Move hexparse to utils and add default PRBS poly

4 files changed, 51 insertions, 35 deletions

diff --git a/src/ConfigParser.cpp b/src/ConfigParser.cpp
index 8e5fed1..e68f98f 100644
--- a/src/ConfigParser.cpp
+++ b/src/ConfigParser.cpp
@@ -112,24 +112,6 @@ static void setup_subchannel_from_ptree(DabSubchannel* subchan,
         std::shared_ptr<dabEnsemble> ensemble,
         const string& subchanuid);
 
-/* a helper class to parse hexadecimal ids */
-static int hexparse(std::string input)
-{
-    int value;
-    if (input.find("0x") == 0) {
-        value = strtoll(input.c_str() + 2, nullptr, 16);
-    }
-    else {
-        value = strtoll(input.c_str(), nullptr, 10);
-    }
-
-    if (errno == ERANGE) {
-        throw runtime_error("hex conversion: value out of range");
-    }
-
-    return value;
-}
-
 static uint16_t get_announcement_flag_from_ptree(
         boost::property_tree::ptree& pt
         )
diff --git a/src/dabInputPrbs.cpp b/src/dabInputPrbs.cpp
index f34c427..f9a62b5 100644
--- a/src/dabInputPrbs.cpp
+++ b/src/dabInputPrbs.cpp
@@ -34,30 +34,36 @@
 #include <limits.h>
 #include <stdlib.h>
 #include <errno.h>
+#include "utils.h"
 
 using namespace std;
 
+// ETS 300 799 Clause G.2.1
+// Preferred polynomial is G(x) = x^20 + x^17 + 1
+const uint32_t PRBS_DEFAULT_POLY = (1 << 19) | (1 << 16) | 1;
+
 int DabInputPrbs::open(const string name)
 {
-    if (name[0] != ':') {
-        throw invalid_argument(
-                "Invalid PRBS address format. Must be prbs://:polynomial.");
+    if (name.empty()) {
+        m_prbs.setup(PRBS_DEFAULT_POLY);
     }
+    else {
+        if (name[0] != ':') {
+            throw invalid_argument(
+                    "Invalid PRBS address format. "
+                    "Must be prbs://:polynomial.");
+        }
 
-    const string poly_str = name.substr(1);
+        const string poly_str = name.substr(1);
 
-    long polynomial = strtol(poly_str.c_str(), (char **)NULL, 10);
-    if ((polynomial == LONG_MIN) || (polynomial == LONG_MAX)) {
-        stringstream ss;
-        ss <<  "Can't convert polynomial number " << poly_str;
-        throw invalid_argument(ss.str());
-    }
+        long polynomial = hexparse(poly_str);
 
-    if (polynomial == 0) {
-        throw invalid_argument("No polynomial given for PRBS input");
-    }
+        if (polynomial == 0) {
+            throw invalid_argument("No polynomial given for PRBS input");
+        }
 
-    m_prbs.setup(polynomial);
+        m_prbs.setup(polynomial);
+    }
     rewind();
 
     return 0;
diff --git a/src/utils.cpp b/src/utils.cpp
index 9976e88..f0df772 100644
--- a/src/utils.cpp
+++ b/src/utils.cpp
@@ -426,3 +426,29 @@ void printEnsemble(const shared_ptr<dabEnsemble> ensemble)
     }
 }
 
+long hexparse(const std::string& input)
+{
+    long value = 0;
+    errno = 0;
+
+    // Do not use strtol's base=0 because
+    // we do not want to accept octal.
+    if (input.find("0x") == 0) {
+        value = strtol(input.c_str() + 2, nullptr, 16);
+    }
+    else {
+        value = strtol(input.c_str(), nullptr, 10);
+    }
+
+    if ((value == LONG_MIN or value == LONG_MAX) and errno == ERANGE) {
+        throw out_of_range("hexparse: value out of range");
+    }
+    else if (value == 0 and errno != 0) {
+        stringstream ss;
+        ss << "hexparse: " << strerror(errno);
+        throw invalid_argument(ss.str());
+    }
+
+    return value;
+}
+
diff --git a/src/utils.h b/src/utils.h
index f65bba8..94712cd 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -26,9 +26,10 @@
    You should have received a copy of the GNU General Public License
    along with ODR-DabMux.  If not, see <http://www.gnu.org/licenses/>.
 */
-#ifndef _UTILS_H
-#define _UTILS_H
+#pragma once
 
+#include <string>
+#include <vector>
 #include <cstdio>
 #include <memory>
 #include "MuxElements.h"
@@ -78,5 +79,6 @@ void printEnsemble(const std::shared_ptr<dabEnsemble> ensemble);
 
 /* Print detailed component information */
 void printComponent(DabComponent* component);
-#endif
+
+long hexparse(const std::string& input);