rds codec

This commit is contained in:
2026-04-25 18:49:03 +02:00
parent ec931f5167
commit 28010e61da
3 changed files with 387 additions and 2 deletions
+22 -1
View File
@@ -6,6 +6,7 @@ import socket
# https://github.com/chrko/python-uecp
import uecp.frame
import uecp.commands
import rds_codec
@uecp.commands.UECPCommand.register_type
class ASCII(uecp.commands.UECPCommand):
@@ -18,6 +19,26 @@ class ASCII(uecp.commands.UECPCommand):
self.ELEMENT_CODE,
2+len(self.data)] + list(b"95") + list(self.data)
class RT_Set(uecp.commands.RadioTextSetCommand):
def encode(self) -> list[int]:
data = [self.ELEMENT_CODE, self.data_set_number, self.programme_service_number]
if (
len(self._radiotext.text) == 0
and self._buffer_configuration
is uecp.commands.RadioTextBufferConfiguration.TRUNCATE_BEFORE
):
data.append(0)
else:
mel = 1 + len(self._radiotext.text)
flags = (
self._buffer_configuration << 5
| self._radiotext.number_of_transmissions << 1
| self._radiotext.a_b_toggle
)
data += [mel, flags]
data += list(self._radiotext.text.encode("rp-rds", "replace"))
return data
DEBUG = False
name_table_path = "/home/user/mixes/.playlist/name_table.txt"
@@ -90,7 +111,7 @@ def update_rds(track_name: str):
f.settimeout(1.0)
uecp_frame = uecp.frame.UECPFrame()
if 0 < len(prt) < 61: prt += "\r" # makes the warning go away
uecp_frame.add_command(uecp.commands.RadioTextSetCommand(prt, 4, True))
uecp_frame.add_command(RT_Set(prt, 0, True))
uecp_frame.add_command(ASCII(f"RTP={rtp}".encode()))
data = uecp_frame.encode()
+1 -1
View File
@@ -8,7 +8,7 @@ version = "0.1"
dependencies = ["log95", "unidecode", "libcache"]
[tool.setuptools]
py-modules = ["radioPlaylist", "radioPlayer", "tinytag"]
py-modules = ["radioPlaylist", "radioPlayer", "tinytag", "rds_codec"]
packages = ["modules"]
[project.scripts]
+364
View File
@@ -0,0 +1,364 @@
"""
rds_codec.py - Python codec for the RDS character set (IEC 62106 / R22_039_1 standard)
Usage:
import rds_codec # registers the codec
# Decode RDS bytes to str
text = b'\\x48\\x65\\x8A\\x6C\\x6F'.decode('rp-rds')
# Encode str to RDS bytes
data = 'Héllo'.encode('rp-rds')
# With error handlers
text = rds_bytes.decode('rp-rds', errors='replace')
text = rds_bytes.decode('rp-rds', errors='ignore')
"""
import codecs
from typing import Tuple
import unidecode
# ---------------------------------------------------------------------------
# Mapping tables (from rdscharset.pdf, R22_039_1 standard)
# ---------------------------------------------------------------------------
# RDS code point -> Unicode code point
_RDS_TO_UCS2: dict[int, int] = {
0x0A: 0x0A,
0x0D: 0x0D,
0x1F: 0x1F,
0x20: 0x20,
0x21: 0x21,
0x22: 0x22,
0x23: 0x23,
0x24: 0xA4,
0x25: 0x25,
0x26: 0x26,
0x27: 0x27,
0x28: 0x28,
0x29: 0x29,
0x2A: 0x2A,
0x2B: 0x2B,
0x2C: 0x2C,
0x2D: 0x2D,
0x2E: 0x2E,
0x2F: 0x2F,
0x30: 0x30,
0x31: 0x31,
0x32: 0x32,
0x33: 0x33,
0x34: 0x34,
0x35: 0x35,
0x36: 0x36,
