youtube_dlc/postprocessor/common.py

   1 from __future__ import unicode_literals
   2
   3 import os
   4
   5 from ..compat import compat_str
   6 from ..utils import (
   7     PostProcessingError,
   8     encodeFilename,
   9 )
  10
  11
  12 class PostProcessor(object):
  13     """Post Processor class.
  14
  15     PostProcessor objects can be added to downloaders with their
  16     add_post_processor() method. When the downloader has finished a
  17     successful download, it will take its internal chain of PostProcessors
  18     and start calling the run() method on each one of them, first with
  19     an initial argument and then with the returned value of the previous
  20     PostProcessor.
  21
  22     The chain will be stopped if one of them ever returns None or the end
  23     of the chain is reached.
  24
  25     PostProcessor objects follow a "mutual registration" process similar
  26     to InfoExtractor objects.
  27
  28     Optionally PostProcessor can use a list of additional command-line arguments
  29     with self._configuration_args.
  30     """
  31
  32     _downloader = None
  33
  34     def __init__(self, downloader=None):
  35         self._downloader = downloader
  36         self.PP_NAME = self.pp_key()
  37
  38     @classmethod
  39     def pp_key(cls):
  40         name = cls.__name__[:-2]
  41         return compat_str(name[6:]) if name[:6].lower() == 'ffmpeg' else name
  42
  43     def to_screen(self, text, prefix=True, *args, **kwargs):
  44         tag = '[%s] ' % self.PP_NAME if prefix else ''
  45         if self._downloader:
  46             return self._downloader.to_screen('%s%s' % (tag, text), *args, **kwargs)
  47
  48     def report_warning(self, text, *args, **kwargs):
  49         if self._downloader:
  50             return self._downloader.report_warning(text, *args, **kwargs)
  51
  52     def report_error(self, text, *args, **kwargs):
  53         if self._downloader:
  54             return self._downloader.report_error(text, *args, **kwargs)
  55
  56     def write_debug(self, text, prefix=True, *args, **kwargs):
  57         tag = '[debug] ' if prefix else ''
  58         if self.get_param('verbose', False):
  59             return self._downloader.to_screen('%s%s' % (tag, text), *args, **kwargs)
  60
  61     def get_param(self, name, default=None, *args, **kwargs):
  62         if self._downloader:
  63             return self._downloader.params.get(name, default, *args, **kwargs)
  64         return default
  65
  66     def set_downloader(self, downloader):
  67         """Sets the downloader for this PP."""
  68         self._downloader = downloader
  69
  70     def run(self, information):
  71         """Run the PostProcessor.
  72
  73         The "information" argument is a dictionary like the ones
  74         composed by InfoExtractors. The only difference is that this
  75         one has an extra field called "filepath" that points to the
  76         downloaded file.
  77
  78         This method returns a tuple, the first element is a list of the files
  79         that can be deleted, and the second of which is the updated
  80         information.
  81
  82         In addition, this method may raise a PostProcessingError
  83         exception if post processing fails.
  84         """
  85         return [], information  # by default, keep file and do nothing
  86
  87     def try_utime(self, path, atime, mtime, errnote='Cannot update utime of file'):
  88         try:
  89             os.utime(encodeFilename(path), (atime, mtime))
  90         except Exception:
  91             self.report_warning(errnote)
  92
  93     def _configuration_args(self, default=[], exe=None):
  94         args = self.get_param('postprocessor_args', {})
  95         pp_key = self.pp_key().lower()
  96
  97         if isinstance(args, (list, tuple)):  # for backward compatibility
  98             return default if pp_key == 'sponskrub' else args
  99         if args is None:
 100             return default
 101         assert isinstance(args, dict)
 102
 103         exe_args = None
 104         if exe is not None:
 105             assert isinstance(exe, compat_str)
 106             exe = exe.lower()
 107             specific_args = args.get('%s+%s' % (pp_key, exe))
 108             if specific_args is not None:
 109                 assert isinstance(specific_args, (list, tuple))
 110                 return specific_args
 111             exe_args = args.get(exe)
 112
 113         pp_args = args.get(pp_key) if pp_key != exe else None
 114         if pp_args is None and exe_args is None:
 115             default = args.get('default', default)
 116             assert isinstance(default, (list, tuple))
 117             return default
 118
 119         if pp_args is None:
 120             pp_args = []
 121         elif exe_args is None:
 122             exe_args = []
 123
 124         assert isinstance(pp_args, (list, tuple))
 125         assert isinstance(exe_args, (list, tuple))
 126         return pp_args + exe_args
 127
 128
 129 class AudioConversionError(PostProcessingError):
 130     pass