Hi. I absolutely love Plex for its easy distribution of media. But sometimes I don’t really understand it. One of those cases is when playing Plex on Chromecasts. I cannot find how or why it sometimes chooses to burn subtitles instead of converting them and would love to be taught about this subject.
For me, these two cases are similar and Chromecast should act the same on both? But it does not. So I wonder, how does Chromecast choose if it transcode or burn the subtitles?
Another question… why is it down sampling the audio and changing the codec in one?
These both attached to the same playback device?
It is Chromecast on both devices. Chromecast does not support 5.1 AAC hence the downsampling
The exact reason can only be seen when you inspect the Plex Media Server.log file.
Scroll to the timestamp when you pressed ‘Playback’
Find those lines which contain MDE:
There are often several lines which are documenting the decision engine going through several iterations before reaching a conclusion.
A spin-off question. Do Chromecasts use HLS streams?
I mean are both examples from the same chromecast?
One is going 6ch AAC to 6 AC3 while the other is 6 AAC to 2 AAC… that’s weird if same device in both examples.
If not the same devices it could be the device in the first doesn’t support side loaded SRT so plex burns in?
The device where the Chromecast is plugged in should inform the CC which audio formats it can direct stream and how many speakers are available.
Unfortunately, this mechanism is not reliable on many TV’s or AVR’s . There are big differences between different devices, brands and models.
If there is not a severe bandwidth restriction and the device informs the CC that it unmderstands AC3 audio and it has 6 speakers, then Plex may transcode surround audio to AC3 5.1 to make playback possible.
If the available network bandwidth is too low (often when playing from remote servers), Plex will reduce audio to stereo.
