techrec/server/forge.py

116 lines
3.6 KiB
Python

from datetime import datetime, timedelta
from time import sleep
import os
from subprocess import Popen
from config_manager import get_config
def get_timefile_exact(time):
'''
time is of type `datetime`; it is not "rounded" to match the real file;
that work is done in get_timefile(time)
'''
return os.path.join(
get_config()['AUDIO_INPUT'],
time.strftime('%Y-%m/%d/rec-%Y-%m-%d-%H-%M-%S-ror.mp3')
)
def round_timefile(exact):
'''
This will round the datetime, so to match the file organization structure
'''
return datetime(exact.year, exact.month, exact.day, exact.hour)
def get_timefile(exact):
return get_timefile_exact(round_timefile(exact))
def get_files_and_intervals(start, end, rounder=round_timefile):
'''
both arguments are datetime objects
returns an iterator whose elements are (filename, start_cut, end_cut)
Cuts are expressed in seconds
'''
if end <= start:
raise ValueError("end < start!")
while start <= end:
begin = rounder(start)
start_cut = (start - begin).total_seconds()
if end < begin + timedelta(seconds=3599):
end_cut = (begin + timedelta(seconds=3599) - end).total_seconds()
else:
end_cut = 0
yield (begin, start_cut, end_cut)
start = begin + timedelta(hours=1)
def mp3_join(named_intervals, target):
'''
Note that these are NOT the intervals returned by get_files_and_intervals,
as they do not supply a filename, but only a datetime.
What we want in input is basically the same thing, but with get_timefile()
applied on the first element
This function make the (quite usual) assumption that the only start_cut (if
any) is at the first file, and the last one is at the last file
'''
ffmpeg = 'ffmpeg' # binary name
startskip = None
endskip = None
files = []
for (filename, start_cut, end_cut) in named_intervals:
# this happens only one time, and only at the first iteration
if start_cut:
assert startskip is None
startskip = start_cut
# this happens only one time, and only at the first iteration
if end_cut:
assert endskip is None
endskip = end_cut
assert '|' not in filename
files.append(filename)
cmdline = [ffmpeg, '-i', 'concat:%s' % '|'.join(files), '-acodec',
'copy']
if startskip is not None:
cmdline += ['-ss', str(startskip)]
if endskip is not None:
cmdline += ['-t', str(len(files)*3600 - (startskip + endskip))]
cmdline += [target]
cmdline += ['-loglevel', 'warning']
return cmdline
def create_mp3(start, end, outfile, options={}, **kwargs):
p = Popen(mp3_join([(get_timefile(begin), start_cut, end_cut)
for begin, start_cut, end_cut
in get_files_and_intervals(start, end)],
outfile))
if get_config()['FORGE_TIMEOUT'] == 0:
p.wait()
else:
start = datetime.now()
while (datetime.now() - start).total_seconds() < \
get_config()['FORGE_TIMEOUT']:
p.poll()
if p.returncode is None:
sleep(1)
else:
break
if p.returncode is None:
os.kill(p.pid, 15)
try:
os.remove(outfile)
except:
pass
raise Exception('timeout') # TODO: make a specific TimeoutError
if p.returncode != 0:
raise OSError("return code was %d" % p.returncode)
return True
def main_cmd(options):
create_mp3(options.starttime, options.endtime, options.outfile)