added a tool that combines 2 logs into one

with mapping of message names

examples/combine_logs.py

@@ -0,0 +1,128 @@
+#!/usr/bin/env python
+
+'''
+merge 2 logs into a 3rd log, mapping some messages from LOG2 to new message names
+'''
+
+import os
+from argparse import ArgumentParser
+from progress.bar import Bar
+import time
+import struct
+
+parser = ArgumentParser(description=__doc__)
+
+parser.add_argument("log1", help="First log")
+parser.add_argument("log2", help="Second log")
+parser.add_argument("logout", metavar="LOGOUT")
+parser.add_argument("--mapping", default="POS:POS2,ATT:ATT2,FOLL:FOL2", help="message type mapping")
+
+args = parser.parse_args()
+
+from pymavlink import mavutil
+from pymavlink import DFReader
+
+log1 = mavutil.mavlink_connection(args.log1)
+log2 = mavutil.mavlink_connection(args.log2)
+output = open(args.logout, mode='wb')
+
+# create a mapping between msg names in log and new msg names
+msg_map = {}
+a = args.mapping.split(',')
+for m in a:
+    b = m.split(':')
+    msg_map[b[0]] = b[1]
+
+fmt_done = {}
+used_ids = set()
+
+def allocate_id():
+    '''
+    allocate an unused id from the ardupilot bin log
+    '''
+    for id in range(100, 254):
+        if not id in log1.id_to_name and not id in used_ids:
+            used_ids.add(id)
+            return id
+    return None
+
+def write_message(m):
+    '''possibly write message from log2'''
+    mtype = m.get_type()
+    if mtype == "FMT":
+        if m.Name not in msg_map.keys():
+            return
+        if m.Name in fmt_done:
+            return
+        id = allocate_id()
+        if id is None:
+            return
+        fmt_done[m.Name] = id
+        m.Name = msg_map[m.Name]
+        fmt = DFReader.DFFormat(id, m.Name, m.Length, m.Format, m.Columns)
+        buf = bytearray(m.get_msgbuf())
+        buf[3] = id
+        for i in range(len(m.Name)):
+            buf[5+i] = m.Name.encode('utf-8')[i]
+        output.write(buf)
+        print("Added %s with id %u" % (m.Name, id))
+        return
+    if mtype not in msg_map.keys() or mtype not in fmt_done:
+        return
+    buf = bytearray(m.get_msgbuf())
+    buf[2] = fmt_done[mtype]
+    output.write(buf)
+
+bar = Bar('Merging logs', max=100)
+
+now = time.time()
+
+print("Processing logs")
+
+m1 = None
+m2 = None
+pct = 0
+
+while True:
+    if m1 is None:
+        m1 = log1.recv_msg()
+    if m2 is None:
+        m2 = log2.recv_msg()
+
+    if m1 is not None and m1.get_type() == "FMT":
+        output.write(m1.get_msgbuf())
+        m1 = None
+        continue
+
+    new_pct = (log1.offset * 100) // log1.data_len
+    if new_pct != pct:
+        bar.next()
+        pct = new_pct
+
+    if m1 is None and m2 is None:
+        # all done
+        break
+
+    if m2 is None and m1 is not None:
+        # pass-thru m1
+        output.write(m1.get_msgbuf())
+        m1 = None
+        continue
+
+    if m1 is None and m2 is not None:
+        # process m2
+        write_message(m2)
+        m2 = None
+        continue
+
+    if m1._timestamp < m2._timestamp:
+        # m1 is older, pass-thru m1
+        #print("write m1", m2._timestamp - m1._timestamp)
+        output.write(m1.get_msgbuf())
+        m1 = None
+        continue
+
+    # m2 is older
+    #print("write m2")
+    write_message(m2)
+    m2 = None