1 files changed, 88 insertions, 0 deletions
diff --git a/gnuradio-core/src/python/gnuradio/audio.py b/gnuradio-core/src/python/gnuradio/audio.py
new file mode 100644
index 0000000000..5a9d09c772
--- /dev/null
+++ b/gnuradio-core/src/python/gnuradio/audio.py
@@ -0,0 +1,88 @@
+#
+# Copyright 2004,2006 Free Software Foundation, Inc.
+# 
+# This file is part of GNU Radio
+# 
+# GNU Radio 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.
+# 
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+# 
+
+"""
+This is the 'generic' audio or soundcard interface.
+
+The behavior of this module is controlled by the [audio] audio_module
+configuration parameter.  If it is 'auto' we attempt to import modules
+from the known_modules list, using the first one imported successfully.
+
+If [audio] audio_module is not 'auto', we assume it's the name of
+an audio module and attempt to import it.
+"""
+
+__all__ = ['source', 'sink']
+
+from gnuradio import gr
+import sys
+
+source = None
+sink = None
+
+
+known_modules = (
+    'audio_alsa', 'audio_oss', 'audio_osx', 'audio_jack', 'audio_portaudio')
+
+
+def try_import(name):
+    """
+    Build a blob of code and try to execute it.
+    If it succeeds we will have set the globals source and sink
+    as side effects.
+
+    returns True or False
+    """
+    global source, sink
+    full_name = "gnuradio." + name
+    code = """
+import %s
+source = %s.source
+sink = %s.sink
+""" % (full_name, full_name, full_name)
+    try:
+        exec code in globals()
+        return True
+    except ImportError:
+        return False
+    
+
+def __init__ ():
+    p = gr.prefs()		# get preferences (config file) object
+    verbose = p.get_bool('audio', 'verbose', False)
+    module = p.get_string('audio', 'audio_module', 'auto')
+
+    if module == 'auto':        # search our list for the first one that we can import
+        for m in known_modules:
+            if try_import(m):
+                if verbose: sys.stderr.write('audio: using %s\n' % (m,))
+                return
+        raise ImportError, 'Unable to locate an audio module.'
+
+    else:                       # use the one the user specified
+        if try_import(module):
+            if verbose: sys.stderr.write('audio: using %s\n' % (module,))
+        else:
+            msg = 'Failed to import user-specified audio module %s' % (module,)
+            if verbose: sys.stderr.write('audio: %s\n' % (msg,))
+            raise ImportError, msg
+
+__init__()