Add hints how the payload of a certain portnum is encoded

meshtastic/portnums.proto

@@ -27,6 +27,7 @@ enum PortNum {
    * Deprecated: do not use in new code (formerly called OPAQUE)
    * A message sent from a device outside of the mesh, in a form the mesh does not understand
    * NOTE: This must be 0, because it is documented in IMeshService.aidl to be so
+   * ENCODING: binary undefined
    */
   UNKNOWN_APP = 0;
 
@@ -34,64 +35,80 @@ enum PortNum {
    * A simple UTF-8 text message, which even the little micros in the mesh
    * can understand and show on their screen eventually in some circumstances
    * even signal might send messages in this form (see below)
+   * ENCODING: UTF-8 Plaintext (?)
    */
   TEXT_MESSAGE_APP = 1;
 
   /*
    * Reserved for built-in GPIO/example app.
    * See remote_hardware.proto/HardwareMessage for details on the message sent/received to this port number
+   * ENCODING: Protobuf
    */
   REMOTE_HARDWARE_APP = 2;
 
   /*
    * The built-in position messaging app.
    * Payload is a [Position](/docs/developers/protobufs/api#position) message
+   * ENCODING: Protobuf
    */
   POSITION_APP = 3;
 
   /*
    * The built-in user info app.
    * Payload is a [User](/docs/developers/protobufs/api#user) message
+   * ENCODING: Protobuf
    */
   NODEINFO_APP = 4;
 
   /*
    * Protocol control packets for mesh protocol use.
    * Payload is a [Routing](/docs/developers/protobufs/api#routing) message
+   * ENCODING: Protobuf
    */
   ROUTING_APP = 5;
 
   /*
    * Admin control packets.
    * Payload is a [AdminMessage](/docs/developers/protobufs/api#adminmessage) message
+   * ENCODING: Protobuf
    */
   ADMIN_APP = 6;
 
   /*
    * Compressed TEXT_MESSAGE payloads.
+   * ENCODING: UTF-8 Plaintext (?) with Unishox2 Compression
+   * NOTE: The Device Firmware converts a TEXT_MESSAGE_APP to TEXT_MESSAGE_COMPRESSED_APP if the compressed
+   * payload is shorter. There's no need for app developers to do this themselves. Also the firmware will decompress
+   * any incoming TEXT_MESSAGE_COMPRESSED_APP payload and convert to TEXT_MESSAGE_APP.
    */
   TEXT_MESSAGE_COMPRESSED_APP = 7;
 
   /*
    * Waypoint payloads.
    * Payload is a [Waypoint](/docs/developers/protobufs/api#waypoint) message
+   * ENCODING: Protobuf
    */
   WAYPOINT_APP = 8;
 
   /*
    * Audio Payloads.
    * Encapsulated codec2 packets. On 2.4 GHZ Bandwidths only for now
+   * ENCODING: codec2 audio frames
+   * NOTE: audio frames contain a 3 byte header (0xc0 0xde 0xc2) and a one byte marker for the decompressed bitrate.
+   * This marker comes from the 'moduleConfig.audio.bitrate' enum minus one.
    */
   AUDIO_APP = 9;
 
   /*
    * Provides a 'ping' service that replies to any packet it receives.
    * Also serves as a small example module.
+   * ENCODING: ASCII Plaintext
    */
   REPLY_APP = 32;
 
   /*
    * Used for the python IP tunnel feature
+   * ENCODING: IP Packet. Handled by the python API, firmware ignores this one and pases on.
    */
   IP_TUNNEL_APP = 33;
 
@@ -101,23 +118,27 @@ enum PortNum {
    * network is forwarded to the RX pin while sending a packet to TX will go out to the Mesh network.
    * Maximum packet size of 240 bytes.
    * Module is disabled by default can be turned on by setting SERIAL_MODULE_ENABLED = 1 in SerialPlugh.cpp.
+   * ENCODING: binary undefined
    */
   SERIAL_APP = 64;
 
   /*
    * STORE_FORWARD_APP (Work in Progress)
    * Maintained by Jm Casler (MC Hamster) : jm@casler.org
+   * ENCODING: Protobuf
    */
   STORE_FORWARD_APP = 65;
 
   /*
    * Optional port for messages for the range test module.
+   * ENCODING: ASCII Plaintext
    */
   RANGE_TEST_APP = 66;
 
   /*
    * Provides a format to send and receive telemetry data from the Meshtastic network.
    * Maintained by Charles Crossan (crossan007) : crossan007@gmail.com
+   * ENCODING: Protobuf
    */
   TELEMETRY_APP = 67;
 
@@ -125,6 +146,7 @@ enum PortNum {
    * Experimental tools for estimating node position without a GPS
    * Maintained by Github user a-f-G-U-C (a Meshtastic contributor)
    * Project files at https://github.com/a-f-G-U-C/Meshtastic-ZPS
+   * ENCODING: arrays of int64 fields
    */
   ZPS_APP = 68;
 
@@ -133,17 +155,20 @@ enum PortNum {
    * as if they did using their LoRa chip.
    * Maintained by GitHub user GUVWAF.
    * Project files at https://github.com/GUVWAF/Meshtasticator
+   * ENCODING: Protobuf (?)
    */
   SIMULATOR_APP = 69;
 
   /*
    * Provides a traceroute functionality to show the route a packet towards
    * a certain destination would take on the mesh.
+   * ENCODING: Protobuf
    */
   TRACEROUTE_APP = 70;
 
   /*
    * Aggregates edge info for the network by sending out a list of each node's neighbors
+   * ENCODING: Protobuf
    */
   NEIGHBORINFO_APP = 71;
 
@@ -156,6 +181,7 @@ enum PortNum {
 
   /*
    * ATAK Forwarder Module https://github.com/paulmandal/atak-forwarder
+   * ENCODING: libcotshrink
    */
   ATAK_FORWARDER = 257;
 
@@ -163,4 +189,4 @@ enum PortNum {
    * Currently we limit port nums to no higher than this value
    */
   MAX = 511;
-}
+}