""" Audio Interchange File Format (AIFF) parser. Author: Victor Stinner Creation: 27 december 2006 """ from hachoir.parser import Parser from hachoir.field import (FieldSet, UInt16, UInt32, Float80, TimestampMac32, RawBytes, NullBytes, String, Enum, PascalString32) from hachoir.core.endian import BIG_ENDIAN from hachoir.core.text_handler import filesizeHandler from hachoir.core.tools import alignValue from hachoir.parser.audio.id3 import ID3v2 CODEC_NAME = { 'ACE2': u"ACE 2-to-1", 'ACE8': u"ACE 8-to-3", 'MAC3': u"MAC 3-to-1", 'MAC6': u"MAC 6-to-1", 'NONE': u"None", 'sowt': u"Little-endian, no compression", } class Comment(FieldSet): def createFields(self): yield TimestampMac32(self, "timestamp") yield PascalString32(self, "text") def parseText(self): yield String(self, "text", self["size"].value) def parseID3(self): yield ID3v2(self, "id3v2", size=self["size"].value * 8) def parseComment(self): yield UInt16(self, "nb_comment") for index in xrange(self["nb_comment"].value): yield Comment(self, "comment[]") def parseCommon(self): yield UInt16(self, "nb_channel") yield UInt32(self, "nb_sample") yield UInt16(self, "sample_size") yield Float80(self, "sample_rate") yield Enum(String(self, "codec", 4, strip="\0", charset="ASCII"), CODEC_NAME) def parseVersion(self): yield TimestampMac32(self, "timestamp") def parseSound(self): yield UInt32(self, "offset") yield UInt32(self, "block_size") size = (self.size - self.current_size) // 8 if size: yield RawBytes(self, "data", size) class Chunk(FieldSet): TAG_INFO = { 'COMM': ('common', "Common chunk", parseCommon), 'COMT': ('comment', "Comment", parseComment), 'NAME': ('name', "Name", parseText), 'AUTH': ('author', "Author", parseText), 'FVER': ('version', "Version", parseVersion), 'SSND': ('sound', "Sound data", parseSound), 'ID3 ': ('id3', "ID3", parseID3), } def __init__(self, *args): FieldSet.__init__(self, *args) self._size = (8 + alignValue(self["size"].value, 2)) * 8 tag = self["type"].value if tag in self.TAG_INFO: self._name, self._description, self._parser = self.TAG_INFO[tag] else: self._parser = None def createFields(self): yield String(self, "type", 4, "Signature (FORM)", charset="ASCII") yield filesizeHandler(UInt32(self, "size")) size = self["size"].value if size: if self._parser: for field in self._parser(self): yield field if size % 2: yield NullBytes(self, "padding", 1) else: yield RawBytes(self, "data", size) class AiffFile(Parser): PARSER_TAGS = { "id": "aiff", "category": "audio", "file_ext": ("aif", "aiff", "aifc"), "mime": (u"audio/x-aiff",), "magic_regex": (("FORM.{4}AIF[CF]", 0),), "min_size": 12 * 8, "description": "Audio Interchange File Format (AIFF)" } endian = BIG_ENDIAN def validate(self): if self.stream.readBytes(0, 4) != "FORM": return "Invalid signature" if self.stream.readBytes(8 * 8, 4) not in ("AIFF", "AIFC"): return "Invalid type" return True def createFields(self): yield String(self, "signature", 4, "Signature (FORM)", charset="ASCII") yield filesizeHandler(UInt32(self, "filesize")) yield String(self, "type", 4, "Form type (AIFF or AIFC)", charset="ASCII") while not self.eof: yield Chunk(self, "chunk[]") def createDescription(self): if self["type"].value == "AIFC": return "Audio Interchange File Format Compressed (AIFC)" else: return "Audio Interchange File Format (AIFF)" def createContentSize(self): return self["filesize"].value * 8