1 files changed, 111 insertions, 0 deletions
diff --git a/eti-udp/etireader.py b/eti-udp/etireader.py
new file mode 100755
index 0000000..9b91ca7
--- /dev/null
+++ b/eti-udp/etireader.py
@@ -0,0 +1,111 @@
+#!/usr/bin/env python
+
+import struct
+import os
+
+ETI_FORMAT_RAW = "RAW"
+ETI_FORMAT_STREAMED = "STREAMED"
+ETI_FORMAT_FRAMED = "FRAMED"
+
+class EtiReaderException(Exception):
+    pass
+
+class EtiReader(object):
+    def __init__(self, filename):
+        self.filename = filename
+        self.fd = open(filename, "rb")
+        self.fmt = self.discover_filetype()
+        print("EtiReader reading {0}, discovered type {1}".format(filename, self.fmt))
+
+    def discover_filetype(self):
+        self.fd.seek(0)
+        sync = False
+        i = 0
+        while True:
+            sync = self.check_sync()
+            if not sync:
+                i = i + 1
+                self.fd.seek(i)
+            else:
+                break
+
+        if i == 0:
+            self.fd.seek(0)
+            return ETI_FORMAT_RAW
+        elif i == 2:
+            self.fd.seek(0)
+            return ETI_FORMAT_STREAMED
+        elif i == 6:
+            self.fd.seek(4)
+            return ETI_FORMAT_FRAMED
+        else:
+            print("ETI File not aligned, supposing RAW!")
+            return ETI_FORMAT_RAW
+                
+
+    def __iter__(self):
+        while True:
+            n = self.next()
+            if n == "":
+                break
+            else:
+                yield n
+
+    def next(self):
+        if self.fmt == ETI_FORMAT_RAW:
+            etiframe = self.fd.read(6144)
+            if etiframe == "":
+                raise EtiReaderException("Unable to read frame")
+            return etiframe
+
+
+        elif self.fmt == ETI_FORMAT_FRAMED or self.fmt == ETI_FORMAT_STREAMED:
+            
+            framesize_pack = self.fd.read(2)
+            if len(framesize_pack) < 2:
+                raise EtiReaderException("Unable to read frame size")
+            framesize = struct.unpack("H", framesize_pack)[0]
+            if framesize == 0 or framesize > 6144:
+                raise EtiReaderException("Framesize: {0}".format(framesize))
+
+            if not self.check_sync():
+                raise EtiReaderException("Unable to read sync")
+
+            self.fd.seek(-2, os.SEEK_CUR)
+            frame = self.fd.read(framesize+2)
+            if len(frame) < framesize:
+                raise EtiReaderException("Unable to read frame")
+            return frame
+
+    def check_sync(self):
+        here = self.fd.tell()
+        sync_pack = self.fd.read(4)
+        self.fd.seek(here)
+
+        sync = struct.unpack("I", sync_pack)[0]
+
+        return sync == 0x49c5f8ff or sync == 0xb63a07ff
+
+
+if __name__ == "__main__":
+    def etireadertest(reader):
+        i = 0
+        for frame in reader:
+            allframes.append(frame)
+            print("Frame {0}, length {1}".format(
+                i, len(frame)))
+            i += 1
+            if i > 10:
+                break
+
+    allframes = []
+    etireadertest(EtiReader("buddard.eti"))
+
+    allframes = []
+    etireadertest(EtiReader("streamed.eti"))
+
+    allframes = []
+    etireadertest(EtiReader("funk.eti"))
+
+    allframes = []
+    etireadertest(EtiReader("funk.raw.eti"))