问题
I write my pet project. At first, it was based on cmake and I set the path to qt libs from the console, e.g. cmake -DPATH_TO_QT:STRING=/home/user/Qt/5.11.1/gcc_64/
The variable PATH_TO_QT was declared as set(PATH_TO_QT "/path/to/your/Qt/" CACHE STRING "Path to Qt")
With this configuration, my project worked very well.
However, I wanted to add in my project Conan Package Manager and I did it. My conanfile.txt:
[requires]
Qt/5.11.1@bincrafters/stable
gtest/1.8.1@bincrafters/stable
libgit2/0.27.7@libgit2pkg/testing
[options]
Qt:qtmultimedia=True
Qt:qtsvg=True
Qt:qttools=True
[generators]
cmake
[imports]
bin, *.pdb -> ./bin
It works. The project builds fine. But in my project, I use QSound:
QSound::play(":/sounds/sounds/open-ended.wav");
In runtime, when the app gives this notification I don't hear it and in the console, I get the next message: using null output device, none available
But in other applications, sound exists.
How to fix this problem?
P.S. Kubuntu 18.04, GCC 7.3, Qt 5.11.1, conan 1.9.1, cmake 3.10.2
P.S2. config.summary
Build type: linux-g++ (x86_64, CPU features: mmx sse sse2)
Configuration: use_gold_linker sse2 aesni sse3 ssse3 sse4_1 sse4_2 avx avx2 avx512f avx512bw avx512cd avx512dq avx512er avx512ifma avx512pf avx512vbmi avx512vl compile_examples enable_new_dtags f16c largefile precompile_header rdrnd shani silent x86SimdAlways shared rpath release c++11 c++14 c++1z concurrent dbus no-pkg-config reduce_exports reduce_relocations stl
Build options:
Mode ................................... release
Optimize release build for size ........ no
Building shared libraries .............. yes
Using C++ standard ..................... C++1z
Using ccache ........................... no
Using gold linker ...................... yes
Using new DTAGS ........................ yes
Using precompiled headers .............. yes
Using LTCG ............................. no
Target compiler supports:
SSE .................................. SSE2 SSE3 SSSE3 SSE4.1 SSE4.2
AVX .................................. AVX AVX2
AVX512 ............................... F ER CD PF DQ BW VL IFMA VBMI
Other x86 ............................ AES F16C RDRAND SHA
Intrinsics without -mXXX option ...... yes
Build parts ............................ libs tools
Qt modules and options:
Qt Concurrent .......................... yes
Qt D-Bus ............................... yes
Qt D-Bus directly linked to libdbus .... no
Qt Gui ................................. yes
Qt Network ............................. yes
Qt Sql ................................. yes
Qt Testlib ............................. yes
Qt Widgets ............................. yes
Qt Xml ................................. yes
Support enabled for:
Using pkg-config ....................... no
udev ................................... no
Using system zlib ...................... no
Qt Core:
DoubleConversion ....................... yes
Using system DoubleConversion ........ no
GLib ................................... no
iconv .................................. yes
ICU .................................... no
Tracing backend ........................ <none>
Logging backends:
journald ............................. no
syslog ............................... no
slog2 ................................ no
Using system PCRE2 ..................... no
Qt Network:
getifaddrs() ........................... yes
IPv6 ifname ............................ yes
libproxy ............................... no
Linux AF_NETLINK ....................... yes
OpenSSL ................................ no
Qt directly linked to OpenSSL ........ no
OpenSSL 1.1 ............................ no
SCTP ................................... no
Use system proxies ..................... yes
Qt Gui:
Accessibility .......................... yes
FreeType ............................... yes
Using system FreeType ................ no
HarfBuzz ............................... yes
Using system HarfBuzz ................ no
Fontconfig ............................. no
Image formats:
GIF .................................. yes
ICO .................................. yes
JPEG ................................. yes
Using system libjpeg ............... no
PNG .................................. yes
