def process_tfdt(self, data):
"Extract baseMediaDecodeTime."
version = ord(data[8])
if version == 0:
self.base_media_decode_time = str_to_uint32(data[12:16])
else:
self.base_media_decode_time = str_to_uint64(data[12:20])
seg = self.input_segments[-1]
seg['base_media_decode_time'] = self.base_media_decode_time
self.tfdt_size = len(data)
return data
def process_sidx(self, data, file_pos):
"Extract sidx parts."
version = ord(data[8])
timescale = str_to_uint32(data[16:20])
if version == 0:
earliest_time = str_to_uint32(data[20:24])
first_offset = str_to_uint32(data[24:28])
pos = 28
else:
earliest_time = str_to_uint32(data[20:28])
first_offset = str_to_uint64(data[28:36])
pos = 36
if first_offset != 0:
raise ValueError("Only supports first_offset == 0")
pos += 2
reference_count = str_to_uint16(data[pos:pos + 2])
pos += 2
sidx_data = {'timescale': timescale, 'segments': []}
offset = file_pos + len(data) + first_offset
start = earliest_time
for i in range(reference_count):
field = str_to_uint32(data[pos:pos + 4])
pos += 4
reference_type = field >> 31
if reference_type != 0:
raise ValueError("Only sidx reference type == 0 supported")
size = field & 0x7fffffff
duration = str_to_uint32(data[pos:pos + 4])
if self.verbose:
print("Input sidx %d: dur=%d" % (i + 1, duration))
pos += 4
field = str_to_uint32(data[pos:pos + 4])
pos += 4
starts_with_sap = field >> 31
if starts_with_sap != 1:
raise ValueError("Only sidx with starts_with_sap supported")
sap_type = (field >> 28) & 0x7
if sap_type != 1:
raise ValueError("Only sap type 1 supported, not %d" %
sap_type)
sap_delta_time = field & 0x0fffffff
if sap_delta_time != 0:
raise ValueError("Only sap_delta_time == 0 supported")
seg_data = {
'offset': offset,
'size': size,
'start': start,
'duration': duration
}
sidx_data['segments'].append(seg_data)
offset += size
start += duration
self.sidx_data = sidx_data
return data
def process_tfdt(self, data, output):
"""Adjust time of tfdt if offset set."""
version = ord(data[8])
if version == 0: # 32-bit baseMediaDecodeTime
tfdt = str_to_uint32(data[12:16])
if self.offset != None:
tfdt += self.offset
output += data[:12] + uint32_to_str(tfdt) + data[16:]
else:
output += data
else:
output = data[:12]
tfdt = str_to_uint64(data[12:20])
if self.offset != None:
tfdt += self.offset
output += uint64_to_str(tfdt)
else:
output += data
self.tfdt = tfdt
return output
def process_tfdt(self, data, output):
"""Adjust time of tfdt if offset set."""
version = ord(data[8])
if version == 0: # 32-bit baseMediaDecodeTime
tfdt = str_to_uint32(data[12:16])
if self.offset != None:
tfdt += self.offset
output += data[:12] + uint32_to_str(tfdt) + data[16:]
else:
output += data
else:
output = data[:12]
tfdt = str_to_uint64(data[12:20])
if self.offset != None:
tfdt += self.offset
output += uint64_to_str(tfdt)
else:
output += data
self.tfdt = tfdt
return output
def process_tfhd(self, data):
"""Check flags and set default values.
We are only interested in some values."""
tf_flags = str_to_uint32(data[8:12]) & 0xffffff
self.track_id = str_to_uint32(data[12:16])
pos = 16
if tf_flags & 0x000001: # base_data_offset_present
base_data_offset = str_to_uint64(data[pos:pos + 8])
pos += 8
if tf_flags & 0x000002: # sample-description-index-present
sample_description_index = str_to_uint32(data[pos:pos + 4])
pos += 4
if tf_flags & 0x000008: # default_sample_duration_present
self.default_sample_duration = str_to_uint32(data[pos:pos + 4])
pos += 4
if tf_flags & 0x000010: # default_sample_size_present
self.default_sample_size = str_to_uint32(data[pos:pos + 4])
pos += 4
if tf_flags & 0x000020: # default_sample_flags_present
self.default_sample_flags = str_to_uint32(data[pos:pos + 4])
pos += 4
return data