python frame utilities

python/utils.py

@@ -0,0 +1,52 @@
+
+def encoding_to_parameters(encoding):
+
+    encodings = [
+        {"bpsc": 1, "cbps":  48, "dbps":  24},
+        {"bpsc": 1, "cbps":  48, "dbps":  36},
+        {"bpsc": 2, "cbps":  96, "dbps":  48},
+        {"bpsc": 2, "cbps":  96, "dbps":  72},
+        {"bpsc": 4, "cbps": 192, "dbps":  96},
+        {"bpsc": 4, "cbps": 192, "dbps": 144},
+        {"bpsc": 6, "cbps": 288, "dbps": 192},
+        {"bpsc": 6, "cbps": 288, "dbps": 216}
+        ]
+
+    enc = encodings[encoding]
+
+    return enc["bpsc"], enc["cbps"], enc["dbps"]
+
+
+def payload_to_symbols(payload, encoding):
+
+    bpsc, cbps, dbps = encoding_to_parameters(encoding)
+
+    # 24 header + 4 crc + payload
+    data_byte = 24 + 4 + payload
+    symbols = int(round((16 + data_byte * 8 + 6) / float(dbps) + 0.5))
+
+    return symbols + 5
+
+
+def mac_payload_to_payload(payload):
+    return payload - 28
+
+
+def payload_to_mac_payload(payload):
+    return payload + 28
+
+
+def payload_to_samples(payload, encoding):
+    return payload_to_symbols(payload, encoding) * 80 + 1
+
+
+def symbols_to_payload(symbols, encoding):
+
+    bpsc, cbps, dbps = encoding_to_parameters(encoding)
+
+
+    bytes = (((symbols - 5) * dbps) - 16 - 6) / 8
+
+    assert(bytes > 28)
+
+    return bytes - 24 - 4