diff options
| -rw-r--r-- | formats/mp3.py | 116 |
1 files changed, 96 insertions, 20 deletions
diff --git a/formats/mp3.py b/formats/mp3.py index 0c91911..c668b47 100644 --- a/formats/mp3.py +++ b/formats/mp3.py @@ -2,18 +2,92 @@ from formats.__base__ import * from utils import to_bytes import subprocess +import struct +import array + +def synchsafe(num): + if num <= 0x7f: + return num + + return synchsafe(num >> 7) << 8 | num & 0x7f + +class ID3Tagger: + # id3v2 frame mapping + __mapping = { + "album": "TALB", + "artist": "TPE1", + "composer": "TCOM", + "date": "TDRC", + "title": "TIT2", + "tracknumber": "TRCK", + } + + # id3v1 offsets + __offset = { + "title": 3, + "artist": 33, + "album": 63, + } + + @staticmethod + def header(size): + return struct.pack(">3s3BI", b"ID3", 4, 0, 0, synchsafe(size)) + + @staticmethod + def frame(name, data): + size = len(data) + 1 + hdr = struct.pack(">4sIHB", name, size, 0, 3) + return hdr + data + + def __init__(self): + self.frames = [] + + self.v1 = array.array("B", b"\x00" * 128) + struct.pack_into("3s", self.v1, 0, b"TAG") + struct.pack_into("B", self.v1, 127, 0xff) + + def frame_size(self): + return sum(map(len, self.frames)) + + def add(self, tag, value): + value = to_bytes(value) + + if tag in self.__mapping: + key = to_bytes(self.__mapping[tag]) + self.frames.append(self.frame(key, value)) + + off = self.__offset.get(tag) + if off: + struct.pack_into("30s", self.v1, off, value) + elif tag is "date": + struct.pack_into("4s", self.v1, 93, value) + elif tag is "tracknumber": + number = int(value.partition(b"/")[0]) + struct.pack_into("B", self.v1, 126, number) + + def write(self, path): + fp = open(path, "r+b") + data = fp.read() + + fp.seek(0) + fp.truncate(0) + + # save id3v2 + fp.write(self.header(self.frame_size())) + for frame in self.frames: + fp.write(frame) + + fp.write(data) + + # save id3v1 + self.v1.tofile(fp) + + fp.close() class Mp3Handler(BaseHandler): name = "mp3" ext = "mp3" - __tag_opts = { - "album": "-a", - "artist": "-A", - "date": "-y", - "title": "-t" - } - def encode(self, opt, info): self.add("cust ext=%s sox -" % self.ext) @@ -25,25 +99,27 @@ class Mp3Handler(BaseHandler): return self.build() - def tag(self, path, tags): - self.add("id3v2", "--id3v1-only") + def do_tag(self, path, tags): + tagger = ID3Tagger() for k, v in tags.items(): - if k in self.__tag_opts and v: - self.add(self.__tag_opts[k]) - self.add(v) + if v and k not in ("tracknumber", "tracktotal"): + tagger.add(k, v) - self.add("-T", "%d/%d" % (tags["tracknumber"], tags["tracktotal"])) - self.add(path) + number = "%d/%d" % (tags["tracknumber"], tags["tracktotal"]) + tagger.add("tracknumber", number) - self.log("Tag [%s] : ", path) + tagger.write(path) + return True - if subprocess.call(self.build(False)): - self.log("FAILED\n") - return False + def tag(self, path, tags): + self.log("Tag [%s] : ", path) + if self.do_tag(path, tags): + self.log("OK\n") + return True - self.log("OK\n") - return True + self.log("FAILED\n") + return False def init(): return Mp3Handler |