add missing constants

add docstrings that describes data breakdown

move SubscribeHeader above  VbanRtPacketHeader

expand assert failure string

vban_cmd/packet.py

@@ -3,10 +3,14 @@ from dataclasses import dataclass
 from .kinds import KindMapClass
 from .util import comp
 
+VBAN_PROTOCOL_TXT = 0x40
+VBAN_PROTOCOL_SERVICE = 0x60
+
 VBAN_SERVICE_RTPACKETREGISTER = 32
 VBAN_SERVICE_RTPACKET = 33
+
 MAX_PACKET_SIZE = 1436
-HEADER_SIZE = 4 + 1 + 1 + 1 + 1 + 16 + 4
+HEADER_SIZE = 4 + 1 + 1 + 1 + 1 + 16
 
 
 @dataclass
@@ -14,28 +18,28 @@ class VbanRtPacket:
     """Represents the body of a VBAN RT data packet"""
 
     _kind: KindMapClass
-    _voicemeeterType: bytes
+    _voicemeeterType: bytes  # data[28:29]
-    _reserved: bytes
+    _reserved: bytes  # data[29:30]
-    _buffersize: bytes
+    _buffersize: bytes  # data[30:32]
-    _voicemeeterVersion: bytes
+    _voicemeeterVersion: bytes  # data[32:36]
-    _optionBits: bytes
+    _optionBits: bytes  # data[36:40]
-    _samplerate: bytes
+    _samplerate: bytes  # data[40:44]
-    _inputLeveldB100: bytes
+    _inputLeveldB100: bytes  # data[44:112]
-    _outputLeveldB100: bytes
+    _outputLeveldB100: bytes  # data[112:240]
-    _TransportBit: bytes
+    _TransportBit: bytes  # data[240:244]
-    _stripState: bytes
+    _stripState: bytes  # data[244:276]
-    _busState: bytes
+    _busState: bytes  # data[276:308]
-    _stripGaindB100Layer1: bytes
+    _stripGaindB100Layer1: bytes  # data[308:324]
-    _stripGaindB100Layer2: bytes
+    _stripGaindB100Layer2: bytes  # data[324:340]
-    _stripGaindB100Layer3: bytes
+    _stripGaindB100Layer3: bytes  # data[340:356]
-    _stripGaindB100Layer4: bytes
+    _stripGaindB100Layer4: bytes  # data[356:372]
-    _stripGaindB100Layer5: bytes
+    _stripGaindB100Layer5: bytes  # data[372:388]
-    _stripGaindB100Layer6: bytes
+    _stripGaindB100Layer6: bytes  # data[388:404]
-    _stripGaindB100Layer7: bytes
+    _stripGaindB100Layer7: bytes  # data[404:420]
-    _stripGaindB100Layer8: bytes
+    _stripGaindB100Layer8: bytes  # data[420:436]
-    _busGaindB100: bytes
+    _busGaindB100: bytes  # data[436:452]
-    _stripLabelUTF8c60: bytes
+    _stripLabelUTF8c60: bytes  # data[452:932]
-    _busLabelUTF8c60: bytes
+    _busLabelUTF8c60: bytes  # data[932:1412]
 
     def _generate_levels(self, levelarray) -> tuple:
         return tuple(
@@ -206,13 +210,42 @@ class VbanRtPacket:
         )
 
 
+@dataclass
+class SubscribeHeader:
+    """Represents the header an RT Packet Service subscription packet"""
+
+    name = "Register RTP"
+    timeout = 15
+    vban: bytes = "VBAN".encode()
+    format_sr: bytes = (VBAN_PROTOCOL_SERVICE).to_bytes(1, "little")
+    format_nbs: bytes = (0).to_bytes(1, "little")
+    format_nbc: bytes = (VBAN_SERVICE_RTPACKETREGISTER).to_bytes(1, "little")
+    format_bit: bytes = (timeout & 0x000000FF).to_bytes(1, "little")  # timeout
+    streamname: bytes = name.encode("ascii") + bytes(16 - len(name))
+    framecounter: bytes = (0).to_bytes(4, "little")
+
+    @property
+    def header(self):
+        header = self.vban
+        header += self.format_sr
+        header += self.format_nbs
+        header += self.format_nbc
+        header += self.format_bit
+        header += self.streamname
+        header += self.framecounter
+        assert (
+            len(header) == HEADER_SIZE + 4
+        ), f"expected header size {HEADER_SIZE} bytes + 4 bytes framecounter ({HEADER_SIZE +4} bytes total)"
+        return header
+
+
 @dataclass
 class VbanRtPacketHeader:
-    """Represents the header of VBAN RT data packet"""
+    """Represents the header of a VBAN RT response packet"""
 
     name = "Voicemeeter-RTP"
     vban: bytes = "VBAN".encode()
-    format_sr: bytes = (0x60).to_bytes(1, "little")
+    format_sr: bytes = (VBAN_PROTOCOL_SERVICE).to_bytes(1, "little")
     format_nbs: bytes = (0).to_bytes(1, "little")
     format_nbc: bytes = (VBAN_SERVICE_RTPACKET).to_bytes(1, "little")
     format_bit: bytes = (0).to_bytes(1, "little")
@@ -226,13 +259,13 @@ class VbanRtPacketHeader:
         header += self.format_nbc
         header += self.format_bit
         header += self.streamname
-        assert len(header) == HEADER_SIZE - 4, f"Header expected {HEADER_SIZE-4} bytes"
+        assert len(header) == HEADER_SIZE, f"expected header size {HEADER_SIZE} bytes"
         return header
 
 
 @dataclass
 class RequestHeader:
-    """Represents a REQUEST RT PACKET header"""
+    """Represents the header of an REQUEST RT PACKET"""
 
     name: str
     bps_index: int
@@ -244,7 +277,7 @@ class RequestHeader:
 
     @property
     def sr(self):
-        return (0x40 + self.bps_index).to_bytes(1, "little")
+        return (VBAN_PROTOCOL_TXT + self.bps_index).to_bytes(1, "little")
 
     @property
     def nbc(self):
@@ -263,32 +296,7 @@ class RequestHeader:
         header += self.bit
         header += self.streamname
         header += self.framecounter
-        assert len(header) == HEADER_SIZE, f"Header expected {HEADER_SIZE} bytes"
+        assert (
-        return header
+            len(header) == HEADER_SIZE + 4
-
+        ), f"expected header size {HEADER_SIZE} bytes + 4 bytes framecounter ({HEADER_SIZE +4} bytes total)"
-
-@dataclass
-class SubscribeHeader:
-    """Represents a packet used to subscribe to the RT Packet Service"""
-
-    name = "Register RTP"
-    timeout = 15
-    vban: bytes = "VBAN".encode()
-    format_sr: bytes = (0x60).to_bytes(1, "little")
-    format_nbs: bytes = (0).to_bytes(1, "little")
-    format_nbc: bytes = (VBAN_SERVICE_RTPACKETREGISTER).to_bytes(1, "little")
-    format_bit: bytes = (timeout & 0x000000FF).to_bytes(1, "little")  # timeout
-    streamname: bytes = name.encode("ascii") + bytes(16 - len(name))
-    framecounter: bytes = (0).to_bytes(4, "little")
-
-    @property
-    def header(self):
-        header = self.vban
-        header += self.format_sr
-        header += self.format_nbs
-        header += self.format_nbc
-        header += self.format_bit
-        header += self.streamname
-        header += self.framecounter
-        assert len(header) == HEADER_SIZE, f"Header expected {HEADER_SIZE} bytes"
         return header