Cut out fragment of a video with burned subtitles for Telegram

video_fragment_to_tg_with_subs.sh

input_file=in.mp4
output_file="${input_file%%.*}"-fragment."${input_file##*.}"
subs_file=  # can be srt file or mkv container with subtitles
start_from=
stop_at=
duration=

# delete lines below that contain empty optional variables from above before use
# if duration is specified, '-to' or 'stop_at' is ignored
ffmpeg \
       -ss "$start_from" -copyts \
       -i "$input_file" \
       -ss "$start_from" \
       -to "$stop_at" \
       -t "$duration" \
       -vf subtitles="$subs_file" \
       -c:v libx264 \
       -crf 26 \
       -ac 2 \
       "$output_file"