#!/usr/bin/env python3 # SPDX-FileCopyrightText: 2025 Blender Studio Tools Authors # # SPDX-License-Identifier: GPL-3.0-or-later """ Blender script to extract render statistics from video strips. This script is meant to be executed within Blender using --python flag, or called from render_stats.py. """ import bpy import csv import json import sys from pathlib import Path from statistics import median import OpenImageIO as oiio CHANNEL_TO_PROCESS = 22 # The "Comp 2" channel # TODO: Ask Blender devs to support channel lookup by name def time_str_to_time_seconds_int(time_str): return int(time_str.split(':')[0]) * 60 + float(time_str.split(':')[1]) def get_frame_metadata(frame_path): """Extract metadata from a frame using OpenImageIO.""" frame_path_str = str(frame_path) if not Path(frame_path_str).exists(): return None try: img_input = oiio.ImageInput.open(frame_path_str) if img_input is None: return None spec = img_input.spec() metadata = {} # Extract the required metadata for attr in spec.extra_attribs: if attr.name == "cycles.ViewLayer.total_time": metadata["render_time"] = attr.value elif attr.name == "cycles.ViewLayer.samples": metadata["samples"] = attr.value elif attr.name == "Scene": metadata["scene"] = attr.value img_input.close() return metadata except Exception as e: print(f"Error reading metadata from {frame_path_str}: {e}", file=sys.stderr) return None def get_strip_frame_paths(strip): """Get all frame paths for a video strip.""" frame_paths = [] if not hasattr(strip, 'directory') or not hasattr(strip, 'elements'): return frame_paths directory = Path(bpy.path.abspath(strip.directory)) for element in strip.elements: frame_path = directory / element.filename if frame_path.exists(): frame_paths.append(frame_path) return frame_paths def write_stat_files(results): # Get the current blend file path blend_file_path = Path(bpy.data.filepath) # Create output filenames based on blend file name blend_filename = blend_file_path.stem output_json = blend_file_path.parent / f"{blend_filename}-render_stats.json" output_csv = blend_file_path.parent / f"{blend_filename}-render_stats.csv" with open(output_json, 'w') as f: json.dump(results, f, indent=2) # Save results to CSV, withs some arbitrary chances to facilitate analysis # For example, we estimate all shots to be rendered at 100 samples with open(output_csv, 'w', newline='') as f: writer = csv.writer(f) # Write header writer.writerow(['shot_name', 'frames_count', 'samples', 'frame_median_time_sec', 'total_time_sec', 'total_time_hours']) # Write data rows for result in results: # If samples is 10, multipliy by 10 to estimate 100 samples if result['samples'] and result['samples'] == 10: result['samples'] = 100 result['frame_median_time_sec'] *= 10 result['total_time_sec'] *= 10 writer.writerow([ result['shot_name'], result['frames_count'], result['samples'], result['frame_median_time_sec'], result['total_time_sec'], result['total_time_sec'] / 3600 if result['total_time_sec'] else None ]) print(f"Results saved to: {output_json}") print(f"Results saved to: {output_csv}") print(f"Processed {len(results)} strips") def main(): # Get the sequence editor if not bpy.context.scene.sequence_editor: print("No sequence editor found in the blend file", file=sys.stderr) sys.exit(1) all_strips = bpy.context.scene.sequence_editor.strips_all # Find all image sequence strips in the desired channel filtered_strips = [s for s in all_strips if s.channel == CHANNEL_TO_PROCESS and s.type == 'IMAGE'] print(f"Processing {len(filtered_strips)} strips in Comp 2 channel") results = [] for strip in filtered_strips: print(f"Processing strip: {strip.name}") # Swap the strip directory from -comp to -lighting, as the render metadata is in the lighting frames strip.directory = strip.directory.replace('-comp/', '-lighting/') # Get all frame paths frame_paths = get_strip_frame_paths(strip) if not frame_paths: print(f"No frames found for strip: {strip.name}", file=sys.stderr) continue frames_data = [] samples_value = None shot_name = None # Process each frame for frame_path in frame_paths: metadata = get_frame_metadata(frame_path) if metadata: frame_info = { "frame_path": str(frame_path), "render_time": metadata.get("render_time"), "samples": metadata.get("samples") } frames_data.append(frame_info) # Get the shot name from the first frame's Scene metadata if shot_name is None and "scene" in metadata: shot_name = metadata["scene"] # Get the first samples value if samples_value is None and "samples" in metadata: samples_value = metadata["samples"] if not frames_data: print(f"No metadata found for strip: {strip.name}", file=sys.stderr) continue # If no shot_name was found in metadata, fall back to strip name if shot_name is None: shot_name = strip.name print(f"Warning: No Scene metadata found for strip {strip.name}, using strip name", file=sys.stderr) # Calculate median render time render_times = [f["render_time"] for f in frames_data if f["render_time"] is not None] render_times_int = [time_str_to_time_seconds_int(t) for t in render_times] median_render_time = int(median(render_times_int)) if render_times_int else None # Create the result object result = { "shot_name": shot_name, "frames": frames_data, "frames_count": len(frames_data), "samples": None if not samples_value else int(samples_value), "frame_median_time_sec": median_render_time, "total_time_sec": None if not median_render_time else median_render_time * len(frames_data) } results.append(result) # Save results to JSON write_stat_files(results) if __name__ == "__main__": main()