[Interest] Qt 5.5.x & NVIDIA Tegra Jetson TK1 video performance issue

Agocs Laszlo laszlo.agocs at theqtcompany.com
Wed Nov 4 10:26:20 CET 2015


* do you have any trics and recommendations how to properly compile Qt on Tegra Jetson TK1 (maybe requires another flags and so on)?

What you have should be good enough. Qt 5.6 comes with Jetson Pro support and it looks more or less the same when it comes to the compiler flags: http://code.qt.io/cgit/qt/qtbase.git/tree/mkspecs/devices/linux-jetson-tk1-pro-g++/qmake.conf

* how to run the GUI application properly with KMS and so on?

You can’t. AFAIK the public TK1 is pretty much X11 only with NVIDIA’s binary drivers. (the Jetson Pro is a different story, though) You could try an open-source stack with Nouveau for KMS, Wayland, etc. but no idea how stable that is nowadays.

Video with Qt Multimedia did not really work out of the box the last time I tried it. It has not been investigated much since. Anyway, the slow speeds are likely related to the camera/GStreamer/QtMultimedia, not Qt in general as Qt apps are known to run pretty well on the TK1.

Best regards,
Laszlo


From: Interest [mailto:interest-bounces at qt-project.org] On Behalf Of Jason H
Sent: 3. november 2015 21:59
To: Denis Shienkov <denis.shienkov at gmail.com>
Cc: Thiago Macieira <thiago.macieira at intel.com>; interest at qt-project.org
Subject: Re: [Interest] Qt 5.5.x & NVIDIA Tegra Jetson TK1 video performance issue

I didn't use that confguration, but I have compiled Qt on an Atom with a Tegra chipset. I vaguely remember optimizing the video stack. By default it was using a CPU renderer, but I beulve the trick was re-compiling GStreamer to use the proper hardware acceleration. There may have been an environment variable involved in getting GStreamer to select the proper back-end -- that is to say GStreamer had it own envionment variable , not a QT_ one -- IIRC.

I am sorry I can't be more specific, but maybe that can get you in the right direction.

Also, I remember using the 'top' command and I think it being rather obvious who who the culprit was who was not using hardware rendering. Once I got it all set, even on that old Atom, it was doing 30fps with less than 10% CPU.

That said, in my experience linuxFB is extremely slow, never use it for video.

If you can't find the DRM device, then you are missing the Direct Render Mode drivers for it. That said, I've never used DRM without X.


Sent: Tuesday, November 03, 2015 at 12:20 PM
From: "Denis Shienkov" <denis.shienkov at gmail.com<mailto:denis.shienkov at gmail.com>>
To: interest at qt-project.org<mailto:interest at qt-project.org>
Cc: "Thiago Macieira" <thiago.macieira at intel.com<mailto:thiago.macieira at intel.com>>
Subject: [Interest] Qt 5.5.x & NVIDIA Tegra Jetson TK1 video performance issue
Hi Qt developers.

I have veeery slow video performance with Qt 5.5.1 and the video camera (frame rate about ~1-3 fps) on Tegra Jetson TK1 device, where the video stream writes via HDMI interface to the monitor.

My stuff is:

* Qt 5.5.1, cross-compiled himself.
* Tegra Jetson TK1 board [1]
* Logitech c920 USB camera (supports 1920x1080 @ 30 Hz) [2]

I compiled Qt with this C++ flags:

{quote}
DISTRO_OPTS += hard-float

QMAKE_INCDIR += /usr/arm-linux-gnueabihf/include \
                /usr/arm-linux-gnueabihf/include/c++/4.8.2 \
                /usr/arm-linux-gnueabihf/include/c++/4.8.2/arm-linux-gnueabihf

TEGRA_TK1_CFLAGS        = -mcpu=cortex-a15 -mfpu=neon-vfpv4 -marm
QMAKE_CFLAGS           += $$TEGRA_TK1_CFLAGS
QMAKE_CXXFLAGS         += $$TEGRA_TK1_CFLAGS
{quote}

with the GStreamer v1.0 , the GL and the EGL (2.0, 3.0) support:

