[mythtv] HVEC frame counting broken

[John Pilkington]

On 24/09/2022 02:18, John P Poet wrote:
> On Fri, Sep 23, 2022 at 7:02 PM John P Poet <jppoet at gmail.com 
> <mailto:jppoet at gmail.com>> wrote:
> 
>     On Fri, Sep 23, 2022 at 6:31 PM Scott Theisen
>     <scott.the.elm at gmail.com <mailto:scott.the.elm at gmail.com>> wrote:
> 
>         On 9/23/22 18:59, David Engel wrote:
>          > On Fri, Sep 23, 2022 at 04:38:19PM -0600, John P Poet wrote:
>          >> On Fri, Sep 23, 2022 at 4:32 PM John P Poet
>         <jppoet at gmail.com <mailto:jppoet at gmail.com>> wrote:
>          >>
>          >>> I just upgraded from 39b850f1a9 to 06da3119d5 and
>         discovered that frame
>          >>> counting is now broken for ffmpeg/nvenc encoded HVEC. The
>         OSD indicates
>          >>> that the shows are twice as long as they really are.
>          >>>
>          >>> This weekend I will do a bisec to figure out which commit
>         did the damage,
>          >>> unless someone else already knows?
>          >>>
>          >> Sorry. Make that  26b2e76ae to 06da3119d5.
>          > It's probably the very, recent, ffmpeg merge.
>          >
>          > While you're in there, though, would you mind looking into the
>          > long-standing issue with mythcommflag --rebuild not working
>         on HEVC
>          > encoded files, or at least those encoded by HandBarke? :)
> 
>         A note on bisecting the recent FFmpeg merge:
>         a1868defe9c48c5ca53e1c5d26010a19ebd7db13..753a94ccb7a39ef66c6f8591e5784bf08a1b002e
> 
>         wont compile (inclusive..exclusive) fully because of how I split
>         the
>         commits.
> 
>         My harmonization of libavcodec/mpegts-mythtv.c is also in the
>         range you
>         gave.  While each commit compiles, I didn't test functionality
>         of each
>         commit.  But, even if the container is an MPEG-TS, I would also
>         suspect
>         the new version of FFmpeg.
> 
>         Could be related to (HEVC):
>         Playback of DVB recordings shows displayed time doubled · Issue
>         #548 ·
>         MythTV/mythtv · GitHub
>         https://github.com/MythTV/mythtv/issues/548
>         <https://github.com/MythTV/mythtv/issues/548>
>         ?
> 
>         Regards,
> 
>         Scott
> 
> 
>     Thank you Scott.
> 
>     What is bizaar is that I went back to 39b850f1a9 and it was still
>     doubling. I could have sworn that was the commit I was running
>     before! I ended up jumping back and back and back until I randomly
>     found 31ee7f9e64 to work correctly. So, now I have to say the
>     problem occured somewhere between 31ee7f9e64 and 3e802f9075. I will
>     try and narrow it down tomorrow.
> 
> 
> Okay, so I was running  39b850f1a9 on my production machine and 
> 26b2e76ae on my development machine. I had not noticed the issue on my 
> dev machine.
> 
> The problem does seem to be between 31ee7f9e64 and 3e802f9075. Looking 
> at the commits in that range, 40fb3cd09d and db93047399 seem like 
> possibilities. My production machine is now recording stuff for the 
> evening so I will test more tomorrow.
> 
> John

Issue #548 was reported as being years-old for some HEVC recordings.  I 
had similar issues with just one of six DVB-T (mpeg2ts) multiplexes, now 
fixed by PR#610.

mythcommflag --rebuild gave good frame counts for me, but gigem says it 
doesn't work with handbrake's HEVC encoding.

It looks to me as if ffmpeg doesn't understand 'with field pictures' 
encoding.

John (Pilkington)