#!/bin/sh
##
## SCRIPT: 00_ffmpeg_mp4_CLIP.sh
##
## PURPOSE: Clip a section out of a '.mp4' movie file --- based on a user-specified
##          start time and a user-specified end-time of the clip.
##
##          Example start and end times:
##          00:00:16 and 00:01:10
##
## METHOD: 
##   1) Put this script in the directory of '.mp4' movie files
##      that you want to clip.
##   2) Edit this script to set the input filename and start & end times.
##   3) Run the script in a terminal window positioned at the directory
##      that holds this script and the movie files.
##
## REFERENCE:
## https://trac.ffmpeg.org/wiki/Seeking
## 
## Examples:
## ffmpeg -ss 00:01:00 -i video.mp4 -to 00:02:00 -c copy cut.mp4
## ffmpeg -i video.mp4 -ss 00:01:00 -to 00:02:00 -c copy cut.mp4
## ffmpeg -ss 00:01:00 -i video.mp4 -to 00:02:00 -c copy -copyts cut.mp4
##
## ffmpeg -ss 00:03:00 -i video.mp4 -t 60 -c copy -avoid_negative_ts 1 cut.mp4
##
## Script started: 2021jul10
##

## NOT GOOD: (dark for ~14 secs)
# ffmpeg \
#   -ss 00:00:16 \
#   -i input.mp4 \
#   -to 00:01:10 \
#   -c copy \
#   -copyts \
#   00_temp.mp4
   
## FAIR: (BUT start-stop times not exact)  
# ffmpeg \
#    -ss 00:00:16 \
#    -i input.mp4 \
#    -to 00:00:50 \
#    -c copy \
#    00_temp.mp4   
   
   
## GOOD:
##    NOTE:
##    If a few seconds at beginning are black,
##    increase the '-ss' time a few seconds.
ffmpeg \
   -i input.mp4 \
   -ss 00:04:20 \
   -to 00:05:00 \
   -c copy \
   00_temp.mp4   
 
# totem 00_temp.mp4
# ffplay 00_temp.mp4

exit