WIP: RTL-SDR Support

.travis.yml

@@ -1,6 +1,6 @@
 language: cpp
 
-dist: trusty
+dist: bionic
 sudo: false
 
 compiler:
@@ -14,6 +14,7 @@ addons:
       - libmbe-dev
       - libsndfile1-dev
       - libitpp-dev
+      - librtlsdr-dev
       - portaudio19-dev
 
 before_script:

CMakeLists.txt

@@ -10,6 +10,7 @@ find_package(LibSndFile REQUIRED)
 find_package(MBE REQUIRED)
 find_package(ITPP REQUIRED)
 find_package(LibPortAudio)
+find_package(RTLSDR)
 
 include_directories(SYSTEM ${LIBSNDFILE_INCLUDE_DIR} ${MBE_INCLUDE_DIR} ${ITPP_INCLUDE_DIR})
 set(LIBS ${MBE_LIBRARY} ${LIBSNDFILE_LIBRARY} ${ITPP_LIBRARY})
@@ -20,9 +21,20 @@ if(PORTAUDIO_FOUND)
     add_definitions(-DUSE_PORTAUDIO)
 endif(PORTAUDIO_FOUND)
 
+if(RTLSDR_FOUND)
+    find_package(Threads)
+    include_directories(SYSTEM ${RTLSDR_INCLUDE_DIRS})
+    list(APPEND LIBS ${RTLSDR_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT})
+    add_definitions(-DUSE_RTLSDR)
+endif(RTLSDR_FOUND)
+
 FILE(GLOB SRCS src/*.c src/*.cpp)
 FILE(GLOB HEADERS include/*.h include/*.hpp)
 
+if(NOT RTLSDR_FOUND)
+    list(REMOVE_ITEM SRCS ${CMAKE_CURRENT_SOURCE_DIR}/src/rtl_sdr_fm.cpp)
+endif(NOT RTLSDR_FOUND)
+
 configure_file("src/git_ver.c.in" "${CMAKE_CURRENT_BINARY_DIR}/git_ver.c" @ONLY)
 list(APPEND SRCS "${CMAKE_CURRENT_BINARY_DIR}/git_ver.c")
 

cmake/FindLibSndFile.cmake

@@ -12,5 +12,5 @@ SET(LIBSNDFILE_NAMES ${LIBSNDFILE_NAMES} sndfile libsndfile)
 FIND_LIBRARY(LIBSNDFILE_LIBRARY NAMES ${LIBSNDFILE_NAMES})
 
 include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(LIBSNDFILE DEFAULT_MSG LIBSNDFILE_LIBRARY
-                                    LIBSNDFILE_INCLUDE_DIR)
+find_package_handle_standard_args(LibSndFile DEFAULT_MSG LIBSNDFILE_LIBRARY
+                                    LIBSNDFILE_INCLUDE_DIR)

cmake/FindRTLSDR.cmake

@@ -0,0 +1,29 @@
+# - Try to find rtlsdr - the hardware driver for the realtek chip in the dvb receivers
+# Once done this will define
+#  RTLSDR_FOUND - System has rtlsdr
+#  RTLSDR_LIBRARIES - The rtlsdr libraries
+#  RTLSDR_INCLUDE_DIRS - The rtlsdr include directories
+#  RTLSDR_LIB_DIRS - The rtlsdr library directories
+
+if (NOT RTLSDR_FOUND)
+
+  find_package(PkgConfig)
+  pkg_check_modules(RTLSDR_PKG librtlsdr)
+  set(RTLSDR_DEFINITIONS ${PC_RTLSDR_CFLAGS_OTHER})
+
+  find_path(RTLSDR_INCLUDE_DIR
+    NAMES rtl-sdr.h
+    HINTS ${RTLSDR_PKG_INCLUDE_DIRS})
+
+  find_library(RTLSDR_LIBRARY
+    NAMES rtlsdr
+    HINTS ${RTLSDR_PKG_LIBRARY_DIRS})
+
+  set(RTLSDR_LIBRARIES ${RTLSDR_LIBRARY})
+  set(RTLSDR_INCLUDE_DIRS ${RTLSDR_INCLUDE_DIR})
+
+  include(FindPackageHandleStandardArgs)
+  find_package_handle_standard_args(RTLSDR DEFAULT_MSG RTLSDR_LIBRARY RTLSDR_INCLUDE_DIR)
+  mark_as_advanced(RTLSDR_INCLUDE_DIR RTLSDR_LIBRARY)
+
+endif (NOT RTLSDR_FOUND)

