Files
chunk_encoder/scene_cutter.py
2025-07-20 15:44:17 +02:00

452 lines
18 KiB
Python

#!/usr/bin/env python3
import subprocess
import json
import os
import sys
import argparse
import re
from collections import Counter
import multiprocessing
import shutil
# --- Utility Functions (from previous scripts) ---
def get_best_hwaccel():
"""
Checks for available FFmpeg hardware acceleration methods and returns the best one
based on the current operating system.
"""
# Determine the priority list based on the operating system
if sys.platform == "win32":
# Windows: CUDA (Nvidia) > QSV (Intel) > D3D11VA (Modern, AMD/All) > DXVA2 (Legacy)
priority = ['cuda', 'qsv', 'd3d11va', 'dxva2']
elif sys.platform == "linux":
# Linux: CUDA (Nvidia) > VAAPI (Intel/AMD)
priority = ['cuda', 'vaapi']
elif sys.platform == "darwin":
# macOS: VideoToolbox is the native framework for Apple Silicon
priority = ['videotoolbox']
else:
# Fallback for other operating systems (e.g., BSD)
priority = []
if not priority:
print(f"No hardware acceleration priority list for this OS ({sys.platform}). Using software.")
return None
print(f"Checking for available hardware acceleration on {sys.platform}...")
try:
result = subprocess.run(
['ffmpeg', '-hide_banner', '-hwaccels'],
capture_output=True, text=True, encoding='utf-8', check=False
)
if result.returncode != 0:
print("Warning: Could not query FFmpeg. Using software decoding.")
return None
available_methods = result.stdout.strip().split('\n')
if len(available_methods) > 1:
available_methods = available_methods[1:]
for method in priority:
if method in available_methods:
print(f"Found best available hardware acceleration: {method}")
return method
print("No high-priority hardware acceleration found. Using software decoding.")
return None
except (FileNotFoundError, Exception):
return None
def get_video_duration(video_path):
"""Gets the duration of a video file in seconds using ffprobe."""
command = ['ffprobe', '-v', 'error', '-show_entries', 'format=duration', '-of', 'default=noprint_wrappers=1:nokey=1', video_path]
try:
result = subprocess.run(command, capture_output=True, text=True, check=True)
return float(result.stdout.strip())
except (FileNotFoundError, subprocess.CalledProcessError, ValueError) as e:
print(f"\nError getting video duration: {e}")
return None
def get_video_resolution(video_path):
"""Gets the resolution (width, height) of a video file using ffprobe's JSON output for robustness."""
command = [
'ffprobe',
'-v', 'quiet',
'-print_format', 'json',
'-show_streams',
video_path
]
try:
result = subprocess.run(command, capture_output=True, text=True, check=True, encoding='utf-8')
data = json.loads(result.stdout)
for stream in data.get('streams', []):
if stream.get('codec_type') == 'video' and 'width' in stream and 'height' in stream:
return int(stream['width']), int(stream['height'])
# If no video stream with resolution is found
raise ValueError("Could not find video stream with resolution in ffprobe output.")
except (FileNotFoundError, subprocess.CalledProcessError, json.JSONDecodeError, ValueError) as e:
print(f"\nError getting video resolution: {e}")
return None, None
# --- Core Logic Functions (Ported 1:1 from cropdetect.py) ---
KNOWN_ASPECT_RATIOS = [
{"name": "HDTV (16:9)", "ratio": 16/9},
{"name": "Widescreen (Scope)", "ratio": 2.39},
{"name": "Widescreen (Flat)", "ratio": 1.85},
{"name": "IMAX Digital (1.90:1)", "ratio": 1.90},
{"name": "Fullscreen (4:3)", "ratio": 4/3},
{"name": "IMAX 70mm (1.43:1)", "ratio": 1.43},
]
def parse_crop_string(crop_str):
"""Parses a 'crop=w:h:x:y' string into a dictionary of integers."""
try:
_, values = crop_str.split('=')
w, h, x, y = map(int, values.split(':'))
return {'w': w, 'h': h, 'x': x, 'y': y}
except (ValueError, IndexError):
return None
def snap_to_known_ar(w, h, x, y, video_w, video_h, tolerance=0.03):
"""Snaps a crop rectangle to the nearest standard aspect ratio if it's close enough."""
