shortcode,video - emit image for local videos in markdown output

news/changelog-1.8.md

@@ -79,6 +79,10 @@ All changes included in 1.8:
 
 - [#13316](https://github.com/quarto-dev/quarto-cli/issues/13316): `code-line-numbers: "1"` correctly highlight the first line now.
 
+### `markdown` formats
+
+- ([#12630])(https://github.com/quarto-dev/quarto-cli/issues/12630)): emit image element for `video` shortcodes targeting local videos.
+
 ## Projects
 
 ### `website`

src/resources/extensions/quarto/video/video.lua

@@ -346,6 +346,15 @@ return {
       return htmlVideo(srcValue, heightValue, widthValue, titleValue, startValue, aspectRatio)
     elseif quarto.doc.is_format("asciidoc") then
       return asciidocVideo(srcValue, heightValue, widthValue, titleValue, startValue, aspectRatio)
+    elseif quarto.doc.is_format("markdown") then
+      if srcValue:sub(1, 4) == "http" then
+        -- For remote videos, we can emit a link
+        return pandoc.Link(srcValue, titleValue or srcValue)
+      else
+        -- For local
+        -- use an image to allow markdown previewers to show video
+        return pandoc.Image(quarto.utils.as_inlines(titleValue), srcValue)
+      end
     else
       -- Fall-back to a link of the source
       return pandoc.Link(srcValue, srcValue)

tests/docs/smoke-all/2025/09/03/issue-12630.qmd

@@ -0,0 +1,11 @@
+---
+title: hello
+_quarto:
+  tests:
+    gfm:
+      ensureFileRegexMatches:
+        - - "\\!\\[\\]\\(local.mp4\\)"
+        - []
+---
+
+{{< video local.mp4 >}}