1 files changed, 101 insertions, 0 deletions
diff --git a/yt_dlp/postprocessor/common.py b/yt_dlp/postprocessor/common.py
new file mode 100644
index 000000000..f8f4e7693
--- /dev/null
+++ b/yt_dlp/postprocessor/common.py
@@ -0,0 +1,101 @@
+from __future__ import unicode_literals
+
+import os
+
+from ..compat import compat_str
+from ..utils import (
+    cli_configuration_args,
+    encodeFilename,
+    PostProcessingError,
+)
+
+
+class PostProcessor(object):
+    """Post Processor class.
+
+    PostProcessor objects can be added to downloaders with their
+    add_post_processor() method. When the downloader has finished a
+    successful download, it will take its internal chain of PostProcessors
+    and start calling the run() method on each one of them, first with
+    an initial argument and then with the returned value of the previous
+    PostProcessor.
+
+    The chain will be stopped if one of them ever returns None or the end
+    of the chain is reached.
+
+    PostProcessor objects follow a "mutual registration" process similar
+    to InfoExtractor objects.
+
+    Optionally PostProcessor can use a list of additional command-line arguments
+    with self._configuration_args.
+    """
+
+    _downloader = None
+
+    def __init__(self, downloader=None):
+        self._downloader = downloader
+        self.PP_NAME = self.pp_key()
+
+    @classmethod
+    def pp_key(cls):
+        name = cls.__name__[:-2]
+        return compat_str(name[6:]) if name[:6].lower() == 'ffmpeg' else name
+
+    def to_screen(self, text, prefix=True, *args, **kwargs):
+        tag = '[%s] ' % self.PP_NAME if prefix else ''
+        if self._downloader:
+            return self._downloader.to_screen('%s%s' % (tag, text), *args, **kwargs)
+
+    def report_warning(self, text, *args, **kwargs):
+        if self._downloader:
+            return self._downloader.report_warning(text, *args, **kwargs)
+
+    def report_error(self, text, *args, **kwargs):
+        if self._downloader:
+            return self._downloader.report_error(text, *args, **kwargs)
+
+    def write_debug(self, text, prefix=True, *args, **kwargs):
+        tag = '[debug] ' if prefix else ''
+        if self.get_param('verbose', False) and self._downloader:
+            return self._downloader.to_screen('%s%s' % (tag, text), *args, **kwargs)
+
+    def get_param(self, name, default=None, *args, **kwargs):
+        if self._downloader:
+            return self._downloader.params.get(name, default, *args, **kwargs)
+        return default
+
+    def set_downloader(self, downloader):
+        """Sets the downloader for this PP."""
+        self._downloader = downloader
+
+    def run(self, information):
+        """Run the PostProcessor.
+
+        The "information" argument is a dictionary like the ones
+        composed by InfoExtractors. The only difference is that this
+        one has an extra field called "filepath" that points to the
+        downloaded file.
+
+        This method returns a tuple, the first element is a list of the files
+        that can be deleted, and the second of which is the updated
+        information.
+
+        In addition, this method may raise a PostProcessingError
+        exception if post processing fails.
+        """
+        return [], information  # by default, keep file and do nothing
+
+    def try_utime(self, path, atime, mtime, errnote='Cannot update utime of file'):
+        try:
+            os.utime(encodeFilename(path), (atime, mtime))
+        except Exception:
+            self.report_warning(errnote)
+
+    def _configuration_args(self, *args, **kwargs):
+        return cli_configuration_args(
+            self._downloader.params.get('postprocessor_args'),
+            self.pp_key().lower(), *args, **kwargs)
+
+
+class AudioConversionError(PostProcessingError):
+    pass