Paper2video

paper2video - paper/assets -> ppt-master deck -> pptx2video render -> narrated MP4

paper2video is a thin orchestrator with exactly one supported path. It does not author slides itself, does not synthesize audio itself, does not composite video itself, and does not gate QA itself. It resolves inputs and one shared trigger decision, then fully delegates:

paper.pdf
  -> skills/paper2assets/scripts/build_package.py       (shared package)
  -> assets/meta/paper_spec.md + assets/meta/narration.json
  -> ppt_options_contract.py resolve-ppt-trigger          (ONE trigger decision)
  -> installed ppt-master skill                          (full workflow, receives the trigger)
  -> installed pptx2video skill / CLI `bootstrap` then `render` (full workflow, receives the trigger)
  -> ppt_stage_validator.py audit-final-pptx-trigger      (proves the handoff held)
  -> video.mp4, video_no_subtitles.mp4, video.pptx

There is only one route. An earlier version of this skill had a second, self-implemented "Route A" that called private narration, duration, and visual-cue scripts and invoked python -m pptx2video.render_video / pptx2video.build_timeline / pptx2video.check_video_package as if they were importable submodules of the installed public package. Those modules do not exist at that import path in the public pptx2video CLI; the entry points are the pptx2video render, pptx2video doctor, and pptx2video bootstrap subcommands. Do not recreate that shortcut. Do not hand-assemble a narration script, a visual-cue file, or a "simplified" render pipeline that skips the installed pptx2video skill. Do not invoke any private submodule path under pptx2video.*. Every render goes through /pptx2video (the installed skill) or the exact pptx2video render CLI invocation in Step 5; there is no lower-effort fallback for a rushed or low-context session.

Why full delegation is mandatory

pptx2video render is not a smoke-test wrapper. Its own CLI (cli.py _render()) always runs the QA pass and always writes assets/meta/reports/video_qa_report.json; there is no --no-qa flag and no way to skip the check itself. A hand-rolled call into an internal module could skip that gate entirely, which is why every render goes through the Step 5 command.

The strict gate is opt-in, and Step 5 opts in. Upstream pptx2video defaults --qa-mode to warn-only, which delivers a bundle despite blocking warnings — the right default for previews and demos, the wrong one for a Paper2Video deliverable. Step 5 therefore passes --qa-mode strict explicitly. Never drop that flag to make a failing render succeed: a blocking warning means the deck is not deliverable, and the repair belongs in ppt-master (Step 3) or the narration, not in the gate. Treat a non-zero exit as a blocking failure to fix, never as a reason to relax the mode or fall back to a simpler local script.

Two child skills, one shared trigger decision

This skill's own job is narrow: resolve inputs, resolve one ppt_trigger value, pass it identically to both child skills, and verify the delivered PPTX actually carries it. Everything else belongs to the child skills:

• ppt-master authors the deck: SVG pages, the Strategist confirmation stage, speaker notes, and PPTX export including native entrance-animation triggers (--animation-trigger).
• pptx2video renders the deck: TTS, word-boundary timing, animation scheduling, subtitles, timeline, and strict media QA (assets/meta/reports/video_qa_report.json).

Both read PowerPoint's native p:timing tree, but for different purposes: ppt-master writes it, and pptx2video's video scheduler reads native row order and narration timing from it, never the click-group number. If each of these two skills is allowed to pick its own default trigger, they can produce a PPTX/MP4 pair whose native badges and playback pacing quietly disagree. This skill's Step 2 exists specifically to prevent that.

The four concepts the old protocol conflated

The single native p:timing tree has to answer four different questions, and the previous version of this skill's protocol used only one field (click-group number) to try to answer all of them, which fails whenever a deck uses after-previous:

The failure this fixes: a deck with 38 after-previous effects is fully valid OOXML, but PowerPoint places every after-previous (automatic) effect in the same native click group, commonly all showing 0 in the Animation Pane's click-group column. That is expected PowerPoint behavior for automatic effects, not data loss and not a rendering bug; effect_order (Pane row order) still exists and is exactly what pptx2video's scheduler uses to place each phase in the video's timeline, together with narration/word timing. The problem in the old protocol was documentation and verification, not the underlying render: nothing told the agent to pick ppt_trigger on purpose before authoring, hand it to both children identically, and check the delivered file. This skill's Step 2 and Step 6 close exactly that gap.

Paths

Run Paper2Video workflow commands from ResearchStudio-Reel/ unless noted.

PAPER2VIDEO=skills/paper2video
PAPER2ASSETS=skills/paper2assets

Install both external skills before starting. Do not clone or vendor either dependency inside ResearchStudio:

npx skills add hugohe3/ppt-master --skill ppt-master
npx skills add ai-nuts/pptx2video --skill pptx2video

Install and verify the public pptx2video CLI runtime. Use a Python 3.11 or newer environment, and track the upstream default branch — this is the install form pptx2video's own SKILL.md documents:

python -m pip install \
  'pptx2video[svg] @ git+https://github.com/ai-nuts/pptx2video.git'
python -m playwright install chromium
python3 -m pptx2video --version
python3 -m pptx2video doctor --svg

Always invoke the runtime as python3 -m pptx2video ..., never as the bare pptx2video command. A host may have an older pptx2video (for example 0.3.0) earlier on PATH than the intended install; the bare command then silently resolves to the wrong version with no error. Compare python3 -m pptx2video --version against pip show pptx2video; when they disagree, fix the environment (pip install target, PATH, virtualenv) before continuing, rather than proceeding and hoping the CLI surface still matches this document.

