tcllibao

libao is a cross-platform audio library that allows programs to output audio using a simple API on a wide variety of platforms.

libao is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version.

It is a Tcl bindings for libao.

License

GNU General Public License version 2, or (at your option) any later version.

Commands

libao::ao initialize
libao::ao default_id
libao::ao driver_id short_name
libao::ao open_live id ?-bits bits? ?-rate samplerate? ?-channels channels? ?-byteformat format?
libao::ao open_file id filename ?-overwrite overwrite? ?-bits bits? ?-rate samplerate? ?-channels channels? ?-byteformat format?
libao::ao play byte_array
libao::ao close
libao::ao shutdown

The short_name you can check https://www.xiph.org/ao/doc/drivers.html.

open_live and open_file -byteformat have 3 values. 1 is Little Endian, 2 is Big Endian, and 4 is NATIVE. If user does not specify, the default value is NATIVE.

open_file -overwrite option if non-zero, the file is automatically overwritten. If zero, then a preexisting file will cause the function to report a failure.

UNIX BUILD

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

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

sudo zypper in libao-devel

Below is an example for Ubuntu:

sudo apt-get install libao-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 tcllibao
$ ./configure --prefix=/opt/tcl
$ make
$ make install

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

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

WINDOWS BUILD

MSYS2/MinGW-W64

First step is to download the libao source package.

If libao version is <= 1.2.0, users need apply 2 patches to fix configure and build failed (patch1, patch2).

Below is the configure.ac diff result (after patch and before):

227c227
< AS_IF([test "x$enable_wmm" != "xno"],
---
> AS_IF([AC_LANG_SOURCE([test "x$enable_wmm" != "xno"],
231c231
<    waveout_old_LIBS="$LIBS"; LIBS="$LIBS -lwinmm -Wl,-lksguid"
---
>    waveout_old_LIBS="$LIBS"; LIBS="$LIBS -lwinmm"
233c233
<    AC_LINK_IFELSE([AC_LANG_SOURCE([
---
>    AC_LINK_IFELSE([

Now build libao:

autoconf
./configure --enable-wmm=yes --prefix=/c/msys64/mingw64
make
make install

Put libao-4.dll to Windows folder or other available folder.

Next step is to build tcllibao:

./configure --with-tcl=/c/tcl/lib
make
make install

Example

Cowork with tclsndfile.

#
# Using libao and libsndfile to play a wav/ogg file
#

package require libao
package require sndfile

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

if {[catch {set data [sndfile snd0 $name READ]}]} {
    puts "sndfile: read file failed."
    exit
}
set encoding [dict get $data encoding]

# only for test seek
snd0 seek 0 SET

libao::ao initialize
set id [libao::ao default_id]

set bits 16
switch $encoding {
  {pcm_16} {
      set bits 16
  }
  {pcm_24} {
      set bits 24
  }
  {pcm_32} {
      set bits 32
  }
  {pcm_s8} {
      set bits 8
  }
  {pcm_u8} {
      set bits 8
  }
  default {
      set bits 16
  }
}

libao::ao open_live $id -bits $bits \
  -rate [dict get $data samplerate] \
  -channels [dict get $data channels] -byteformat 4

# libao needs use read_short to get data
while {[catch {set buffer [snd0 read_short]}] == 0} {
    libao::ao play $buffer
}

snd0 close
libao::ao close
libao::ao shutdown

Cowork with tclmpg123.

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

package require libao
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
}
set bits [dict get $data bits]

# only for test seek function
mpg0 seek 0 SET

libao::ao initialize
set id [libao::ao default_id]

libao::ao open_live $id -bits $bits \
  -rate [dict get $data samplerate] \
  -channels [dict get $data channels]

while {[catch {set buffer [mpg0 read]}] == 0} {
    libao::ao play $buffer
}

mpg0 close
libao::ao close
libao::ao shutdown