trims videos from start for a few seconds

trim.sh

#!/bin/bash

# Set default values for input and output formats
input_format="mkv"
output_format="mkv"

# Folder containing the video files
input_folder="./"   # Change this if needed

# Create a directory for processed files
output_folder="./dir"

# Ensure the output folder exists
mkdir -p "$output_folder"

# Define the time duration for the first chapter (11 seconds in this case)
cut_time="0.01"

# Optional: allow users to specify input and output formats as arguments
if [ ! -z "$1" ]; then
    input_format="$1"
fi

if [ ! -z "$2" ]; then
    output_format="$2"
fi

# Loop through each video file in the folder with the specified input format
for file in "$input_folder"*."$input_format"; do
    # Generate the output file name by replacing the extension with the desired output format
    output_file="$output_folder/$(basename "${file%.*}").$output_format"
    
    # Trim the first 11 seconds (which is the first chapter) without re-encoding
    ffmpeg -ss "$cut_time" -i "$file" -map 0 -c copy "$output_file"
    
    echo "Processed $file, removed first $cut_time seconds (first chapter), and saved to $output_file"
done