Using system libpng ................ no
EGL .................................... no
OpenVG ................................. no
OpenGL:
Desktop OpenGL ....................... yes
OpenGL ES 2.0 ........................ no
OpenGL ES 3.0 ........................ no
OpenGL ES 3.1 ........................ no
OpenGL ES 3.2 ........................ no
Vulkan ................................. no
Session Management ..................... yes
Features used by QPA backends:
evdev .................................. yes
libinput ............................... no
INTEGRITY HID .......................... no
mtdev .................................. no
tslib .................................. no
xkbcommon-evdev ........................ no
QPA backends:
DirectFB ............................... no
EGLFS .................................. no
LinuxFB ................................ yes
VNC .................................... yes
Mir client ............................. no
X11:
Using system-provided XCB libraries .. no
EGL on X11 ........................... no
Xinput2 .............................. no
XCB XKB .............................. yes
XLib ................................. yes
XCB render ........................... yes
XCB GLX .............................. yes
XCB Xlib ............................. yes
Using system-provided xkbcommon ...... no
Native painting (experimental) ....... no
Qt Widgets:
GTK+ ................................... no
Styles ................................. Fusion Windows
Qt PrintSupport:
CUPS ................................... no
Qt Sql:
DB2 (IBM) .............................. no
InterBase .............................. no
MySql .................................. no
OCI (Oracle) ........................... no
ODBC ................................... no
PostgreSQL ............................. no
SQLite2 ................................ no
SQLite ................................. yes
Using system provided SQLite ......... no
TDS (Sybase) ........................... no
Qt Testlib:
Tester for item models ................. yes
Qt Multimedia:
ALSA ................................... no
GStreamer 1.0 .......................... no
GStreamer 0.10 ......................... no
Video for Linux ........................ yes
OpenAL ................................. no
PulseAudio ............................. no
Resource Policy (libresourceqt5) ....... no
Windows Audio Services ................. no
DirectShow ............................. no
Windows Media Foundation ............... no
Note: Also available for Linux: linux-clang linux-icc
Note: Disabling X11 Accessibility Bridge: D-Bus or AT-SPI is missing.
回答1:
I solved the problem myself. So if you have the same problem you can try to install the next dev-libs:
sudo aptitude install libfontconfig1-dev libdbus-1-dev libfreetype6-dev libudev-dev libicu-dev libsqlite3-dev libxslt1-dev libssl-dev libasound2-dev libavcodec-dev libavformat-dev \
libswscale-dev libgstreamer0.10-dev libgstreamer-plugins-base0.10-dev gstreamer-tools gstreamer0.10-plugins-good gstreamer0.10-plugins-bad libraspberrypi-dev libpulse-dev \
libx11-dev libglib2.0-dev libcups2-dev freetds-dev libsqlite0-dev libpq-dev libiodbc2-dev libmysqlclient-dev firebird-dev libpng12-dev libjpeg9-dev libgst-dev libxext-dev libxcb1 \
libxcb1-dev libx11-xcb1 libx11-xcb-dev libxcb-keysyms1 libxcb-keysyms1-dev libxcb-image0 libxcb-image0-dev libxcb-shm0 libxcb-shm0-dev libxcb-icccm4 libxcb-icccm4-dev \
libxcb-sync0 libxcb-sync1-dev libxcb-render-util0 libxcb-render-util0-dev libxcb-xfixes0-dev libxrender-dev libxcb-shape0-dev libxcb-randr0-dev libxcb-glx0-dev libxi-dev libdrm-dev gstreamer0.10-alsa
If you don't want to install gstreamer0.10 you can install gstreamer1.0:
sudo aptitude install gstreamer1.0-omx gstreamer1.0-omx-generic libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev gstreamer-tools gstreamer1.0-plugins-good gstreamer1.0-plugins-bad
回答2:
had the same issue and after installing the qt multimedia plugin access to audio devices worked.
E.g: sudo apt install libqt5multimedia5-plugins
来源：https://stackoverflow.com/questions/53569427/qt-conan-using-null-output-device-none-available