If live tv is always “buffering” as seen in the screen shot, is it a transcoding issue or a network bandwidth issue or something else?
Could be both, but, yes, usually cpu. MPEG2VIDEO isn’t recognized by most clients, Roku included.
Reference Plex KB article to determine which -
https://support.plex.tv/hc/en-us/articles/201575036-Why-is-my-video-stream-buffering-
I wish the CPU would show pegged out so I could blame that and move on.
I for some reason think that 30% CPU should mean it has headroom, but maybe the built in GPU just can’t keep up?
That article describes how to enable/what to look for in logs re: CPU/GPU buffering.
GPU can’t do 100% of transcoding jobs though. There’s always audio and other parts that can’t be HW accelerated, and those are/can usually only be done on a single core. If you have a 4 core processor, yeah, you’re maxing the CPU if it’s higher than 25%.
Rule out network by placing everything on GbE temporarily. If you have WiFi anything, even if 5ghz 10m from router, it’s susceptible to noise/shared usage/contention. 15m ethernet cables can be had cheap for testing.
Yea I hardwired to the Roku tonight. Been testing on web client but I’m not sure what client is “preferred” so I was using Roku for some testing as well. Thank you for pointing me to the correct log files, much appreciated.
Dec 04, 2017 21:24:18.661 [0x7f8f6e48f700] DEBUG - Request: [127.0.0.1:47042 (Loopback)] PUT /video/:/transcode/session/a8cefeda-74af-44f5-9ae6-951508dac802/cddbda0f-9608-4df8-8e38-66685acddcd0/progress?progress=-1.0&size=-22&remaining=-1&speed=0.9 (14 live) Signed-in Token (iced98lx) Dec 04, 2017 21:24:18.662 [0x7f8f777ff700] DEBUG - Completed: [127.0.0.1:47042] 206 PUT /video/:/transcode/session/a8cefeda-74af-44f5-9ae6-951508dac802/cddbda0f-9608-4df8-8e38-66685acddcd0/progress?progress=-1.0&size=-22&remaining=-1&speed=0.9 (14 live) 1ms 326 bytes Dec 04, 2017 21:24:18.889 [0x7f8f77511700] DEBUG - Auth: authenticated user 1 as iced98lx
Appears despite being able to transcode high bitrate 1080p H264 to other bitrates easily it just can’t do MPEG2 -> H264 above 480. Sub-channels that are 480 play without issue. Main channels in 1080i/720i seem to have constant buffering.
I guess the integrated GPU’s clockspeed isn’t high enough to do HW transcode of those streams. I’ll go order a HD Home Run extend so it will not have to transcode. Guess I should have gotten a faster CPU.
@iced98lx - Just so you know, I’ll post here what I’ve said before. Though I was specifically mentioning Roku client, it’s true of any client, depending on its capabilities.
Basically, yes, an Extend will definitely save some CPU/GPU transcoding, there’s still quite a bit of work going on by the server.
(Pardon the partial bold, it quoted that way but wasn’t intended)
All, I’d like to point out the below, all of which do/could increase the load of the CPU.
Many do not realize the work the server is doing to make it compatible with devices.For Roku…(in North America… other countries broadcast different signals)
Plex Server
- is doing time shifting(DVR recording) while watching live. (This often spins my fans)
- is converting the container - MPEG2-TS to (MP4/MKV?) (Roku doesn’t do mpeg2-ts, even if HDHR Extend encodes it in h264)
- is converting the Transport Stream (TS) to Roku compatible HLS.
- may be downsampling 25mbps+ TS stream bitrate down to ??mbps client compatible.
- may be converting 60fps streams to Roku compatible 30fps (depending on 1) network broadcast source and 2) the Plex Extend tuner’s advanced quality setting)
- may be/is converting the audio stream to stereo if your Roku isn’t connected by HDMI to a 5.1 Dolby (AC3) receiver.
Just some pointers. There’s more to video streams than the encoding type. h264 encoding is a tiny part of a huge list of container types and content variables than just the encoding type.
If you have an HDHR Extend and are seeing h264 to h264, that at least shows you have the Extend feeding Plex correctly.
Thanks for the information and tips, I’m certainly not a streaming media wizard, just a frustrated user who dusted off my very old HDHomeRunDual out of the closet and remembers streaming and recording live TV on much much older systems that certainly didn’t have any GPU acceleration.
If I read your post correctly no matter the setting I put on the transcoder of the HD Home Run extend PMS is still going to be doing some transcoding. Will setting it to lower settings ease the burden? All my clients are now hard wired gigabit so I’m not AS worried about bandwidth I guess. It’s odd to me only because I routinely transcode other media (1080p Blu Ray sourced movies to 720 or even lower for mobile device and remote playback) without any hiccups so I was hopeful there was a solution.
I’m not tied to the Roku3, I consume much of our content on Windows systems via the web player and am open to a more powerful client for the theater screen but PMS doesn’t “endorse” a client as the sort of “Best option” so I’m not sure what is better than the Roku. I assume that is due to the variety of media and encoding someone may have. Perhaps I’ll pick up a shield and try that.
