# HLD Author Download HLD Author for Windows Download HLD Author for Mac {% hint style="warning" %} HLD Author is currently in beta and has some known issues and limitations. See [below](https://app.gitbook.com/o/-MX3JS7bUvT5jVmoXUcj/s/E9AhVJoaDxXfUQueIzAL/~/edit/~/changes/29/apps-and-tools/hld-author#known-issues) for more details {% endhint %} {% embed url="" %} HLD Author is a desktop application for previewing and preparing video content for use with the HLD [Demo Media Player](/managing-content/using-the-demo-media-player.md). It allows you to validate how a video will appear on an HLD and, if needed, export a version that is compatible with the Demo Media Player included with your display. HLD Author is intended for quick validation and preparation of video content. It is not currently used for content creation — to create content, see our content pipelines for [video editors](/content-pipelines/creating-with-video-editors.md), [3D tools](/content-pipelines/creating-videos-with-3d-tools.md), [GenAI](/content-pipelines/creating-videos-with-genai.md), and [real-world footage](/content-pipelines/filming-real-world-content.md).
## What is HLD Author? HLD Author is a desktop application that helps you: * Preview how your video will appear on an HLD without requiring physical access to the display * Validate whether a video is compatible with the HLD Demo Media Player * Export a properly formatted version **only when required** for the Demo Media Player Please note that you should not export your videos from HLD Author if you intend to use them with third-party digital signage solutions, like BrightSign players or Yodeck, as these tools have their own video processing conventions. If you need advanced, scriptable, or batch video processing, we provide another tool, **HLD Encoder** (coming soon).
## Loading your video To begin, click **Load Video** and select a video file from your computer. Supported formats are `.mp4`, `.avi`, and `.mov`. Once loaded, your video will appear in the HLD preview. You can use this preview to evaluate framing and overall presentation before exporting. ### Camera controls * **Left-click + drag**: Rotate around the display * **Scroll wheel**: Zoom in and out These controls help you understand how your content reads from different viewing angles.
## Video validation When a video is loaded, HLD Author automatically checks whether it is compatible with the Demo Media Player.
If the video does not meet the required specifications, a popup will appear explaining that the video must be re-encoded to work correctly with the Demo Media Player. You may dismiss this warning and continue previewing. Re-encoding is **not required** for previewing. To understand what changes HLD Author applies during export, see our documentation on [media specs and encoding](/resources/media-specs-and-encoding.md).
## Exporting for the Demo Media Player Click **Export** to generate a Demo Media Player–compatible version of your video. {% hint style="warning" %} **Only export from HLD Author if you plan to use the HLD Demo Media Player.** Do **not** use exported files from HLD Author with other digital signage players such as BrightSign. {% endhint %} #### Export Behavior * The exported file will have `_HLD_encoded` appended to the filename * Audio is preserved * A progress bar shows export status * You may set the output location manually or use the folder button to browse * When complete, you can open the export folder directly The exported video is compatible with **all HLD sizes** (16″, 27″, and 86″) when used with the Demo Media Player. The device selector dropdown is only used to preview in a realistic simulation of that HLD and does not affect export behavior.
## Sample content and tutorials On the left side of the app, you’ll find sample videos demonstrating different types of HLD content, including: * Real people * Animated characters * Product visuals Each sample includes a **“See how it’s made”** link that opens a relevant tutorial explaining the content creation approach at a high level. These examples are intended to provide inspiration and context, not prescriptive workflows.
## Documentation and support * **Docs and guides** (bottom left) link to content creation workflows, including DCC tools and AI-generated content * **Support** (top right) links to FAQs and ways to contact our support team If you are new to the HLD ecosystem, these resources provide additional background on how the display works and how to create effective content.
## Advanced workflows If you need: * Batch processing * Command-line control * Integration into automated pipelines See HLD Encoder (coming soon), which is designed for advanced and production-scale video preparation.
## Known issues * HLD Author currently requires the [HEVC Windows Video Extension](https://apps.microsoft.com/detail/9nmzlz57r3t7?hl=en-US) — previews may not work if you do not have this installed. Subsequent versions will include HEVC decoding and this will no longer be required. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://hlddocs.lookingglassfactory.com/apps-and-tools/hld-author.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.