[mythtv] 10 times better H.265/HEVC decoding performance with WinTV compared to MythTV. Why?

[Bjoern Voigt]

Andreas Mayer wrote:
> > I tested --enable-cuda, --enable-cuvid, --enable-nvenc and
> --enable-libnpp.
> I did that as well (with cuda 8.0) but as far as I know mythtv
> currently has no cuda/cuvid video decoding support.
> I have made some tests with ffplay (3.3.4 packman) and mythffplay
> (0.29 fixes built with ffmpeg cuda/cuvid/nvenc), but until now I was
> not able to play 4K HEVC content without frame drops (but currently
> I'm scaling down to 1920x1080 because I have no 4K display available
> and my mainboard is already some years old).
Ok. 4K is currently not my problem, because I have no 4K content and no
5K display. But if I buy a new graphics card, I would take one with 4K
support so be safe in the next years.

> > Would it be a good idea to upgrade the Nvidia card to a graphics card
> > with HEVC decoding support (e.g. GTX 1030 or GTX 1050)? I mean, is the
> > VDPAU HEVC support stable?
> I'm using Astra DVB-S2 HEVC test channels here (I have no DVB-T2
> hardware available), but they all use HEVC Main 10 profile which VDPAU
> currently does not support (and may never support, even if the
> hardware, like my GT 1030 would have support).
> What's the HEVC profile and resolution in Germany?
> If the profile is Main you my be lucky.
> vdpauinfo on my Mythtv box (used as backend
> http://www.areadvd.de/news/dvb-t2-hd-1080p-option-fuer-deutsches-dvb-t2-angebot-bis-zu-50-sender-via-antenne/and
> frontend) shows (with Nvidia driver 384.90 on OpenSuSE Leap 42.3):
> name                        level macbs width height
> ----------------------------------------------------
> ...
> HEVC_MAIN                      153 262144  8192  8192
> HEVC_MAIN_10                   --- not supported ---
> HEVC_MAIN_STILL                --- not supported ---
> HEVC_MAIN_12                   --- not supported ---
> HEVC_MAIN_444                  --- not supported ---
> VDPAU for mpeg2 ts 1920x1080i works fine here.
DVB-T2 HD in Germany probably does not require 10 Bit HEVC. This article
(http://www.areadvd.de/news/dvb-t2-hd-1080p-option-fuer-deutsches-dvb-t2-angebot-bis-zu-50-sender-via-antenne/,
in German) sums up, that TV devices must comply with the following
specification:

  * 1080p (1920x1080 progressive)
  * 50 FPS (frames per second)
  * HEVC/H.265
  * 8-Bit color depth

Here are some more detailed codec information from a random recorded
MythTV DVB-T2 stream.

$ mediainfo /var/video/1769_20171101161500.ts
General
ID                                       : 259 (0x103)
Complete name                            : /var/video/1769_20171101161500.ts
Format                                   : MPEG-TS
File size                                : 1.07 GiB
Duration                                 : 44 min 59 s
Overall bit rate mode                    : Variable
Overall bit rate                         : 3 393 kb/s

Video
ID                                       : 2110 (0x83E)
Menu ID                                  : 1 (0x1)
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : Main at L4.1@Main
Codec ID                                 : 36
Duration                                 : 23 h 0 min
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Display aspect ratio                     : 16:9
Frame rate                               : 50.000 FPS
Standard                                 : Component
Color space                              : YUV
Chroma subsampling                       : 4:2:0 (Type 0)
Bit depth                                : 8 bits
Color range                              : Limited
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709

Audio #1
ID                                       : 2120 (0x848)
Menu ID                                  : 1 (0x1)
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Muxing mode                              : LATM
Codec ID                                 : 17-2
Duration                                 : 44 min 59 s
Bit rate mode                            : Variable
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 kHz
Frame rate                               : 46.875 FPS (1024 SPF)
Compression mode                         : Lossy
Delay relative to video                  : -408 ms
Language                                 : German

Audio #2
ID                                       : 2121 (0x849)
Menu ID                                  : 1 (0x1)
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : HE-AAC / LC
Format settings                          : NBC
Muxing mode                              : LATM
Codec ID                                 : 17-2
Duration                                 : 44 min 59 s
Bit rate mode                            : Variable
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 kHz / 24.0 kHz
Frame rate                               : 23.438 FPS (1024 SPF)
Compression mode                         : Lossy
Delay relative to video                  : -216 ms

Text
ID                                       : 2130 (0x852)-150
Menu ID                                  : 1 (0x1)
Format                                   : Teletext Subtitle
Language                                 : German

Other
ID                                       : 2130 (0x852)-100
Menu ID                                  : 1 (0x1)
Format                                   : Teletext
Language                                 : German

Menu
ID                                       : 2100 (0x834)
Menu ID                                  : 1 (0x1)
Duration                                 : 44 min 59 s
List                                     : 2110 (0x83E) (HEVC) / 2120
(0x848) (AAC, German) / 2121 (0x849) (AAC) / 2130 (0x852)-100 (Teletext,
de) / 2130 (0x852)-150 (Teletext Subtitle, de) / 1170 (0x492) () / 1176
(0x498) () / 2171 (0x87B) () / 5171 (0x1433) ()
Language                                 :  / German /  / German / German

Greetings,
Björn