debian/control

@@ -2,8 +2,8 @@ Source: dsd
 Section: hamradio
 Priority: optional
 Maintainer: Jared Szechy <jared.szechy@gmail.com>
-Build-Depends: debhelper (>= 9), libmbe-dev, libitpp-dev, libsndfile1-dev,
- portaudio19-dev, cmake, git, help2man
+Build-Depends: debhelper (>= 9), libmbe-dev, libitpp-dev, librtlsdr-dev
+ libsndfile1-dev, portaudio19-dev, cmake, git, help2man
 Standards-Version: 4.1.4
 Homepage: https://github.com/szechyjs/dsd
 Vcs-Git: https://github.com/szechyjs/dsd.git
@@ -17,4 +17,4 @@ Pre-Depends: ${misc:Pre-Depends}
 Depends: ${shlibs:Depends}, ${misc:Depends}
 Description: Digital Speech Decoder
  DSD is able to decode several digital voice formats from discriminator tap
- audio and synthesize the decoded speech.
+ audio and synthesize the decoded speech.

debian/copyright

@@ -20,6 +20,14 @@ Files: src/dstar_header.c include/dstar_header.h include/fcs.h
 Copyright: Copyright (C) 2010 by Kristoff Bonne, ON1ARF
 License: GPL-2
 
+Files: src/rtl_sdr_fm.cpp
+Copyright: Copyright (C) 2012 by Steve Markgraf <steve@steve-m.de>
+ Copyright (C) 2012 by Hoernchen <la@tfc-server.de>
+ Copyright (C) 2012 by Kyle Keen <keenerd@gmail.com>
+ Copyright (C) 2013 by Elias Oenal <EliasOenal@gmail.com>
+ Copyright (C) 2014 by Kyle Keen <keenerd@gmail.com>
+License: GPL-2
+
 Files: include/descramble.h
 Copyright: Copyright (C) 2011 by Jonathan Naylor, G4KLX
 License: GPL-2
@@ -103,4 +111,4 @@ License: BSL-1.0
  SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
  FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
  ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
- DEALINGS IN THE SOFTWARE.
+ DEALINGS IN THE SOFTWARE.

include/dsd.h

@@ -58,11 +58,14 @@
 #define PA_LATENCY_OUT 0.100
 #endif
 
+#ifdef USE_RTLSDR
+#include <rtl-sdr.h>
+#endif
+
 /*
  * global variables
  */
-int exitflag;
-
+static volatile int exitflag;
 
 typedef struct
 {
@@ -85,7 +88,9 @@ typedef struct
 #ifdef USE_PORTAUDIO
   PaStream* audio_in_pa_stream;
 #endif
-  int audio_in_type; // 0 for device, 1 for file, 2 for portaudio
+  uint32_t rtlsdr_center_freq;
+  int rtlsdr_ppm_error;
+  int audio_in_type; // 0 for device, 1 for file, 2 for portaudio, 3 for rtlsdr
   char audio_out_dev[1024];
   int audio_out_fd;
   SNDFILE *audio_out_file;
@@ -317,4 +322,15 @@ void processDSTAR_HD (dsd_opts * opts, dsd_state * state);
 short dmr_filter(short sample);
 short nxdn_filter(short sample);
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+void open_rtlsdr_stream(dsd_opts *opts);
+void cleanup_rtlsdr_stream();
+void get_rtlsdr_sample(int16_t *sample);
+void rtlsdr_sighandler();
+#ifdef __cplusplus
+}
+#endif
+
 #endif // DSD_H

src/dsd_audio.c

@@ -500,6 +500,10 @@ openAudioInDevice (dsd_opts * opts)
 		exit(1);
 #endif
 	}
+  else if(strncmp(opts->audio_in_dev, "rtl:", 3) == 0)
+  {
+    opts->audio_in_type = 3;
+  }
 	else
 	{
   struct stat stat_buf;

src/dsd_main.c

@@ -274,6 +274,8 @@ usage ()
   printf ("  -n            Do not send synthesized speech to audio output device\n");
   printf ("  -w <file>     Output synthesized speech to a .wav file\n");
   printf ("  -a            Display port audio devices\n");
+  printf ("  -c <hertz>    RTL-SDR center frequency\n");
+  printf ("  -P <num>      RTL-SDR ppm error (default = 0)\n");
   printf ("\n");
   printf ("Scanner control options:\n");
   printf ("  -B <num>      Serial port baud rate (default=115200)\n");
@@ -327,6 +329,12 @@ liveScanner (dsd_opts * opts, dsd_state * state)
 			return;
 		}
 	}
+#endif
+#ifdef USE_RTLSDR
+  if(opts->audio_in_type == 3)
+  {
+    open_rtlsdr_stream(opts);
+  }
 #endif
 	while (1)
     {
@@ -411,6 +419,14 @@ cleanupAndExit (dsd_opts * opts, dsd_state * state)
 	}
 #endif
 
