Source code for hello.video.clip

import re
import shutil
import sys
from pathlib import Path

import cv2 as cv
import numpy as np

pattern_decimal = re.compile(r"\d+(\.\d+)?")

suffix_set = set(".avi,.mp4,.MOV".split(","))

help_doc_str = """
- press `esc` to exit
- press `space` change mode
- press `u` speed up
- press `d` slow down
- press `n` go further
- press `b` take a step back
- press `f` freeze or not
"""


[docs]def find_videos(input_dir): video_paths = [] for f in sorted(Path(input_dir).glob("**/*")): if f.suffix in suffix_set: video_paths.append(f.as_posix()) return video_paths
[docs]def tag_video(video_path, factor): cap = cv.VideoCapture(video_path) cap_fps = int(cap.get(cv.CAP_PROP_FPS)) frame_count = int(cap.get(cv.CAP_PROP_FRAME_COUNT)) frame_width = int(cap.get(cv.CAP_PROP_FRAME_WIDTH)) tag_frames = np.full((30, frame_count, 3), (255, 0, 0), dtype="uint8") curr_pos, step_size, freeze, keep = 0, 1, 0, 1 while curr_pos < frame_count: this_pos = int(cap.get(cv.CAP_PROP_POS_FRAMES)) if this_pos != curr_pos: cap.set(cv.CAP_PROP_POS_FRAMES, curr_pos) this_pos = curr_pos ret, frame = cap.read() if not ret: print("Can't receive frame (stream end?). Exiting ...") break banner = np.full((30, frame_width, 3), (0, 0, 255), dtype="uint8") txt = f"{curr_pos=}/{frame_count}, {step_size=}*{cap_fps}, {freeze=}, {keep=}" cv.putText(banner, txt, (15, 25), cv.FONT_HERSHEY_SIMPLEX, 1.0, (255, 255, 255), 2) tag_bar = cv.resize(tag_frames, (frame_width, 30), interpolation=cv.INTER_NEAREST) center = (int(curr_pos / frame_count * frame_width), 15) cv.circle(tag_bar, center, 5, (255, 255, 255), -1) image = np.concatenate((banner, frame, tag_bar)) if factor is not None: image = cv.resize(image, None, fx=factor, fy=factor, interpolation=cv.INTER_NEAREST) cv.imshow(video_path, image) key = cv.waitKey(0) if key == 27: # esc break elif key == 32: # space keep = int(not keep) elif key == ord("u"): step_size = step_size * 2 elif key == ord("d"): step_size = step_size // 2 step_size = max(1, step_size) elif key == ord("n"): curr_pos = this_pos + step_size * cap_fps if freeze == 0: if keep == 1: tag_frames[:, this_pos:curr_pos] = (0, 255, 0) else: tag_frames[:, this_pos:curr_pos] = (0, 0, 255) elif key == ord("b"): curr_pos = this_pos - step_size * cap_fps curr_pos = max(0, curr_pos) elif key == ord("f"): freeze = int(not freeze) cv.destroyAllWindows() cap.release() return tag_frames[0, :, 1]
[docs]def clip_video(video_path, tag_frames, output_dir): txt_file = Path(video_path).with_suffix(".txt") clip_text_file(txt_file, tag_frames, output_dir) outfile = Path(output_dir) / f"data/{Path(video_path).stem}.mp4" fourcc = cv.VideoWriter_fourcc(*"mp4v") cap = cv.VideoCapture(video_path) fps = int(cap.get(cv.CAP_PROP_FPS)) width = int(cap.get(cv.CAP_PROP_FRAME_WIDTH)) height = int(cap.get(cv.CAP_PROP_FRAME_HEIGHT)) out = cv.VideoWriter(str(outfile), fourcc, fps, (width, height)) frame_count = tag_frames.size print(f"[{outfile}] Saving ...") curr_pos = 0 while curr_pos < frame_count: ret, frame = cap.read() if not ret: print("Can't receive frame (stream end?). Exiting ...") break if tag_frames[curr_pos] > 0: out.write(frame) curr_pos += 1 cap.release() out.release()
[docs]def clip_text_file(infile, tag_frames, output_dir): if not Path(infile).is_file(): return None frame_count = tag_frames.size curr_pos = 0 head, data = [], [] with open(infile, "r") as f: lines = [l.strip() for l in f.readlines()] lines = [l for l in lines if l] for line in lines: if curr_pos >= frame_count: break if pattern_decimal.match(line): if tag_frames[curr_pos] > 0: data.append(line) curr_pos += 1 else: head.append(line) outfile = Path(output_dir) / f"data/{Path(infile).name}" with open(outfile, "w") as f: f.write("\n".join(head)) f.write("\n") f.write("\n".join(data)) return outfile
[docs]def func(input_dir, output_dir, factor): input_dir = Path(input_dir) if input_dir.is_file(): video_paths = [input_dir.as_posix()] input_dir = input_dir.parent else: video_paths = find_videos(input_dir) if output_dir is not None: output_dir = Path(output_dir) else: new_name = f"{input_dir.name}_clip" output_dir = input_dir.with_name(new_name) shutil.rmtree(output_dir, ignore_errors=True) (output_dir / "data").mkdir(parents=True, exist_ok=False) for video_path in video_paths: tag_frames = tag_video(video_path, factor) if tag_frames.max() > 0: clip_video(video_path, tag_frames, output_dir) return f"\n[OUTDIR]\n{output_dir}"
[docs]def parse_args(args=None): from argparse import ArgumentDefaultsHelpFormatter, ArgumentParser parser = ArgumentParser(formatter_class=ArgumentDefaultsHelpFormatter) parser.add_argument("input_dir", type=str, help="videos dir or file path") parser.add_argument("-o", "--output_dir", type=str, default=None, help="output dir") parser.add_argument("-f", "--factor", type=float, default=None, help="resize factor") args = parser.parse_args(args=args) return vars(args)
[docs]def main(args=None): print(help_doc_str) kwargs = parse_args(args) print(f"{__file__}: {kwargs}") print(func(**kwargs)) return 0
if __name__ == "__main__": sys.exit(main())