tplusesimple

PulseAudio is a network-capable sound server program distributed by freedesktop.org.

The simple API is designed for applications with very basic sound playback or capture needs. It can only support a single stream per connection and has no handling of complex features like events, channel mappings and volume control.

This extension is Tcl bindings for PulseAudio simple API. Capture function added to current codebase but not actually verify.

License

LGPL 2.1, or (at your option) any later version.

Commands

pulseaudio::simple HANDLE ?-appname name? ?-direction direction? ?-format format? ?-rate samplerate? ?-channels channels?
HANDLE read
HANDLE write byte_aray
HANDLE flush
HANDLE drain
HANDLE get_latency
HANDLE close

-direction could setup below value: PLAYBACK, RECORD, and default setting is PLAYBACK

-format could setup below value: SAMPLE_U8, SAMPLE_ALAW, SAMPLE_ULAW, SAMPLE_S16LE, SAMPLE_S16BE, SAMPLE_FLOAT32LE, SAMPLE_FLOAT32LE, SAMPLE_S32LE, SAMPLE_S32BE, SAMPLE_S24LE, SAMPLE_S24BE, SAMPLE_S24_32LE, SAMPLE_S24_32BE, default setting is SAMPLE_S16LE

Once the connection is established to the server, data can start flowing. read method read some data from the server. write write some data to the server. Note that these operations always block.

flush method will throw away all data currently in buffers.

drain method will wait for all sent data to finish playing.

Once playback or capture is complete, the connection should be closed and resources freed. This is done through close method.

Linux Build

I only test tpulsesimple under openSUSE LEAP 42.2 and Ubuntu 14.04.

Users need install libpulse development files. Below is an example for openSUSE:

sudo zypper in libpulse-devel

Below is an example for Ubuntu:

sudo apt-get install libpulse-dev

Building under most UNIX systems is easy, just run the configure script and then run make. For more information about the build process, see the tcl/unix/README file in the Tcl src dist. The following minimal example will install the extension in the /opt/tcl directory.

$ cd tpulsesimple
$ ./configure --prefix=/opt/tcl
$ make
$ make install

If you need setup directory containing tcl configuration (tclConfig.sh), below is an example:

$ cd tpulsesimple
$ ./configure --with-tcl=/opt/activetcl/lib
$ make
$ make install

Examples

Cowork with tclmpg123.

#
# Using PulseAudio and libmpg123 to play a mp3 file
#

package require tpulsesimple
package require mpg123

if {$argc > 0} {
  set name [lindex $argv 0]
} else {
  puts "Please input filename."
  exit
}

if {[catch {set data [mpg123 mpg0 $name]}]} {
  puts "mpg123: read file failed."
  exit
}

pulseaudio::simple simple0 -direction PLAYBACK \
  -appname "PlayMP3" \
  -format SAMPLE_S16LE \
  -rate [dict get $data samplerate] \
  -channels [dict get $data channels]

while {[catch {set buffer [mpg0 read]}] == 0} {
  simple0 write $buffer
}

mpg0 close
simple0 close