0x37: 0x37,
0x38: 0x38,
0x39: 0x39,
0x3A: 0x3A,
0x3B: 0x3B,
0x3C: 0x3C,
0x3D: 0x3D,
0x3E: 0x3E,
0x3F: 0x3F,
0x40: 0x40,
0x41: 0x41,
0x42: 0x42,
0x43: 0x43,
0x44: 0x44,
0x45: 0x45,
0x46: 0x46,
0x47: 0x47,
0x48: 0x48,
0x49: 0x49,
0x4A: 0x4A,
0x4B: 0x4B,
0x4C: 0x4C,
0x4D: 0x4D,
0x4E: 0x4E,
0x4F: 0x4F,
0x50: 0x50,
0x51: 0x51,
0x52: 0x52,
0x53: 0x53,
0x54: 0x54,
0x55: 0x55,
0x56: 0x56,
0x57: 0x57,
0x58: 0x58,
0x59: 0x59,
0x5A: 0x5A,
0x5B: 0x5B,
0x5C: 0x5C,
0x5D: 0x5D,
0x5E: 0x2015,
0x5F: 0x005F,
0x60: 0x2016,
0x61: 0x61,
0x62: 0x62,
0x63: 0x63,
0x64: 0x64,
0x65: 0x65,
0x66: 0x66,
0x67: 0x67,
0x68: 0x68,
0x69: 0x69,
0x6A: 0x6A,
0x6B: 0x6B,
0x6C: 0x6C,
0x6D: 0x6D,
0x6E: 0x6E,
0x6F: 0x6F,
0x70: 0x70,
0x71: 0x71,
0x72: 0x72,
0x73: 0x73,
0x74: 0x74,
0x75: 0x75,
0x76: 0x76,
0x77: 0x77,
0x78: 0x78,
0x79: 0x79,
0x7A: 0x7A,
0x7B: 0x7B,
0x7C: 0x7C,
0x7D: 0x7D,
0x7E: 0x203E,
0x80: 0xE1,
0x81: 0xE0,
0x82: 0xE9,
0x83: 0xE8,
0x84: 0xED,
0x85: 0xEC,
0x86: 0xF3,
0x87: 0xF2,
0x88: 0xFA,
0x89: 0xF9,
0x8A: 0xD1,
0x8B: 0xC7,
0x8C: 0x15E,
0x8D: 0xDF,
0x8E: 0xA1,
0x8F: 0x132,
0x90: 0xE2,
0x91: 0xE4,
0x92: 0xEA,
0x93: 0xEB,
0x94: 0xEE,
0x95: 0xEF,
0x96: 0xF4,
0x97: 0xF6,
0x98: 0xFB,
0x99: 0xFC,
0x9A: 0xF1,
0x9B: 0xE7,
0x9C: 0x15F,
0x9D: 0x11F,
0x9E: 0x131,
0x9F: 0x133,
0xA0: 0xAA,
0xA1: 0x3B1,
0xA2: 0xA9,
0xA3: 0x2030,
0xA4: 0x11E,
0xA5: 0x11B,
0xA6: 0x148,
0xA7: 0x151,
0xA8: 0x3C0,
0xA9: 0x20AC,
0xAA: 0xA3,
0xAB: 0x24,
0xAC: 0x2190,
0xAD: 0x2191,
0xAE: 0x2192,
0xAF: 0x2193,
0xB0: 0xBA,
0xB1: 0xB9,
0xB2: 0xB2,
0xB3: 0xB3,
0xB4: 0xB1,
0xB5: 0x130,
0xB6: 0x144,
0xB7: 0x171,
0xB8: 0xB5,
0xB9: 0xBF,
0xBA: 0xF7,
0xBB: 0xBB,
0xBC: 0xBC,
0xBD: 0xBD,
0xBE: 0xBE,
0xBF: 0xA7,
0xC0: 0xC1,
0xC1: 0xC0,
0xC2: 0xC9,
0xC3: 0xC8,
0xC4: 0xCD,
0xC5: 0xCC,
0xC6: 0xD3,
0xC7: 0xD2,
0xC8: 0xDA,
0xC9: 0xD9,
0xCA: 0x158,
0xCB: 0x10C,
0xCC: 0x160,
0xCD: 0x17D,
0xCE: 0xD0,
0xCF: 0x13F,
0xD0: 0xC2,
0xD1: 0xC4,
0xD2: 0xCA,
0xD3: 0xCB,
0xD4: 0xCE,
0xD5: 0xCF,
0xD6: 0xD4,
0xD7: 0xD6,
0xD8: 0xDB,
0xD9: 0xDC,
0xDA: 0x159,
0xDB: 0x10D,
0xDC: 0x161,
0xDD: 0x17E,
0xDE: 0x111,
0xDF: 0x140,
0xE0: 0xC3,
0xE1: 0xC5,
0xE2: 0xC6,
0xE3: 0x152,
0xE4: 0x177,
0xE5: 0xDD,
0xE6: 0xD5,
0xE7: 0xD8,
0xE8: 0xDE,
0xE9: 0x14A,
0xEA: 0x154,
0xEB: 0x106,
0xEC: 0x15A,
0xED: 0x179,
0xEE: 0x166,
0xEF: 0xF0,
0xF0: 0xE3,
0xF1: 0xE5,
0xF2: 0xE6,
0xF3: 0x153,
0xF4: 0x175,
0xF5: 0xFD,
0xF6: 0xF5,
0xF7: 0xF8,
0xF8: 0x00FE,
0xF9: 0x14B,
0xFA: 0x155,
0xFB: 0x107,
0xFC: 0x15B,
0xFD: 0x17A,
0xFE: 0x167,
}
# Reverse map: Unicode code point -> RDS byte
_UCS2_TO_RDS: dict[int, int] = {v: k for k, v in _RDS_TO_UCS2.items()}
# ---------------------------------------------------------------------------
# Codec implementation
# ---------------------------------------------------------------------------
def _rds_decode(data: bytes, errors: str = "strict") -> Tuple[str, int]:
"""Decode RDS-encoded bytes to a Unicode string."""
