import errno
import shlex
import subprocess
__version__ = "0.3.2"
class FFmpeg(object):
"""Wrapper for various `FFmpeg <https://www.ffmpeg.org/>`_ related applications (ffmpeg,
ffprobe).
"""
def __init__(
self, executable="ffmpeg", global_options=None, inputs=None, outputs=None
):
"""Initialize FFmpeg command line wrapper.
Compiles FFmpeg command line from passed arguments (executable path, options, inputs and
outputs). ``inputs`` and ``outputs`` are dictionares containing inputs/outputs as keys and
their respective options as values. One dictionary value (set of options) must be either a
single space separated string, or a list or strings without spaces (i.e. each part of the
option is a separate item of the list, the result of calling ``split()`` on the options
string). If the value is a list, it cannot be mixed, i.e. cannot contain items with spaces.
An exception are complex FFmpeg command lines that contain quotes: the quoted part must be
one string, even if it contains spaces (see *Examples* for more info).
For more info about FFmpeg command line format see `here
<https://ffmpeg.org/ffmpeg.html#Synopsis>`_.
:param str executable: path to ffmpeg executable; by default the ``ffmpeg`` command will be
searched for in the ``PATH``, but can be overridden with an absolute path to ``ffmpeg``
executable
:param iterable global_options: global options passed to ``ffmpeg`` executable (e.g.
``-y``, ``-v`` etc.); can be specified either as a list/tuple/set of strings, or one
space-separated string; by default no global options are passed
:param dict inputs: a dictionary specifying one or more input arguments as keys with their
corresponding options (either as a list of strings or a single space separated string) as
values
:param dict outputs: a dictionary specifying one or more output arguments as keys with their
corresponding options (either as a list of strings or a single space separated string) as
values
"""
self.executable = executable
self._cmd = [executable]
global_options = global_options or []
if _is_sequence(global_options):
normalized_global_options = []
for opt in global_options:
normalized_global_options += shlex.split(opt)
else:
normalized_global_options = shlex.split(global_options)
self._cmd += normalized_global_options
self._cmd += _merge_args_opts(inputs, add_input_option=True)
self._cmd += _merge_args_opts(outputs)
self.cmd = subprocess.list2cmdline(self._cmd)
self.process = None
def __repr__(self):
return "<{0!r} {1!r}>".format(self.__class__.__name__, self.cmd)
def run(self, input_data=None, stdout=None, stderr=None, env=None, **kwargs):
"""Execute FFmpeg command line.
``input_data`` can contain input for FFmpeg in case ``pipe`` protocol is used for input.
``stdout`` and ``stderr`` specify where to redirect the ``stdout`` and ``stderr`` of the
process. By default no redirection is done, which means all output goes to running shell
(this mode should normally only be used for debugging purposes). If FFmpeg ``pipe`` protocol
is used for output, ``stdout`` must be redirected to a pipe by passing `subprocess.PIPE` as
``stdout`` argument. You can pass custom environment to ffmpeg process with ``env``.
Returns a 2-tuple containing ``stdout`` and ``stderr`` of the process. If there was no
redirection or if the output was redirected to e.g. `os.devnull`, the value returned will
be a tuple of two `None` values, otherwise it will contain the actual ``stdout`` and
``stderr`` data returned by ffmpeg process.
More info about ``pipe`` protocol `here <https://ffmpeg.org/ffmpeg-protocols.html#pipe>`_.
:param str input_data: input data for FFmpeg to deal with (audio, video etc.) as bytes (e.g.
the result of reading a file in binary mode)
:param stdout: redirect FFmpeg ``stdout`` there (default is `None` which means no
redirection)
:param stderr: redirect FFmpeg ``stderr`` there (default is `None` which means no
redirection)
:param env: custom environment for ffmpeg process
:param kwargs: any other keyword arguments to be forwarded to `subprocess.Popen
<https://docs.python.org/3/library/subprocess.html#subprocess.Popen>`_
:return: a 2-tuple containing ``stdout`` and ``stderr`` of the process
:rtype: tuple
:raise: `FFRuntimeError` in case FFmpeg command exits with a non-zero code;
`FFExecutableNotFoundError` in case the executable path passed was not valid
"""
try:
self.process = subprocess.Popen(
self._cmd,
stdin=subprocess.PIPE,
stdout=stdout,
stderr=stderr,
env=env,
**kwargs
)
except OSError as e:
if e.errno == errno.ENOENT:
raise FFExecutableNotFoundError(
"Executable '{0}' not found".format(self.executable)
)
else:
raise
out = self.process.communicate(input=input_data)
if self.process.returncode != 0:
raise FFRuntimeError(self.cmd, self.process.returncode, out[0], out[1])
return out
class FFprobe(FFmpeg):
"""Wrapper for `ffprobe <https://www.ffmpeg.org/ffprobe.html>`_."""
def __init__(self, executable="ffprobe", global_options="", inputs=None):
"""Create an instance of FFprobe.
Compiles FFprobe command line from passed arguments (executable path, options, inputs).
FFprobe executable by default is taken from ``PATH`` but can be overridden with an
absolute path. For more info about FFprobe command line format see
`here <https://ffmpeg.org/ffprobe.html#Synopsis>`_.
:param str executable: absolute path to ffprobe executable
:param iterable global_options: global options passed to ffmpeg executable; can be specified
either as a list/tuple of strings or a space-separated string
:param dict inputs: a dictionary specifying one or more inputs as keys with their
corresponding options as values
"""
super(FFprobe, self).__init__(
executable=executable, global_options=global_options, inputs=inputs
)
class FFExecutableNotFoundError(Exception):
"""Raise when FFmpeg/FFprobe executable was not found."""
class FFRuntimeError(Exception):
"""Raise when FFmpeg/FFprobe command line execution returns a non-zero exit code.
The resulting exception object will contain the attributes relates to command line execution:
``cmd``, ``exit_code``, ``stdout``, ``stderr``.
"""
def __init__(self, cmd, exit_code, stdout, stderr):
self.cmd = cmd
self.exit_code = exit_code
self.stdout = stdout
self.stderr = stderr
message = "`{0}` exited with status {1}\n\nSTDOUT:\n{2}\n\nSTDERR:\n{3}".format(
self.cmd, exit_code, (stdout or b"").decode(), (stderr or b"").decode()
)
super(FFRuntimeError, self).__init__(message)
def _is_sequence(obj):
"""Check if the object is a sequence (list, tuple etc.).
:param object obj: an object to be checked
:return: True if the object is iterable but is not a string, False otherwise
:rtype: bool
"""
return hasattr(obj, "__iter__") and not isinstance(obj, str)
def _merge_args_opts(args_opts_dict, **kwargs):
"""Merge options with their corresponding arguments.
Iterates over the dictionary holding arguments (keys) and options (values). Merges each
options string with its corresponding argument.
:param dict args_opts_dict: a dictionary of arguments and options
:param dict kwargs: *input_option* - if specified prepends ``-i`` to input argument
:return: merged list of strings with arguments and their corresponding options
:rtype: list
"""
merged = []
if not args_opts_dict:
return merged
for arg, opt in args_opts_dict.items():
if not _is_sequence(opt):
opt = shlex.split(opt or "")
merged += opt
if not arg:
continue
if "add_input_option" in kwargs:
merged.append("-i")
merged.append(arg)
return merged