[mythtv-users] Channel scanner won't find a specific channel

Sun Feb 7 23:41:28 UTC 2016

On 07/02/16 20:41, David Parker wrote:
> On Sun, Feb 7, 2016 at 2:49 AM, HP-mini <blm-ubunet at slingshot.co.nz
> <mailto:blm-ubunet at slingshot.co.nz>> wrote:
>

>      >
>
>     That 60p sample plays fine here (Videos) in master with ffmpeg CPU &
>     VDPAU.
>     I did not try the file with dummy recorder.
>     I noticed that the OP was using ffmpeg CPU decode.
>     CPU decode here uses 35% on mid-range core2duo, no jitter problems (OSD
>     playback meter).
>
>
> Thanks for the info.  I just monitored the CPU usage on my MythTV box
> while a few different videos were playing, and it was consistently in
> the 5%-10% range except for the moment the video started.
>
> This is what I see when I play the sample I posted, while it's being all
> weird and choppy:
>
> 2016-02-07 15:28:16.094440 I  Player(2): FPS:   30.22 Mean: 33090
> Std.Dev:  1930 CPUs: 101% 100%
> 2016-02-07 15:28:22.128193 I  Player(2): FPS:   39.61 Mean: 25243
> Std.Dev:  8344 CPUs: 8% 9% 6%
> 2016-02-07 15:28:28.678682 I  Player(2): FPS:   36.49 Mean: 27405
> Std.Dev:  7991 CPUs: 7% 7% 8%
> 2016-02-07 15:28:35.579324 I  Player(2): FPS:   34.64 Mean: 28871
> Std.Dev:  7393 CPUs: 5% 6% 7%
> 2016-02-07 15:28:40.979659 I  Player(2): FPS:   44.26 Mean: 22593
> Std.Dev:  7991 CPUs: 8% 9% 9%
> 2016-02-07 15:28:46.680104 I  Player(2): FPS:   41.93 Mean: 23849
> Std.Dev:  8265 CPUs: 8% 8% 7%
> 2016-02-07 15:28:53.130608 I  Player(2): FPS:   37.05 Mean: 26987
> Std.Dev:  8102 CPUs: 8% 7% 9%
> 2016-02-07 15:28:59.281147 I  Player(2): FPS:   38.86 Mean: 25732
> Std.Dev:  8317 CPUs: 7% 9% 8%
>
> Note the 30-40 FPS, when it's supposed to be 60.
>
> This is what happens when I play the 30 FPS recording from a different
> channel, which plays fine:
>
> 2016-02-07 15:29:20.983329 I  Player(2): FPS:   28.97 Mean: 34520
> Std.Dev: 19131 CPUs: 266% 100% 100%
> 2016-02-07 15:29:25.017039 I  Player(2): FPS:   29.50 Mean: 33894
> Std.Dev:  3016 CPUs: 12% 8% 10%
> 2016-02-07 15:29:29.000619 I  Player(2): FPS:   29.88 Mean: 33472
> Std.Dev:  1534 CPUs: 8% 8% 9%
> 2016-02-07 15:29:33.101074 I  Player(2): FPS:   29.02 Mean: 34454
> Std.Dev:  4190 CPUs: 9% 7% 9%
> 2016-02-07 15:29:37.067977 I  Player(2): FPS:   30.00 Mean: 33332
> Std.Dev:    75 CPUs: 10% 9% 11%
> 2016-02-07 15:29:41.034890 I  Player(2): FPS:   30.00 Mean: 33332
> Std.Dev:    73 CPUs: 8% 9% 10%
> 2016-02-07 15:29:45.051846 I  Player(2): FPS:   29.63 Mean: 33753
> Std.Dev:  2633 CPUs: 10% 8% 10%
> 2016-02-07 15:29:49.118807 I  Player(2): FPS:   29.26 Mean: 34173
> Std.Dev:  3669 CPUs: 9% 8% 9%
>
> And this is what happens when I play the transcoded version of the
> problematic video:
>
> 2016-02-07 15:30:22.154231 I  Player(2): FPS:   59.51 Mean: 16803
> Std.Dev:  1911 CPUs: 100% 100% 100%
> 2016-02-07 15:30:26.137813 I  Player(2): FPS:   60.00 Mean: 16665
> Std.Dev:    95 CPUs: 11% 11% 10%
> 2016-02-07 15:30:30.138094 I  Player(2): FPS:   59.75 Mean: 16735
> Std.Dev:  1079 CPUs: 11% 12% 12%
> 2016-02-07 15:30:34.138641 I  Player(2): FPS:   59.75 Mean: 16736
> Std.Dev:  1064 CPUs: 10% 12% 13%
> 2016-02-07 15:30:38.122093 I  Player(2): FPS:   60.01 Mean: 16664
> Std.Dev:    96 CPUs: 11% 11% 11%
> 2016-02-07 15:30:42.105712 I  Player(2): FPS:   60.00 Mean: 16665
> Std.Dev:    97 CPUs: 11% 12% 13%
> 2016-02-07 15:30:46.089376 I  Player(2): FPS:   60.00 Mean: 16665
> Std.Dev:    92 CPUs: 12% 11% 16%
> 2016-02-07 15:30:50.073166 I  Player(2): FPS:   60.00 Mean: 16666
> Std.Dev:   140 CPUs: 15% 12% 12%
>
> It maintains 60 FPS and there are no playback issues at all.  So there
> seems to be something about recorded video from this channel which
> causes a massive drop in framerate on this particular PC, and whatever
> this issue is, it's corrected by mythtranscode.  Any thoughts?  Just a
> wild guess, but is it possible the CPU in this PC is missing an
> instruction set which is needed for efficiently decoding the video
> stream from this channel?
>
> The continued help is much appreciated.

A few more random thoughts:

Your sample has played ok for me with the likely players I've tried on 
this box (myth, vlc, SMplayer) and surprisingly it also plays via UPnP 
on my TV.  Your mythfrontend seems to wish to play at 30 fps, but so far 
I haven't seen any reason for this.  It certainly looks as if your box 
has enough raw power to cope.  I don't know what experiments you've done 
with the frontend Playback Profiles and perhaps the Playback OSD, but I 
don't feel able to suggest changes there.

Mythtranscode -m produces mpeg-ps files, rather than the original 
mpeg-ts.  I also have a version converted to .mkv

There are instances of 'PES packet size mismatch', but they aren't 
continually repeated and look like startup glitches.

vlc reports continuously (in Messages)

avcodec warning: plane 0 not aligned
avcodec warning: disabling direct rendering

but it seems to do that with most files that aren't UK SD ts or ps format...

John