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# -*- coding: utf-8 -*-
from __future__ import absolute_import
import codecs
from .base import Type
class IsoBmff(Type):
"""
Implements the ISO-BMFF base type.
"""
def __init__(self, mime, extension):
super(IsoBmff, self).__init__(
mime=mime,
extension=extension
)
def _is_isobmff(self, buf):
if len(buf) < 16 or buf[4:8] != b'ftyp':
return False
if len(buf) < int(codecs.encode(buf[0:4], 'hex'), 16):
return False
return True
def _get_ftyp(self, buf):
ftyp_len = int(codecs.encode(buf[0:4], 'hex'), 16)
major_brand = buf[8:12].decode(errors='ignore')
minor_version = int(codecs.encode(buf[12:16], 'hex'), 16)
compatible_brands = []
for i in range(16, ftyp_len, 4):
compatible_brands.append(buf[i:i+4].decode(errors='ignore'))
return major_brand, minor_version, compatible_brands
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