kitsumed · March 4, 2025 21:10
diff --git a/readme.md b/readme.md
diff --git a/PoC.py b/PoC.py
 '''
 Copyright 2025 kitsumed (Med)

 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 '''
 import os
 import subprocess
 import sys
 import shutil
 import re

 def find_ffmpeg():
    """Finds ffmpeg executable in the system PATH or local directory."""
    ffmpeg_exec = "ffmpeg"
    if shutil.which(ffmpeg_exec):
        return ffmpeg_exec
    local_path = os.path.join(os.path.dirname(__file__), ffmpeg_exec)
    if os.path.exists(local_path):
        return local_path
    print("Error: FFmpeg not found.")
    sys.exit(1)

 def create_empty_video(output_file):
    """Creates an empty video (black screen, very low bitrate)."""
    ffmpeg = find_ffmpeg()
    
    # Build the ffmpeg command to create a black screen video with very low bitrate
    ffmpeg_cmd = [ffmpeg, "-f", "lavfi", "-t", "1", "-i", "color=c=black:s=1x1:r=1", 
                  "-c:v", "libvpx-vp9", "-b:v", "1k", "-an", output_file]  # Very low bitrate video
    subprocess.run(ffmpeg_cmd, check=True)
    print(f"Created empty video: {output_file}")

 def concatenate_videos(primary_video, complex_video1, complex_video2, output_file):
    """Concatenates videos using FFmpeg with VP9 encoding and proper mapping."""
    ffmpeg = find_ffmpeg()

    # Build ffmpeg command to concatenate videos
    ffmpeg_cmd = [ffmpeg, "-y", "-i", primary_video, "-i", complex_video1, "-i", complex_video2]
    
    # Map audio
    ffmpeg_cmd += ["-map", "0:a:0"]

    # Map video tracks
    ffmpeg_cmd += ["-map", "0:v:0", "-map", "1:v:0", "-map", "2:v:0"]
    
    ffmpeg_cmd += [
        "-c:v", "libvpx-vp9", "-c:a", "libopus", "-b:a", "256k",
        "-metadata:s:v:0", "title=Complex 1",
        "-metadata:s:v:1", "title=Complex 2",
        "-metadata:s:v:2", "title=Primary Video"
    ]
    
    ffmpeg_cmd.append(output_file)
    
    subprocess.run(ffmpeg_cmd, check=True)

 def modify_video_track_to_complex(webm_file):
    complexTitle = b"Complex "
    # Title defined inside the metadata
    title_pattern = re.compile(b"Complex ", re.IGNORECASE)
    track_type_pattern = b'\x83\x81\x01'  # The TrackType (83 81) and value (01) to replace with 03
    modified_count = 0

    with open(webm_file, "r+b") as f:
        # Get the size of the file
        file_size = os.path.getsize(webm_file)

        # Up to 1MB of bytes or less depending on file size
        max_read_size = min(file_size, 1024 * 1024)

        # Read with max_read_size
        chunk = f.read(max_read_size)

        offset = 0  # Start offset for searching the "Complex " in the file
        while offset < len(chunk):
            # Search for the "Complex Video" title and corresponding track type
            matches = [m.start() for m in title_pattern.finditer(chunk[offset:])]
            
            if not matches:
                break  # No more matches found, exit the loop

            for title_pos in matches:
                # Calculate the absolute position of the match in the file
                title_pos_absolute = offset + title_pos

                # Start searching for the TrackType Video (83 81 01) after the title position
                index = title_pos_absolute
                f.seek(index)  # Move the file pointer to the position of the title
                chunk_data = f.read(1024)  # Read 1024 bytes after the title position

                # Search for the track type marker (83 81 01) within the chunk
                track_pos = chunk_data.find(track_type_pattern)

                if track_pos != -1:
                    # Absolute position of the found track type marker in the file
                    track_pos_absolute = f.tell() - len(chunk_data) + track_pos

                    # Move the file pointer to the position of the track type
                    f.seek(track_pos_absolute + 2)  # Move to the '01' byte
                    f.write(b'\x03')  # Replace '01' with '03'
                    modified_count += 1
                    print(f"Modified track at position: {track_pos_absolute}")

            # Update offset to search beyond the current "Complex "
            offset += matches[-1] + len(b"Complex ")  # Move offset to just after the last match

    if modified_count > 0:
        print(f"Modified {modified_count} video track(s) with 'Complex ' title to a Complex TrackType (3) in {webm_file}")
    else:
        print("No matching video tracks found for modification.")

