Create a gist now

Instantly share code, notes, and snippets.

OpenCV script to match a recurring "boundary between content and post-roll ad" frame and write an EDL to stop playback there
#!/usr/bin/env python2
# -*- coding: utf-8 -*-
# pylint: disable=line-too-long
"""Utility for generating MPV EDL files to skip recurring post-roll ads.
1. Use MPV's screenshot hotkey to extract a frame that's consistently present
at the boundary between the content and the ad.
2. Run this script with the screenshot specified via the --template argument.
3. Play the resulting EDL file in MPV.
(MPV EDL files are like playlists which can specify pieces of video files
rather than entire files)
Sources used to develop this:
Stuff I tried but threw out because of a bug outside my control:
Sources used during development:
""" # NOQA
from __future__ import (absolute_import, division, print_function,
with_statement, unicode_literals)
__author__ = "Stephan Sokolow (deitarion/SSokolow)"
__appname__ = "TYT Post-Roll Ad Eliminator"
__version__ = "0.1"
__license__ = "MIT"
VIDEO_GLOBS = ['*.mp4', '*.webm']
FRAME_GLOBS = ['*.png', '*.jpg']
import fnmatch, logging, os, re
import cv2
import as cv # pylint: disable=no-name-in-module,import-error
import numpy as np
log = logging.getLogger(__name__)
# Borrowed from:
# (Revision: bc784a5fe3c2d4275fef5ec16612bd67142eb0f8)
# TODO: Put this up on PyPI so I don't have to copy it around.
def multiglob_compile(globs, prefix=False, re_flags=0):
"""Generate a single "A or B or C" regex from a list of shell globs.
:param globs: Patterns to be processed by :mod:`fnmatch`.
:type globs: iterable of :class:`~__builtins__.str`
:param prefix: If ``True``, then :meth:`~re.RegexObject.match` will
perform prefix matching rather than exact string matching.
:type prefix: :class:`~__builtins__.bool`
:rtype: :class:`re.RegexObject`
if not globs:
# An empty globs list should only match empty strings
return re.compile('^$')
elif prefix:
globs = [x + '*' for x in globs]
return re.compile('|'.join(fnmatch.translate(x) for x in globs), re_flags)
video_ext_re = multiglob_compile(VIDEO_GLOBS, re.I)
frame_ext_re = multiglob_compile(FRAME_GLOBS, re.I)
def seek_stream(stream, offset):
"""If offset is negative, it will be treated as a "seconds from the end"
value, analogous to Python list indexing.
fps = stream.get(cv.CV_CAP_PROP_FPS)
if offset > 0:
offset *= fps
elif offset < 0:
frame_count = stream.get(cv.CV_CAP_PROP_FRAME_COUNT)
offset = frame_count + (offset * fps)
# It seems seeking via CV_CAP_PROP_POS_MSEC doesn't work
stream.set(cv.CV_CAP_PROP_POS_FRAMES, offset)
def find_frame(stream, template, start_pos=None, last_match=False):
"""Given a video stream and a frame, find its offset in seconds.
If start_pos is negative, it will be treated as a "seconds from the end"
value, analogous to Python list indexing.
Does NOT release the stream when finished so it can be used in a manner
similar to
Returns the offset in seconds or None for no match.
offset, match = 0, None
# Seek to near the end to minimize processing load
if start_pos is not None:
log.debug("Seeking to %s..." % start_pos)
seek_stream(stream, start_pos)
while stream.isOpened():
success, frame =
if not success:
offset = stream.get(cv.CV_CAP_PROP_POS_MSEC) / 1000
# Use template-matching to find the frame signifying the end of content
# pylint: disable=no-member
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
res = cv2.matchTemplate(gray, template, cv2.TM_CCOEFF_NORMED)
threshold = 0.8
loc = np.where(res >= threshold) # pylint: disable=no-member
if len(loc[0]): # bool(loc[0]) gives undesired results
match = offset
log.debug("Match at %s", match)
if match and not last_match:
log.debug("Returning first match: %s", match)
return match
log.debug("Returning last match (last offset: %s): %s", offset, match)
return match
def analyze_file(video_path, template_path, start_pos=0, last_match=False):
"""High-level wrapper to ease analyzing multiple videos in a single run"""
# pylint: disable=no-member
template = cv2.imread(template_path, 0)
stream = cv2.VideoCapture(video_path)
# TODO: Figure out how to deduplicate this
end = (stream.get(cv.CV_CAP_PROP_FRAME_COUNT) /
except ZeroDivisionError:"FPS is zero in %s. Returning None as end.", video_path)
end = None
offset = find_frame(stream, template, start_pos, last_match)
cv2.destroyAllWindows() # TODO: Do I need this anymore?
