Hello [Anyone Using MPEG-4]

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Tytteboevsen
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Hello [Anyone Using MPEG-4]

Post by Tytteboevsen » Fri Oct 25, 2019 10:58 am

Hello Forums

I did a mythtv setup years ago and want to do it again. I also wanted to say hello to the forums. I am from Denmark and in that subforum the last post was from 2014 so i thought i'd get more replies here.

I remember having some problems with setting up mythtv last time and i will probably post some questions again.

I remember one of the problems was that the danish signal is in mpeg4 and not mpeg2. that gave me some problems. Also automatic channel scanning did not work so i had to manually search, which took a long time, but the good thing is you only have to do it once.

Anybody else recieving in mpeg4 and have some good ideas for me?

I plan on setting up a server to use for backend and a rpi 4 for frontend.

The server will also be hosting some sites i have made and function as a nas. Is this a bad idea?

Best regards
Morten
Last edited by bill6502 on Fri Oct 25, 2019 11:25 pm, edited 1 time in total.
Reason: Added question to Subject

blm-ubunet
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Re: Hello

Post by blm-ubunet » Fri Oct 25, 2019 8:22 pm

More than half the world uses mpeg4 video & audio codecs in a mpeg(2) transport stream.
All digital FTA broadcasting has been H264(mpeg4-part10)/AAC/(opt. A52) over DVB-T/S here for more than 10 years.

The UK uses DVB-T2 for HD resolution H264 codec.

The problems can occur with use of :-
- mixed T & T2 modulation (okay in later MythTV)
- H265/HEVC video compression. (MythTV no go without very powerful CPU)

Make sure your tuner card is supported in LinuxTV.
Don't use USB tuners.

The tuner scanning is greatly improved in recent versions (esp. in master).
You may still want to use w_scan & dvbv5_scan tools.

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Steve Goodey
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Re: Hello

Post by Steve Goodey » Fri Oct 25, 2019 8:45 pm

Don't use USB tuners.
I've used USB tuners for years with no problems. Have I been lucky?

Tytteboevsen
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Re: Hello

Post by Tytteboevsen » Fri Oct 25, 2019 10:13 pm

I was using anysee usb tuners with no problem.

I was and am using cable tv so thats DVB-C.

I just remember i had a lot of problems deleting commercials and recompress it. what i red back then was that the US was using mpeg 2. I think i might be confused with the transport stream and the codec.

I am glad scanning is improved. I hope it works for me too.

On a side note. Is DVB-C illegal in the UK. I think i red that a long time ago, and it just came to mind when you said you where using DVB-T...

blm-ubunet
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Re: Hello [Anyone Using MPEG-4]

Post by blm-ubunet » Sat Oct 26, 2019 12:52 am

I also used the nova-t-500 'usb interface on a PCI card' tunercard for many years .. was rock solid until it died in a lightning/thunderstorm.

But external USB means:-
- nasty small weak antenna connections
- barely adequate mechanical strength
- probably marginal RF design
- typically cheaply made (to a price point) disposable
- dynamic enumeration at boot.

I just would never recommend a USB tuner over an internal card.
Network tuner is a good option for low (under)powered SBC like PI etc.

I don't think or see why DVB-C would be illegal anywhere, are you confusing with CAM & encrypted streams?
T terrestial ground based Tx
S space GeoStationaryOrbit satellite Tx
C cable

Very common in NA to have ISP & cable & phone bundles.
There are cable operators in UK, NZ & Aust, but optical fibre & streaming is going to decimate any traditional broadcast or cable TV.

Cutting H264 video is problematic still.
The "lossless-cut" script only works with transport streams with zero offset between audio & video (HDPVR).
I used to use this:
https://gist.github.com/BipedalTV/3174241
I always meant to figure out how to remux the AV PTS packet offset out of the TS before cutting..

Tytteboevsen
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Re: Hello [Anyone Using MPEG-4]

Post by Tytteboevsen » Sat Oct 26, 2019 6:39 am

blm-ubunet wrote:
Sat Oct 26, 2019 12:52 am
[...] I don't think or see why DVB-C would be illegal anywhere, are you confusing with CAM & encrypted streams? [...]
I could most definately be confusing them.

Thank you for the link.

Well i guess ill just have to mark the commercials so it will skip them. Or maybe even just record from non-commercial channels...

I remember trying to write a python script to delete the commercials. Never got it working though.

blm-ubunet
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Re: Hello [Anyone Using MPEG-4]

Post by blm-ubunet » Sun Oct 27, 2019 3:58 am

Broadcast H264 cutting was always a tricky because of early video packets, LATM AAC, B-frame keyframes & slice refresh etc all which caused years of issues with ffmpeg.
But really all that was needed was a packet filter "bgrep", I never got that finished.

The ad breaks here are exactly 4 minutes & with wireless keyboard & fast videocard, skipping 4 minutes is near instantaneous.
I have 8TB archive & 2TB recording HDD so cutting ads not required & was to slow on CPU.

The Nvidia GT1050TI can transcode (2) parallel H264 videos at 16x real-time using NVDEC NVENC.
I've not worked out how to drive that from ffmpeg.

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