From 8c8653a1a28693a36fc522c0230c44c5ee456a73 Mon Sep 17 00:00:00 2001
From: George Hines <george.hines@3dr.com>
Date: Wed, 6 Apr 2016 17:12:40 -0700
Subject: [PATCH] initial commit of matlab px4 log importer

---
 matlab/analysis/importPX4log.m | 91 ++++++++++++++++++++++++++++++++++
 1 file changed, 91 insertions(+)
 create mode 100644 matlab/analysis/importPX4log.m

diff --git a/matlab/analysis/importPX4log.m b/matlab/analysis/importPX4log.m
new file mode 100644
index 0000000000..be2da6e58e
--- /dev/null
+++ b/matlab/analysis/importPX4log.m
@@ -0,0 +1,91 @@
+function importPX4log(fname)
+fid = fopen(fname,'r','b');
+bytes_read = 0;
+
+BLOCK_SIZE = 8192;
+MSG_HEADER_LEN = 3;
+MSG_HEAD1 = uint8(hex2dec('A3'));
+MSG_HEAD2 = uint8(hex2dec('95'));
+MSG_FORMAT_PACKET_LEN = 89;
+MSG_FORMAT_STRUCT = 'BB4s16s64s';
+MSG_TYPE_FORMAT = uint8(hex2dec('80'));
+
+% FORMAT_TO_STRUCT = {
+%     "b": ("b", None),
+%     "B": ("B", None),
+%     "h": ("h", None),
+%     "H": ("H", None),
+%     "i": ("i", None),
+%     "I": ("I", None),
+%     "f": ("f", None),
+%     "n": ("4s", None),
+%     "N": ("16s", None),
+%     "Z": ("64s", None),
+%     "c": ("h", 0.01),
+%     "C": ("H", 0.01),
+%     "e": ("i", 0.01),
+%     "E": ("I", 0.01),
+%     "L": ("i", 0.0000001),
+%     "M": ("b", None),
+%     "q": ("q", None),
+%     "Q": ("Q", None),
+%     }
+
+while 1
+    chunk = fread(fid,BLOCK_SIZE,'uint8');
+    if numel(chunk) == 0;
+        break
+    end
+    buffer = chunk;
+    ptr = 1;
+    while numel(buffer) - ptr >= MSG_HEADER_LEN
+        head1 = buffer(ptr);
+        head2 = buffer(ptr+1);
+        msg_type = buffer(ptr+2);
+        
+        if msg_type == MSG_TYPE_FORMAT
+            if numel(buffer) - ptr < MSG_FORMAT_PACKET_LEN
+                break;
+            end
+            % return new pointer, and all message descriptor info
+            LOCAL_parse_message_descriptors(buffer, ptr, MSG_TYPE_FORMAT, MSG_FORMAT_STRUCT, MSG_FORMAT_PACKET_LEN);
+        else
+            msg_descr = msg_descrs{msg_type,:};
+            msg_length = msg_descr{1};
+            if numel(buffer) - ptr < msg_length
+                break;
+            end
+            % return new pointer, and all message info
+            LOCAL_parse_message(buffer, MSG_HEADER_LEN, msg_descr);
+        end
+    end
+    bytes_read = bytes_read + ptr;
+end
+
+end
+
+function [ptr, msg_descrs] = LOCAL_parse_message_descriptors(buffer, ptr, MSG_TYPE_FORMAT, MSG_FORMAT_STRUCT, MSG_FORMAT_PACKET_LEN)
+thisBlock = buffer((ptr+3):(ptr+MSG_FORMAT_PACKET_LEN));
+msg_type = thisBlock(1);
+if msg_type ~= MSG_TYPE_FORMAT
+    msg_length = thisBlock(2);
+    msg_name = LOCAL_parse_string(thisBlock(3:6));
+    msg_format = LOCAL_parse_string(thisBlock(7:22));
+    msg_labels = strsplit(LOCAL_parse_string(thisBlock(23:end)),',');
+    msg_struct = [];
+    msg_mults = [];
+end
+ptr = ptr + MSG_FORMAT_PACKET_LEN;
+end
+
+function LOCAL_parse_message(buffer, ptr, MSG_HEADER_LEN, msg_descr)
+end
+
+function str = LOCAL_parse_string(byteArray)
+    firstZero = find(byteArray==0);
+    if ~isempty(firstZero)
+        str = char(byteArray(1:firstZero-1))';
+    else
+        str = char(byteArray)';
+    end
+end
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