create map track video from Exif tags

getmaps.sh

#!/bin/sh

# getmap.sh - download static maps from Google Maps
# Copyright (C) 2018 Matteo Croce <mcroce@redhat.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

[ $# -lt 2 ] && exec echo "usage: $0 <file.mp4> *.jpg"

out=$1
shift

for i in mencoder MP4Box phototrack; do
	which $i 2>/dev/null >/dev/null || exec echo "missing tool: $i"
done

key='<your google key>'

trap "rm -rf /tmp/map-$$.csv /tmp/map-$$.264 /tmp/map-$$" EXIT

phototrack "$@" >/tmp/map-$$.csv

i=0
urls=$(awk -F, '!/^timestamp/{print "https://maps.googleapis.com/maps/api/staticmap?language=it&key='"$key"'&center="$2","$3"&zoom=7&scale=2&size=320x320&markers=anchor:center|icon:http://i.imgur.com/ODjBo2X.png|"$2","$3}' /tmp/map-$$.csv)

mkdir /tmp/map-$$
for u in $urls; do
	n=$(printf %05d $i)
	curl -s "$u" >"/tmp/map-$$/$n.png"
	i=$((i + 1))
	echo -ne "\r$n"
done

mencoder "mf:///tmp/map-$$/*.png" -vf harddup -nosound -ovc x264 -x264encopts crf=22:preset=slower -of rawvideo -o /tmp/map-$$.264
MP4Box -new -no-iod -no-sys -brand mp42 -fps 25 -add /tmp/map-$$.264 "$out"

ls -lh "$out"

phototrack.go

/*
 * phototrack - get track CSV file from Exif tags
 * Copyright (C) 2018 Matteo Croce <mcroce@redhat.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

package main

import (
	"fmt"
	"os"
	"regexp"
	"strconv"
	"time"

	"github.com/xiam/exif"
)

const (
	timeLayout = "2006:01:02 15:04:05"
)

type latLong struct {
	lat float64
	lon float64
}

func exifDate(s string) (time.Time, error) {
	return time.ParseInLocation(timeLayout, s, time.Local)
}

var coordRe = regexp.MustCompile(`^(\d+),\s+(\d+),\s+(\d+\.\d+)(\s+[NESW])?$`)

func exifLatLong(s string) (latlong float64, err error) {
	coord := coordRe.FindStringSubmatch(s)
	if len(coord) != 4 && len(coord) != 5 {
		return 0, fmt.Errorf("invalid coord %s", s)
	}

	deg, err := strconv.Atoi(coord[1])
	if err != nil {
		return 0, err
	}

	min, err := strconv.Atoi(coord[2])
	if err != nil {
		return 0, err
	}

	sec, err := strconv.ParseFloat(coord[3], 64)
	if err != nil {
		return 0, err
	}

	decimal := float64(deg) + float64(min)/60 + float64(sec)/3600
	if len(coord[4]) > 0 {
		switch coord[4] {
		case "W":
			fallthrough
		case "S":
			decimal = -decimal
		case "N":
		case "E":
		default:
			return 0, fmt.Errorf("invalid cardinal %s", coord[4])
		}
	}

	return decimal, nil
}

func getTags(path string) (int64, *latLong, error) {
	data, err := exif.Read(path)
	if err != nil {
		return 0, nil, err
	}

	date, err := exifDate(data.Tags["Date and Time"])
	if err != nil {
		return 0, nil, err
	}

	var ll *latLong

	if lat, err := exifLatLong(data.Tags["Latitude"]); err == nil {
		if lon, err := exifLatLong(data.Tags["Longitude"]); err == nil {
			ll = &latLong{lat, lon}
		}
	}

	return date.Unix(), ll, nil
}

func printScaled(times []int64, start, end *latLong) {
	for i, ts := range times {
		fmt.Printf("%d,%f,%f\n", ts,
			start.lat+(end.lat-start.lat)/float64(len(times)+1)*float64(i+1),
			start.lon+(end.lon-start.lon)/float64(len(times)+1)*float64(i+1))
	}
}

func printTags(paths []string) error {
	var lastLL *latLong
	var lastTS []int64

	for _, file := range paths {
		date, coord, err := getTags(file)
		if err != nil {
			return err
		}
		if coord != nil {
			if lastTS != nil {
				printScaled(lastTS, lastLL, coord)
				lastTS = nil
			}
			fmt.Printf("%d,%f,%f\n", date, coord.lat, coord.lon)
			lastLL = coord
		} else {
			lastTS = append(lastTS, date)
		}
	}

	return nil
}

func main() {
	if len(os.Args) < 2 {
		fmt.Fprintln(os.Stderr, "usage:", os.Args[0], "files...")
		os.Exit(1)
	}

	fmt.Println("timestamp,latitude,longitude")

	if err := printTags(os.Args[1:]); err != nil {
		panic(err)
	}
}