def __init__(self, fileobj): header = fileobj.read(76) if len(header) != 76 or not header.startswith("MAC "): raise MonkeysAudioHeaderError("not a Monkey's Audio file") self.version = cdata.ushort_le(header[4:6]) if self.version >= 3980: (blocks_per_frame, final_frame_blocks, total_frames, self.bits_per_sample, self.channels, self.sample_rate) = struct.unpack("<IIIHHI", header[56:76]) else: compression_level = cdata.ushort_le(header[6:8]) self.channels, self.sample_rate = struct.unpack( "<HI", header[10:16]) total_frames, final_frame_blocks = struct.unpack( "<II", header[24:32]) if self.version >= 3950: blocks_per_frame = 73728 * 4 elif self.version >= 3900 or (self.version >= 3800 and compression_level == 4): blocks_per_frame = 73728 else: blocks_per_frame = 9216 self.version /= 1000.0 self.length = 0.0 if self.sample_rate != 0 and total_frames > 0: total_blocks = ((total_frames - 1) * blocks_per_frame + final_frame_blocks) self.length = float(total_blocks) / self.sample_rate
def __init__(self, fileobj): header = fileobj.read(32) if len(header) != 32: raise MusepackHeaderError("not a Musepack file") # Skip ID3v2 tags if header[:3] == "ID3": size = 10 + BitPaddedInt(header[6:10]) fileobj.seek(size) header = fileobj.read(32) if len(header) != 32: raise MusepackHeaderError("not a Musepack file") # SV7 if header.startswith("MP+"): self.version = ord(header[3]) & 0xF if self.version < 7: raise MusepackHeaderError("not a Musepack file") frames = cdata.uint_le(header[4:8]) flags = cdata.uint_le(header[8:12]) self.title_peak, self.title_gain = struct.unpack( "<Hh", header[12:16]) self.album_peak, self.album_gain = struct.unpack( "<Hh", header[16:20]) self.title_gain /= 100.0 self.album_gain /= 100.0 self.title_peak /= 65535.0 self.album_peak /= 65535.0 self.sample_rate = RATES[(flags >> 16) & 0x0003] self.bitrate = 0 # SV4-SV6 else: header_dword = cdata.uint_le(header[0:4]) self.version = (header_dword >> 11) & 0x03FF; if self.version < 4 or self.version > 6: raise MusepackHeaderError("not a Musepack file") self.bitrate = (header_dword >> 23) & 0x01FF; self.sample_rate = 44100 if self.version >= 5: frames = cdata.uint_le(header[4:8]) else: frames = cdata.ushort_le(header[6:8]) if self.version < 6: frames -= 1 self.channels = 2 self.length = float(frames * 1152 - 576) / self.sample_rate if not self.bitrate and self.length != 0: fileobj.seek(0, 2) self.bitrate = int(fileobj.tell() * 8 / (self.length * 1000) + 0.5)