Changeset 5283

Timestamp:

10/09/07 09:44:48 (6 years ago)

Author:

jgaeddert

Message:

fixing bug; flags/counters not set properly. Packetizer/depacketizer now works properly for situations with bit inversions

Location:

experimental/components/Packetizer/trunk/Packetizer-metadata

Files:

• src/PacketizerDSP.cpp (modified) (2 diffs)
• tests/Depacketizer_testsuite.h (modified) (2 diffs)

experimental/components/Packetizer/trunk/Packetizer-metadata/src/PacketizerDSP.cpp

@@ -207 +207 @@
         if ( abs(rxy) > correlator_threshold ) {
             //printf("\nPN sync code found!!\n\n");
+            invert_bits = ( rxy < 0 ) ? true : false;
             num_bits_read = i+1;
             num_control_codes_extracted = 0;
@@ -253 +254 @@
                 ConfigurePacketType( (PacketType) new_packet_type );
                 num_bits_read = i+1;
+                num_subheader_bits_read = 0;
                 return true;
             }

experimental/components/Packetizer/trunk/Packetizer-metadata/tests/Depacketizer_testsuite.h

@@ -49 +49 @@
     }
 
+    //
+    // Basic test for creating and extracting a packet of type PACKET_RAW_400
+    // 
     void test_ExtractPacketHeader_01() {
         // generate input buffer
@@ -125 +128 @@
     }
 
+    //
+    // Test extracting a packet with bit inversion
+    // 
+    void test_ExtractPacketHeader_02() {
+        // generate input buffer
+        char * input;
+        input = (char*) calloc( 400, sizeof(char) );
+        input[0] = 1;
+        input[1] = 0;
+        input[2] = 1;
+
+        // generate packet buffer
+        char * packet;
+        packet = (char*) calloc( 1024, sizeof(char) );
+        memset( packet, 0x01, 1024*sizeof(char) );
+
+        // generate output buffer
+        char * output;
+        output = (char*) calloc( 1024, sizeof(char) );
+        memset( output, 0x01, 1024*sizeof(char) );
+
+        bool found_header;
+        bool packet_type_extracted;
+        bool packet_subheader_extracted;
+        bool packet_data_extracted;
+        unsigned int n;
+
+        // assemble packet
+        unsigned int packet_length(1024);
+        AssemblePacket( input, 400, packet, packet_length, PACKET_RAW_400 );
+
+        // flip all the bits
+        for (unsigned int i=0; i<1024; i++)
+            packet[i] = 1-packet[i];
+
+        // try to extract packet header
+        unsigned int N(0);                      // total bits read from input
+        found_header = ExtractPacketHeader( packet+N, 1024, n );
+        N += n;
+        TS_ASSERT_EQUALS(found_header, true);       // should have found header
+        TS_ASSERT_EQUALS(n, PN_SYNC_CODE_LENGTH);   // should have only read 63 values
+        TS_ASSERT_EQUALS(rxy, -PN_SYNC_CODE_LENGTH);// correlator should be negative
+
+        // try to extract packet type
+        packet_type_extracted = ExtractPacketType( packet+N, 500, n );
+        N += n;
+        TS_ASSERT_EQUALS(packet_type_extracted, true);
+        TS_ASSERT_EQUALS(n, NUM_CONTROL_CODES*PN_CONTROL_CODE_LENGTH);    // should have read control codes
+        TS_ASSERT_EQUALS( N, PN_SYNC_CODE_LENGTH + NUM_CONTROL_CODES*PN_CONTROL_CODE_LENGTH);
+
+        TS_ASSERT_EQUALS(new_packet_type, 0);
+
+        // try to extract the subheader
+        packet_subheader_extracted = ExtractPacketSubheader( packet+N, 500, n );
+        N += n;
+        TS_ASSERT_EQUALS(packet_subheader_extracted, true);
+        TS_ASSERT_EQUALS(n, 21);
+        TS_ASSERT_EQUALS(N, 112);
+
+        // try to extract packet data
+        n = 1024;
+        packet_data_extracted = ExtractPacketData( packet+N, 400, output, n );
+        N += n;
+        TS_ASSERT_EQUALS( packet_data_extracted, true );
+        TS_ASSERT_EQUALS( n, 400 );
+
+        // output data should be the same, even though the packet was decoded with bit inversions;
+        // the P/N sync correlator should have detected this and corrected for it appropriately
+        TS_ASSERT_SAME_DATA( input, output, 400 );
+        
+        free(input);
+        free(packet);
+        free(output);
+    }
+
 };