mcopy/app/lib/ffmpeg/index.js

'use strict';

const uuid = require('uuid').v4;
const path = require('path');
const fs = require('fs-extra');

const exec = require('exec');
//const spawn = require('spawn');
const exit = require('exit');

let system = {};
let TMPDIR;

function padded_frame (i) {
	let len = (i + '').length;
	let str = i + '';
	for (let x = 0; x < 5 - len; x++) {
		str = '0' + str;
	}
	return str;
}

async function frame (video, frame, obj) {
	let padded = padded_frame(frame);
	let ext = 'tif';
	let tmpoutput;
	let cmd;
	let output;

	if (system.platform !== 'nix') {
		ext = 'png';
	}

	tmpoutput = path.join(TMPDIR, `export-${padded}.${ext}`)

	cmd = `ffmpeg -i "${video}" -vf select='gte(n\\,${frame})' -vframes 1 -compression_algo raw -pix_fmt rgb24 "${tmpoutput}"`

	//ffmpeg -i "${video}" -ss 00:00:07.000 -vframes 1 "export-${time}.jpg"
	//ffmpeg -i "${video}" -compression_algo raw -pix_fmt rgb24 "export-%05d.tiff"
	//-vf "select=gte(n\,${frame})" -compression_algo raw -pix_fmt rgb24 "export-${padded}.png"

	try {
		output = await exec(cmd);
		console.log(cmd);
	} catch (err) {
		console.error(err);
	}

	if (output) console.log(`"${output}"`);

}

async function frames (video, obj) {
	let tmppath = TMPDIR;
	let ext = 'tif';
	let tmpoutput;

	if (system.platform !== 'nix') {
		ext = 'png';
	}

	tmpoutput = path.join(tmppath, `export-%05d.${ext}`);
	try {
		await fs.mkdir(tmppath)
	} catch (Err) {
		console.error(err);
	}

	//ffmpeg -i "${video}" -compression_algo raw -pix_fmt rgb24 "${tmpoutput}"
}

async function clear (frame) {
	let padded = padded_frame(frame);
	let ext = 'tif';
	let tmppath;
	let tmpoutput;
	let cmd;
	let exists;

	if (system.platform !== 'nix') {
		ext = 'png';
	}

	tmppath = path.join(TMPDIR, `export-${padded}.${ext}`);

	try {
		exists = await fs.exists(tmppath);
	} catch (err) {
		console.error(err);
	}

	if (!exists) return false;

	try {
		await fs.unlink(tmppath);
		console.log(`Cleared frame ${tmppath}`);
	} catch (err) {
		console.error(err);
	}

	return true;
}

async function clearAll () {
	let tmppath = TMPDIR;
	let files;
	try {
		files = await fs.readdir(tmppath);
	} catch (err) {
		console.error(err);
	}
	if (files) {
		files.forEach(async (file, index) => {
			try {
				await fs.unlink(path.join(tmppath, file));
			} catch (err) {
				console.error(err);
			}
		});
	}
}

async function checkDir () {
	let exists;
	try {
		exists = await fs.exists(TMPDIR);
	} catch (err) {
		console.error('Error checking for tmp dir', err);
	}

	if (!exists) {
		try {
			await fs.mkdir(TMPDIR);
			console.log(`Created tmpdir ${TMPDIR}`);
		} catch (err) {
			console.error('Error creating tmp dir', err);
		}
	}
	try {
		await clearAll();
	} catch (err) {
		console.error(err);
	}
}

module.exports = (sys) => {
	system = sys;
	TMPDIR = path.join(system.tmp, 'intval_go_node');

	checkDir();

	return {
		frames,
		frame,
		clear,
		clearAll
	}
}