fix: remove pi model check for JPEG signature

Author: gregnr

package.json

@@ -22,9 +22,7 @@
     "test": "jest --runInBand",
     "prepublishOnly": "yarn clean && yarn build"
   },
-  "dependencies": {
-    "systeminformation": "4"
-  },
+  "dependencies": {},
   "devDependencies": {
     "@lcdev/eslint-config": "0.2",
     "@lcdev/jest": "0.2",

src/lib/still-camera.ts

@@ -1,4 +1,3 @@
-import * as si from 'systeminformation';
 import { AwbMode, ExposureMode, Flip, Rotation } from '..';
 import { spawnPromise } from '../util';
 import { getSharedArgs } from './shared-args';
@@ -25,6 +24,8 @@ export interface StillOptions {
 export default class StillCamera {
   private readonly options: StillOptions;
 
+  static readonly jpegSignature = Buffer.from([0xff, 0xd8, 0xff, 0xe1]);
+
   constructor(options: StillOptions = {}) {
     this.options = {
       rotation: Rotation.Rotate0,
@@ -34,23 +35,6 @@ export default class StillCamera {
     };
   }
 
-  static async getJpegSignature() {
-    const systemInfo = await si.system();
-    switch (systemInfo.model) {
-      case 'BCM2711':
-      case 'BCM2835 - Pi 3 Model B':
-      case 'BCM2835 - Pi 3 Model B+':
-      case 'BCM2835 - Pi 4 Model B':
-      case 'BCM2835 - Pi Zero':
-      case 'BCM2835 - Pi Zero W':
-        return Buffer.from([0xff, 0xd8, 0xff, 0xe1]);
-      default:
-        throw new Error(
-          `Could not determine JPEG signature. Unknown system model '${systemInfo.model}'`,
-        );
-    }
-  }
-
   async takeImage() {
     try {
       return await spawnPromise('raspistill', [

src/lib/stream-camera.ts

@@ -1,7 +1,6 @@
 import { ChildProcessWithoutNullStreams, spawn } from 'child_process';
 import { EventEmitter } from 'events';
 import * as stream from 'stream';
-import * as si from 'systeminformation';
 import { AwbMode, ExposureMode, Flip, Rotation } from '..';
 import { getSharedArgs } from './shared-args';
 
@@ -53,6 +52,8 @@ class StreamCamera extends EventEmitter {
   private childProcess?: ChildProcessWithoutNullStreams;
   private streams: Array<stream.Readable> = [];
 
+  static readonly jpegSignature = Buffer.from([0xff, 0xd8, 0xff, 0xdb, 0x00, 0x84, 0x00]);
+
   constructor(options: StreamOptions = {}) {
     super();
 
@@ -67,23 +68,6 @@ class StreamCamera extends EventEmitter {
     };
   }
 
-  static async getJpegSignature() {
-    const systemInfo = await si.system();
-    switch (systemInfo.model) {
-      case 'BCM2711':
-      case 'BCM2835 - Pi 3 Model B':
-      case 'BCM2835 - Pi 3 Model B+':
-      case 'BCM2835 - Pi 4 Model B':
-      case 'BCM2835 - Pi Zero':
-      case 'BCM2835 - Pi Zero W':
-        return Buffer.from([0xff, 0xd8, 0xff, 0xdb, 0x00, 0x84, 0x00]);
-      default:
-        throw new Error(
-          `Could not determine JPEG signature. Unknown system model '${systemInfo.model}'`,
-        );
-    }
-  }
-
   startCapture(): Promise<void> {
     // eslint-disable-next-line no-async-promise-executor
     return new Promise(async (resolve, reject) => {
@@ -183,7 +167,6 @@ class StreamCamera extends EventEmitter {
         // Wait for first data event to resolve promise
         this.childProcess.stdout.once('data', () => resolve());
 
-        const jpegSignature = await StreamCamera.getJpegSignature();
         let stdoutBuffer = Buffer.alloc(0);
 
         // Listen for image data events and parse MJPEG frames if codec is MJPEG
@@ -196,14 +179,17 @@ class StreamCamera extends EventEmitter {
 
           // Extract all image frames from the current buffer
           while (true) {
-            const signatureIndex = stdoutBuffer.indexOf(jpegSignature, 0);
+            const signatureIndex = stdoutBuffer.indexOf(StreamCamera.jpegSignature, 0);
 
             if (signatureIndex === -1) break;
 
             // Make sure the signature starts at the beginning of the buffer
             if (signatureIndex > 0) stdoutBuffer = stdoutBuffer.slice(signatureIndex);
 
-            const nextSignatureIndex = stdoutBuffer.indexOf(jpegSignature, jpegSignature.length);
+            const nextSignatureIndex = stdoutBuffer.indexOf(
+              StreamCamera.jpegSignature,
+              StreamCamera.jpegSignature.length,
+            );
 
             if (nextSignatureIndex === -1) break;
 

yarn.lock

@@ -3969,11 +3969,6 @@ symbol-tree@^3.2.2:
   version "3.2.2"
   resolved "https://registry.yarnpkg.com/symbol-tree/-/symbol-tree-3.2.2.tgz#ae27db38f660a7ae2e1c3b7d1bc290819b8519e6"
 
-systeminformation@4:
-  version "4.23.0"
-  resolved "https://registry.yarnpkg.com/systeminformation/-/systeminformation-4.23.0.tgz#9a38262d3f6c2db4b7b5abd4808a2035c8a162c2"
-  integrity sha512-Gx24ttVOuqKpaGJ5bMYOt/Y7VTntc/Du6h0oh1evKPjxXdSeAcwk1+xsTxEizN3+ZuuVyoHl5hV0jtlHDOGeYA==
-
 table@^5.2.3:
   version "5.4.6"
   resolved "https://registry.yarnpkg.com/table/-/table-5.4.6.tgz#1292d19500ce3f86053b05f0e8e7e4a3bb21079e"