Live TV Transcoding & Buffering.... Why? and why such a high bitrate?

[DarrenClimie-Newman 6]

Hi All,

Hope someone can help.

I current run Emby on a QNAS NAS, and added the HDHomeRun Dual Channel about a year ago. I've never really looked into this issue until now, as I dont use it overly often. However, on some channels via LIVE TV using a Firestick (2nd Gen), they are unwatchable, and buffer every few seconds. (Quest TV in this example).

I did a bit of research earlier today, and came across that it maybe something to do with the playback device not supporting the MPEG2 video format, so I checked the specification of the Firestick Gen2, and they do indeed support MPEG2, and I also confirmed that using the Informer app on the device:

My next step was to determine if this was an issue with the HDHomeRun streams or whether this was specific to Emby. I installed the HDHomeRun app on the Firestick and played a few channels, including the problematic channel, Quest TV. It played perfectly fine, buffer free and in perfect playback.

I turned my attention back to Emby, and looked at the playback details of 2 channels (BBC1 and Quest TV). I noticed 2 things, one I cant explain and the other for the reason Quest TV buffers so badly, but i dont know why.

Here is BBC1 playback with stats for nerds turned on. Firstly, its transcoding to H264, even though its original media is MPEG2, a codec that the device supports, and the bitrate is only 5.36Mbps, and the playback is perfectly fine.


Here is the dashboard view from the server showing the same details:

When I try and play the problematic channel, Quest TV (amongst a few others also), it also transcodes even though its an MPEG2 codec original stream, but this time its bitrate is up at 80Mbps, which i'm sure is the reason it buffers so badly.


Here is the dashboard view showing the same details:

If I playback any channel via the HDHomeRun App, no issues at all. If i playback via Emby Theater on my Win10 PC, with Nvidia GPU, it direct plays no problems also. So it seems its a problme with Emby identifying that the playback devices doesnt think it supports MPEG2, when it clearly does.

What i also dont understand, is why one channel can have a bitrate of around 5Mbps, and another at 80+Mbps? I checked another channel that buffers, and it also has a bitrate of around 85Mbps.

Even if i playback a HD channel (BBC1 HD), the bitrate is only 21Mbps. Playback is perfectly fine, no buffering.

So the 2 main questions are, why is Emby transcoding MPEG2 to H264, when the playback devices supports MPEG2? and why are some channel running at a bitrate of 80+Mbps?!

I've included my latest log files when testing just now.

Any help would be appreciated!

Thanks

 

embyserver.txt ffmpeg-transcode-a55b9727-9c40-40fe-84b7-11dce2fc4e0c_1.txt

[ebr 14929]

Hi.  It looks like it is an interlaced channel which the current server version is forcing to transcode.  The next server release will allow it to direct stream again.

[DarrenClimie-Newman 6]

Hi @ebr

OK thanks good to know then. Any ideas on when the next Server release will be GA?

Thanks 

[ebr 14929]

Sorry, no we do not know that at this point.