 # Ask primary video and complex2, don't ask complex1 as this script does not add a additional TrackType to complex1
 def main():
    # Get input for video files
    primary_video = input("Enter the path for the primary video (Android): ")
    complex_video2 = input("Enter the path for the second complex video (Firefox/VLC/Chromium-based/Electron): ")

    # Get output file path
    output_file = input("Enter the output file name (e.g., output.webm): ")

    # We know complex1 is never gonna play, so we create a "template" file with a small size to reduce the final output size
    create_empty_video("empty_complex1_small.webm")
    # Process the videos based on user input
    concatenate_videos(primary_video, "empty_complex1_small.webm", complex_video2, output_file)
    modify_video_track_to_complex(output_file)
    print("Processing complete.")
 if __name__ == "__main__":
    main()
	'''
	Copyright 2025 kitsumed (Med)

	Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

	The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	'''
	import os
	import subprocess
	import sys
	import shutil
	import re

	def find_ffmpeg():
	"""Finds ffmpeg executable in the system PATH or local directory."""
	ffmpeg_exec = "ffmpeg"
	if shutil.which(ffmpeg_exec):
	return ffmpeg_exec
	local_path = os.path.join(os.path.dirname(__file__), ffmpeg_exec)
	if os.path.exists(local_path):
	return local_path
	print("Error: FFmpeg not found.")
	sys.exit(1)

	def create_empty_video(output_file):
	"""Creates an empty video (black screen, very low bitrate)."""
	ffmpeg = find_ffmpeg()

	# Build the ffmpeg command to create a black screen video with very low bitrate
	ffmpeg_cmd = [ffmpeg, "-f", "lavfi", "-t", "1", "-i", "color=c=black:s=1x1:r=1",
	"-c:v", "libvpx-vp9", "-b:v", "1k", "-an", output_file] # Very low bitrate video
	subprocess.run(ffmpeg_cmd, check=True)
	print(f"Created empty video: {output_file}")

	def concatenate_videos(primary_video, complex_video1, complex_video2, output_file):
	"""Concatenates videos using FFmpeg with VP9 encoding and proper mapping."""
	ffmpeg = find_ffmpeg()

	# Build ffmpeg command to concatenate videos
	ffmpeg_cmd = [ffmpeg, "-y", "-i", primary_video, "-i", complex_video1, "-i", complex_video2]

	# Map audio
	ffmpeg_cmd += ["-map", "0:a:0"]

	# Map video tracks
	ffmpeg_cmd += ["-map", "0:v:0", "-map", "1:v:0", "-map", "2:v:0"]

	ffmpeg_cmd += [
	"-c:v", "libvpx-vp9", "-c:a", "libopus", "-b:a", "256k",
	"-metadata:s:v:0", "title=Complex 1",
	"-metadata:s:v:1", "title=Complex 2",
	"-metadata:s:v:2", "title=Primary Video"
	]

	ffmpeg_cmd.append(output_file)

	subprocess.run(ffmpeg_cmd, check=True)

	def modify_video_track_to_complex(webm_file):
	complexTitle = b"Complex "
	# Title defined inside the metadata
	title_pattern = re.compile(b"Complex ", re.IGNORECASE)
	track_type_pattern = b'\x83\x81\x01' # The TrackType (83 81) and value (01) to replace with 03
	modified_count = 0

	with open(webm_file, "r+b") as f:
	# Get the size of the file
	file_size = os.path.getsize(webm_file)

	# Up to 1MB of bytes or less depending on file size
	max_read_size = min(file_size, 1024 * 1024)

	# Read with max_read_size
	chunk = f.read(max_read_size)

	offset = 0 # Start offset for searching the "Complex " in the file
	while offset < len(chunk):
	# Search for the "Complex Video" title and corresponding track type
	matches = [m.start() for m in title_pattern.finditer(chunk[offset:])]

	if not matches:
	break # No more matches found, exit the loop

	for title_pos in matches:
	# Calculate the absolute position of the match in the file
	title_pos_absolute = offset + title_pos

	# Start searching for the TrackType Video (83 81 01) after the title position
	index = title_pos_absolute
	f.seek(index) # Move the file pointer to the position of the title
	chunk_data = f.read(1024) # Read 1024 bytes after the title position

	# Search for the track type marker (83 81 01) within the chunk
	track_pos = chunk_data.find(track_type_pattern)

	if track_pos != -1:
	# Absolute position of the found track type marker in the file
	track_pos_absolute = f.tell() - len(chunk_data) + track_pos

	# Move the file pointer to the position of the track type
	f.seek(track_pos_absolute + 2) # Move to the '01' byte
	f.write(b'\x03') # Replace '01' with '03'
	modified_count += 1
	print(f"Modified track at position: {track_pos_absolute}")

	# Update offset to search beyond the current "Complex "
	offset += matches[-1] + len(b"Complex ") # Move offset to just after the last match

	if modified_count > 0:
	print(f"Modified {modified_count} video track(s) with 'Complex ' title to a Complex TrackType (3) in {webm_file}")
	else:
	print("No matching video tracks found for modification.")

	# Ask primary video and complex2, don't ask complex1 as this script does not add a additional TrackType to complex1
	def main():
	# Get input for video files
	primary_video = input("Enter the path for the primary video (Android): ")
	complex_video2 = input("Enter the path for the second complex video (Firefox/VLC/Chromium-based/Electron): ")

	# Get output file path
	output_file = input("Enter the output file name (e.g., output.webm): ")

	# We know complex1 is never gonna play, so we create a "template" file with a small size to reduce the final output size
	create_empty_video("empty_complex1_small.webm")
	# Process the videos based on user input
	concatenate_videos(primary_video, "empty_complex1_small.webm", complex_video2, output_file)
	modify_video_track_to_complex(output_file)
	print("Processing complete.")
	if __name__ == "__main__":
	main()
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