server/helpers/image-utils.ts

   1 import { copy, readFile, remove, rename } from 'fs-extra'
   2 import * as Jimp from 'jimp'
   3 import { extname } from 'path'
   4 import { convertWebPToJPG, processGIF } from './ffmpeg-utils'
   5 import { logger } from './logger'
   6
   7 async function processImage (
   8   path: string,
   9   destination: string,
  10   newSize: { width: number, height: number },
  11   keepOriginal = false
  12 ) {
  13   const extension = extname(path)
  14
  15   if (path === destination) {
  16     throw new Error('Jimp/FFmpeg needs an input path different that the output path.')
  17   }
  18
  19   logger.debug('Processing image %s to %s.', path, destination)
  20
  21   // Use FFmpeg to process GIF
  22   if (extension === '.gif') {
  23     await processGIF(path, destination, newSize)
  24   } else {
  25     await jimpProcessor(path, destination, newSize, extension)
  26   }
  27
  28   if (keepOriginal !== true) await remove(path)
  29 }
  30
  31 // ---------------------------------------------------------------------------
  32
  33 export {
  34   processImage
  35 }
  36
  37 // ---------------------------------------------------------------------------
  38
  39 async function jimpProcessor (path: string, destination: string, newSize: { width: number, height: number }, inputExt: string) {
  40   let jimpInstance: Jimp
  41   const inputBuffer = await readFile(path)
  42
  43   try {
  44     jimpInstance = await Jimp.read(inputBuffer)
  45   } catch (err) {
  46     logger.debug('Cannot read %s with jimp. Try to convert the image using ffmpeg first.', path, { err })
  47
  48     const newName = path + '.jpg'
  49     await convertWebPToJPG(path, newName)
  50     await rename(newName, path)
  51
  52     jimpInstance = await Jimp.read(path)
  53   }
  54
  55   await remove(destination)
  56
  57   // Optimization if the source file has the appropriate size
  58   if (await skipProcessing({ jimpInstance, newSize, imageBytes: inputBuffer.byteLength, inputExt, outputExt: extname(destination) })) {
  59     return copy(path, destination)
  60   }
  61
  62   await jimpInstance
  63     .resize(newSize.width, newSize.height)
  64     .quality(80)
  65     .writeAsync(destination)
  66 }
  67
  68 function skipProcessing (options: {
  69   jimpInstance: Jimp
  70   newSize: { width: number, height: number }
  71   imageBytes: number
  72   inputExt: string
  73   outputExt: string
  74 }) {
  75   const { jimpInstance, newSize, imageBytes, inputExt, outputExt } = options
  76   const { width, height } = newSize
  77
  78   if (jimpInstance.getWidth() > width || jimpInstance.getHeight() > height) return false
  79   if (inputExt !== outputExt) return false
  80
  81   const kB = 1000
  82
  83   if (height >= 1000) return imageBytes <= 200 * kB
  84   if (height >= 500) return imageBytes <= 100 * kB
  85
  86   return imageBytes <= 15 * kB
  87 }