Amazon Fire TV Cube 2nd Gen - Won't Direct Play supported files

Plex Players Streaming Devices
1

Server Version#: 1.21.0.3711
Player Version#: 8.9.1.21593

I have a brand new Amazon Fire TV Cube (2nd generation model). I’ve installed the Plex app on to it. However, I’m finding that it refuses to direct-play anything. It force transcodes everything. I looked up the supported codecs on Amazon’s website (https://developer.amazon.com/de/docs/fire-tv/device-specifications-fire-tv-cube.html), and all of the video files I’ve tried to stream are supported by the device:

Example: mkv container, h264 High@L4, ac3 audio, srt subtitles

This should be a no-brainer to stream directly to the device (as a matter of fact, if I play this file via the VLC app, it plays perfectly). However Plex for some reason thinks it needs to be transcoded from h264 to h264.

After taking a look at the Android.xml profile I found that it’s missing a lot of the supported codecs that could be directly streamed to the device.

Is there a Fire TV Cube specific XML that would allow direct streaming of these ???

2

The Plex app will check with the device what codecs are supported. Keep in mind that Amazon’s doc only list the codec, but not every codec is supported in every container. Also, codecs can have certain parameters that can prevent them from direct playing.

Please play the file from the Fire TV, then grab the logs, Android, Android TV, Fire TV Logs | Plex Support. Also provide the XML from PMS so we can check what codecs are involved Investigate Media Information and Formats | Plex Support.

3

Here’s the info from the “network logging”

I attempted to play two videos. One was an HD h264 encoded mkv, the other a 4K HEVC encoded mkv.

NetworkLogging.txt (1.2 MB)

4

Here’s the XML for the 4k file.

4k.txt (6.9 KB)

5

Here’s the XML for the HD file.

hd.txt (3.8 KB)

6

For that Star Trek episode, the file has EAC3 audio. Does your TV support EAC3? Your logs show the app tried to passthrough the audio but something failed along the way. The app then changed and fed the EAC3 directly to the Fire TV which decoded it to PCM and sent that to your TV.

The same thing with the 4K file. That also has EAC3 audio.

7

The Fire TV cube is connected via HDMI to an Onkyo receiver that is completely capable of playing EAC3 audio (as well as many other digital audio formats). Fire TV specs also list EAC3 as a compatible digital audio format.

Both of these files stream perfectly on the Fire TV cube using Emby, with no transcoding at all. The issue is not the video file. For some reason PLEX doesn’t seem to understand that it’s running on a device capable of handling these.

8

BTW, when playing on the Plex app, if I bring up the Playback info, it shows that the EAC3 stream is not being transcoded. It’s the video stream that is being transcoded (from H264 to H264…which doesn’t make sense), and it appears the SRT text subtitles are being burned into the transcoded video, even though I’ve set it to only burn in image formats.

20201204_180036
20201204_180036816×612 131 KB

9

As shown in that error and as I mentioned, the app did try using the EAC3 audio as-is (direct play), but it failed. Somewhere in the hardware chain, this failed, when the app direct plays, it sends the audio as-is and it’s up to the device (Fire Stick) to handle the rest.

Since it did copy the audio, it’s possible that the audio at a low level is fine and that the mkv file has a bad header information regarding the audio. The Fire TV or the receiver could have had trouble reading the data and that’s the failure. When Plex copies the stream (direct stream), it repacks the audio which may have removes the error.

For the video transcoding, it’s due to the failed attempt to direct play. The app doesn’t know why it failed, so for safety reasons, it chooses to transcode the video instead. This is still related to the original failure of the EAC3 audio.

10

This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.