over-video/aux.py
Overwatch 60cb65998c Rewrite using a modular command assembler; new features include:
- "extract audio" workflow: video -> wav|ogg
 - majorly cleaned up code
 - both --audio and --video codec options now accept "copy" and "drop"
 - dropped ogv support
2014-08-27 21:19:41 +02:00

165 lines
3.6 KiB
Python

#! /bin/env python3
# encoding: utf-8
import os
import pathlib
import queue
import subprocess
import sys
import threading
# --------------------------------------------------
def capture_output(stream, fifo):
while True:
chunk = stream.read1(128)
if chunk:
fifo.put(chunk)
else:
fifo.put(None) # indicates a process has terminated
break
stream.close()
class Command:
"""
A shell command with argument substitution and output capture.
>>> c = Command(["process.sh", "-x", "ARGUMENT"])
>>> c.ARGUMENT = "file.txt"
>>> c.dump()
['process.sh', '-x', 'file.txt']
>>> c.run(stderr=False) # capture stdout
>>> c.get_output()
b'some output'
>>> c.get_output()
b'' # there was no output since the last call
>>> c.get_output()
b'more of it\nand some more'
>>> c.get_output()
None # indicates the process ended and there is no more output
"""
def __init__(self, *sequence):
self.__dict__["sequence_original"] = list(sequence)
self.reset()
def __setattr__(self, name, value):
found = False
for i, word in enumerate(self.sequence):
if word == name:
self.sequence[i] = value
found = True
#if not found:
#raise AttributeError("Command has no attribute \'%s\'" %(name))
def reset(self):
self.__dict__["sequence"] = list(self.sequence_original)
self.__dict__["thread"] = None
self.__dict__["fifo"] = None
self.__dict__["terminated"] = False
def dump(self, sequence=None):
out = []
if not sequence:
sequence = self.sequence
for item in sequence:
if type(item) is list:
out += self.dump(item)
elif type(item) is Command:
out += item.dump()
elif item is not None:
out.append(str(item))
return out
def run(self, stderr=False):
"""
Executes the command in the current environment.
stderr capture stderr instead of stdout
"""
self.__dict__["process"] = subprocess.Popen(self.dump(), stdout=subprocess.PIPE, stderr=subprocess.PIPE, bufsize=1)
self.__dict__["fifo"] = queue.Queue()
self.__dict__["thread"] = threading.Thread(
target=capture_output,
args=(self.process.stderr if stderr else self.process.stdout, self.fifo)
)
self.__dict__["terminated"] = False
self.thread.daemon = True # thread dies with the program
self.thread.start()
def get_output(self, blocking=False):
"""
Returns the output of a currently running process and clears the buffer.
Returns None if no process is running and no more output is available.
blocking block until some output is available or the process terminates
"""
buffer = []
if self.terminated:
return None
if blocking:
buffer.append(self.fifo.get())
while not self.fifo.empty():
buffer.append(self.fifo.get_nowait()) # FIXME nowait needed?
if None in buffer:
self.__dict__["terminated"] = True
if len(buffer) == 1:
return None
else:
assert(buffer[-1] is None)
del buffer[-1]
return b"".join(buffer)
def get_all_output(self):
buffer = []
while True:
chunk = self.get_output(blocking=True)
if chunk is None:
break
else:
buffer.append(chunk)
return b''.join(buffer) if buffer else None
# --------------------------------------------------
def parse_fps(raw):
if "/" in raw:
num, den = (int(x) for x in raw.split("/"))
return float(num) / float(den)
return float(raw)
# --------------------------------------------------
def to_Path(raw_path):
'''
Returns pathlib.Path pointing to raw_path, handling "~/" correctly.
To be removed after python:3.5 move.
'''
if raw_path.startswith('~'):
raw_path = os.path.expanduser(raw_path)
return pathlib.Path(raw_path)