return offset, end
def make_edl(video_path, template_path, start_pos=0):
"""Highest-level wrapper to make it easy for other scripts to call this"""
edl_path = os.path.splitext(video_path)[0] + '.mpv.edl'
if os.path.exists(edl_path):"EDL already exists. Skipping %r", video_path)
offset, _ = analyze_file(video_path, template_path, start_pos, True)
if offset is not None:
# TODO: Skip if (end - offset) < 3sec
video_name = os.path.basename(video_path)
if video_name.startswith('#'): # '#LoserDonald' is not a comment
video_name = './{}'.format(video_name)
video_name = video_name.encode('utf8') # %len% is byte-based
with open(edl_path, 'w') as edl:
edl.write(b"# mpv EDL v0\n%{}%{},0,{:f}".format(
len(video_name), video_name, offset))
return bool(offset)
def main():
"""The main entry point, compatible with setuptools entry points."""
# If we're running on Python 2, take responsibility for preventing
# output from causing UnicodeEncodeErrors. (Done here so it should only
# happen when not being imported by some other program.)
import sys
if sys.version_info.major < 3:
sys.setdefaultencoding('utf-8') # pylint: disable=no-member
from argparse import ArgumentParser, RawTextHelpFormatter
parser = ArgumentParser(formatter_class=RawTextHelpFormatter,
description=__doc__.replace('\r\n', '\n').split('\n--snip--\n')[0])
parser.add_argument('--version', action='version',
version="%%(prog)s v%s" % __version__)
parser.add_argument('-v', '--verbose', action="count",
default=2, help="Increase the verbosity. Use twice for extra effect")
parser.add_argument('-q', '--quiet', action="count",
default=0, help="Decrease the verbosity. Use twice for extra effect")
parser.add_argument('--cron', action='store_true',
default=False, help='Silence potentially routine error messages and '
"set a niceness of 19 so OpenCL doesn't interfere with the desktop")
parser.add_argument('-t', '--template', action='append',
help="The frame to search for within the video stream. May be given "
"multiple times to specify a fallback chain. If a directory path "
"is provided, the image files within will be sorted by name "
"and added to the fallback chain. (default: the current directory"
parser.add_argument('--skip-to', default=-30, type=int,
help="Seek to this position (in seconds) before processing to reduce "
"wasted CPU cycles. Negative values are relative to the end of "
"the file. (default: %(default)s)")
parser.add_argument('video', nargs='*', help="Path to video file "
"(The current working directory will be searched for "
"video files if none are provided)")
args = parser.parse_args()
# Set up clean logging to stderr
log_levels = [logging.CRITICAL, logging.ERROR, logging.WARNING,
logging.INFO, logging.DEBUG]
args.verbose = min(args.verbose - args.quiet, len(log_levels) - 1)
args.verbose = max(args.verbose, 0)
format='%(levelname)s: %(message)s')
# Minimize CPU scheduler priority if --cron
if args.cron:
# Glob for videos if no positional args were given
paths =
if not paths:
paths = [x for x in os.listdir('.') if video_ext_re.match(x)]
# Resolve directories in the template list and default to ['.']
templates = []
for tmpl in args.template or ['.']:
if os.path.isdir(tmpl):
templates.extend(x for x in sorted(os.listdir(tmpl))
if frame_ext_re.match(x))
log.debug("Using templates: %r", templates)
# Process with fallback template support
for path in paths:
for tmpl in templates:
try:"Processing %r with %r", path, tmpl)
success = make_edl(path, tmpl, args.skip_to)
if success:
raise Exception()
except Exception: # pylint: disable=broad-except"No match for %s in %s", tmpl, path)
if not args.cron:
log.error("Failed to make EDL for %r", path)
if __name__ == '__main__':
# vim: set sw=4 sts=4 expandtab :
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment