#!/bin/bash

if [ -z "$1" -o -z "$2" -o -z "$3" ]; then
    echo "Usage: $0 input start end"
    exit 1
fi

input="$1"
ss="$2"
endpos="$3"
let duration="$endpos - $ss"
output="${input%%.*}-trimmed.${input##*.}"

if [ "$input" = "$output" ]; then
    echo "Internal error! Would overwrite "$input" with output file"
    exit 1
fi

avconv -ss "$ss" -t "$duration" -i "$input" -acodec copy "$output"