fix: use limited range in SDR

[hgaiser]

Thanks to hgaiser/moonshine#123

Also, PSNR values went from (main) :

  PASS: PSNR = 61.57 dB
  PASS: PSNR = 58.82 dB
  PASS: PSNR = 62.29 dB
  PASS: PSNR = 63.95 dB
  PASS: PSNR = 53.34 dB
  PASS: PSNR = 55.93 dB
  PASS: PSNR = 59.51 dB
  PASS: PSNR = 53.25 dB

To:

  PASS: PSNR = 61.57 dB
  PASS: PSNR = 58.82 dB
  PASS: PSNR = 62.29 dB
  PASS: PSNR = 63.95 dB
  PASS: PSNR = 59.87 dB
  PASS: PSNR = 61.23 dB
  PASS: PSNR = 59.51 dB
  PASS: PSNR = 59.65 dB

The only two that changed (and improved!) were for H265 encoding.