def process_tfdt(self, data):
"""Generate new timestamps for tfdt and change size of boxes above if needed.
Try to keep in 32 bits if possible."""
version = data[8]
if self.track_timescale is not None:
tfdt_offset = self.offset * self.track_timescale
else:
tfdt_offset = 0
if version == 0: # 32-bit baseMediaDecodeTime
base_media_decode_time = str_to_uint32(data[12:16])
new_base_media_decode_time = base_media_decode_time + tfdt_offset
if new_base_media_decode_time < 4294967296:
output = data[:12]
output += uint32_to_str(new_base_media_decode_time)
else:
# print "Forced to change to 64-bit tfdt."
self.size_change = 4
output = uint32_to_str(
str_to_uint32(data[:4]) + self.size_change)
output += data[4:8]
output += b'\x01'
output += data[9:12]
output += uint64_to_str(new_base_media_decode_time)
else: # 64-bit
# print "Staying at 64-bit tfdt."
output = data[:12]
base_media_decode_time = str_to_uint64(data[12:20])
new_base_media_decode_time = base_media_decode_time + tfdt_offset
output += uint64_to_str(new_base_media_decode_time)
self.tfdt_value = new_base_media_decode_time
return output
def process_sidx(self, data):
"Process sidx data and add to output."
if not KEEP_SIDX:
return b""
output = b""
version = data[8]
timescale = str_to_uint32(data[16:20])
if version == 0:
# print("Changing sidx version to 1")
size = str_to_uint32(data[0:4])
sidx_size_expansion = 8
output += uint32_to_str(size + sidx_size_expansion)
output += data[4:8]
output += b'\x01'
output += data[9:20]
earliest_presentation_time = str_to_uint32(data[20:24])
first_offset = str_to_uint32(data[24:28])
else:
output += data[0:20]
earliest_presentation_time = str_to_uint64(data[20:28])
first_offset = str_to_uint64(data[28:36])
new_presentation_time = earliest_presentation_time + timescale * self.offset
output += uint64_to_str(new_presentation_time)
output += uint64_to_str(first_offset)
if version == 0:
output += data[28:]
else:
output += data[36:]
return output
def process_tkhd(self, data):
"Set trackID and time."
version = data[8]
output = data[:12]
if version == 1:
if self.creation_modfication_time:
output += uint64_to_str(self.creation_modfication_time)
output += uint64_to_str(self.creation_modfication_time)
else:
output += data[12:28]
output += uint32_to_str(self.track_id)
output += uint32_to_str(0)
output += uint64_to_str(0) # duration
pos = 44
else:
if self.creation_modfication_time:
output += uint32_to_str(self.creation_modfication_time)
output += uint32_to_str(self.creation_modfication_time)
else:
output += data[12:20]
output += uint32_to_str(self.track_id)
output += uint32_to_str(0)
output += uint32_to_str(0) # duration
pos = 32
output += data[pos:]
return output
def create_sidx(self, seg_size):
"""Return a sidx box which can be inserted right before the moof.
This is optional, but some clients require it to present."""
output = uint32_to_str(52) # Size of box
output += b'sidx\x01\x00\x00\x00' # type, version and flags
output += b'\x00\x00\x00\x01' # refID
output += uint32_to_str(self.track_timescale)
output += uint64_to_str(self.tfdt_value) # decode_time for now
output += uint64_to_str(0) # first_offset = 0
output += b'\x00\x00\x00\x01' # reserved and reference_count
# Next 1 bit reference type + 31 bit size of segment
output += uint32_to_str(seg_size)
output += uint32_to_str(self.duration)
output += b'\x90\x00\x00\x00'
return output
def process_saio(self, data):
"Process saio and possibly change offset by size_change if needed."
version_flags = str_to_uint32(data[8:12])
version = version_flags >> 24
flags = version_flags & 0xffffff
pos = 12
if flags & 0x1:
pos += 8
entry_count = str_to_uint32(data[pos:pos + 4])
pos += 4
output = data[:pos]
delta_offset = self.size_change
if version == 0:
for i in range(entry_count):
offset = str_to_uint32(data[pos:pos + 4])
pos += 4
output += uint32_to_str(offset + delta_offset)
if i == 0:
self.new_saio_value = offset + delta_offset
else:
for i in range(entry_count):
offset = str_to_uint64(data[pos:pos + 8])
pos += 8
output += uint64_to_str(offset + delta_offset)
if i == 0:
self.new_saio_value = offset + delta_offset
return output
def process_tfdt(self, data):
"Process a tfdt box and set the baseMediaDecodeTime."
version = ord(data[8])
assert version == 1, "Can only handle tfdt version 1 (64-bit tfdt)."
output = data[:12]
output += uint64_to_str(self.tfdt_time)
return output
def _insert_timing_data(self, data):
"Help function to insert timestamps and timescale in similar boxes."
version = data[8]
output = data[:12]
if version == 1:
if self.creation_modfication_time:
output += uint64_to_str(self.creation_modfication_time)
output += uint64_to_str(self.creation_modfication_time)
else:
output += data[12:28]
output += uint32_to_str(self.timescale)
output += uint64_to_str(0) # duration
else:
if self.creation_modfication_time:
output += uint32_to_str(self.creation_modfication_time)
output += uint32_to_str(self.creation_modfication_time)
else:
output += data[12:20]
output += uint32_to_str(self.timescale)
output += uint32_to_str(0)
return output
def process_tfdt_to_64bit(self, data, output):
"""Generate new timestamps for tfdt and change size of boxes above if needed.
Note that the input output will be returned and can have another size."""
version = data[8]
tfdt_offset = self.offset * self.track_timescale
if version == 0: # 32-bit baseMediaDecodeTime
self.size_change = 4
output = uint32_to_str(str_to_uint32(data[:4]) + self.size_change)
output += data[4:8]
output += b'\x01'
output += data[9:12]
base_media_decode_time = str_to_uint32(data[12:16])
else: # 64-bit
output = data[:12]
base_media_decode_time = str_to_uint64(data[12:20])
new_base_media_decode_time = base_media_decode_time + tfdt_offset
output += uint64_to_str(new_base_media_decode_time)
self.tfdt_value = new_base_media_decode_time
return output