if h == 0: return f"crop={w}:{h}:{x}:{y}", None
detected_ratio = w / h
best_match = None
smallest_diff = float('inf')
for ar in KNOWN_ASPECT_RATIOS:
diff = abs(detected_ratio - ar['ratio'])
if diff < smallest_diff:
smallest_diff = diff
best_match = ar
if not best_match or (smallest_diff / best_match['ratio']) >= tolerance:
return f"crop={w}:{h}:{x}:{y}", None
# Heuristic: if width is close to full video width, it's letterboxed.
if abs(w - video_w) < 16:
new_h = round(video_w / best_match['ratio'])
# Round height up to the nearest multiple of 8 for cleaner dimensions.
if new_h % 8 != 0:
new_h = new_h + (8 - (new_h % 8))
new_y = round((video_h - new_h) / 2)
if new_y % 2 != 0: new_y -= 1 # Ensure y offset is even
return f"crop={video_w}:{new_h}:0:{new_y}", best_match['name']
# Heuristic: if height is close to full video height, it's pillarboxed.
if abs(h - video_h) < 16:
new_w = round(video_h * best_match['ratio'])
# Round width up to the nearest multiple of 8.
if new_w % 8 != 0:
new_w = new_w + (8 - (new_w % 8))
new_x = round((video_w - new_w) / 2)
if new_x % 2 != 0: new_x -= 1 # Ensure x offset is even
return f"crop={new_w}:{video_h}:{new_x}:0", best_match['name']
return f"crop={w}:{h}:{x}:{y}", None
def cluster_crop_values(crop_counts, tolerance=8):
"""Groups similar crop values into clusters based on the top-left corner."""
clusters = []
temp_counts = crop_counts.copy()
while temp_counts:
center_str, _ = temp_counts.most_common(1)[0]
parsed_center = parse_crop_string(center_str)
if not parsed_center:
del temp_counts[center_str]; continue
cx, cy = parsed_center['x'], parsed_center['y']
cluster_total_count = 0
crops_to_remove = []
for crop_str, count in temp_counts.items():
parsed_crop = parse_crop_string(crop_str)
if parsed_crop and abs(parsed_crop['x'] - cx) <= tolerance and abs(parsed_crop['y'] - cy) <= tolerance:
cluster_total_count += count
crops_to_remove.append(crop_str)
if cluster_total_count > 0:
clusters.append({'center': center_str, 'count': cluster_total_count})
for crop_str in crops_to_remove:
del temp_counts[crop_str]
return sorted(clusters, key=lambda c: c['count'], reverse=True)
def calculate_bounding_box(crop_keys):
"""Calculates a bounding box that contains all given crop rectangles."""
min_x, max_x = float('inf'), float('-inf')
min_y, max_y = float('inf'), float('-inf')
for key in crop_keys:
parsed = parse_crop_string(key)
if parsed:
x, y, w, h = parsed['x'], parsed['y'], parsed['w'], parsed['h']
min_x = min(min_x, x)
min_y = min(min_y, y)
max_x = max(max_x, x + w)
max_y = max(max_y, y + h)
final_w, final_h = (max_x - min_x), (max_y - min_y)
if final_w % 2 != 0: final_w -= 1
if final_h % 2 != 0: final_h -= 1
return f"crop={final_w}:{final_h}:{min_x}:{min_y}"
def analyze_segment_for_crop(task_args):
"""Worker process to analyze one video segment for crop values."""
seek_time, input_file = task_args
ffmpeg_args = ['ffmpeg', '-hide_banner', '-ss', str(seek_time), '-i', input_file, '-t', '1', '-vf', 'cropdetect', '-f', 'null', '-']
result = subprocess.run(ffmpeg_args, capture_output=True, text=True, encoding='utf-8')
return re.findall(r'crop=\d+:\d+:\d+:\d+', result.stderr)
def detect_crop(video_path, hwaccel=None):
"""
Detects black bars using the full, robust logic from cropdetect.py, including
multiprocess analysis, clustering, and aspect ratio snapping.
"""
print("\nStarting robust crop detection (1:1 logic from cropdetect.py)...")
