shared/ffmpeg/shared/encoder-options.ts

   1 import { FfmpegCommand } from 'fluent-ffmpeg'
   2 import { EncoderOptions } from '@shared/models'
   3 import { buildStreamSuffix } from '../ffmpeg-utils'
   4
   5 export function addDefaultEncoderGlobalParams (command: FfmpegCommand) {
   6   // avoid issues when transcoding some files: https://trac.ffmpeg.org/ticket/6375
   7   command.outputOption('-max_muxing_queue_size 1024')
   8          // strip all metadata
   9          .outputOption('-map_metadata -1')
  10          // allows import of source material with incompatible pixel formats (e.g. MJPEG video)
  11          .outputOption('-pix_fmt yuv420p')
  12 }
  13
  14 export function addDefaultEncoderParams (options: {
  15   command: FfmpegCommand
  16   encoder: 'libx264' | string
  17   fps: number
  18
  19   streamNum?: number
  20 }) {
  21   const { command, encoder, fps, streamNum } = options
  22
  23   if (encoder === 'libx264') {
  24     // 3.1 is the minimal resource allocation for our highest supported resolution
  25     command.outputOption(buildStreamSuffix('-level:v', streamNum) + ' 3.1')
  26
  27     if (fps) {
  28       // Keyframe interval of 2 seconds for faster seeking and resolution switching.
  29       // https://streaminglearningcenter.com/blogs/whats-the-right-keyframe-interval.html
  30       // https://superuser.com/a/908325
  31       command.outputOption(buildStreamSuffix('-g:v', streamNum) + ' ' + (fps * 2))
  32     }
  33   }
  34 }
  35
  36 export function applyEncoderOptions (command: FfmpegCommand, options: EncoderOptions) {
  37   command.inputOptions(options.inputOptions ?? [])
  38     .outputOptions(options.outputOptions ?? [])
  39 }