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):
"""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_tfhd(self, data):
"Process tfhd (assuming that we know the ttml size size)."
tf_flags = str_to_uint32(data[8:12]) & 0xffffff
pos = 16
if tf_flags & 0x01:
raise MediaSegmentFilterError(
"base-data-offset-present not supported in ttml segments")
if tf_flags & 0x02:
pos += 4
if tf_flags & 0x08:
self.default_sample_duration = str_to_uint32(data[pos:pos + 4])
pos += 4
elif self.ttml_size:
raise MediaSegmentFilterError(
"Cannot handle ttml segments with default_sample_duration absent"
)
output = data[:pos]
if self.ttml_size:
if tf_flags & 0x10:
# old_ttml__size = str_to_uint32(data[pos:pos+4])
output += uint32_to_str(self.ttml_size)
# print("Changed ttml sample size from %d to %d" % (old_ttml__size, self.ttml_size))
pos += 4
else:
raise MediaSegmentFilterError(
"Cannot handle ttml segments if default_sample_size_offset is absent"
)
if self.ttml_size:
output += data[pos:]
else:
output = data
return output
def parse_trun(self, data, pos):
"Parse trun box and find position of data_offset."
flags = str_to_uint32(data[8:12]) & 0xffffff
data_offset_present = flags & 1
if data_offset_present:
self.trun_data_offset = str_to_uint32(data[16:20])
self.trun_data_offset_in_traf = pos + 16 - self.traf_start
def process_trex(self, data):
# track_id = str_to_uint32(data[12:16])
self.default_sample_description_index = str_to_uint32(data[16:20])
self.default_sample_duration = str_to_uint32(data[20:24])
self.default_sample_size = str_to_uint32(data[24:28])
self.default_sample_flags = str_to_uint32(data[28:32])
return data
def process_tkhd(self, data):
"Filter track header box and find track_id."
assert self.track_id is None, "Multiple tracks in init file %s. Not supported." % self.filename
version = data[8]
if version == 0:
self._track_id = str_to_uint32(data[20:24])
elif version == 1:
self._track_id = str_to_uint32(data[28:32])
return data
def process_mvhd(self, data):
"Set duration in mvhd."
version = data[8]
output = b""
if version == 1:
self.movie_timescale = str_to_uint32(data[28:32])
output += data[:32]
output += b'\x00' * 8 # duration
output += data[40:]
else: # version = 0
self.movie_timescale = str_to_uint32(data[20:24])
output += data[:24]
output += b'\x00' * 4 # duration
output += data[28:]
return output
def process_tfhd(self, data):
"Process a tfhd box and set trackID, defaultSampleDuration and defaultSampleSize"
tf_flags = str_to_uint32(data[8:12]) & 0xffffff
assert tf_flags == 0x020018, "Can only handle certain tf_flags combinations"
output = data[:12]
output += uint32_to_str(self.track_id)
output += uint32_to_str(self.default_sample_duration)
output += uint32_to_str(len(self.ttml_data))
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
def process_trun(self, data):
"Get total duration from trun. Fix offset if self.size_change is non-zero."
flags = str_to_uint32(data[8:12]) & 0xffffff
sample_count = str_to_uint32(data[12:16])
pos = 16
data_offset_present = False
if flags & 0x1: # Data offset present
data_offset_present = True
pos += 4
if flags & 0x4:
pos += 4 # First sample flags present
sample_duration_present = flags & 0x100
sample_size_present = flags & 0x200
sample_flags_present = flags & 0x400
sample_comp_time_present = flags & 0x800
duration = 0
for _ in range(sample_count):
if sample_duration_present:
duration += str_to_uint32(data[pos:pos + 4])
pos += 4
elif self.default_sample_duration is not None:
duration += self.default_sample_duration
if sample_size_present:
pos += 4
if sample_flags_present:
pos += 4
if sample_comp_time_present:
pos += 4
self.duration = duration
# Modify data_offset
output = data[:16]
if data_offset_present and self.size_change > 0:
offset = str_to_sint32(data[16:20])
offset += self.size_change
output += sint32_to_str(offset)
else:
output += data[16:20]
output += data[20:]
return output
def find_and_process_mdat(self, data):
"Change the ttml part of mdat and update mdat size. Return full new data."
