Sound backend

Dependencies:

Required:

• libxenbe

Optional:

• alsa
• pulse
• Doxygen

How to configure

mkdir ${BUILD_DIR}
cd ${BUILD_DIR}
cmake ${PATH_TO_SOURCES} -D${VAR1}=${VAL1} -D{VAR2}=${VAL2} ...

There are variables and options. Options can be set to ON and OFF.

Supported options:

Option	Description
WITH_DOC	Creates target to build documentation. It required Doxygen to be installed. If configured, documentation can be create with make doc
WITH_PULSE	Builds with pulse audio backend
WITH_ALSA	Builds with alsa backend
WITH_MOCKBELIB	Use test mock backend library

Supported variables:

Variable	Description
CMAKE_BUILD_TYPE	Realease, Debug, RelWithDebInfo, MinSizeRel
CMAKE_INSTALL_PREFIX	Default install path
XEN_INCLUDE_PATH	Path to Xen tools includes if they are located in non standard place
XENBE_INCLUDE_PATH	Path to libxenbe includes if they are located in non standard place
IF_INCLUDE_PATH	Path to the interface headers if they are located in non standard place
XENBEMOCK_INCLUDE_PATH	Path to the mock headers if they are located in non standard place
XEN_LIB_PATH	Path to Xen tools libraries if they are located in non standard place
XENBE_LIB_PATH	Path to libxenbe if it is located in non standard place
XENBEMOCK_LIB_PATH	Path to libxenbemock if it is located in non standard place

Example:

// Debug build with pulse backend
cmake ${PATH_TO_SOURCES} -DWITH_PULSE=ON -DCMAKE_BUILD_TYPE=Debug

How to build:

cd ${BUILD_DIR}
make     // build sources
make doc // build documentation

How to install

make install // to default location
make DESTDIR=${PATH_TO_INSTALL} install //to other location

Configuration:

Backend configuration is done in domain configuration file. See vsnd on http://xenbits.xen.org/docs/unstable-staging/man/xl.cfg.5.html#Devices

In order to match virtual stream with real one, stream unique-id parameter is used. This parameter has following format:

pcmtype<device>propname:propvalue

All fields except pcmtype are optional.

• pcmtype - specifies PCM type: "pulse" or "alsa";
• device - device name
  • for pulse: sink or source name
  • for alsa: alsa device like HW:0;1 (note that ";" used instead of "," because "," is field separator in domain config file)
• propname (relevant for pulse) - stream property name: like media.role etc.
• propvalue (relevant for pulse) - stream property value: like navi, phone etc.

Stream property is used to identify pulse stream by other system modules such as audio manager etc.

Some configuration examples:

# The backend will provide default pulse device for the configured stream playback.
vsnd = [[ 'card, backend=DomD, buffer-size=65536, short-name=VCard, long-name=Virtual sound card, sample-rates=48000, sample-formats=s16_le',
          'pcm, name=dev1', 'stream, unique-id=pulse, type=P' ]]

# The backend will use ALSA device hw:0,0 for playback. Pay attention that "0,0" have to be replaced by "0;0", and sample format is s24_le.
vsnd = [[ 'card, backend=DomD, buffer-size=32768, short-name=VCard, long-name=Virtual sound card, sample-rates=48000, sample-formats=s24_le',
          'pcm, name=dev1', 'stream, unique-id=alsa<hw:0;0>, type=P' ]]

Other unique-id values example:

# the backend will provide default pulse device for the configured stream
unique-id=pulse
# the backend will provide pulse pci-0000_00_1f.3.analog-stereo device for the configured stream
unique-id=pulse<pci-0000_00_1f.3.analog-stereo> 
# the backend will provide default pulse device for the configured stream and set media.role property of stream to navi
unique-id=pulse<>media.role:navi
# the backend will provide alsa card0 device 0 for the configured stream 
unique-id=alsa<hw:0;0>

How to run:

snd_be -v${LOG_MASK}

Example:

snd_be -v *:Debug