iissmart 0 Posted May 16, 2019 Share Posted May 16, 2019 (edited) I have an emby server on an Ubuntu 16.04 x64 server, and my client is an NVIDIA shield tv. When playing a file with TRUEHD audio the playback is Dolby Digital. I don't see any settings to control output for TrueHD. Can the logs help identify why it is transcoding? I can play the same file in Kodi and Plex without any transcoding. Stream mapping: Stream #0:0 -> #0:0 (copy) Stream #0:1 -> #0:1 (truehd (native) -> ac3 (native)) Log.txt Edited May 16, 2019 by iissmart Link to comment Share on other sites More sharing options...
ebr 14904 Posted May 16, 2019 Share Posted May 16, 2019 Hi. According to that log, we tried to direct play that item and encountered an error so we re-tried with a remux with an audio conversion and that succeeded. If you can follow the instructions to send a log from the app after playing this item for a few seconds, we can see what the original error is. Thanks. Link to comment Share on other sites More sharing options...
iissmart 0 Posted May 16, 2019 Author Share Posted May 16, 2019 Logs have been sent from the client just before sending this message. 1. Enabled debug options 2. Navigated to Game of Thrones, season 1 episode 1 3. Hit play, episode started playing with DD audio instead of TrueHD 4. Waited a few seconds, then backed out and sent logs from the main menu Emby user on the local server should be iissmart. Let me know if you need anything else! Link to comment Share on other sites More sharing options...
ebr 14904 Posted May 17, 2019 Share Posted May 17, 2019 Never seen this one before but Exo doesn't like the encoding of this video. ContentCompAlgo 0 not supported Link to comment Share on other sites More sharing options...
iissmart 0 Posted May 17, 2019 Author Share Posted May 17, 2019 Strange, because it plays perfectly in Kodi and Plex. I've attached the mediainfo output for the file, if that helps. I tested other shows/movies with TrueHD and Atmos audio tracks, and Emby played them back perfectly. So it does seem to be something unique with these Game of Thrones episodes. Other episodes in the same season have the same issue in Emby. I don't fully understand the error - is it something server side or client side? mediainfo.txt Link to comment Share on other sites More sharing options...
ebr 14904 Posted May 18, 2019 Share Posted May 18, 2019 I believe the contents in the MKV are zlib compressed and that is not supported by our player. Link to comment Share on other sites More sharing options...
iissmart 0 Posted May 18, 2019 Author Share Posted May 18, 2019 I see zlib compression in the subtitles, but not in the audio stream. mkvinfo output attached. I do see in the spec where ContentCompAlgo of 0 is zlib, but that doesn't entirely make sense given the mkvinfo output... mkvinfo.txt Link to comment Share on other sites More sharing options...
Luke 37020 Posted May 18, 2019 Share Posted May 18, 2019 Since you see it in the subtitles, can you try remuxing to remove the subtitle stream? Link to comment Share on other sites More sharing options...
iissmart 0 Posted May 19, 2019 Author Share Posted May 19, 2019 Remuxing and excluding all subtitles causes TrueHD to work on this file! So the zlib compressed subtitles are causing it to initially fail for some reason? I ran mkvalidator on the original file and it says the file is valid. Link to comment Share on other sites More sharing options...
Luke 37020 Posted May 19, 2019 Share Posted May 19, 2019 It's valid, it's just not yet supported by the player software that we're using. Link to comment Share on other sites More sharing options...
iissmart 0 Posted May 19, 2019 Author Share Posted May 19, 2019 I'm not sure I fully understand. I tested playback of a different movie with very similar characteristics to this Game of Thrones episode (1080p remux, primary atmos audio track with a few other DD audio tracks, and multiple subtitle tracks compressed with zlib) and it plays with TrueHD audio as expected in Emby. Subtitles are off for everything, so I'm not sure how subtitles are impacting the audio track in Game of Thrones. Link to comment Share on other sites More sharing options...
iissmart 0 Posted May 20, 2019 Author Share Posted May 20, 2019 I tested extracting all video, audio, subtitle tracks and chapters from the original episode and muxing them into a new mkv in the same order. Surprisingly, this played back with TrueHD audio, even with the zlib compressed subtitles included! Comparing mediainfo between the two files, the new one is missing a Title and Language field for all tracks (likely something I'd have to manually enter?), but additionally the Default flag is set for the first subtitle in the new file, and not in the original. So, I tried using mkvpropedit to disable the default flag in the new file. Now, Emby starts transcoding the file to DD again! Strangely, using mkvpropedit to reset the default flag back to 1 for the subtitle track doesn't seem to fix it; Emby still transcodes to DD. I have to recreate the entire mkv with mkvmerge to get it to playback TrueHD again. Link to comment Share on other sites More sharing options...
ebr 14904 Posted May 20, 2019 Share Posted May 20, 2019 so I'm not sure how subtitles are impacting the audio track in Game of Thrones. Indirectly... The app only knows that the player threw an error attempting to direct play the file so, in response to that, it attempts to play it a different way and its next attempt is to try converting the audio (because many playback errors can be caused by the audio track). The process to convert the audio also happens to change how the subtitles are delivered which then fixes the problem. Does that make sense? Link to comment Share on other sites More sharing options...
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