Choppy live TV/recordings [SOLVED]

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devnull
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Choppy live TV/recordings [SOLVED]

Post by devnull »

Hello there,

I have a MythTV instance that has been running fine for 4 years (at least, it's running Ubuntu 18.04), so I figure it's high time to update.

So I hooked up a new SSD (just in case I want to roll back) and set everything up again.

The differences between the old system and new:

* OS (Pop!_OS 22.04 instead of Ubuntu 18.04)
* MythTV version (32 instead of ... 29.. maybe?)

Everything else is the same (storage device, mobo, cpu, QuadHD tuner, SD via XMLTV, MariaDB)

----

The problem now is that live TV and recordings thereof are choppy sometimes, roughly 75% of the time. I can tune to a channel and get smooth playback, but I can tune again to the same channel and fps drops to 15-20. I haven't been able to figure out reliable reproduction steps yet.

I will try to change the storage location to the SSD (it currently records to a 1TB HDD), but I am thinking that is not the bottleneck as the old installation wrote to that HDD with no problems.

I'm mostly just looking for some hints as to which direction to investigate. Thanks!

I did read through these topics already:
Last edited by devnull on Tue Nov 29, 2022 3:36 am, edited 1 time in total.
devnull
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Joined: Tue Sep 24, 2019 9:08 pm
Canada

Re: Choppy live TV/recordings

Post by devnull »

Sorted!

I went into the recordings folder and discovered that the recordings were not choppy at all, so it meant that there were playback issues.

In MythTV settings, I went to Settings > Video > Playback and changed the Video Playback Profile from "NVDEC Normal" to "VDPAU Normal", and now my playback is great!

It is likely due to the lack of a video card on this machine. I am using the Intel integrated graphics, which is quite slow, relatively.
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kmdewaal
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Re: Choppy live TV/recordings

Post by kmdewaal »

You might want to try VAAPI.
devnull
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Joined: Tue Sep 24, 2019 9:08 pm
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Re: Choppy live TV/recordings

Post by devnull »

Sure!

Ah... What does it do vs VDPAU :?

Edit: ah, Google is your friend :D

VDPAU (developed by NVIDIA)
VA-API (developed by Intel)
NVDECODE (NVIDIA for discrete cards?)
devnull
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Re: Choppy live TV/recordings

Post by devnull »

Hi, I am back with some anecdotal testing results.

VA-API — not so good. Choppy playback.
VDPAU — good, smooth playback
V4L2 Codecs — good, smooth playback

So despite VA-API written for Intel processors, it doesn't seem to do so well at least in my testing.
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kmdewaal
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Re: Choppy live TV/recordings

Post by kmdewaal »

Surprising, the VAAPI works quite well here on Intel graphics.... but at least you have two options that give you good playback.
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