Filter out SoapyAudio devices

When gr-osmosdr is compiled with SoapySDR support and SoapyAudio is
installed the audio device is picked as a first choice when detecting
devices but grgsm tools are not able to work with audio devices. So in
such cases the user has to always specify the correct SDR device in the
args parameter which is a bit inconvenient.

When args is not specified call osmosdr.device_find to get all devices
and filter out unspported ones like SoapyAudio devices. When args is
specifed just try to create osmosdr.source with whatever value has been
specified.

Add -l and --list-devices command line option that prints information
about all detected devices.

Example commands:
  grgsm_capture --list-devices
  grgsm_capture --list-devices --args=nofake
  grgsm_capture --args=uhd,type=b210 -a 111 capture.cfile
  grgsm_livemon --args=rtl
  grgsm_livemon --args=uhd,type=b210

Change-Id: Ib84081041ca6c2bc18b9da0c32bac9d3ecef65ca

apps/grgsm_livemon.grc

@@ -2844,7 +2844,7 @@
     </param>
     <param>
       <key>args</key>
-      <value>args</value>
+      <value>str(grgsm.device.get_default_args(args))</value>
     </param>
     <param>
       <key>_enabled</key>

apps/grgsm_livemon_headless.grc

@@ -2414,7 +2414,7 @@
     </param>
     <param>
       <key>args</key>
-      <value>args</value>
+      <value>str(grgsm.device.get_default_args(args))</value>
     </param>
     <param>
       <key>_enabled</key>

apps/grgsm_scanner

@@ -36,7 +36,7 @@ import os
 import osmosdr
 import pmt
 import time
-
+import sys
 
 # from wideband_receiver import *
 
@@ -208,7 +208,8 @@ class wideband_scanner(gr.top_block):
 
         # if no file name is given process data from rtl_sdr source
         print "Args=", args
-        self.rtlsdr_source = osmosdr.source(args="numchan=" + str(1) + " " + args)
+        self.rtlsdr_source = osmosdr.source(args="numchan=" + str(1) + " " +
+                str(grgsm.device.get_default_args(args)))
         #self.rtlsdr_source.set_min_output_buffer(int(sample_rate*rec_len)) #this line causes segfaults on HackRF
         self.rtlsdr_source.set_sample_rate(sample_rate)
 
@@ -387,7 +388,10 @@ def argument_parser():
     parser.add_option("-g", "--gain", dest="gain", type="eng_float", default=24.0,
                       help="Set gain [default=%default]")
     parser.add_option("", "--args", dest="args", type="string", default="",
-                      help="Set device arguments [default=%default]")
+                      help="Set device arguments [default=%default]."
+                      " Use --list-devices the view the available devices")
+    parser.add_option("-l", "--list-devices", action="store_true",
+                      help="List available SDR devices, use --args to specify hints")
     parser.add_option("--speed", dest="speed", type="intx", default=4,
                       help="Scan speed [default=%default]. Value range 0-5.")
     parser.add_option("-v", "--verbose", action="store_true",
@@ -404,6 +408,10 @@ def main(options = None):
     if options is None:
         (options, args) = argument_parser().parse_args()
 
+    if options.list_devices:
+        grgsm.device.print_devices(options.args)
+        sys.exit(0)
+
     if options.band not in grgsm.arfcn.get_bands():
         parser.error("Invalid GSM band\n")
 

apps/helpers/grgsm_capture

@@ -53,8 +53,8 @@ class grgsm_capture(gr.top_block):
         # Setting up RF source
         ##################################################
 
-        self.sdr_source = \
-                    osmosdr.source(args="numchan=" + str(1) + " " + device_args)
+        self.sdr_source = osmosdr.source(args="numchan=" + str(1) + " " +
+                str(grgsm.device.get_default_args(device_args)))
 
         self.sdr_source.set_sample_rate(samp_rate)
         self.sdr_source.set_center_freq(freq, 0)
@@ -141,12 +141,19 @@ if __name__ == '__main__':
 
     osmogroup.add_option("", "--args", dest="device_args", type="string",
                       default="", help="Set device arguments "
-                      "[default=%default]")
+                      "[default=%default]. Use --list-devices the view the available devices")
+
+    osmogroup.add_option("-l", "--list-devices", action="store_true",
+                      help="List available SDR devices, use --args to specify hints")
 
     parser.add_option_group(osmogroup)
 
     (options, args) = parser.parse_args()
 
+    if options.list_devices:
+        grgsm.device.print_devices(options.device_args)
+        sys.exit(0)
+
     if not args:
         parser.error("Please provide an output file name to save the captured data\n")
 

python/__init__.py

@@ -59,6 +59,7 @@ from gsm_gmsk_mod import gsm_gmsk_mod
 from fn_time import *
 from txtime_bursts_tagger import *
 import arfcn
+import device
 
 
 #

python/misc_utils/CMakeLists.txt

@@ -23,5 +23,6 @@ GR_PYTHON_INSTALL(
     clock_offset_corrector_tagged.py
     hier_block.py 
     fn_time.py
+    device.py
     DESTINATION ${GR_PYTHON_DIR}/grgsm
 )

python/misc_utils/device.py

@@ -0,0 +1,64 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# @file
+# @author (C) 2019 by Vasil Velichkov <vvvelichkov@gmail.com>
+# @section LICENSE
+#
+# Gr-gsm 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 3, or (at your option)
+# any later version.
+#
+# Gr-gsm 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 gr-gsm; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+#
+
+import osmosdr
+import os
+
+def get_devices(hint=""):
+    return osmosdr.device_find(osmosdr.device_t(hint))
+
+def match(dev, filters):
+    for f in filters:
+        for k, v in f.items():
+            if (k not in dev or dev[k] != v):
+                break
+        else:
+            return True
+    return False
+
+def exclude(devices, filters = ({'driver': 'audio'},)):
+    return [dev for dev in devices if not match(dev, filters)]
+
+def get_all_args(hint="nofake"):
+    return map(lambda dev: dev.to_string(), exclude(get_devices(hint)))
+
+def get_default_args(args):
+    # The presence of GRC_BLOCKS_PATH environment variable indicates that
+    # gnuradio-companion compiles a flowgraph and in this case no exception
+    # have to be thrown otherwise the generaged python script will be invalid.
+    # This allows compilation of flowgraphs without an SDR device.
+    if args or os.getenv("GRC_BLOCKS_PATH"):
+        return args
+
+    devices = get_all_args("nofake")
+    if not devices:
+        raise RuntimeError("Unable to find any supported SDR devices")
+
+    return devices[0]
+
+def print_devices(hint=""):
+    devices = exclude(get_devices(hint))
+    if devices:
+        print("\n".join(map(lambda dev: dev.to_string(), devices)))
+    else:
+        print("Unable to find any supported SDR devices")