# Copyright (c) 2020 Johannes Nolte
# SPDX-License-Identifier: GPL-3.0-or-later
import errno
import logging
import subprocess
[docs]class FFmpeg(object):
"""Wrapper for `FFmpeg <https://www.ffmpeg.org/>`.
Args:
source (pathlib.path): path to source file
target (pathlib.path): path to target file
options (str): string containing options for ffmpeg as use in
console (arguments separated by space)
executable (str, optional): path to ffmpeg executable. Defaults to
'ffmpeg': Can be overwritten in case e.g libav is used.
"""
def __init__(self, source, target, options=None, executable="ffmpeg"):
"""Initialize ffmpeg command line wrapper.
"""
self.executable = executable
self._source = source
self._target = target
self._cmd = [executable]
self.exit_status = -1
self._cmd.extend(["-i", str(source)])
if options:
self._cmd.extend(options.split())
self._cmd.append(str(target))
self.cmd = subprocess.list2cmdline(self._cmd)
self.process = None
def __repr__(self):
return "<{0!r} {1!r}>".format(self.__class__.__name__, self.cmd)
def __enter__(self):
return self
def __exit__(self, exc_type, exc_val, exc_tb):
if not self.exit_status == 0:
if self._target.exists():
self._target.unlink()
[docs] def run(self):
"""Execute ffmpeg command line. Log stderr output.
Raises:
FFRuntimeError : in case ffmpeg command exits with a
non-zero code.
FFExecutableNotFoundError: in case the executable path passed
as not valid.
"""
try:
process_result = subprocess.run(self._cmd, stderr=subprocess.PIPE)
except OSError as e:
if e.errno == errno.ENOENT:
raise FFExecutableNotFoundError(
"Executable '{0}' not found".format(self.executable)
)
else:
raise
logging.debug(process_result.stderr.decode())
self.exit_status = process_result.returncode
if self.exit_status != 0:
raise FFRuntimeError(
self.cmd,
process_result.returncode,
process_result.stdout,
process_result.stderr,
)
[docs]class FFExecutableNotFoundError(Exception):
"""Raise when ffmpeg executable was not found."""
[docs]class FFRuntimeError(Exception):
"""Raise when ffmpeg command line execution returns a non-zero exit code.
"""
def __init__(self, cmd, exit_code, stdout, stderr):
self.cmd = cmd
self.exit_code = exit_code
self.stdout = (stdout or b"").decode()
self.stderr = (stderr or b"").decode()
message = "`{0}` exited with status {1}\n\nSTDOUT:\n{2}\n\nSTDERR:\n{3}".format(
self.cmd, exit_code, stdout, stderr
)
super(FFRuntimeError, self).__init__(message)