For remapping frames of a timelapse created with the Ricoh Theta

remap_all.js

// Tested with Node.js 0.10 and with "nona" from Hugin 2013.
//
// Used to create: <https://vine.co/v/O5DI55QZnii>
//
// Original images from the Theta need to be in the sub directory `raw_frames`.
//
// Remaped images go into the sub directory `frames`.
//
// Remapping is parameterized, see the function `createPtoFile`.
//
// Written by Felix E. Klee <felix.klee@inka.de>.
//
// To the extent possible under law, the author(s) have dedicated all copyright
// and related and neighboring rights to this software to the public domain
// worldwide. This software is distributed without any warranty. You should
// have received a copy of the CC0 Public Domain Dedication along with this
// software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.

/*jslint node: true, maxlen: 79 */

'use strict';

var fs = require('fs'),
    execFile = require('child_process').execFile,
    remapFrames,
    remapFrame,
    ptoFilename = 'remap.pto',
    createPtoFile,
    exitWithOutput,
    numberOfFiles;

exitWithOutput = function (dataToOutput, code) {
    console.error(dataToOutput);
    process.exit(code);
};

createPtoFile = function (n, onSuccess) {
    var t = numberOfFiles * 2, // total number of frames
        l = t - 1, // last frame
        fieldOfView =
            100 +
            150 * (1 - Math.pow(n / l - 1, 4)) + // ease out
            4 * l / (l - n), // warp
        pitch =
            10 + // some offset necessary to avoid unexpected flip
            180 * n / t,
        s = [
            [
                'p', 'f4', 'w1500', 'h1500',
                'v' + fieldOfView,
                'R0', 'nJPEG'
            ].join(' '),
            [
                'i', 'f4', 'w3584', 'h1792', 'v360',
                'r90',
                'p90' + pitch, // better use `p` instead of `p90` (bug)
                'y90',
                'n"input.jpg"'
            ].join(' ')
        ].join('\n');

    fs.writeFile(ptoFilename, s, function (err) {
        if (err) {
            exitWithOutput(err, 1);
        }
        onSuccess();
    });
};

remapFrame = function (filename, frameNumber, onSuccess) {
    var outputFilename = String('000' + frameNumber).slice(-3);

    execFile("nona", [
        '-o',
        'frames/' + outputFilename,
        ptoFilename,
        'raw_frames/' + filename
    ], function (err) {
        if (err) {
            exitWithOutput(err, 1);
        }
        onSuccess();
    });
};

remapFrames = function (filenames, frameNumber) {
    var filename;

    if (filenames.length === 0) {
        if (numberOfFiles > 0) {
            process.stdout.write('\n');
        }
        return;
    }

    if (frameNumber === undefined) {
        frameNumber = 0;
    }

    process.stdout.write('.');

    // Here: Every file is used twice, for smoother animation:
    filename = filenames[0];
    if (frameNumber % 2 === 1) {
        filenames.shift();
    }

    createPtoFile(frameNumber, function () {
        remapFrame(filename, frameNumber, function () {
            remapFrames(filenames, frameNumber + 1);
        });
    });
};

fs.readdir('raw_frames', function (err, filenames) {
    if (err) {
        exitWithOutput(err, err.errno);
    }
    numberOfFiles = filenames.length;
    remapFrames(filenames);
});