# --- Parameters from original script ---
significant_crop_threshold = 5.0
num_workers = max(1, multiprocessing.cpu_count() // 2)
# --- Probing ---
duration = get_video_duration(video_path)
width, height = get_video_resolution(video_path)
if not all([duration, width, height]):
print("Could not get video metadata. Aborting crop detection.")
return None
# --- Analysis ---
num_tasks = num_workers * 4
segment_duration = max(1, duration // num_tasks)
tasks = [(i * segment_duration, video_path) for i in range(num_tasks)]
print(f"Analyzing {len(tasks)} segments across {num_workers} worker(s)...")
all_crops = []
with multiprocessing.Pool(processes=num_workers) as pool:
for i, result in enumerate(pool.imap_unordered(analyze_segment_for_crop, tasks), 1):
all_crops.extend(result)
sys.stdout.write(f"\rAnalyzing Segments: {i}/{len(tasks)} completed...")
sys.stdout.flush()
print("\nAnalysis complete.")
if not all_crops:
print("No black bars detected.")
return None
# --- Decision Logic ---
crop_counts = Counter(all_crops)
clusters = cluster_crop_values(crop_counts)
total_detections = sum(c['count'] for c in clusters)
if total_detections == 0:
print("No valid crop detections found.")
return None
significant_clusters = [c for c in clusters if (c['count'] / total_detections * 100) >= significant_crop_threshold]
final_crop = None
ar_label = None
if not significant_clusters:
print(f"No single crop value meets the {significant_crop_threshold}% significance threshold. No crop will be applied.")
return None
elif len(significant_clusters) == 1:
print("A single dominant aspect ratio was found.")
final_crop = significant_clusters[0]['center']
else: # Mixed AR
print("Mixed aspect ratios detected. Calculating a safe 'master' crop.")
crop_keys = [c['center'] for c in significant_clusters]
final_crop = calculate_bounding_box(crop_keys)
# --- Snapping ---
parsed = parse_crop_string(final_crop)
if not parsed: return None
snapped_crop, ar_label = snap_to_known_ar(parsed['w'], parsed['h'], parsed['x'], parsed['y'], width, height)
if ar_label:
print(f"The detected crop snaps to the '{ar_label}' aspect ratio.")
# --- Final Check ---
parsed_snapped = parse_crop_string(snapped_crop)
if parsed_snapped and parsed_snapped['w'] == width and parsed_snapped['h'] == height:
print("Final crop matches source resolution. No cropping needed.")
return None
print(f"Robust crop detection finished. Recommended filter: {snapped_crop}")
return snapped_crop
def detect_scenes(video_path, json_output_path, hwaccel=None, threshold=0.23, crop_filter=None):
"""Uses FFmpeg to detect scene changes and saves timestamps to a JSON file."""
print(f"\nStarting scene detection for: {os.path.basename(video_path)}")
# NOTE: Hardware acceleration is intentionally disabled for scene detection.
# The scenedetect filter can be unreliable with hwaccel contexts as it
# operates on CPU frames. The performance gain is negligible for this step.
command = ['ffmpeg', '-hide_banner']
filters = []
if crop_filter:
print(f"Applying crop filter during scene detection: {crop_filter}")
filters.append(crop_filter)
filters.append(f"select='gt(scene,{threshold})',showinfo")
filter_string = ",".join(filters)
# Add -map 0:v:0 to explicitly select the first video stream, ignoring cover art.
command.extend(['-i', video_path, '-map', '0:v:0', '-vf', filter_string, '-f', 'null', '-'])
try:
process = subprocess.Popen(command, stderr=subprocess.PIPE, text=True, encoding='utf-8')
scene_timestamps = []
for line in iter(process.stderr.readline, ''):
if 'pts_time:' in line:
timestamp_str = line.split('pts_time:')[1].split()[0]
scene_timestamps.append(float(timestamp_str))
elif line.strip().startswith('frame='):
sys.stderr.write(f'\r{line.strip()}')
sys.stderr.flush()
process.wait()
sys.stderr.write('\n')
sys.stderr.flush()
if process.returncode != 0:
print(f"\nWarning: FFmpeg may have encountered an error (exit code: {process.returncode}).")
with open(json_output_path, 'w') as json_file:
json.dump(scene_timestamps, json_file, indent=4)
print(f"Scene detection completed. {len(scene_timestamps)} scenes found.")
return True
except (FileNotFoundError, Exception) as e:
print(f"\nAn error occurred during scene detection: {e}")
return False
def cut_video_into_scenes(video_path, json_path, max_segment_length, hwaccel=None, crop_filter=None):
"""Cuts a video into segments, ensuring no segment exceeds a maximum length."""
print(f"\nStarting segment cutting for: {os.path.basename(video_path)}")
try:
with open(json_path, 'r') as f:
scene_timestamps = json.load(f)
except (FileNotFoundError, json.JSONDecodeError) as e:
print(f"\nError reading scene file '{json_path}': {e}")
return
video_duration = get_video_duration(video_path)
if video_duration is None: return
output_dir = "cuts"
os.makedirs(output_dir, exist_ok=True)
print(f"Output will be saved to the '{output_dir}' directory.")
