add script for modifying packet timestamps

Ccs/scripts/mod_pkt_times.py

+#!/usr/bin/env python3
+"""
+Add offset to PUS packet timestamps for data stored in a binary file (SMILE)
+"""
+
+import os
+
+
+def run(fn, toff=None, outfile=None):
+    with open(fn, 'rb') as fd:
+        pkts = cfl.extract_pus(fd)
+
+    # calculate offset from file's mtime and last packet timestamp if toff is not given
+    if toff is None:
+        print('Calculating time offset from file modification time and last TM packet timestamp...')
+        idx = -1
+        pkt_time = None
+        while abs(idx) <= len(pkts):
+            if not (pkts[idx][0] >> 4) & 1:
+                pkt_time = int.from_bytes(pkts[idx][10:14], 'big')
+                break
+
+        if pkt_time is None:
+            print('No TM packet found for reference')
+            return
+
+        toff = int(os.path.getmtime(fn)) - pkt_time
+
+    print('TOFF =', toff)
+
+    if outfile is None:
+        outfile = fn + '.tmod'
+
+    with open(outfile, 'wb') as fd:
+        for pkt in pkts:
+            # check if pkt is TC
+            if (pkt[0] >> 4) & 1:
+                fd.write(pkt)
+            else:
+                fd.write(mod_time(pkt, toff))
+
+    print('Modified packets written to {}.'.format(os.path.abspath(outfile)))
+
+
+def mod_time(pkt, ofs):
+    nw = pkt[:10] + (int.from_bytes(pkt[10:14], 'big') + ofs).to_bytes(4, 'big') + pkt[14:-2]
+    return nw + cfl.crc(nw).to_bytes(2, 'big')
+
+
+filename = '301123_LFT_cold_phase2_minus117_tcs'
+offset = 1234567
+# run(filename, toff=offset)
+
+
+if __name__ == '__main__':
+
+    import sys
+    import confignator
+
+    cfg = confignator.get_config()
+    sys.path.append(cfg['paths']['ccs'])
+
+    import ccs_function_lib as cfl
+
+    filename = sys.argv[1]
+    if len(sys.argv) > 2:
+        offset = int(sys.argv[2])
+    else:
+        offset = None
+
+    run(filename, toff=offset)