{quote}
/home/builder/Projects/qt5/./configure \
-v \
-release \
-opensource \
-confirm-license \
-make libs \
-prefix /opt/qt-5.5 \
-device tegra-tk1 \
-device-option CROSS_COMPILE=/usr/bin/arm-linux-gnueabihf- \
-sysroot /home/builder/Projects/tegra/rootfs \
-optimized-qmake \
-alsa \
-gstreamer 1.0 \
-nomake examples \
-nomake tests \
-no-compile-examples \
-no-gtkstyle \
-no-qml-debug \
-no-nis \
-no-mtdev \
-no-evdev \
-no-tslib \
-no-harfbuzz \
-no-openssl \
-no-libproxy \
-no-pulseaudio \
-no-cups \
-no-icu \
-no-fontconfig \
-no-sql-db2 \
-no-sql-mysql \
-no-sql-oci \
-no-sql-odbc \
-no-sql-psql \
-no-sql-sqlite \
-no-sql-sqlite2 \
-no-sql-ibase \
-no-sql-tds \
-no-directfb \
-no-xcb \
-no-xcb-xlib \
-no-glib \
-system-zlib \
-qt-libjpeg \
-qt-libpng \
-qt-freetype \
-opengl es2 \
-skip qt3d \
-skip qtactiveqt \
-skip qtandroidextras \
-skip qtcanvas3d \
-skip qtconnectivity \
-skip qtdoc \
-skip qtdocgallery \
-skip qtenginio \
-skip qtfeedback \
-skip qtimageformats \
-skip qtlocation \
-skip qtmacextras \
-skip qtpim \
-skip qtqa \
-skip qtquick1 \
-skip qtquickcontrols \
-skip qtrepotools \
-skip qtsensors \
-skip qtserialport \
-skip qtsystems \
-skip qttools \
-skip qttranslations \
-skip qtwayland \
-skip qtwebchannel \
-skip qtwebengine \
-skip qtwebkit \
-skip qtwebkit-examples \
-skip qtwebsockets \
-skip qtwinextras \
 {quote}

Resulting configuration are following:

{quote}
Support enabled for:
  Accessibility .......... yes
  ALSA ................... yes
  CUPS ................... no
  Evdev .................. no
  FontConfig ............. no
  FreeType ............... qt
  Glib ................... no
  GStreamer .............. yes (1.0)
  GTK theme .............. no
  HarfBuzz ............... no
  Iconv .................. yes
  ICU .................... no
  Image formats:
    GIF .................. yes (plugin, using bundled copy)
    JPEG ................. yes (plugin, using bundled copy)
    PNG .................. yes (in QtGui, using bundled copy)
  journald ............... no
  libinput................ no
  mtdev .................. no
  Networking:
    getaddrinfo .......... yes
    getifaddrs ........... yes
    IPv6 ifname .......... yes
    libproxy.............. no
    OpenSSL .............. no
  NIS .................... no
  OpenGL / OpenVG:
    EGL .................. yes
    OpenGL ............... yes (OpenGL ES 2.0+)
    OpenVG ............... no
  PCRE ................... yes (bundled copy)
  pkg-config ............. yes
  PulseAudio ............. no
  QPA backends:
    DirectFB ............. no
    EGLFS ................ yes
      EGLFS i.MX6....... . no
      EGLFS KMS .......... yes
      EGLFS Mali ......... no
      EGLFS Raspberry Pi . no
      EGLFS X11 .......... yes
    LinuxFB .............. yes
    XCB .................. no
  Session management ..... yes
  SQL drivers:
    DB2 .................. no
    InterBase ............ no
    MySQL ................ no
    OCI .................. no
    ODBC ................. no
    PostgreSQL ........... no
    SQLite 2 ............. no
    SQLite ............... no
    TDS .................. no
  tslib .................. no
  udev ................... yes
  xkbcommon-x11........... no
  xkbcommon-evdev......... no
  zlib ................... yes (system library)
{quote}

I tried to launch the QtMultimedia's Camera example (which does not use QML) via SSH connection
to the Tegra's device, like:

= using LinuxFB =

{quote}
$ ./camera -platform linuxfb:fb=/dev/fb1
{quote}

= using EGLFS via X =
{quote}
$ export DISPLAY=:0
$ export QT_QPA_EGLFS_INTEGRATION=eglfs_x11
$ startx &
$ ./camera -platform eglfs
{quote}

= using EGLFS via KMS =

{quote}
$ export DISPLAY=
$ export QT_QPA_EGLFS_INTEGRATION=eglfs_kms
$ ./camera -platform eglfs
{quote}

Use of LinuxFB and EGLFS via X gives very slow video performance (~3 fps as I spoke before).

Use of EGLFS via KMS gives folloving error:

{quote}
Could not find DRM device
Aborted
{quote}

I found out in the google yours blog [3] from Laszlo Agocs in which Tegra Jetson is mentioned,
but there are no details about building, running and so on.

So, my question is:

* do you have any trics and recommendations how to properly compile Qt on Tegra Jetson TK1 (maybe requires another flags and so on)?
* how to run the GUI application properly with KMS and so on?
* how to check that are used the HW rendering instead of SW rendering of video?


BR,
Denis

===========
[1] http://elinux.org/Jetson_TK1
[2] http://support.logitech.com/product/hd-pro-webcam-c920
[3] https://blog.qt.io/blog/2015/03/03/qt-weekly-28-qt-and-cuda-on-the-jetson-tk1/

_______________________________________________ Interest mailing list Interest at qt-project.org<mailto:Interest at qt-project.org> http://lists.qt-project.org/mailman/listinfo/interest
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.qt-project.org/pipermail/interest/attachments/20151104/a0fd4d8c/attachment.html>


More information about the Interest mailing list