[mythtv-users] IPTV recorder seems broken -- large jumpy files

[Brian J. Murrell]

On Sat, 2018-03-17 at 22:58 +0000, Mark Perkins wrote:
> 
> On 18/03/18 08:41, Mark Perkins wrote:
> > 
> > Have you tried using ffmpeg -i or mediainfo or something equivalent
> > to
> > compare the file created by mythtv to the file created from ffmpeg?

I didn't.  I ended up replacing the IPTV recorder with my own External
recorder based on "ffmpeg -i "$URL" -acodec copy -vcodec copy -f
mpegts"

> Just to put some additional words around this. I use the IPTV
> recorder 
> functionality for my recordings. I have a box with USB DVB-T tuners 
> attached that runs mumudvb to rebroadcast the streams to multicast
> IP. I 
> can then subscribe to those streams from as many mythbackends as I
> like 
> simultaneously from anywhere on my network. I picked a SD recording
> from 
> the news last night which was 588MiB for 27min which is fairly 
> comparable to your 1GB per hour. So I don't think your large file
> sizes 
> are necessarily a problem with the IPTV recorder functionality but 
> perhaps related to what is specifically being transmitted in the
> stream. 

No disagreement.  ffmpeg seems to handle whatever is in the stream
better than mythtv though, which is what is interesting about it.  The
URL I am recording from is:

https://cbclivedai5-i.akamaihd.net/hls/live/567235/event2/CBOT/master1.m3u8

I wouldn't be surprised if it's geoblocked outside of Canada though.

> If I had to guess, based on your sizes, perhaps the IPTV recorder
> has 
> recorded an entire multiplex not just a specific channel / stream? 

I'm not sure it's that simple.  I think it's more related to the
jumpiness.  By jumpiness I mean that it will play a few minutes of the
recording and then seemingly go back to the beginning but this time
play a few more minutes than last time but then again, jump back to the
beginning and play yet a longer segment.  I doubt there is any actual
jumping around in the stream and it's more like the stream is being
repeatedly written to the file from the beginning with each segment
writing a few more minutes than the last one.

Cheers,
b.
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