def test_fix_preroll_buffering_with_trim(self):
"""
We can fix buffering occurred from preroll by using trim filter.
"""
ff = self.ffmpeg
ff < self.preroll
ff < self.source
output = outputs.output_file('original.mp4',
codecs.VideoCodec("libx264"))
original = outputs.output_file('original.mp4',
codecs.VideoCodec("libx264"))
preroll_stream = self.preroll.streams[0]
source_stream = self.source.streams[0]
concat = preroll_stream | filters.Concat(VIDEO)
source_stream | concat
split = concat | filters.Split(VIDEO)
split > output
pd = preroll_stream.meta.duration
sd = source_stream.meta.duration
trim = split | filters.Trim(VIDEO, start=pd, end=pd + sd)
trim | filters.SetPTS(VIDEO) > original
ff > original
ff > output
ff.check_buffering()
def test_detect_trim_buffering(self):
"""
When trim and concat filters are used for editing timeline, buffering
may occur if order of scenes in output file does not match order of same
scenes in input file.
"""
cases = [
(False, [1.0, 2.0], [2.0, 3.0]),
(True, [2.0, 3.0], [1.0, 2.0]),
(True, [2.0, 3.0], [2.0, 4.0]),
]
for case in cases:
with self.subTest(case):
raises, first, second = case
ff = FFMPEG()
s1 = inputs.Stream(VIDEO, self.source.streams[0].meta)
s2 = inputs.Stream(VIDEO, self.source.streams[1].meta)
ff < inputs.input_file('input.mp4', s1, s2)
split = ff.video | filters.Split(VIDEO)
t1 = split | filters.Trim(VIDEO, *first)
p1 = t1 | filters.SetPTS(VIDEO)
t2 = split | filters.Trim(VIDEO, *second)
p2 = t2 | filters.SetPTS(VIDEO)
concat = p1 | filters.Concat(VIDEO)
output = outputs.output_file('output.mp4',
codecs.VideoCodec('libx264'))
p2 | concat > output
ff > output
try:
ff.check_buffering()
except BufferError as e:
self.assertTrue(raises, e)
else:
self.assertFalse(raises)
def test_fix_trim_buffering(self):
"""
Trim buffering could be fixed with multiple source file deconding.
"""
ff = FFMPEG()
v1 = inputs.Stream(VIDEO, self.source.streams[0].meta)
a1 = inputs.Stream(AUDIO, self.source.streams[1].meta)
v2 = inputs.Stream(VIDEO, self.source.streams[0].meta)
a2 = inputs.Stream(AUDIO, self.source.streams[1].meta)
in1 = ff < inputs.input_file('input.mp4', v1, a1)
in2 = ff < inputs.input_file('input.mp4', v2, a2)
p1 = in1.video | filters.Trim(VIDEO, 2.0, 3.0) | filters.SetPTS(VIDEO)
p2 = in2.video | filters.Trim(VIDEO, 1.0, 2.0) | filters.SetPTS(VIDEO)
output = outputs.output_file('output.mp4',
codecs.VideoCodec('libx264'))
concat = p1 | filters.Concat(VIDEO)
p2 | concat > output
ff > output
ff.check_buffering()