaded from ProStudioMasters. I’m not sure it is legal to share it on a public forum like this. I’m about to go out of town for two weeks and don’t have time to work through the logs, but if there is somewhere I can send you a copy of the flac file privately I am happy to do so.
Any word on a fix for this yet?
Did you ever provide the logs from PMS and the Shield? If you can reproduce and share new ones now, I can take a look. Also provide the full XML for that file from Plex Web.
I sent the file I have the issue with to uglymagoo and he said he could reproduce it and would send it into Plex (at least that is what I thought he said he was going to do.)
Basically anything I download from ProStudioMasters at 96k or higher errors out and ends up either sending a transcoding error to the screen or after 15 or so seconds gets transcoded to MP3. It makes those tracks unplayable in Plex through Nvidia Shield.
Attached is the XML file for one of the tracks with this issue.109138.txt (1.9 KB)
Here is the reply I got from an email from uglymagoo:
Plex Forums https://forums.plex.tv/
uglymagoo sent you a message
I am able to reproduce the error. As I expected. Direct play is tried by failing. Fallback to server transcode. I will send the file to engineering.
And BTW, the same files play direct through the ROKU using Plex.
Thanks. I was able to find the issue files by uglymagoo. The team has looked at the issue. There appears to be a problem with the audio player in Android handling that format. The audio player is fairly basic and my guess is failing on the 24-bit encoding.
FYI - A CD is only encoded in 16-bit, so you don’t get any better quality using 24-bit, unless your source is an audio master. I would suggest just stick to 16-bit.
We are looking to update the audio player in the future but I do not have any info on when that might happen.
I just picked up a Shield TV last night and having the same issue. But not only with my 24-bit FLAC files, but also with 16-bit FLAC (ripped from CD’s).
And not sure if it’s related to same player issue, but audio is out of sync with my h.264 and H.265 videos (although more noticeable with 265 (audio is AC3)). Audio is fine with Plex DVR recordings (which are mpeg). If I switch from original quality to automatic, then I don’t have any sync issues, but then PMS transcodes (even 264 -> 264, AC3 -> AAC 5.1).
Shield is running latest update of Android and latest version of Plex app. If I play the same files from my PMS server (Win10 64bit with standard PMP (not UWP)), I don’t have either of those issues.
Next is to see if I can can get the Android beta to test channel grid. Although might have to use HDHR app until you support channel surfing.
I don’t think it is specifically 24bit. Many of my 24bit files play without issue. The downloads from ProStudioMasters that are high res like the files I provided are the only ones that will not play on Shield TV. A HUGH issue for anyone that listens to high res content. Sometimes it will transcode (and sometimes it just fails), but when it does work it transcodes to MP3 after many seconds of silence (for each track) which sort of defeats the purpose of high res music files. Even in Android fails on a particular file I would think PLEX should be able to fall back to something more reasonable than MP3.