+#ifdef USE_RTLSDR
+  if(opts->audio_in_type == 3)
+  {
+    // TODO: cleanup demod threads
+    cleanup_rtlsdr_stream();
+  }
+#endif
+
   printf("\n");
   printf("Total audio errors: %i\n", state->debug_audio_errors);
   printf("Total header errors: %i\n", state->debug_header_errors);
@@ -447,6 +463,35 @@ sigfun (int sig)
 {
     exitflag = 1;
     signal (SIGINT, SIG_DFL);
+#ifdef USE_RTLSDR
+    rtlsdr_sighandler();
+#endif
+}
+
+double atofs(char *s)
+{
+	char last;
+	int len;
+	double suff = 1.0;
+	len = strlen(s);
+	last = s[len-1];
+	s[len-1] = '\0';
+	switch (last) {
+		case 'g':
+		case 'G':
+			suff *= 1e3;
+		case 'm':
+		case 'M':
+			suff *= 1e3;
+		case 'k':
+		case 'K':
+			suff *= 1e3;
+			suff *= atof(s);
+			s[len-1] = last;
+			return suff;
+	}
+	s[len-1] = last;
+	return atof(s);
 }
 
 int
@@ -469,7 +514,7 @@ main (int argc, char **argv)
   exitflag = 0;
   signal (SIGINT, sigfun);
 
-  while ((c = getopt (argc, argv, "haep:qstv:z:i:o:d:g:nw:B:C:R:f:m:u:x:A:S:M:rl")) != -1)
+  while ((c = getopt (argc, argv, "haep:P:qstv:z:i:o:d:c:g:nw:B:C:R:f:m:u:x:A:S:M:rl")) != -1)
     {
       opterr = 0;
       switch (c)
@@ -506,6 +551,9 @@ main (int argc, char **argv)
              opts.unmute_encrypted_p25 = 1;
             }
           break;
+        case 'P':
+          sscanf (optarg, "%i", &opts.rtlsdr_ppm_error);
+          break;
         case 'q':
           opts.errorbars = 0;
           opts.verbose = 0;
@@ -551,6 +599,10 @@ main (int argc, char **argv)
           opts.mbe_out_dir[1023] = '\0';
           printf ("Writing mbe data files to directory %s\n", opts.mbe_out_dir);
           break;
+        case 'c':
+          opts.rtlsdr_center_freq = (uint32_t)atofs(optarg);
+          printf("Using center freq: %i\n", opts.rtlsdr_center_freq);
+          break;
         case 'g':
           sscanf (optarg, "%f", &opts.audio_gain);
           if (opts.audio_gain < (float) 0 )

src/dsd_symbol.c

@@ -88,18 +88,25 @@ getSymbol (dsd_opts * opts, dsd_state * state, int have_sync)
               cleanupAndExit (opts, state);
           }
       }
-	  else
-	  {
+      else if (opts->audio_in_type == 2)
+      {
 #ifdef USE_PORTAUDIO
-		PaError err = Pa_ReadStream( opts->audio_in_pa_stream, &sample, 1 );
-		if( err != paNoError )
-		{
-    			fprintf( stderr, "An error occured while using the portaudio input stream\n" );
-    			fprintf( stderr, "Error number: %d\n", err );
-    			fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
-		}
+        PaError err = Pa_ReadStream( opts->audio_in_pa_stream, &sample, 1 );
+        if( err != paNoError )
+        {
+              fprintf( stderr, "An error occured while using the portaudio input stream\n" );
+              fprintf( stderr, "Error number: %d\n", err );
+              fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
+        }
 #endif
-	  }
+	    }
+      else if (opts->audio_in_type == 3)
+      {
+#ifdef USE_RTLSDR
+        // TODO: need to read demodulated stream here
+        get_rtlsdr_sample(&sample);
+#endif
+      }
 
 #ifdef TRACE_DSD
       state->debug_sample_index++;