Add UECP parser prototype for RadioText extraction

2 files changed, 225 insertions, 0 deletions

diff --git a/uecpparse/crc.py b/uecpparse/crc.py
new file mode 100644
index 0000000..813542a
--- /dev/null
+++ b/uecpparse/crc.py
@@ -0,0 +1,57 @@
+#library for crc16 calculation
+
+
+crc16tab = [
+    0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
+    0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
+    0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
+    0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
+    0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
+    0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
+    0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
+    0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
+    0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
+    0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
+    0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
+    0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
+    0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
+    0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
+    0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
+    0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
+    0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
+    0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
+    0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
+    0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
+    0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
+    0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
+    0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
+    0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
+    0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
+    0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
+    0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
+    0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
+    0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
+    0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
+    0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
+    0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0 ]
+
+def crc16(data, l_crc=0xffff):
+    for d in data:
+        #print("crc 0x{:x} 0x{:x}".format(ord(d), l_crc))
+        l_crc = (l_crc << 8) ^ crc16tab[(l_crc >> 8) ^ d]
+        l_crc = l_crc & 0xFFFF
+
+    return l_crc
+
+def crc_ccitt(data):
+    crc = 0xFFFF
+
+    for d in data:
+        crc = (((crc >> 8) & 0xFF) | (crc << 8)) & 0xFFFF
+        crc ^= d
+        crc ^= ((crc & 0xff) >> 4) & 0xFFFF
+        crc ^= ((crc << 8) << 4) & 0xFFFF
+        crc ^= (((crc & 0xff) << 4) << 1) & 0xFFFF
+
+    return ((crc ^ 0xFFFF) & 0xFFFF);
+
diff --git a/uecpparse/uecp_parse.py b/uecpparse/uecp_parse.py
new file mode 100755
index 0000000..cdfccd5
--- /dev/null
+++ b/uecpparse/uecp_parse.py
@@ -0,0 +1,168 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# The MIT License (MIT)
+#
+# Copyright (c) 2016 Matthias P. Braendli
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+#    The above copyright notice and this permission notice shall be included in
+#    all copies or substantial portions of the Software.
+#
+#    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+#    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+#    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+#    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+#    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+#    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+#    THE SOFTWARE.
+#
+#
+# A UECP decoder, reading from a file generated by
+# my patched VLC, from ancillary MP2 bytes in a MPEG-TS
+#
+# Please refer to RDS UECP specification
+
+import sys
+import struct
+import crc
+
+# Message Element Codes
+uecp_mec_names = {
+        0x01: "PI"             , # Program Identification
+        0x02: "PS"             , # Program Service name
+        0x06: "PIN"            , # Program Item Number
+        0x04: "DI_PTYI"        , # Decoder Information / Dynamic PTY Indicator
+        0x03: "TA_TP"          , # Traffic Anouncement / Traffic Programme
+        0x05: "MS"             , # Music / Speech switch
+        0x07: "PTY"            , # Programme Type
+        0x3E: "PTYN"           , # Programme Type Name
+        0x0A: "RT"             , # RadioText
+        0x0D: "RTC"            , # Real Time Clock
+        0x19: "CT"             , # Enable RTC (group 4 version A) transmits
+        0x1C: "DSN_SELECT"     , # Set active Data Set
+        0x0B: "PSN_ENABLE"     , # Enable / disable a specific PSN
+        0x1E: "RDSON"          , # Enable / disable the RDS output signal
+        0x23: "SET_SITE_ADDR"  , # Add a site address to the encoder
+        0x27: "SET_ENC_ADDR"   , # Add an encoder address to the encoder
+        0x17: "MSG_REQUEST"    , # Request data from the encoder
+        0x18: "MSG_ACK"        , # ACK of a received message
+        0x2C: "SET_COMM_MODE"  } # Set communication mode for the encoder
+
+def usage():
+    print("Usage:\n{} <filename>".format(sys.argv[0]))
+
+if len(sys.argv) < 2:
+    usage()
+    sys.exit(1)
+
+class UECP_Message_Decoder():
+    def __init__(self, message_bytes):
+        """Create a message decoder that creates
+        Message Elements from a message"""
+        self.message = message_bytes
+        self.mec = message_bytes[0]
+        assert(0x01 <= self.mec <= 0xFD)
+
+        if self.mec in uecp_mec_names:
+            name = uecp_mec_names[self.mec]
+            print("  MEC={}".format(name))
+            if name == "PS":
+                dsn = message_bytes[1]
+                psn = message_bytes[2]
+                ps  = message_bytes[3:-1]
+                print("    PS DSN={:02x} PSN={:02x} ".format(dsn, psn) + "".join(chr(d) for d in ps))
+            elif name == "RT":
+                dsn = message_bytes[1]
+                psn = message_bytes[2]
+                mel = message_bytes[3]
+                med = message_bytes[4:-1]
+                print("    RT DSN={:02x} PSN={:02x} MEL={:02} ".format(dsn, psn, mel) + " ".join("{:02x}".format(d) for d in med))
+
+        else:
+            print("  MEC={}".format(self.mec))
+
+class UECP_Frame_Decoder():
+    def __init__(self, uecp_bytes):
+        """Create a new decoder from bytes containing a
+        complete UECP frame, from STA to STO.
