def extract_strings(data, keys):
fd = BytesIO(keys)
keys = [fd.read(16) for i in range(U8.read(fd))]
if not keys:
return
fd = BytesIO(data)
for i in range(U32LE.read(fd)):
msg = fd.read(U32LE.read(fd))
key = keys[i % len(keys)]
return Decryptor(key).decrypt(msg)
def iter_tags(self, fd=None, buf=None, skip_header=None):
flags = U8.read(fd)
quality = flags & 15
version = flags >> 4
lookup_size = U16BE.read(fd)
enc_table = fd.read(lookup_size)
key = b""
iv = b""
for i in range(16):
key += fd.read(1)
iv += fd.read(1)
if not (key and iv):
return
dec_table = self.decrypt_data(key, iv, enc_table)
dstream = BytesIO(dec_table)
# Decode lookup table (ported from K-S-V BeatConvert.php)
while True:
flags = U8.read(dstream)
if not flags:
break
typ = flags >> 4
encrypted = (flags & 4) > 0
keyframe = (flags & 2) > 0
config = (flags & 1) > 0
time = U32BE.read(dstream)
data_length = U32BE.read(dstream)
if encrypted:
raw_length = U32BE.read(dstream)
else:
raw_length = data_length
# Decrypt encrypted tags
data = fd.read(data_length)
if encrypted:
data = self.decrypt_data(key, iv, data)
data = data[:raw_length]
# Create video tag
if typ == 1:
if version == 2:
if config:
avc = AVCVideoData(AVC_PACKET_TYPE_SEQUENCE_HEADER,
data=data)
else:
avc = AVCVideoData(AVC_PACKET_TYPE_NALU, data=data)
if keyframe:
videodata = VideoData(VIDEO_FRAME_TYPE_KEY_FRAME,
VIDEO_CODEC_ID_AVC, avc)
else:
videodata = VideoData(VIDEO_FRAME_TYPE_INTER_FRAME,
VIDEO_CODEC_ID_AVC, avc)
else:
videodata = RawData(data)
yield Tag(TAG_TYPE_VIDEO, time, videodata)
# Create audio tag
if typ == 2:
if version == 2:
if config:
aac = AACAudioData(AAC_PACKET_TYPE_SEQUENCE_HEADER,
data)
else:
aac = AACAudioData(AAC_PACKET_TYPE_RAW, data)
audiodata = AudioData(codec=AUDIO_CODEC_ID_AAC,
rate=AUDIO_RATE_44_KHZ,
bits=AUDIO_BIT_RATE_16,
type=AUDIO_TYPE_STEREO,
data=aac)
else:
audiodata = RawData(data)
yield Tag(TAG_TYPE_AUDIO, time, audiodata)
def iter_tags(self, fd=None, buf=None, skip_header=None):
flags = U8.read(fd)
quality = flags & 15
version = flags >> 4
lookup_size = U16BE.read(fd)
enc_table = fd.read(lookup_size)
key = b""
iv = b""
for i in range(16):
key += fd.read(1)
iv += fd.read(1)
if not (key and iv):
return
dec_table = self.decrypt_data(key, iv, enc_table)
dstream = BytesIO(dec_table)
# Decode lookup table (ported from K-S-V BeatConvert.php)
while True:
flags = U8.read(dstream)
if not flags:
break
typ = flags >> 4
encrypted = (flags & 4) > 0
keyframe = (flags & 2) > 0
config = (flags & 1) > 0
time = U32BE.read(dstream)
data_length = U32BE.read(dstream)
if encrypted:
raw_length = U32BE.read(dstream)
else:
raw_length = data_length
# Decrypt encrypted tags
data = fd.read(data_length)
if encrypted:
data = self.decrypt_data(key, iv, data)
data = data[:raw_length]
# Create video tag
if typ == 1:
if version == 2:
if config:
avc = AVCVideoData(AVC_PACKET_TYPE_SEQUENCE_HEADER,
data=data)
else:
avc = AVCVideoData(AVC_PACKET_TYPE_NALU, data=data)
if keyframe:
videodata = VideoData(VIDEO_FRAME_TYPE_KEY_FRAME,
VIDEO_CODEC_ID_AVC, avc)
else:
videodata = VideoData(VIDEO_FRAME_TYPE_INTER_FRAME,
VIDEO_CODEC_ID_AVC, avc)
else:
videodata = RawData(data)
yield Tag(TAG_TYPE_VIDEO, time, videodata)
# Create audio tag
if typ == 2:
if version == 2:
if config:
aac = AACAudioData(AAC_PACKET_TYPE_SEQUENCE_HEADER,
data)
else:
aac = AACAudioData(AAC_PACKET_TYPE_RAW, data)
audiodata = AudioData(codec=AUDIO_CODEC_ID_AAC,
rate=AUDIO_RATE_44_KHZ,
bits=AUDIO_BIT_RATE_16,
type=AUDIO_TYPE_STEREO,
data=aac)
else:
audiodata = RawData(data)
yield Tag(TAG_TYPE_AUDIO, time, audiodata)