print(f"Enforcing maximum segment length of {max_segment_length} seconds...")
segment_boundaries = [0.0] + sorted(list(set(scene_timestamps))) + [video_duration]
final_cut_points = []
for i in range(len(segment_boundaries) - 1):
start, end = segment_boundaries[i], segment_boundaries[i+1]
current_time = start
while (end - current_time) > max_segment_length:
current_time += max_segment_length
final_cut_points.append(current_time)
final_cut_points.append(end)
final_cut_points = sorted(list(set(final_cut_points)))
if final_cut_points and final_cut_points[-1] >= video_duration - 0.1:
final_cut_points.pop()
print(f"Original scenes: {len(scene_timestamps)}. Total segments after splitting: {len(final_cut_points) + 1}.")
segment_times_str = ",".join(map(str, final_cut_points))
base_name = os.path.splitext(os.path.basename(video_path))[0]
output_pattern = os.path.join(output_dir, f"{base_name}_segment%03d.mkv")
# Add -loglevel error to hide info messages and -stats to show progress
command = ['ffmpeg', '-hide_banner', '-loglevel', 'error', '-stats']
if hwaccel:
command.extend(['-hwaccel', hwaccel])
command.extend(['-i', video_path])
if crop_filter:
print(f"Applying crop filter during cutting: {crop_filter}")
command.extend(['-vf', crop_filter])
# Add -map 0:v:0 to explicitly select the first video stream for cutting.
# Combine with -an/-sn to ensure no other streams are processed.
command.extend(['-map', '0:v:0', '-c:v', 'utvideo', '-an', '-sn', '-dn', '-map_metadata', '-1', '-map_chapters', '-1', '-f', 'segment', '-segment_times', segment_times_str, '-segment_start_number', '1', '-reset_timestamps', '1', output_pattern])
print("\nStarting FFmpeg to cut all segments in a single pass...")
try:
# -stats will print progress to stderr, which subprocess.run will display
subprocess.run(command, check=True)
total_segments = len(final_cut_points) + 1
print(f"Successfully created {total_segments} segments in the '{output_dir}' directory.")
except (FileNotFoundError, subprocess.CalledProcessError, Exception) as e:
print(f"\nAn error occurred during cutting: {e}")
# --- Main Orchestrator ---
def main():
parser = argparse.ArgumentParser(
description="A comprehensive video processing script to detect scenes and cut segments.",
formatter_class=argparse.RawTextHelpFormatter
)
parser.add_argument("video_path", help="Path to the input video file.")
parser.add_argument(
"--autocrop",
action='store_true',
help="Automatically detect and apply cropping to remove black bars. Default: False"
)
parser.add_argument(
"--so", "--sceneonly",
action='store_true',
dest='sceneonly', # Explicitly set the destination attribute name
help="Only run scene detection and create the .scenes.json file."
)
parser.add_argument(
"--segtime",
type=int,
default=10,
help="Maximum length of any cut segment in seconds. Default: 10"
)
parser.add_argument(
"-t", "--threshold",
type=float,
default=0.23,
help="Scene detection threshold (0.0 to 1.0). Lower is more sensitive. Default: 0.23"
)
args = parser.parse_args()
if not os.path.isfile(args.video_path):
print(f"Error: Input file not found: '{args.video_path}'")
sys.exit(1)
base_name = os.path.splitext(args.video_path)[0]
json_path = f"{base_name}.scenes.json"
hwaccel_method = get_best_hwaccel()
crop_filter = None
if args.autocrop:
crop_filter = detect_crop(args.video_path, hwaccel_method)
if args.sceneonly:
detect_scenes(args.video_path, json_path, hwaccel_method, args.threshold, crop_filter)
sys.exit(0)
# --- Full Workflow (Detect if needed, then Cut) ---
if not os.path.isfile(json_path):
print("--- Scene file not found, running detection first ---")
if not detect_scenes(args.video_path, json_path, hwaccel_method, args.threshold, crop_filter):
print("\nScene detection failed. Aborting process.")
sys.exit(1)
else:
print(f"--- Found existing scene file: {os.path.basename(json_path)} ---")
cut_video_into_scenes(args.video_path, json_path, args.segtime, hwaccel_method, crop_filter)
if __name__ == "__main__":
main()