+        See 2.2.1 General Frame Format"""
+        assert(uecp_bytes[0] == 0xfe)
+        assert(uecp_bytes[-1] == 0xff)
+        self.trapped_data = uecp_bytes
+        self.untrap()
+        self.decode_frame()
+
+    def untrap(self):
+        """Unescapes characters as defined in 2.2.9"""
+        self.data = [0xfe]
+
+        next_untrap = False
+        for b in self.trapped_data[1:-1]:
+            if next_untrap:
+                next_untrap = False
+                if b == 0x00:
+                    self.data.append(0xFD)
+                elif b == 0x01:
+                    self.data.append(0xFE)
+                elif b == 0x02:
+                    self.data.append(0xFF)
+                else:
+                    raise ValueError("untrap {} invalid".format(b))
+            elif b == 0xFD:
+                next_untrap = True
+            elif b == 0xFE or b == 0xFF:
+                raise ValueError("untrapped data {} invalid".format(b))
+            else:
+                self.data.append(b)
+        self.data.append(0xff)
+
+    def check_crc(self):
+        if 0:
+            print("B " + " ".join("{:02x}".format(b) for b in self.data))
+            for i in range(1, len(self.data)):
+                print(" i={:02} crc=0x{:04x} calc1=0x{:04x} calc2=0x{:04x}".format(i,
+                    self.crc,
+                    0xffff ^ crc.crc16(self.data[1:i]),
+                    crc.crc_ccitt(self.data[1:i])))
+
+        self.crc_calc = crc.crc_ccitt(self.data[1:4+self.mfl])
+        return self.crc_calc == self.crc
+
+    def decode_frame(self):
+        """Decodes an untrapped frame"""
+        self.addr = self.data[1] * 256 + self.data[2]
+        self.sqc  = self.data[3]
+        self.mfl  = self.data[4]
+        self.msg  = self.data[5:5+self.mfl]
+        assert(self.mfl + 8 == len(self.data))
+        self.crc  = self.data[5+self.mfl] * 256 + self.data[5+self.mfl+1]
+        self.crc_ok = self.check_crc()
+
+        UECP_Message_Decoder(self.msg)
+
+in_fd = open(sys.argv[1], "r")
+for line in in_fd:
+    line_bytes = [int(i, 16) for i in line.split()]
+
+    line_bytes.reverse()
+
+    anc_header = line_bytes[0]
+    if anc_header == 0xfd:
+        anc_len = line_bytes[1]
+        if anc_len > 0:
+            anc_bytes = line_bytes[2:2+anc_len]
+
+            if anc_bytes[-1] == 0xff:
+                uecp = UECP_Frame_Decoder(anc_bytes)
+
+                print("Addr={} sqc={} mfl={} msg={} crc=0x{:04x} crc_calc=0x{:04x} ok={}".format(
+                    uecp.addr, uecp.sqc, uecp.mfl,
+                    uecp.msg, uecp.crc, uecp.crc_calc, uecp.crc_ok))
+