pos = 0
output = b""
while pos < len(data):
size = str_to_uint32(data[pos:pos + 4])
boxtype = data[pos + 4:pos + 8]
if boxtype != b'mdat':
output += data[pos:pos + size]
else:
output += self.update_ttml_mdat(data[pos:pos + size])
pos += size
return output
def process_styp(self, data):
"Process styp and make sure lmsg presence follows the lmsg flag parameter. Add scte35 box if appropriate"
lmsg = self.lmsg
output = b""
size = str_to_uint32(data[:4])
pos = 8
brands = []
while pos < size:
brand = data[pos:pos + 4]
if brand != b"lmsg":
brands.append(brand)
pos += 4
if lmsg:
brands.append(b"lmsg")
new_size = 8 + 4 * len(brands)
output += uint32_to_str(new_size)
output += b"styp"
for brand in brands:
output += brand
scte35box = self.create_scte35box()
output += scte35box
return output
def process_trun(self, data):
"""Process trun box."""
# pylint: disable=too-many-locals,too-many-branches,too-many-statements
output = data[:16]
flags = str_to_uint32(data[8:12]) & 0xffffff
sample_count = str_to_uint32(data[12:16])
pos = 16
# data_offset_present = False
if flags & 0x1: # Data offset present
# data_offset_present = True
self.trun_offset = str_to_uint32(data[16:20])
output += uint32_to_str(self.trun_offset)
pos += 4
if flags & 0x4:
pos += 4 # First sample flags present
sample_duration_present = flags & 0x100
sample_size_present = flags & 0x200
sample_flags_present = flags & 0x400
sample_comp_time_present = flags & 0x800
sample_time_tfdt = self.tfdt
orig_sample_pos = 0
for i in range(sample_count):
duration = 0
size = 0
flags = 0
comp_time = 0
if sample_duration_present:
duration = str_to_uint32(data[pos:pos + 4])
pos += 4
if sample_size_present:
size = str_to_uint32(data[pos:pos + 4])
pos += 4
if sample_flags_present:
flags = str_to_uint32(data[pos:pos + 4])
pos += 4
if sample_comp_time_present:
comp_time = str_to_uint32(data[pos:pos + 4])
pos += 4
start_time = 0
if i == 0:
start_time = (sample_time_tfdt) / float(self.time_scale)
else:
start_time = (sample_time_tfdt + comp_time) / float(
self.time_scale)
end_time = (sample_time_tfdt + comp_time + duration) / float(
self.time_scale)
# start_time = (sample_time_tfdt) / float(self.time_scale)
# end_time = (sample_time_tfdt + duration) / float(self.time_scale)
# print("startTime:", start_time, "(", comp_time, ")", ", endTime:", end_time)
scc_samples = self.get_scc_data(start_time, end_time)
orig_sample_pos += size
if len(scc_samples):
print(
" ", i, "SampleTime: " + str(
(sample_time_tfdt) / float(self.time_scale)),
"num samples to add: ", len(scc_samples))
scc_generated_data = generate_data(scc_samples)
self.scc_map.append({
'pos': orig_sample_pos,
'scc': scc_generated_data,
'len': len(scc_generated_data)
})
size += len(scc_generated_data)
if sample_duration_present:
output += uint32_to_str(duration)
if sample_size_present:
output += uint32_to_str(size)
if sample_flags_present:
output += uint32_to_str(flags)
if sample_comp_time_present:
output += uint32_to_str(comp_time)
sample_time_tfdt += duration
return output
def process_mdhd(self, data):
"Process mdhd to get track_timscale."
self._track_timescale = str_to_uint32(data[20:24])
return data
def check_box(self, data):
"Check the type of box starting at position pos."
size = str_to_uint32(data[:4])
boxtype = data[4:8]
return (size, boxtype)