Create a time lapse video from a set of real-time dash cam clips.

dashcam-time-lapse.sh

#!/bin/bash
#
# Batch Time-Lapse creation script.
#
# This script can be used to speed up, trim, and finally concatenate tens or
# even hundreds of video clips, e.g. from a dash cam. You can do other things,
# too, but the main things this script does include:
#
#   1. Copy across and speed up video clips from an input dir to an output dir.
#   2. Trim off the first x frames of each of the copied/sped up clips.
#   3. Concatenate (join together) all the clips into one final sped up clip.
#
# Assumptions:
#
#   - `ffmpeg` is installed (`brew install ffmpeg` on macOS).
#   - All video clips are the same format, and from the same long time-based-
#     split recording from one dash cam or other recording device.
#
# @author Jeff Geerling, 2016.
# @see http://www.jeffgeerling.com/blog/2016/converting-batch-dashcam-videos-one-much-smaller-timelapse

# Video file options and locations.
INPUT_DIR="/Volumes/MOBIUS/DCIM/100HDDVR"
OUTPUT_DIR="/Users/jgeerling/Desktop/RoadTrip"
OUTPUT_FILE_NAME="timelapse.mov"
VIDEO_EXTENSION="MOV"

# How much to speed up the clips. Quick reference:
# - 0.50 = 2x
# - 0.10 = 10x
# - 0.05 = 50x
# - 0.01 = 100x
SPEEDUP="0.05"

# How much to trim off each sped-up clip. One frame @ 30fps = "00.03".
TRIM_AMOUNT="00.12"

# Create a directory in which processed files will be stored.
mkdir -p "$OUTPUT_DIR"

# Enter the input directory (where all the clips are stored).
cd "$INPUT_DIR"

# Loop through all the files, creating sped-up versions of each in the dest dir.
for FILE in *.$VIDEO_EXTENSION; do
  VIDEO_NAME="${FILE%.*}"
  # e.g. `ffmpeg -i video.mov -v "setpts=0.50*PTS" -an /path/to/speedy.mov`
  ffmpeg -i $FILE -vf "setpts=$SPEEDUP*PTS" -an "$OUTPUT_DIR/$VIDEO_NAME-speedy.$VIDEO_EXTENSION"
done

# Enter the output directory (where the sped-up versions are stored).
cd "$OUTPUT_DIR"

# Create a directory in which cropped/final length sped-up clips will be stored.
mkdir -p cropped

# Trim off the first x frames of each of the processed clips.
for FILE in *.$VIDEO_EXTENSION; do
  VIDEO_NAME="${FILE%.*}"
  # e.g. `ffmpeg -i video.mov -v "setpts=0.50*PTS" -an /path/to/speedy.mov`
  ffmpeg -i $FILE -ss $TRIM_AMOUNT -an "$OUTPUT_DIR/cropped/$VIDEO_NAME.$VIDEO_EXTENSION"
done

# Enter the cropped output directory (where the trimmed versions are stored).
cd "$OUTPUT_DIR/cropped"

# Create a file listing all the videos in the current directory.
printf "file '%s'\n" *.$VIDEO_EXTENSION > concat.txt

# Concatenate all the videos using the file listing.
ffmpeg -f concat -i concat.txt -c copy $OUTPUT_FILE_NAME

Thanks, was very useful starter script to time-lapse my Unifi security cameras.

Just updated the script to wrap $INPUT_DIR and $OUTPUT_DIR in double quotes so paths with spaces in file/folder names would work.