Extract the first frame of a 1280x720 video, convert it to an image, then crop and resize both the image and original video to 480x3680

extract_video_frame.py

import cv2
import os
from fractions import Fraction
import subprocess

# === Settings ===
video_file = 'videos/video.mp4'
output_image_file = 'first_frame_clipped.jpg'
output_image_resized_file = 'first_frame_resized.jpg'
output_video_file = 'clipped_video.mp4'
target_aspect = Fraction(4, 3)

# === Setup Paths ===
video_path = os.path.join(os.getcwd(), video_file)
print("Checking video path:", video_file)
print("Video file exists:", os.path.exists(video_path))

# === Load Video ===
cap = cv2.VideoCapture(video_path)

if not cap.isOpened():
    print("❌ Failed to open video file.")
else:
    success, frame = cap.read()
    if success:
        print("✅ First frame captured successfully.")

        height, width = frame.shape[:2]
        aspect_fraction = Fraction(width, height).limit_denominator()
        print(f"📐 Original Dimensions: {width} x {height}")
        print(f"🧮 Original Aspect Ratio: {aspect_fraction.numerator}:{aspect_fraction.denominator}")

        # === Calculate crop for 4:3 ===
        target_width = (height * target_aspect.numerator) // target_aspect.denominator
        print(f"✂️ Cropping to 4:3 → New width: {target_width}")

        x_start = (width - target_width) // 2
        x_end = x_start + target_width
        cropped_frame = frame[:, x_start:x_end]
        print(f"📸 Saved cropped frame as '{output_image_file}'")
        cv2.imwrite(output_image_file, cropped_frame)

        # === Resize image to half dimensions ===
        resized_frame = cv2.resize(cropped_frame, (target_width // 2, height // 2), interpolation=cv2.INTER_AREA)
        cv2.imwrite(output_image_resized_file, resized_frame)
        print(f"🖼️ Saved resized image as '{output_image_resized_file}' ({target_width // 2} x {height // 2})")

        # === Crop and scale video using ffmpeg ===
        ffmpeg_cmd = [
            'ffmpeg',
            '-y',  # auto overwrite
            '-i', video_path,
            '-filter:v', f'crop={target_width}:{height},scale={target_width // 2}:{height // 2}',
            '-c:a', 'copy',
            output_video_file
        ]
        print(f"🎞️ Cropping and downscaling video to {target_width // 2} x {height // 2}...")

        result = subprocess.run(ffmpeg_cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True)
        if result.returncode == 0:
            print(f"✅ Cropped and scaled video saved as '{output_video_file}'")
        else:
            print("❌ ffmpeg error:")
            print(result.stderr)

        # === Show final sizes and aspect ratios ===
        clipped_height, clipped_width = resized_frame.shape[:2]
        clipped_aspect = Fraction(clipped_width, clipped_height).limit_denominator()
        print(f"🖼️ Final Image Size: {clipped_width} x {clipped_height}")
        print(f"🔲 Final Image Aspect Ratio: {clipped_aspect.numerator}:{clipped_aspect.denominator}")

        # === Confirm video size using ffprobe ===
        ffprobe_cmd = [
            'ffprobe', '-v', 'error',
            '-select_streams', 'v:0',
            '-show_entries', 'stream=width,height',
            '-of', 'csv=p=0:s=x',
            output_video_file
        ]
        probe = subprocess.run(ffprobe_cmd, stdout=subprocess.PIPE, text=True)
        if probe.returncode == 0:
            vid_width, vid_height = map(int, probe.stdout.strip().split('x'))
            vid_aspect = Fraction(vid_width, vid_height).limit_denominator()
            print(f"🎬 Final Video Size: {vid_width} x {vid_height}")
            print(f"🎞️ Final Video Aspect Ratio: {vid_aspect.numerator}:{vid_aspect.denominator}")
        else:
            print("⚠️ Failed to get final video dimensions using ffprobe.")

    else:
        print("❌ Failed to read the first frame.")

cap.release()