crc?

plugin.lua

@@ -12,6 +12,11 @@ user_data_len = 0
 
 --#region Functions implemented or used in C
 
+---Executes a CRC-16 CCIIT
+---@param data string
+---@return integer
+function crc16(data) end
+
 ---Starts the initialization sequence, also calls the on_init function
 ---@return nil
 function set_rds_program_defaults() end

scripts/0-rds2_oda.lua

@@ -44,6 +44,7 @@ function rds2_group(stream)
     local oda = _RDS2_ODAs[_RDS2_ODA_pointer]
     local channel_offset = 16 * ((not oda.file_related) and 1 or 0)
     local channel = ((_RDS2_ODA_pointer - 1 + channel_offset) & 0x3F)
+    if oda.file_related then channel = channel & 0xF end
 
     _RDS2_ODA_pointer = _RDS2_ODA_pointer + 1
 
@@ -78,9 +79,11 @@ function rds2_group(stream)
             local channel_bitshift = 8
             local fid = (a & 0xC000) >> 14
             local fn_msb = (a >> 13) & 1
-            if fid == 0 and fn_msb == 0 then return true, 0, b, c, d
-            elseif fid == 0 and fn_msb == 1 then channel = channel & 0xF
+            if fid == 0 and fn_msb == 0 then
+                warn("RDS2 ODA is tunneling (A or B) over C")
+                return true, 0, b, c, d -- Tunnel, not sure why but sure
             --FID = 1 means a normal ODA group
+            --FID = 2 means a RFT file
             elseif fid == 2 and fn_msb == 0 then channel_bitshift = 0 end -- This is AID
             return generated, (channel << channel_bitshift) | a, b, c, d
         end

scripts/1-rft.lua

@@ -3,11 +3,15 @@ _Rft_file = ""
 _Rft_file_segment = 0
 _Rft_toggle = false
 _Rft_last_id = -1
-_Rft_version = 0 -- TODO
+_Rft_version = 0
+_Rft_crc_mode = -1
+_Rft_crc_state = 0
+_Rft_crc_sent = false
+_Rft_aid = 0xFF7F
 
 local function start_rft()
     if _Rft_oda_id == nil then
-        _Rft_oda_id = register_oda_rds2(0xFF7F, 0, true)
+        _Rft_oda_id = register_oda_rds2(_Rft_aid, 0, true)
         set_oda_handler_rds2(_Rft_oda_id, function ()
             if #_Rft_file == 0 then return false, 0, 0, 0, 0 end
 
@@ -15,6 +19,14 @@ local function start_rft()
             local seg = _Rft_file_segment
             local base = seg * 5 + 1
 
+            if not _Rft_crc_sent and _Rft_crc_mode ~= -1 then
+                --- TODO: warn that if we have over 511 segments, we can't have CRC if we want per-segment crc
+                _Rft_crc_sent = true
+                if _Rft_crc_mode ~= 0 then warn("rft: No other crc than mode 0 is supported as of now") end
+                _Rft_crc_mode = 0
+                return true, (2 << 14), _Rft_aid, (1 << 28) | (_Rft_crc_mode & 7) << 25 | (seg & 511), crc16(_Rft_file)
+            end
+
             local function b(i) return string.byte(_Rft_file, base + i) or 0 end
 
             local word1 = (((_Rft_toggle and 1 or 0) << 7) | ((seg >> 8) & 0x7F))
@@ -23,9 +35,7 @@ local function start_rft()
             local word4 = (b(3) << 8) | b(4)
 
             _Rft_file_segment = seg + 1
-            if _Rft_file_segment >= total_segments then
-                _Rft_file_segment = 0
-            end
+            if _Rft_file_segment >= total_segments then _Rft_file_segment = 0 end
 
             return true, (2 << 12) | word1, word2, word3, word4
         end)
@@ -36,7 +46,8 @@ end
 ---Loads the file into RFT and initializes it if needed, note that this needs RDR2 mode 2
 ---@param path string
 ---@param id integer
-function load_station_logo(path, id)
+---@param crc boolean
+function load_station_logo(path, id, crc)
     local file = io.open(path, "rb")
     if not file then error("Could not open file") end
     _Rft_file = file:read("*a")
@@ -44,13 +55,21 @@ function load_station_logo(path, id)
 
     if id == _Rft_last_id then 
         _Rft_toggle = not _Rft_toggle
+        _Rft_crc_state = 0
+        _Rft_crc_sent = false
         _Rft_version = _Rft_version + 1
         if _Rft_version > 7 then _Rft_version = 0 end
     end
 
+    if crc then
+        _Rft_crc_mode = 0
+    else
+        _Rft_crc_mode = -1
+    end
+
     if #_Rft_file > 262143 then error("The file is too large", 2) end
     if _Rft_oda_id == nil then start_rft() end
 ---@diagnostic disable-next-line: param-type-mismatch
-    set_oda_id_data_rds2(_Rft_oda_id, #_Rft_file | (id & 63) << 18 | (_Rft_version & 7) << 24 | 0 << 27)
+    set_oda_id_data_rds2(_Rft_oda_id, #_Rft_file | (id & 63) << 18 | (_Rft_version & 7) << 24 | ((_Rft_crc_mode ~= -1) and 1 or 0) << 27)
     _Rft_last_id = id
 end

src/common.h

@@ -4,9 +4,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
-#ifndef _WIN32
 #include <unistd.h>
-#endif
 #include <string.h>
 #include <math.h>
 #include <stdbool.h>

src/lib.c

@@ -25,7 +25,7 @@ inline int _strncpy(char *dest, const char *src, int n) {
 	}
 	return i;
 }
-uint16_t crc16_ccitt(char* data, uint16_t len) {
+uint16_t crc16_ccitt(const char* data, uint16_t len) {
 	uint16_t i, crc=0xFFFF;
 	for (i=0; i < len; i++ ) {
 		crc = (unsigned char)(crc >> 8) | (crc << 8);

src/lib.h

@@ -8,7 +8,7 @@ void msleep(unsigned long ms);
 int _strnlen(const char *s, int maxlen);
 int _strncpy(char *dest, const char *src, int n);
 
-uint16_t crc16_ccitt(char *data, uint16_t len);
+uint16_t crc16_ccitt(const char *data, uint16_t len);
 
 uint16_t get_block_from_group(RDSGroup *group, uint8_t block);
 

src/lua_rds.c

@@ -406,6 +406,13 @@ int lua_get_available_rds_streams(lua_State *localL) {
     return 1;
 }
 
+int lua_crc16(lua_State *localL) {
+    size_t len;
+    const char* data = luaL_checklstring(localL, 1, &len);
+    lua_pushinteger(localL, crc16_ccitt(data, len));
+    return 1;
+}
+
 void init_lua(RDSModulator* rds_mod) {
     static int mutex_initialized = 0;
     mod = rds_mod;
@@ -524,6 +531,8 @@ void init_lua(RDSModulator* rds_mod) {
     lua_register(L, "get_userdata", lua_get_userdata);
     lua_register(L, "get_userdata_offset", lua_get_userdata_offset);
 
+    lua_register(L, "crc16", lua_crc16);
+
     if (luaL_loadfile(L, "/etc/rds95.lua") != LUA_OK) {
         fprintf(stderr, "Lua error loading file: %s\n", lua_tostring(L, -1));
         lua_pop(L, 1);