#!/bin/bash

# Check if all required arguments are provided
if [ $# -lt 3 ]; then
    echo "Usage: $0 <input_file> <output_file> <start_time>"
    echo ""
    echo "Arguments:"
    echo "  <input_file>   Path to the input video file."
    echo "  <output_file>  Path to the output video file."
    echo "  <start_time>   Start time in format HH:MM:SS or seconds."
    echo ""
    echo "Example:"
    echo "  $0 input.mp4 output.mp4 00:01:00"
    echo ""
    echo "Note: The output file will start from <start_time> and will include all remaining content of the input file."
    exit 1
fi

# Assign input arguments to variables
input_file=$1
output_file=$2
start_time=$3

# Check if the input file exists
if [ ! -f "$input_file" ]; then
    echo "Error: The input file '$input_file' does not exist."
    exit 1
fi

# Run the ffmpeg command
ffmpeg -i "$input_file" -ss "$start_time" -vcodec copy -acodec copy "$output_file"

# Check if the ffmpeg command succeeded
if [ $? -eq 0 ]; then
    echo "Video extraction completed successfully. Output saved to '$output_file'."
else
    echo "Error: ffmpeg failed to extract the video."
    exit 1
fi