1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
"""utility routines to slice sound files at given timestamps"""
import os
from aubio import source, sink
_max_timestamp = 1e120
def slice_source_at_stamps(source_file, timestamps, timestamps_end=None,
output_dir=None, samplerate=0, hopsize=256):
""" slice a sound file at given timestamps """
if timestamps is None or len(timestamps) == 0:
raise ValueError("no timestamps given")
if timestamps[0] != 0:
timestamps = [0] + timestamps
if timestamps_end is not None:
timestamps_end = [timestamps[1] - 1] + timestamps_end
if timestamps_end is not None:
if len(timestamps_end) != len(timestamps):
raise ValueError("len(timestamps_end) != len(timestamps)")
else:
timestamps_end = [t - 1 for t in timestamps[1:]] + [_max_timestamp]
regions = list(zip(timestamps, timestamps_end))
#print regions
source_base_name, _ = os.path.splitext(os.path.basename(source_file))
if output_dir is not None:
if not os.path.isdir(output_dir):
os.makedirs(output_dir)
source_base_name = os.path.join(output_dir, source_base_name)
def new_sink_name(source_base_name, timestamp, samplerate):
""" create a sink based on a timestamp in samples, converted in seconds """
timestamp_seconds = timestamp / float(samplerate)
return source_base_name + "_%011.6f" % timestamp_seconds + '.wav'
# open source file
_source = source(source_file, samplerate, hopsize)
samplerate = _source.samplerate
total_frames = 0
slices = []
while True:
# get hopsize new samples from source
vec, read = _source.do_multi()
# if the total number of frames read will exceed the next region start
if len(regions) and total_frames + read >= regions[0][0]:
#print "getting", regions[0], "at", total_frames
# get next region
start_stamp, end_stamp = regions.pop(0)
# create a name for the sink
new_sink_path = new_sink_name(source_base_name, start_stamp, samplerate)
# create its sink
_sink = sink(new_sink_path, samplerate, _source.channels)
# create a dictionary containing all this
new_slice = {'start_stamp': start_stamp, 'end_stamp': end_stamp, 'sink': _sink}
# append the dictionary to the current list of slices
slices.append(new_slice)
for current_slice in slices:
start_stamp = current_slice['start_stamp']
end_stamp = current_slice['end_stamp']
_sink = current_slice['sink']
# sample index to start writing from new source vector
start = max(start_stamp - total_frames, 0)
# number of samples yet to written be until end of region
remaining = end_stamp - total_frames + 1
#print current_slice, remaining, start
# not enough frames remaining, time to split
if remaining < read:
if remaining > start:
# write remaining samples from current region
_sink.do_multi(vec[:, start:remaining], remaining - start)
#print "closing region", "remaining", remaining
# close this file
_sink.close()
elif read > start:
# write all the samples
_sink.do_multi(vec[:, start:read], read - start)
total_frames += read
if read < hopsize:
break
|
