Source code for aeneas.ffmpegwrapper

#!/usr/bin/env python
# coding=utf-8

# aeneas is a Python/C library and a set of tools
# to automagically synchronize audio and text (aka forced alignment)
# Copyright (C) 2012-2013, Alberto Pettarin (
# Copyright (C) 2013-2015, ReadBeyond Srl   (
# Copyright (C) 2015-2017, Alberto Pettarin (
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# GNU Affero General Public License for more details.
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <>.

This module contains the following classes:

* :class:`~aeneas.ffmpegwrapper.FFMPEGWrapper`, a wrapper around ``ffmpeg`` to convert audio files;
* :class:`~aeneas.ffmpegwrapper.FFMPEGPathError`, representing a failure to locate the ``ffmpeg`` executable.

from __future__ import absolute_import
from __future__ import print_function
import subprocess

from aeneas.logger import Loggable
from aeneas.runtimeconfiguration import RuntimeConfiguration
import aeneas.globalfunctions as gf

[docs]class FFMPEGPathError(Exception): """ Error raised when the path to ``ffmpeg`` is not a valid executable. .. versionadded:: 1.4.1 """ pass
[docs]class FFMPEGWrapper(Loggable): """ A wrapper around ``ffmpeg`` to convert audio files. In abstract terms, it will perform a call like:: $ ffmpeg -i /path/to/input.mp3 [parameters] /path/to/output.wav :param rconf: a runtime configuration :type rconf: :class:`~aeneas.runtimeconfiguration.RuntimeConfiguration` :param logger: the logger object :type logger: :class:`~aeneas.logger.Logger` """ FFMPEG_SAMPLE_8000 = ["-ar", "8000"] """ Single parameter for ``ffmpeg``: 8000 Hz sampling """ FFMPEG_SAMPLE_16000 = ["-ar", "16000"] """ Single parameter for ``ffmpeg``: 16000 Hz sampling """ FFMPEG_SAMPLE_22050 = ["-ar", "22050"] """ Single parameter for ``ffmpeg``: 22050 Hz sampling """ FFMPEG_SAMPLE_44100 = ["-ar", "44100"] """ Single parameter for ``ffmpeg``: 44100 Hz sampling """ FFMPEG_SAMPLE_48000 = ["-ar", "48000"] """ Single parameter for ``ffmpeg``: 48000 Hz sampling """ FFMPEG_MONO = ["-ac", "1"] """ Single parameter for ``ffmpeg``: mono (1 channel) """ FFMPEG_STEREO = ["-ac", "2"] """ Single parameter for ``ffmpeg``: stereo (2 channels) """ FFMPEG_OVERWRITE = ["-y"] """ Single parameter for ``ffmpeg``: force overwriting output file """ FFMPEG_PLAIN_HEADER = ["-map_metadata", "-1", "-flags", "+bitexact"] """ Single parameter for ``ffmpeg``: generate WAVE header without extra chunks (e.g., the INFO chunk) """ FFMPEG_FORMAT_WAVE = ["-f", "wav"] """ Single parameter for ``ffmpeg``: produce output in ``wav`` format (must be the second to last argument to ``ffmpeg``, just before path of the output file) """ FFMPEG_PARAMETERS_SAMPLE_KEEP = ( FFMPEG_MONO + FFMPEG_OVERWRITE + FFMPEG_PLAIN_HEADER + FFMPEG_FORMAT_WAVE ) """ Set of parameters for ``ffmpeg`` without changing the sampling rate """ FFMPEG_PARAMETERS_SAMPLE_8000 = ( FFMPEG_MONO + FFMPEG_SAMPLE_8000 + FFMPEG_OVERWRITE + FFMPEG_PLAIN_HEADER + FFMPEG_FORMAT_WAVE ) """ Set of parameters for ``ffmpeg`` with 8000 Hz sampling """ FFMPEG_PARAMETERS_SAMPLE_16000 = ( FFMPEG_MONO + FFMPEG_SAMPLE_16000 + FFMPEG_OVERWRITE + FFMPEG_PLAIN_HEADER + FFMPEG_FORMAT_WAVE ) """ Set of parameters for ``ffmpeg`` with 16000 Hz sampling """ FFMPEG_PARAMETERS_SAMPLE_22050 = ( FFMPEG_MONO + FFMPEG_SAMPLE_22050 + FFMPEG_OVERWRITE + FFMPEG_PLAIN_HEADER + FFMPEG_FORMAT_WAVE ) """ Set of parameters for ``ffmpeg`` with 22050 Hz sampling """ FFMPEG_PARAMETERS_SAMPLE_44100 = ( FFMPEG_MONO + FFMPEG_SAMPLE_44100 + FFMPEG_OVERWRITE + FFMPEG_PLAIN_HEADER + FFMPEG_FORMAT_WAVE ) """ Set of parameters for ``ffmpeg`` with 44100 Hz sampling """ FFMPEG_PARAMETERS_SAMPLE_48000 = ( FFMPEG_MONO + FFMPEG_SAMPLE_48000 + FFMPEG_OVERWRITE + FFMPEG_PLAIN_HEADER + FFMPEG_FORMAT_WAVE ) """ Set of parameters for ``ffmpeg`` with 48000 Hz sampling """ FFMPEG_PARAMETERS_MAP = { 8000: FFMPEG_PARAMETERS_SAMPLE_8000, 16000: FFMPEG_PARAMETERS_SAMPLE_16000, 22050: FFMPEG_PARAMETERS_SAMPLE_22050, 44100: FFMPEG_PARAMETERS_SAMPLE_44100, 48000: FFMPEG_PARAMETERS_SAMPLE_48000 } """ Map sample rate to parameter list """ FFMPEG_PARAMETERS_DEFAULT = FFMPEG_PARAMETERS_SAMPLE_16000 """ Default set of parameters for ``ffmpeg`` """ TAG = u"FFMPEGWrapper"
[docs] def convert( self, input_file_path, output_file_path, head_length=None, process_length=None ): """ Convert the audio file at ``input_file_path`` into ``output_file_path``, using the parameters set in the constructor or through the ``parameters`` property. You can skip the beginning of the audio file by specifying ``head_length`` seconds to skip (if it is ``None``, start at time zero), and you can specify to convert only ``process_length`` seconds (if it is ``None``, process the entire input file length). By specifying both ``head_length`` and ``process_length``, you can skip a portion at the beginning and at the end of the original input file. :param string input_file_path: the path of the audio file to convert :param string output_file_path: the path of the converted audio file :param float head_length: skip these many seconds from the beginning of the audio file :param float process_length: process these many seconds of the audio file :raises: :class:`~aeneas.ffmpegwrapper.FFMPEGPathError`: if the path to the ``ffmpeg`` executable cannot be called :raises: OSError: if ``input_file_path`` does not exist or ``output_file_path`` cannot be written """ # test if we can read the input file if not gf.file_can_be_read(input_file_path): self.log_exc(u"Input file '%s' cannot be read" % (input_file_path), None, True, OSError) # test if we can write the output file if not gf.file_can_be_written(output_file_path): self.log_exc(u"Output file '%s' cannot be written" % (output_file_path), None, True, OSError) # call ffmpeg arguments = [self.rconf[RuntimeConfiguration.FFMPEG_PATH]] arguments.extend(["-i", input_file_path]) if head_length is not None: arguments.extend(["-ss", head_length]) if process_length is not None: arguments.extend(["-t", process_length]) if self.rconf.sample_rate in self.FFMPEG_PARAMETERS_MAP: arguments.extend(self.FFMPEG_PARAMETERS_MAP[self.rconf.sample_rate]) else: arguments.extend(self.FFMPEG_PARAMETERS_DEFAULT) arguments.append(output_file_path) self.log([u"Calling with arguments '%s'", arguments]) try: proc = subprocess.Popen( arguments, stdout=subprocess.PIPE, stdin=subprocess.PIPE, stderr=subprocess.PIPE ) proc.communicate() proc.stdout.close() proc.stdin.close() proc.stderr.close() except OSError as exc: self.log_exc(u"Unable to call the '%s' ffmpeg executable" % (self.rconf[RuntimeConfiguration.FFMPEG_PATH]), exc, True, FFMPEGPathError) self.log(u"Call completed") # check if the output file exists if not gf.file_exists(output_file_path): self.log_exc(u"Output file '%s' was not written" % (output_file_path), None, True, OSError) # returning the output file path self.log([u"Returning output file path '%s'", output_file_path]) return output_file_path