get most of bash script into node

2021-03-01 16:54:03 -07:00
parent b44ad9c362
commit 87e2f87302
3 changed files with 810 additions and 18 deletions
--- a/index.js
+++ b/index.js
@@ -1,22 +1,100 @@
-const spawn = require('child_process').spawn;
+const spawn = require('child_process').spawn
+const fs = require('fs')
+const youtubedl = require('youtube-dl-exec')
+const tmp = require('tmp')

-function readFromRegion(frame: Buffer, x: int, y: int, width: int, height: int) {
-	const convert = spawn('convert', ['-', '-negate', '-crop', `${width}x${height}+${x}+${y}`, '-'])
-	const result = new Buffer(512 * 1024)
-	let resultSize = 0
+const STREAM_URL = "https://www.youtube.com/henrikomagnifico/live"

-	convert.stdout.on('data', (data) => {
-		if (data.length + resultSize > result.length) {
-			// Buffer not big enough
-		} else {
-			resultSize += data.length
-			data.copy(result)
-		}
-	});
+function readText(tmpfile, charWhitelist) {
+	return new Promise((resolve, reject) => {
+		const tesseract = charWhitelist ? spawn('tesseract', [tmpfile.name, '-', '-c', `tessedit_char_whitelist="${charWhitelist}`]) : spawn('tesseract', [tmpfile.name, '-'])
+		let recognizedString = ''

-	convert.on('exit', (code) => {
+		tesseract.stdout.on('data', (data) => {
+			recognizedString += data;
+		})

-	});
-
-	convert.stdin.write(frame)
+		tesseract.on('exit', (code) => {
+			tmpfile.removeCallback()
+			if (code !== 0) {
+				reject()
+			} else {
+				resolve(recognizedString)
+			}
+		})
+	})
 }
+
+function thresholdImage(image, threshold) {
+
+}
+
+function getRegion(frame, x, y, width, height) { // Returns Promise<Buffer>
+    console.log("retrieving region")
+	const threshold = "15%"
+	return new Promise(function (resolve, reject) {
+		const tmpFile = tmp.fileSync()
+		const convert = spawn('convert', [`png:${frame.name}`, '-negate', '-crop', `${width}x${height}+${x}+${y}`, '-white-threshold', threshold, `png:${tmpFile.name}`])
+
+		convert.stderr.on('data', data => console.error(data.toString()))
+
+		convert.on('exit', (code) => {
+			if (code !== 0) {
+				reject()
+			} else {
+				console.log("got region", tmpFile.name)
+				resolve(tmpFile);
+			}
+		});
+	});
+}
+
+function getFrame(url) {
+	return new Promise((resolve, reject) => { // Returns Promise<Buffer>
+	    const frameFile = tmp.fileSync()
+		const ffmpeg = spawn('ffmpeg', ['-i', url, '-y', '-f', 'image2', '-c:v', 'png', '-frames:v', '1', frameFile.name])
+
+		ffmpeg.stderr.on('data', data => console.error(data.toString()))
+
+		ffmpeg.on('exit', (code) => {
+			if (code !== 0) {
+				reject()
+			} else {
+				console.log("got frame", frameFile.name)
+				resolve(frameFile)
+			}
+		})
+	});
+}
+
+function getYoutubeStream() {
+	return new Promise((resolve, reject) => {
+		youtubedl(STREAM_URL, {
+			dumpJson: true,
+			format: "best"
+		}).then(output => resolve(output.url))
+			.catch(err => reject(err))
+	})
+}
+
+getYoutubeStream()
+	.then(url => getFrame(url))
+	.then(frame => {
+		let title = '',
+			album = '',
+			duration = ''
+
+		const titlePromise = getRegion(frame, 432, 906, 1487, 54).then(titleRegion => readText(titleRegion))
+		const albumPromise = getRegion(frame, 440, 957, 1487, 32).then(albumRegion => readText(albumRegion))
+		const durationPromise = getRegion(frame, 0, 1028, 235, 34).then(durationRegion => readText(durationRegion, "1234567890:/"))
+
+		console.log("waiting for processors")
+		Promise.all([titlePromise, albumPromise, durationPromise]).then(values => {
+			frame.removeCallback()
+			title = values[0].trim()
+			album = values[1].trim()
+			duration = values[2].trim()
+
+			console.log(`${album}: ${title} (${duration})`)
+		}).catch(err => console.error(err))
+	}).catch(err => console.error(err))