@@ -0,0 +1,66 @@
+name: dscan-snap-multi
+on:
+  push:
+    branches: [ci/dscan-snap-multi]
+jobs:
+  snap:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest]
+    timeout-minutes: 40
+    steps:
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 24
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+      - name: ffmpeg
+        shell: bash
+        run: (command -v ffmpeg >/dev/null) || (choco install ffmpeg -y --no-progress >/dev/null 2>&1 || sudo apt-get install -y ffmpeg >/dev/null)
+      - name: build project
+        shell: python
+        run: |
+          import os,subprocess
+          os.makedirs("proj/compositions",exist_ok=True); os.chdir("proj")
+          open("hyperframes.json","w").write("{}")
+          subprocess.run(["ffmpeg","-v","error","-y","-f","lavfi","-i","color=c=0x2255aa:s=300x300","-frames:v","1","logo.png"],check=True)
+          beats=[(14.5,"A"),(18.5,"B"),(22.5,"C"),(25.01,"D"),(27.01,"E")]
+          def tmpl(cid,body,js,css=""):
+              return f'<template id="{cid}-template"><div data-composition-id="{cid}" data-width="1920" data-height="1080" data-duration="30">{body}<style>[data-composition-id="{cid}"]{{position:relative;width:1920px;height:1080px;font-family:Arial;color:#fff}}{css}</style><script>(function(){{const tl=gsap.timeline({{paused:true}});{js}window.__timelines=window.__timelines||{{}};window.__timelines["{cid}"]=tl;}})();</script></div></template>'
+          # brand: the same logo repeated at every beat
+          body="".join(f'<img class="logo" id="logo{i}" src="../logo.png" style="position:absolute;left:{100+i*300}px;top:100px;width:200px;opacity:0">' for i,_ in enumerate(beats))
+          js="".join(f'tl.to("#logo{i}",{{opacity:1,duration:0.2}},{t-0.6});tl.to("#logo{i}",{{opacity:0,duration:0.2}},{t+1.2});' for i,(t,_) in enumerate(beats))
+          open("compositions/brand.html","w").write(tmpl("brand",body,js))
+          body="".join(f'<div id="ttl{i}" style="position:absolute;left:120px;top:500px;font-size:96px;opacity:0">Title {n} text</div>' for i,(t,n) in enumerate(beats))
+          js="".join(f'tl.to("#ttl{i}",{{opacity:1,duration:0.2}},{t-0.6});tl.to("#ttl{i}",{{opacity:0,duration:0.2}},{t+1.2});' for i,(t,_) in enumerate(beats))
+          open("compositions/titles.html","w").write(tmpl("titles",body,js))
+          body="".join(f'<div id="cap{i}" style="position:absolute;left:300px;top:900px;font-size:56px;opacity:0">Caption line {n}</div>' for i,(t,n) in enumerate(beats))
+          js="".join(f'tl.to("#cap{i}",{{opacity:1,duration:0.1}},{t-0.5});tl.to("#cap{i}",{{opacity:0,duration:0.1}},{t+1.0});' for i,(t,_) in enumerate(beats))
+          open("compositions/captions.html","w").write(tmpl("captions",body,js))
+          layers="".join(f'<div id="{c}-layer" data-composition-id="{c}" data-composition-src="compositions/{c}.html" data-start="0" data-duration="30" data-track-index="{k}"></div>' for k,c in enumerate(["brand","titles","captions"],1))
+          open("index.html","w").write(f'<!doctype html><html><head><meta charset="utf-8"><script src="https://cdn.jsdelivr.net/npm/gsap@3.12.5/dist/gsap.min.js"></script></head><body style="margin:0;background:#101820"><div id="root" data-composition-id="main" data-start="0" data-duration="30" data-width="1920" data-height="1080">{layers}</div><script>window.__timelines=window.__timelines||{{}};window.__timelines["main"]=gsap.timeline({{paused:true}});</script></body></html>')
+      - name: multi vs solo
+        shell: python
+        continue-on-error: true
+        run: |
+          import os,subprocess,hashlib,glob
+          os.chdir("proj")
+          times=["14.5","18.5","22.5","25.01","27.01"]
+          def snap(at,out):
+              r=subprocess.run(["npx","-y","hyperframes@0.8.219","snapshot","--at",at,"--no-end","--describe","false","-o",out],capture_output=True,text=True,shell=(os.name=="nt"))
+              if r.returncode: print("EXIT",r.returncode,r.stdout[-400:],r.stderr[-400:])
+              return sorted(glob.glob(out+"/*.png"))
+          def h(p): d=open(p,"rb").read(); return hashlib.sha256(d).hexdigest()[:10],len(d)
+          multi=snap(",".join(times),"multi")
+          rows=[]
+          for i,t in enumerate(times):
+              solo=snap(t,"solo%d"%i)
+              rows.append((t,h(multi[i]),h(solo[0])))
+          for t,m,s in rows: print("AT",t,"multi",m,"solo",s,"SAME" if m==s else "DIFF")
+          # also run multi twice more to see run-to-run stability
+          for k in (2,3):
+              again=snap(",".join(times),"multi%d"%k)
+              print("MULTI-RUN",k,[h(p)==h(multi[i]) for i,p in enumerate(again)])