1 hunk out of 1 hunk failed

[about-bl4nk]

When I run by the tutorial on https://www.artificialworlds.net/blog/2018/01/07/recording-gameplay-videos-on-retropie/ when I'm supposed to run
bash build-retroarch-with-ffmpeg.sh
I get this output:
`+ echo 'Building RetroArch with ffmpeg enabled'
Building RetroArch with ffmpeg enabled

• echo --------------------------------------

---

• echo

• echo '=== Downloading patch file ==='
  === Downloading patch file ===

• wget https://raw.githubusercontent.com/andybalaam/retropie-recording/master/enable-ffmpeg.patch
  --2022-05-26 19:46:16-- https://raw.githubusercontent.com/andybalaam/retropie-recording/master/enable-ffmpeg.patch
  Resolving raw.githubusercontent.com (raw.githubusercontent.com)... 185.199.108.133, 185.199.109.133, 185.199.110.133, ...
  Connecting to raw.githubusercontent.com (raw.githubusercontent.com)|185.199.108.133|:443... connected.
  HTTP request sent, awaiting response... 200 OK
  Length: 690 [text/plain]
  Saving to: ‘enable-ffmpeg.patch.3’

enable-ffmpeg.patch.3 100%[=============================>] 690 --.-KB/s in 0s

2022-05-26 19:46:17 (2.41 MB/s) - ‘enable-ffmpeg.patch.3’ saved [690/690]

• echo '=== Patching RetroArch code to enable ffmpeg ==='
  === Patching RetroArch code to enable ffmpeg ===
• cd RetroPie-Setup
• patch -p1
  patching file scriptmodules/emulators/retroarch.sh
  Hunk FFMPEG build fail #1 FAILED at 40.
  1 out of 1 hunk FAILED -- saving rejects to file scriptmodules/emulators/retroarch.sh.rej
  `
  Why is it doing this?