Editing HDR Source Clips

Documentation Documentation - English
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Introduction

Some users report that their clip looks “washed out” or “pale” in Shotcut compared to media players. This is often because the clip is encoded as High Dynamic Range (HDR). Shotcut has very limited support for editing HDR, and most users do not want to bother with HDR output. So, HDR clips can be converted to SDR that Shotcut can edit.

Identifying HDR Clips

To identify HDR clips in Shotcut, open the clip and view the Properties panel. In the properties panel, look for the “Color transfer” field in the Video tab.

The following Color transfer types are HDR:

  • SMPTE ST2084 (PQ)
  • SMPTE ST428
  • ARIB B67 (HLG)

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Transcode HDR to SDR

When opening HDR clips in Shotcut, you may be prompted to convert the file. If you are not prompted, follow these steps:

  1. Click Convert… in the Properties panel. A dialog window opens.
  2. Open the “Advanced” section of the dialog.
  3. Ensure that the Convert to BT.709 colorspace checkbox is checked.
  4. Click OK to start the conversion.

After the conversion is complete, the clip will be replaced with the converted clip.

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Convert Color With a LUT

Instead of converting a HLG HDR clip, you can use it as-is with or without a proxy and use a LUT to convert it to SDR. Our Resources page has a LUTs section with some freely downloadable LUTs from NBC/Universal that can convert from HLG HDR to BT.709 SDR. “SL” in the file name means scene light, and “DL” means display light. Use either of these with the LUT (3D) video filter.

How to Edit HLG HDR Video With Shotcut

Version 25.05 of Shotcut added limited support for editing, processing, and exporting HDR video. This is focused on HLG HDR at this time because my cameras are iPhone and GoPro HERO13 that both can shoot in HLG. It is also possible to record in log color, but that is not the focus here.

Limitations

  • No embedded HDR preview! You can only see the HDR video as HDR in Shotcut when using a Blackmagic Design SDI/HDMI device with Settings > Player > External Monitor. As an upside for this, since HLG is supposed to provide a satisfactory experience when viewed on a SDR screen, this gives you a way to simultaneously preview both SDR and HDR.
  • If you want to do any filtering, transitions, or track blending/compositing you must enable Settings > GPU Effects and limit yourself to video filters with the tags #gpu or #10bit on 10-bit video sources. (GPU filters always support a 10-bit workflow but not all CPU video filters.)
  • When not using GPU Effects, you can do a simple cuts-only editing (trimming and sequencing). It is OK to include text on a solid color or still image with this, but its color will look a little different than the preview.
  • There is a bug in version 25.05 converting color range of 10-bit video between full and limited. You should export the same range as the source. This has been fixed for the next version.

A Simple, Inexpensive Setup for HLG HDR

This also includes how I do 5.1 surround sound.

  • recording with GoPro MAX and HERO13 cameras – less than $500 each,
  • previewing on a 42" 4K HDR (800 nits) Samsung TV I bought in 2018 for about $650,
  • using a Blackmagic Design DeckLink Mini Monitor 4K that I bought this year for $200, and
  • playing through a Sony AV receiver I bought in 2018 for less than $200.

Shotcut Settings

  • Turn on Settings > GPU Effects.
  • Choose Settings > Audio Channels > 6 (5.1 surround) if desired.
  • Create and use a custom Video Mode with Colorspace = ITU-R BT.2020.
  • Ignore conversion dialogs when importing video.
  • Add and edit media as usual. For video filters on HLG video sources, use only #gpu and #10bit filters. You can use these tags when searching filters.
  • To convert first order (4 channel) Ambisonic audio to 5.1 surround, use the Ambisonic Decoder audio filter.
  • It improves performance to use proxies and preview scaling, but the proxy for HLG must have been created with version 25.05 or later.
  • It may be beneficial to use a SDR2HLG LUT on the BT.709 video sources. Otherwise, consider to do some manual color adjustment.
  • In Export, select a preset from the “ten_bit” category. I have tested AV1, HEVC, and ProRes.
  • If the Shotcut version is 25.05 and the source HLG video is primarily full color range (for example, GoPro HERO13 is but not iPhone), set Export > Video > Color range = Full (JPEG).
  • In Export > Other add the line color_trc=arib-std-b67.
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