def cross_fade(self, seg1, seg2, duration):
"""Add a linear crossfade to the composition between two
segments.
:param seg1: First segment (fading out)
:type seg1: :py:class:`radiotool.composer.Segment`
:param seg2: Second segment (fading in)
:type seg2: :py:class:`radiotool.composer.Segment`
:param duration: Duration of crossfade (in seconds)
"""
if seg1.comp_location + seg1.duration - seg2.comp_location < 2:
dur = int(duration * seg1.track.samplerate)
if dur % 2 == 1:
dur -= 1
if dur / 2 > seg1.duration:
dur = seg1.duration * 2
if dur / 2 > seg2.duration:
dur = seg2.duration * 2
# we're going to compute the crossfade and then create a RawTrack
# for the resulting frames
if seg2.start - (dur / 2) < 0:
diff = seg2.start
seg2.start = 0
seg2.duration -= diff
seg2.comp_location -= diff
dur = 2 * diff
else:
seg2.start -= dur / 2
seg2.duration += dur / 2
seg2.comp_location -= dur / 2
seg1.duration += dur / 2
out_frames = seg1.get_frames(channels=self.channels)[-dur:]
seg1.duration -= dur
in_frames = seg2.get_frames(channels=self.channels)[:dur]
seg2.start += dur
seg2.duration -= dur
seg2.comp_location += dur
# compute the crossfade
in_frames = in_frames[: min(map(len, [in_frames, out_frames]))]
out_frames = out_frames[: min(map(len, [in_frames, out_frames]))]
cf_frames = radiotool.utils.linear(out_frames, in_frames)
# cf_frames = equal_power(out_frames, in_frames)
raw_track = RawTrack(cf_frames, name="crossfade", samplerate=seg1.track.samplerate)
rs_comp_location = (seg1.comp_location + seg1.duration) / float(seg1.track.samplerate)
rs_duration = raw_track.duration / float(raw_track.samplerate)
raw_seg = Segment(raw_track, rs_comp_location, 0.0, rs_duration)
# will this fix a bug?
raw_seg.duration = raw_track.duration
raw_seg.comp_location = seg1.comp_location + seg1.duration
self.add_track(raw_track)
self.add_segment(raw_seg)
return raw_seg
else:
print seg1.comp_location + seg1.duration, seg2.comp_location
raise Exception(
"Segments must be adjacent"
"to add a crossfade ({}, {})".format(seg1.comp_location + seg1.duration, seg2.comp_location)
)
def cross_fade(self, seg1, seg2, duration):
"""Add a linear crossfade to the composition between two
segments.
:param seg1: First segment (fading out)
:type seg1: :py:class:`radiotool.composer.Segment`
:param seg2: Second segment (fading in)
:type seg2: :py:class:`radiotool.composer.Segment`
:param duration: Duration of crossfade (in seconds)
"""
if seg1.comp_location + seg1.duration - seg2.comp_location < 2:
dur = int(duration * seg1.track.samplerate)
if dur % 2 == 1:
dur -= 1
if dur / 2 > seg1.duration:
dur = seg1.duration * 2
if dur / 2 > seg2.duration:
dur = seg2.duration * 2
# we're going to compute the crossfade and then create a RawTrack
# for the resulting frames
if seg2.start - (dur / 2) < 0:
diff = seg2.start
seg2.start = 0
seg2.duration -= diff
seg2.comp_location -= diff
dur = 2 * diff
else:
seg2.start -= (dur / 2)
seg2.duration += (dur / 2)
seg2.comp_location -= (dur / 2)
seg1.duration += (dur / 2)
out_frames = seg1.get_frames(channels=self.channels)[-dur:]
seg1.duration -= dur
in_frames = seg2.get_frames(channels=self.channels)[:dur]
seg2.start += dur
seg2.duration -= dur
seg2.comp_location += dur
# compute the crossfade
in_frames = in_frames[:min(map(len, [in_frames, out_frames]))]
out_frames = out_frames[:min(map(len, [in_frames, out_frames]))]
cf_frames = radiotool.utils.linear(out_frames, in_frames)
# cf_frames = equal_power(out_frames, in_frames)
raw_track = RawTrack(cf_frames,
name="crossfade",
samplerate=seg1.track.samplerate)
rs_comp_location = (seg1.comp_location + seg1.duration) /\
float(seg1.track.samplerate)
rs_duration = raw_track.duration / float(raw_track.samplerate)
raw_seg = Segment(raw_track, rs_comp_location, 0.0, rs_duration)
# will this fix a bug?
raw_seg.duration = raw_track.duration
raw_seg.comp_location = seg1.comp_location + seg1.duration
self.add_track(raw_track)
self.add_segment(raw_seg)
return raw_seg
else:
print seg1.comp_location + seg1.duration, seg2.comp_location
raise Exception("Segments must be adjacent"
"to add a crossfade ({}, {})".format(
seg1.comp_location + seg1.duration,
seg2.comp_location))
