Ingest GoPro videos, extract telemetry with exiftool, and merge/compress with ffmpeg

gpx.fmt

#------------------------------------------------------------------------------
# File:         gpx.fmt
#
# Description:  Example ExifTool print format file to generate a GPX track log
#
# Usage:        exiftool -p gpx.fmt -ee3 FILE [...] > out.gpx
#
# Requires:     ExifTool version 10.49 or later
#
# Revisions:    2010/02/05 - P. Harvey created
#               2018/01/04 - PH Added IF to be sure position exists
#               2018/01/06 - PH Use DateFmt function instead of -d option
#               2019/10/24 - PH Preserve sub-seconds in GPSDateTime value
#               2023/02/19 - WJL Change version to 1.1 to support Garmin VIRB Edit
#
# Notes:     1) Input file(s) must contain GPSLatitude and GPSLongitude.
#            2) The -ee3 option is to extract the full track from video files.
#            3) The -fileOrder option may be used to control the order of the
#               generated track points when processing multiple files.
#            4) Coordinates are written at full resolution.  To change this,
#               remove the "#" from the GPSLatitude/Longitude tag names below
#               and use the -c option to set the desired precision.
#------------------------------------------------------------------------------
#[HEAD]<?xml version="1.1" encoding="utf-8"?>
#[HEAD]<gpx version="1.1"
#[HEAD] creator="ExifTool $ExifToolVersion"
#[HEAD] xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
#[HEAD] xmlns="http://www.topografix.com/GPX/1/1"
#[HEAD] xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/0/gpx.xsd">
#[HEAD]<trk>
#[HEAD]<number>1</number>
#[HEAD]<trkseg>
#[IF]  $gpslatitude $gpslongitude
#[BODY]<trkpt lat="$gpslatitude#" lon="$gpslongitude#">
#[BODY]  <ele>$gpsaltitude#</ele>
#[BODY]  <time>${gpsdatetime#;my ($ss)=/\.\d+/g;DateFmt("%Y-%m-%dT%H:%M:%SZ");s/Z/${ss}Z/ if $ss}</time>
#[BODY]</trkpt>
#[TAIL]</trkseg>
#[TAIL]</trk>
#[TAIL]</gpx>

ingest.clj

#!/usr/bin/env bb

(require '[clojure.tools.cli :refer [parse-opts]])
(require '[babashka.process :refer [shell]])

(def sibling-files
    (set (map #(.getName %)
              (file-seq (clojure.java.io/file ".")))))

(defn ingest-video [video-number]
  (let [files (filter #(contains? sibling-files %)
                      (map #(format "GH%02d%s.MP4" % video-number)
                           (range 1 100)))]
    (println "Ingesting files:" files)
    (let [gpx-data (->> (shell {:out :string} (str "exiftool -ee -p gpx.fmt " (str/join " " files)))
                      :out
                      str/split-lines)
          timestamp (->> gpx-data
                        (map #(re-matches #"\s*<time>(.+)</time>" %))
                        (remove nil?)
                        first
                        second
                        (filter #(Character/isDigit %))
                        (apply str))
          gpx-filename (str "GoPro-" timestamp ".gpx")
          files-filename (str "GoPro-" timestamp ".files")
          mp4-filename (str "GoPro-" timestamp ".mp4")]
         (println "Writing filelist: " files-filename)
         (spit files-filename (str/join "\n" (map #(str "file '" % "'") files)))
         (println "Writing GPX file:" gpx-filename)
         (spit gpx-filename (str/join "\n" gpx-data))
         (println "Ready to run ffmpeg:")
         (println (str "  $ ffmpeg -f concat -i " files-filename " -vcodec libx265 -crf 30 -acodec copy " mp4-filename)))))

(defn preflight-ingest-video [first-filename]
  (if (not (and (= "GH" (subs first-filename 0 2))
                (= ".MP4" (subs first-filename 8 12))))
    (println "Filename does not match expected pattern.")
    (let [video-number (subs first-filename 4 8)]
      (if (not (= "01" (subs first-filename 2 4)))
        (println "Does not appear to be the first video. Try" (str "GH01" video-number ".MP4"))
        (ingest-video video-number)))))

(def required-opts #{:input})
(def cli-options
  [["-i" "--input INPUT.MP4" "First video file"
  :validate-fn #(contains? sibling-files %)
  :validate-msg "File not found in current directory"]])
(defn missing-required?
  "Returns true if opts is missing any of the required-opts"
  [opts]
  (not-every? opts required-opts))

(let [{:keys [options errors]} (parse-opts *command-line-args* cli-options)]
  (if errors
    (doseq [error errors]
      (println error))
    (if (missing-required? options)
      (println "Missing required option(s).")
      (preflight-ingest-video (:input options)))))