Question: Why would Plex transcode h264 to H264 to remote player

General Discussions
1

Hi,

Why would my (Plex on a QNAP) server transcode "H264 (hw) to H264 (hw) to my sister (running Plex player on her Mac) when it shouldn’t require any transcoding at all. My upload connection is 18mbps and the film is 1080p with an 8mbps stream.

Also, when I limit the upload to 10mbps, the audio also gets transcoded from AC3 to OPUS.

Neither of these are a problem, but I don’t understand it.

thanks!
James.

2

A few questions…

-Is your sisters download bandwidth able to handle 8Mb/s?
-How is your sisters client setup? Is it set to auto quality? is it set to a bandwidth lower than 8Mb/s?
-There is more than one flavour of H.264 with different profiles. Can your sisters client handle the flavour of H.264 you are streaming?
-What is your sisters Plex client? Can this client handle the type of H.264 you have in your file?

Answering these questions w2ill give us a good starting point.

3

Hi,

Thanks for replying!

Yes, she has a fibre connection, and 8mbps download is no issue for her

My server is v1.12.0.4829 on a QNAP
My sister’s player in question Plex for Mac.v 3.37.2.

I also have Plex for Mac v 3.37.2 and when I play the movie (locally) it is direct play for both audio and video which (I think) answers your h264 questions.

thanks! :smile:
James.

4

There is no “Plex for Mac” as such.
Did she install “Plex Media Server for Mac”
or
“Plex Media Player for Mac”?

It should be the latter.

5

Hi Otto,

You are correct, it’s the player (I did actually write that - sorry if it was not clear). The whole question is based upon transcoding to her player.

My sister’s player in question Plex for Mac.v 3.37.2.

thanks!
James.

6

When you really want to know, then you have to look in the log file (set it to debug mode first) for lines containing MDE. This will detail the reason.

On possible reason could be, that your file has an average data rate of 8Mb/s, but there are spikes in it for which your limit of approx. 0.8 x 18 Mb/s is temporarily exceeded.

7

Hi eckarth,

Thanks for that - will do.

…where do you get the calculation 0.8 x 18mbps from? (I get the 18mbps, but not the 0.8) - thanks!

8

Somehow the Plex server determines your bandwidth. Then it sets itself an upper limit of about 80% of that. The intention is that other services will still have access to some band width.

9

got it - thanks!