introduce device discovery api

This API allows to acquire a list of devices connected to the host and
creates an argument string ready to be passed to a source object for
cunstruction.

Each device_t entry contains a "label" entry, which holds the generic
device name which may be shown to the user for device selection.

For certain radio hardware extended entries ("name", "serial", "type")
may be available to make bijective device addressing possible.

The argument string for target types "rtl_tcp" and "file" might be
constructed using the osmosdr::device_t class facilities.

Example:

 #include <osmosdr_device.h>
 #include <osmosdr_source_c.h>

osmosdr::devices_t devs = osmosdr::device::find();

BOOST_FOREACH(osmosdr::device_t &dev, devs) // try to create each dev
  osmosdr_source_c_sptr src = osmosdr_make_source_c(dev.to_string());

1 files changed, 10 insertions, 2 deletions

diff --git a/lib/fcd/fcd_source.cc b/lib/fcd/fcd_source.cc
index fa6caeb..f590388 100644
--- a/lib/fcd/fcd_source.cc
+++ b/lib/fcd/fcd_source.cc
@@ -38,6 +38,11 @@ fcd_source_sptr make_fcd_source(const std::string &args)
   return gnuradio::get_initial_sptr(new fcd_source(args));
 }
 
+/*
+ 2 [V10            ]: USB-Audio - FUNcube Dongle V1.0
+                      Hanlincrest Ltd. FUNcube Dongle V1.0 at usb-0000:00:1d.0-2, full speed
+ */
+
 static std::vector< std::string > _get_devices()
 {
   std::vector< std::string > devices;
@@ -102,8 +107,11 @@ std::vector< std::string > fcd_source::get_devices()
   int id = 0;
   std::vector< std::string > devices;
 
-  BOOST_FOREACH( std::string dev, _get_devices() )
-    devices.push_back( "fcd=" + boost::lexical_cast< std::string >( id++ ) );
+  BOOST_FOREACH( std::string dev, _get_devices() ) {
+    std::string args = "fcd=" + boost::lexical_cast< std::string >( id++ );
+    args += ",label='FunCube Dongle'";
+    devices.push_back( args );
+  }
 
   return devices;
 }