Extend ordered, we’ll see if that helps the situation. If not I’ll have to ignore Live TV on Plex and have 4 tuners to record with for playback later, which (when it actually records and doesn’t have tuner handoff issues, so, 1 in 4 times) works fine.
Okay. So I’ve been doing some testing, this goes with my other thread I guess (https://forums.plex.tv/discussion/298183/live-tv-transcoding-settings-defaults#latest).
I’m not sure how transcoding works from a technical stand point with live tv but it appears if I try to watch recorded TV without optimizing it (making the assumption this is mostly the same as watching the stream from the HRHD) I see the same buffer issues, and the same convert speed. If I set the output to a lower quality output it plays fine, with speeds of 1.8+, transcoding ahead and resting as designed.
Is it not possible to change the default transcoding output for live TV streams and achieve similar results for lower powered systems??
@iced98lx said:
Okay. So I’ve been doing some testing, this goes with my other thread I guess (https://forums.plex.tv/discussion/298183/live-tv-transcoding-settings-defaults#latest).I’m not sure how transcoding works from a technical stand point with live tv but it appears if I try to watch recorded TV without optimizing it (making the assumption this is mostly the same as watching the stream from the HRHD) I see the same buffer issues, and the same convert speed. If I set the output to a lower quality output it plays fine, with speeds of 1.8+, transcoding ahead and resting as designed.
Is it not possible to change the default transcoding output for live TV streams and achieve similar results for lower powered systems??
regarding default transcoding for live TV streams, on Fire Stick, you can set the default quality for streams and this seems to apply to live TV as well. For example I have it on 4Mbps 720p and live TV starts on that and I can also go change it. The problem when you do that is that you mostly lose live TV timeshifting (at least I do) because timeshifting only works on the original stream quality. If I change the quality of live TV to “Original quality” then timeshifting comes back (I can seek back and forth up to time now on a live TV stream that I am also recording).
I hope this helps!
K
@tachtevrenidis said:
@iced98lx said:
Okay. So I’ve been doing some testing, this goes with my other thread I guess (https://forums.plex.tv/discussion/298183/live-tv-transcoding-settings-defaults#latest).I’m not sure how transcoding works from a technical stand point with live tv but it appears if I try to watch recorded TV without optimizing it (making the assumption this is mostly the same as watching the stream from the HRHD) I see the same buffer issues, and the same convert speed. If I set the output to a lower quality output it plays fine, with speeds of 1.8+, transcoding ahead and resting as designed.
Is it not possible to change the default transcoding output for live TV streams and achieve similar results for lower powered systems??
regarding default transcoding for live TV streams, on Fire Stick, you can set the default quality for streams and this seems to apply to live TV as well. For example I have it on 4Mbps 720p and live TV starts on that and I can also go change it. The problem when you do that is that you mostly lose live TV timeshifting (at least I do) because timeshifting only works on the original stream quality. If I change the quality of live TV to “Original quality” then timeshifting comes back (I can seek back and forth up to time now on a live TV stream that I am also recording).
I hope this helps!
K
That is helpful, it says that after it decodes the MPEG2 and is encoding it into H264 it is listening to decoding settings. I can probably go to Settings → Web and Uncheck “Use recommended settings” for home streaming and force all streams lower and see if it forces the live tv transcoding to a lower resolution on web as well. If it does, I can see if that fixes the issue, and if so ask for a setting specific to live tv.
An upgrade I recently made to my Plex server (8 year old i7-860, 16GB RAM, SSD System Drive, 4 Mechanical HDD’s, Windows Server 2012 R2 Essentials) that eliminated my buffering woes, especially for live TV, was installing an NVMe M.2 drive for a PLEX transcode drive. It’s only purpose is for Plex transcoding, and hosting the system paging file.
The motherboard in my server only supports SATA 2, so that’s one bottleneck, and I didn’t want to use my system drive for the Plex transcode folder location (even though it’s an SSD). I used the mechanical hard drive pool for the Plex transcode folder which led to the use of many four letter words as I endured buffering (mainly streaming to mobile devices) which was particularly bothersome for live TV. Drawing conclusions from watching the transcode folders, while streaming live TV it appears two folders are generated…one for the live TV “raw” files coming in from the HDHomeRun…and another for the transcoded versions being streamed to a device. So a whole lot of file creation and hard drive accessing going on.
In general terms an NVMe M.2 drive theoretically provides the bandwidth of up to four SATA channels in/out. Pair that with SSD technology and you can read, write and stream quite a bit faster. Because of the age of my server I had to use a PCI 3.0 x4 adapter card to get the NVME M.2 drive to work. The upgrade set me back $170, but it has completely eliminated the messages about my server not being fast enough to transcode the media.
Individual results may vary, but at this point I think an NVMe M.2 transcode drive is a buffering eliminating upgrade well worth the money if you can afford it.