chars = []
for i, byte in enumerate(data):
ucs = _RDS_TO_UCS2.get(byte)
if ucs is not None:
chars.append(chr(ucs))
else:
if errors == 'strict':
raise UnicodeDecodeError(
'rds', data, i, i + 1,
f'RDS byte 0x{byte:02X} has no Unicode mapping'
)
elif errors == 'replace':
chars.append('\uFFFD')
elif errors == 'ignore':
pass
else:
raise LookupError(f"unknown error handler '{errors}'")
return ''.join(chars), len(data)
def _rds_encode(text: str, errors: str = 'strict') -> Tuple[bytes, int]:
"""Encode a Unicode string to RDS bytes."""
out = []
for i, ch in enumerate(text):
rds = _UCS2_TO_RDS.get(ord(ch))
if rds is not None:
out.append(rds)
else:
if errors == 'strict':
raise UnicodeEncodeError(
'rds', text, i, i + 1,
f'U+{ord(ch):04X} ({ch!r}) has no RDS mapping'
)
elif errors == 'replace':
rds2 = _UCS2_TO_RDS.get(ord(unidecode.unidecode(ch, "replace", " ")))
if rds2 is not None: out.append(rds2)
else: out.append(0x20) # substitute with space
elif errors == 'ignore':
pass
else:
raise LookupError(f"unknown error handler '{errors}'")
return bytes(out), len(text)
class RDSIncrementalDecoder(codecs.BufferedIncrementalDecoder):
def _buffer_decode(self, data: bytes, errors: str, final: bool):
return _rds_decode(data, errors)
class RDSIncrementalEncoder(codecs.IncrementalEncoder):
def encode(self, text: str, final: bool = False) -> bytes:
result, _ = _rds_encode(text, self.errors)
return result
class RDSStreamReader(codecs.StreamReader):
def decode(self, data: bytes, errors: str = 'strict'):
return _rds_decode(data, errors)
class RDSStreamWriter(codecs.StreamWriter):
def encode(self, text: str, errors: str = 'strict'):
return _rds_encode(text, errors)
_CODEC_INFO = codecs.CodecInfo(
name='rds',
encode=_rds_encode,
decode=_rds_decode, # pyright: ignore[reportArgumentType]
incrementalencoder=RDSIncrementalEncoder,
incrementaldecoder=RDSIncrementalDecoder,
streamreader=RDSStreamReader,
streamwriter=RDSStreamWriter,
)
def _rds_lookup(name: str):
if name in ('rp-rds', 'rds-charset', 'rds_charset'):
return _CODEC_INFO
return None
# Register the codec when this module is imported
codecs.register(_rds_lookup)
# ---------------------------------------------------------------------------
# Convenience helpers
# ---------------------------------------------------------------------------
def decode(data: bytes, errors: str = 'strict') -> str:
"""Decode RDS bytes to a Python str."""
text, _ = _rds_decode(data, errors)
return text
def encode(text: str, errors: str = 'strict') -> bytes:
"""Encode a Python str to RDS bytes."""
data, _ = _rds_encode(text, errors)
return data