gpx2exif.js

/*jshint esversion: 6 */

const exiftool = require("exiftool-vendored").exiftool; //yarn add exiftool-vendored
const gpxParser = require("gpxparser"); //yarn add gpxparser
const fs = require("fs");

var gpx = new gpxParser();
gpx.parse(fs.readFileSync("c:/data/Geo.gpx"));
var mainTrack = gpx.tracks[0];

console.log("let's go!");

//TODO: handle the async better
const dirName = "c:/data/";
fs.readdir(dirName, (err, fileNames) => {
  fileNames.filter(s => !s.endsWith(".gpx")).forEach((fileName) => {
    exiftool
      .read(dirName + fileName)
      .then((tags) => {
        var dateTaken = tags.DateTimeOriginal.toDate();
        //the dst timing is already done
        //if (tags.DaylightSavings === "Yes") {
        //  dateTaken.setHours(dateTaken.getHours() - 1);
        //}
        const firstGpxTrackBefore = mainTrack.points
          .filter(p => p.time < dateTaken && dateTaken - p.time < 1000 * 60)
          .slice(-1)
          .pop();
        const firstGpxTrackAfter = mainTrack.points.filter(
          p => p.time > dateTaken && p.time - dateTaken < 1000 * 60
        )[0];

        var finalPoint = {};
        if (firstGpxTrackBefore && firstGpxTrackAfter) {
          //TODO: interpolate instead of average
          finalPoint = {
            lat: (firstGpxTrackBefore.lat + firstGpxTrackAfter.lat) / 2.0,
            lon: (firstGpxTrackBefore.lon + firstGpxTrackAfter.lon) / 2.0,
            ele: (firstGpxTrackBefore.ele + firstGpxTrackAfter.ele) / 2.0,
          };
        } else {
          finalPoint = firstGpxTrackBefore || firstGpxTrackAfter || finalPoint;
        }
        if (finalPoint.lat && finalPoint.lon && finalPoint.ele) {
          exiftool
            .write(
              dirName + fileName,
              {
                GPSLatitude: finalPoint.lat,
                GPSLatitudeRef: finalPoint.lat,
                GPSLongitude: finalPoint.lon,
                GPSLongitudeRef: finalPoint.lon,
                GPSAltitude: finalPoint.ele,
              },
              ["-overwrite_original"]
            )
            .then(() => {
              console.log(`finished: ${fileName}`);
            })
            .catch((err) => {
              console.log(err);
            });
        } else {
          console.log(`no trackpoint that matches ${fileName}`);
        }
      })
      .catch((err) => {
        console.log(err);
      });
  });
});