diff options
Diffstat (limited to 'dbpl/dbpl.py')
| -rw-r--r-- | dbpl/dbpl.py | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/dbpl/dbpl.py b/dbpl/dbpl.py new file mode 100644 index 0000000..153cf21 --- /dev/null +++ b/dbpl/dbpl.py @@ -0,0 +1,297 @@ +from __future__ import annotations +from typing import List, Optional +from struct import pack, unpack +from enum import Enum + +import os + + +class Flag(Enum): + IS_SUBTRACK = 1 << 0 # file is not single-track, might have metainfo in external file + IS_READONLY = 1 << 1 # check this flag to block tag writing (e.g. in iso.wv) + HAS_EMBEDDED_CUESHEET = 1 << 2 + + TAG_ID3V1 = 1 << 8 + TAG_ID3V22 = 1 << 9 + TAG_ID3V23 = 1 << 10 + TAG_ID3V24 = 1 << 11 + TAG_APEV2 = 1 << 12 + TAG_VORBISCOMMENTS = 1 << 13 + TAG_CUESHEET = 1 << 14 + TAG_ICY = 1 << 15 + TAG_ITUNES = 1 << 16 + + TAG_MASK = 0x000fff00 + + +class Track: + uri = Optional[str] + decoder = Optional[str] + num = Optional[int] + startsample = Optional[int] + endsample = Optional[int] + duration = Optional[float] + filetype = Optional[str] + replaygain_albumgain = Optional[int] + replaygain_albumpeak = Optional[int] + replaygain_trackgain = Optional[int] + replaygain_trackpeak = Optional[int] + flags: int + meta: dict + + def __init__(self): + self.uri = '' + self.decoder = '' + self.num = 0 + self.startsample = 0 + self.endsample = 0 + self.duration = 0 + self.filetype = '' + self.replaygain_albumgain = 0 + self.replaygain_albumpeak = 0 + self.replaygain_trackgain = 0 + self.replaygain_trackpeak = 0 + self.flags = 0 + self.meta = {} + + def get_uri(self) -> str: + return self.meta[':URI'] if ':URI' in self.meta else self.uri + + def set_uri(self, uri) -> None: + self.uri = uri + self.meta[':URI'] = uri + + def get_startsample(self) -> int: + return self.meta[':STARTSAMPLE'] if ':STARTSAMPLE' in self.meta else self.startsample + + def set_startsample(self, value) -> None: + self.startsample = value + self.meta[':STARTSAMPLE'] = value + + def get_endsample(self) -> int: + return self.meta[':ENDSAMPLE'] if ':ENDSAMPLE' in self.meta else self.endsample + + def set_endsample(self, value) -> None: + self.endsample = value + self.meta[':ENDSAMPLE'] = value + + def get_writable_meta(self) -> dict: + meta = {} + for key, value in self.meta.items(): + if key[0] != '_' and key[0] != '!': + meta[key] = value + return meta + + def pack(self) -> bytes: + buf = bytearray() + + uri_b = self.get_uri().encode() + buf.extend(pack('H', len(uri_b))) + buf.extend(uri_b) + + if self.decoder: + decoder_b = self.decoder.encode() + buf.append(len(decoder_b)) + buf.extend(decoder_b) + else: + buf.append(0) + + buf.extend(pack('h', self.num)) + buf.extend(pack('i', self.get_startsample())) + buf.extend(pack('i', self.get_endsample())) + buf.extend(pack('f', self.duration)) + + ft_b = self.filetype.encode() + buf.append(len(ft_b)) + if len(self.filetype): + buf.extend(ft_b) + + buf.extend(pack('f', self.replaygain_albumgain)) + buf.extend(pack('f', self.replaygain_albumpeak)) + buf.extend(pack('f', self.replaygain_trackgain)) + buf.extend(pack('f', self.replaygain_trackpeak)) + buf.extend(pack('I', self.flags)) + + meta = self.get_writable_meta() + buf.extend(pack('h', len(meta))) + + for key, value in meta.items(): + value = str(value).encode() + key = key.encode() + key_len, value_len = len(key), len(value) + + buf.extend(pack('H', key_len)) + if key_len: + buf.extend(key) + + buf.extend(pack('H', value_len)) + if value_len: + buf.extend(value) + + return bytes(buf) + + +class Playlist: + MINOR_VERSION = 2 + MAJOR_VERSION = 1 + + major_version: Optional[int] + minor_version: Optional[int] + tracks = List[Track] + meta: dict + + def __init__(self, file: str): + self.file = file + self.major_version = None + self.minor_version = None + self.tracks = [] + self.meta = {} + + self.read() + + def add_track(self, track: Track) -> None: + self.tracks.append(track) + + def pack(self) -> bytes: + pass + + def read(self) -> None: + with open(self.file, 'rb') as f: + magic = f.read(4) + if magic != b'DBPL': + raise ValueError('invalid magic value') + + # uint8_t + self.major_version, self.minor_version = unpack('BB', f.read(2)) + + if self.major_version != 1: + raise ValueError('invalid major version %d' % self.major_version) + + if self.minor_version < 1: + raise ValueError('invalid minor version %d' % self.minor_version) + + # uint32_t + tracks_count = unpack('I', f.read(4))[0] + + for i in range(tracks_count): + track = Track() + + if self.minor_version <= 2: + # uint16_t + uri_len = unpack('H', f.read(2))[0] + track.uri = f.read(uri_len).decode() + + # uint8_t + decoder_len = unpack('B', f.read(1))[0] + if decoder_len >= 20: + raise ValueError('invalid decoder length %d' % decoder_len) + + if decoder_len: + track.decoder = f.read(decoder_len).decode() + + # int16_t + track.num = unpack('h', f.read(2))[0] + + # int32_t + ss, es = unpack('ii', f.read(8)) + track.set_startsample(ss) + track.set_endsample(es) + + # float + track.duration = unpack('f', f.read(4))[0] + + if self.minor_version <= 2: + # legacy filetype support, they say + # uint8_t + filetype_len = unpack('B', f.read(1))[0] + if filetype_len: + track.filetype = f.read(filetype_len).decode() + + # floats + ag, ap, tg, tp = unpack('ffff', f.read(16)) + if ag != 0: + track.replaygain_albumgain = ag + if ap != 0 and ap != 1: + track.replaygain_albumpeak = ap + if tg != 0: + track.replaygain_trackgain = tg + if tp != 0 and tp != 1: + track.replaygain_trackpeak = tp + + if self.minor_version >= 2: + # uint32_t + track.flags = unpack('I', f.read(4))[0] + elif track.startsample > 0 or track.endsample > 0 or track.num > 0: + track.flags |= Flag.IS_SUBTRACK + + # int16_t + meta_count = unpack('h', f.read(2))[0] + for j in range(meta_count): + # uint16_t + value_len = unpack('H', f.read(2))[0] + if value_len >= 20000: + raise ValueError('invalid key length') + + key = f.read(value_len).decode() + + value_len = unpack('H', f.read(2))[0] + if value_len >= 20000: + f.seek(value_len, os.SEEK_CUR) + else: + value = f.read(value_len) + if key[0] == ':': + if key == ':STARTSAMPLE': + track.set_startsample(int(value)) + elif key == ':ENDSAMPLE': + track.set_endsample(int(value)) + else: + track.meta[key] = value.decode() + else: + track.meta[key] = value.decode() + + self.add_track(track) + + assert tracks_count == len(self.tracks) + + # playlist metadata + # int16_t + meta_count = unpack('H', f.read(2))[0] + for i in range(meta_count): + # int16_t + key_len = unpack('h', f.read(2))[0] + if key_len < 0 or key_len >= 20000: + raise ValueError('invalid length') + + key = f.read(key_len).decode() + + # int16_t + value_len = unpack('h', f.read(2))[0] + if value_len < 0 or value_len >= 20000: + f.seek(value_len, os.SEEK_CUR) + else: + value = f.read(value_len) + self.meta[key] = value.decode() + + def save(self, file: str = None) -> None: + if file is None: + file = self.file + + with open(file, 'wb') as f: + f.write(b'DBPL') + f.write(pack('BB', Playlist.MAJOR_VERSION, Playlist.MINOR_VERSION)) + f.write(pack('I', len(self.tracks))) + for track in self.tracks: + f.write(track.pack()) + + f.write(pack('h', len(self.meta))) + for key, value in self.meta.items(): + value = str(value) + key_len, value_len = len(key), len(value) + + f.write(pack('H', key_len)) + if key_len: + f.write(key.encode()) + + f.write(pack('H', value_len)) + if value_len: + f.write(value.encode()) |