Motion in transcoded MPEG2 blocky regardless of settings

[TheWebMachine 5]

Yep, me again. With the search still hating on me. lol

It seems no matter what I set the transcoding setting to, even the absolute insane of quality params, transcoding from MPEG2 (Live TV/Recordings) results in any sort of excessive motion blocking up the video...even a swipe effect on the evening news results in full screen blockiness for up to several seconds. This is device agnostic so long as Transcoding is involved.

What could I do to improve upon this? If I watch DirectStream in pure MPEG2 the picture is flawless. Is there perhaps some ffmpeg flag that could be changed/added to help?

 

Also, to preclude me making a second post on a similar note, I'm going to expand a little on my Topic:

I have Roku TVs, not boxes/sticks, which means my devices natively support MPEG2 (including the TS container) because they have TV tuners built into them, unlike their stick/box counterparts. As it stands, there's no way to tell Emby this or for it to detect it. So, while once in a blue moon Live or Recorded will DirectStream, most of the time (99%) it transcodes the video or recontainers, which is entirely unnecessary for RokuTVs and just gums things up (plus exacerbates the Recording mid-Live I posted about).

This leads me to a couple of Qs:

1) Why is it not 100% of the time one way or the other when there is no change in the content (all MPEG2TS)? It randomly decides to play it natively, but usually doesn't.

2) Does, and if so how does, Emby's Roku app (or server) identify which Roku model it is and does it use this info to determine its capabilities? If it doesn't currently, does that seem "doable?" As the variety of Roku devices grow, tracking capabilities would come in handy to ensure a smooth experience for all.

Yes, I know this would technically fall into the Roku category, but this is also a "to transcode or not to transcode issue." Wasn't sure on which end the transcoding decision gets made. I figured I might also trigger the wrath of the forum bots if I posted 3 topics in 10 minutes. I'll "move" this second bit to Roku section if necessary and requested.

[Carlo 4561]

Hi, just curious, but is this only happening on 1080i broadcasts and not 720p broadcasts?

[TheWebMachine 5]

 

9 hours ago, cayars said:

Hi, just curious, but is this only happening on 1080i broadcasts and not 720p broadcasts?

Are you referring to the blockiness in transcode or the RokuTVs needlessly transcoding MPEG2?

I'll report back later tonight after I have a chance to do some testing, as I suspect I can answer your question either way. Broadcasts here range from 480p-1080i, so I should be able to get a decent sample set.

[Carlo 4561]

Did you get a chance to do any testing?

Curious what you find.

[TheWebMachine 5]

Ok, you *have* to be onto something here. So, here are observations:

1) A channel/recording at 720p *ALWAYS* DirectStreams (container not supported).

2) A channel/recording at 1080p Transcodes video to h264 (container not supported) at least 85% of the time.

3) About 15% of the time, a 1080p DirectStreams (container not supported). The same channel will do this randomly, by just leaving playback and returning multiple times.

4) In all cases, the original media is MPEGTS container, MPEG2VIDEO (12-20mbit), AC3.

5) In all cases, the MPEGTS container is not supported and M3U8 is used instead.

So, can we get an advanced option, either server-side or in Roku app to force DirectPlay for MPEG2TS? Is there any reason to tie up the server with even a re-containering if a RokuTV can take it all native? I did some testing in the HD HomeRun Roku app and all the channels could be watched flawlessly (and in better quality than Emby transcodes even with insane quality settings), as my tuner has no built-in transcoding. Would DirectPlay preclude anything like rewinding Live TV channels?

[Happy2Play 9785]

3 hours ago, TheWebMachine said:

there any reason to tie up the server with even a re-containering if a RokuTV can take it all native?

Would DirectPlay preclude anything like rewinding Live TV channels?

There are other topics discussing this but if you were to directplay you will loose FF/RW functionality.

@speechlesmaybe able to comment more.

[Luke 42086]

Hi @TheWebMachine has this answered your questions?

[TheWebMachine 5]

4 hours ago, Luke said:

Hi @TheWebMachine has this answered your questions?

No. My two issues in the OP are late to start record when transcoding and severe blockiness in transcoded mpeg2. The DirectPlay option would be of no interest if it kills FW/RW. DirectStream should not be transcoding mpeg2 on RokuTVs, so a way to tackle that distinction would be helpful from a performance perspective.

The late record is a nuisance, but the blockiness in transcode from mpeg2 is a killer, as you can't watch *anything* with lots of motion, including sports and many other shows. You're basically stuck watching the news if you want a clear picture. 

Oh, and I'm using NVENC/NVDEC. I didn't mention that before, but it is possibly relevant.

[TheWebMachine 5]

Sorry, I realized my mention of late to record was in another thread. The remainder stands, however.

[Luke 42086]

On 6/14/2021 at 8:20 PM, TheWebMachine said:

Sorry, I realized my mention of late to record was in another thread. The remainder stands, however.

Can we please look at a specific example?

 

Thanks.