49 lines
1.2 KiB
JavaScript
Executable File
49 lines
1.2 KiB
JavaScript
Executable File
// programs/input.js
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'use strict';
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const fs = require('fs');
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const path = require('path');
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function byIdCaptureCandidates() {
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const dir = '/dev/v4l/by-id';
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try {
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if (!fs.existsSync(dir)) return [];
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return fs.readdirSync(dir)
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.filter(n => n.endsWith('-index0'))
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.map(n => fs.realpathSync(path.join(dir, n)));
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} catch {
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return [];
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}
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}
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function naiveVideoNodes() {
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try {
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return fs.readdirSync('/dev')
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.filter(n => /^video\d+$/.test(n))
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.map(n => path.join('/dev', n))
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.sort((a, b) => Number(a.replace(/\D/g, '')) - Number(b.replace(/\D/g, '')));
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} catch {
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return ['/dev/video0', '/dev/video2'];
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}
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}
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function pickDevices(env = process.env) {
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const DEV0 = env.DEV0 || null;
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const DEV1 = env.DEV1 || null;
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if (DEV0 && DEV1) return [DEV0, DEV1];
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const byId = byIdCaptureCandidates();
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if (DEV0 || DEV1) {
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const pool = byId.length ? byId : naiveVideoNodes();
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const d0 = DEV0 || pool[0];
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const d1 = DEV1 || pool.find(d => d !== d0) || pool[1];
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return [d0, d1];
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}
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if (byId.length >= 2) return [byId[0], byId[1]];
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const naive = naiveVideoNodes();
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return [naive[0], naive[1]];
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}
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module.exports = { pickDevices }; |