Track the upstream default branch; do not pin a release tag. pptx2video ships features between tags, so a tag pin silently withholds them from every paper2video user. Reinstall from the default branch to pick up upstream fixes.

Do not hard-code a host-specific skill directory. Users may run this repository from Codex, Claude Code, a shell, or another agent. This skill itself never calls a private path under pptx2video.*; it always calls the installed skill (/pptx2video) or the public pptx2video render / pptx2video doctor / pptx2video bootstrap CLI subcommands.

Output Contract

Follow the shared paper2assets v2 layout. The bundle top level holds only deliverable files plus manifest.json; everything else lives under assets/:

<video_outdir>/
  video.mp4                  # required, burned-in subtitles in an appended black bottom band
  video_no_subtitles.mp4     # required, raw/pre-subtitle playback copy for paper2reel
  video.pptx                 # required, the same delivered deck pptx2video rendered from
  manifest.json              # schema_version "paper2video.v1", layout "v2-assets"
  assets/
    audio/                          # script.json, per-block TTS, word timings
    captions/                       # video.srt, video.vtt
    slides/                         # rendered slide frames used by the MP4
    clips/                          # raw render intermediate
    meta/                           # timeline.json, QA and authority reports

This layout, and every file inside it, is produced by pptx2video render itself; Step 5 below is the only place this skill writes into <video_outdir>. Do not hand-assemble any part of this tree before that step.

Pick <video_outdir> before any file writes. Resolve deterministically:

1. An explicit <video_outdir> argument from the caller wins. Honor it verbatim; the defaults below only fire when no path was passed.
2. A paper2assets package already exists -> reuse its folder verbatim as <video_outdir>. The canonical detection signal is <dir>/assets/meta/paper_spec.md; <dir>/manifest.json with "layout": "v2-assets" is a confirming hint when present.
3. Otherwise (a bare PDF is the only input) -> default to <input_pdf_dir>/<pdf_stem>/, matching the paper2assets default convention so a later paper2assets run lands in the same bundle.

pptx2video render refuses to write into a path that already exists, so Step 5 renders into a fresh temporary bundle for exactly this reason and then this skill promotes the result into <video_outdir> (see Step 5).

Step 1: Build or reuse the shared paper2assets package

python skills/paper2assets/scripts/build_package.py <paper.pdf> --outdir "$VIDEO_OUT"

If paper_spec.md already exists, sync structured claims and narration instead of re-extracting:

python skills/paper2assets/scripts/build_package.py <paper.pdf> \
  --outdir "$VIDEO_OUT" \
  --skip-extract \
  --paper-spec "$VIDEO_OUT/assets/meta/paper_spec.md"

assets/meta/narration.json is the canonical narration order for this run: one {"id", "heading", "text"} entry per section, in the same order poster, blog, and video all use. Do not reorder or rewrite it here; ppt-master reads the paper2assets package to author slides in this order, and Step 4 passes narration to pptx2video from the same source.

Step 2: Resolve the one shared ppt_trigger decision

This is the single most important step in this skill. Resolve ppt_trigger before invoking ppt-master, and pass the exact same resolved value to both ppt-master and pptx2video. Never let either child skill fall back to its own independent default.

python3 skills/paper2video/scripts/ppt_options_contract.py resolve-ppt-trigger \
  --ppt-trigger {auto,on-click,after-previous}

• Omit --ppt-trigger, or pass auto, when the user has not stated a preference. This resolves to on-click, because a downloaded PPTX with a continuous 1..N Animation Pane badge sequence is the more broadly useful default deliverable, and the rendered MP4 still auto-plays with no manual click either way (see below).
• Pass on-click explicitly when the user wants a presenter-controllable, numbered PPTX.
• Pass after-previous only when the user explicitly asks for a PPTX that also auto-plays natively in PowerPoint (not merely "a video that plays itself" -- the rendered MP4 always plays itself regardless of this choice).

The command prints one JSON object; treat every field as a literal value to carry into the next two steps, not as a suggestion:

{
  "ppt_trigger": "on-click",
  "ppt_master_animation_trigger": "on-click",
  "pptx2video_click_group_policy": "normalize"
}

{
  "ppt_trigger": "after-previous",
  "ppt_master_animation_trigger": "after-previous",
  "pptx2video_click_group_policy": "preserve"
}

ppt_master_animation_trigger is the exact value for ppt-master's --animation-trigger flag in Step 3. pptx2video_click_group_policy is the exact value for pptx2video's --click-group-policy flag in Step 5. Both come from this one command so the two child skills can never disagree about the user's trigger intent. Record the printed JSON (for example into $VIDEO_OUT/assets/meta/ppt_trigger_handoff.json) so Step 6's audit and any retry use the same resolved value.

Why the rendered MP4 auto-plays either way. pptx2video's video scheduler places every entrance phase in the timeline using native Animation Pane row order (effect_order) plus narration/word-boundary timing; it never consults PowerPoint's click-group number. Choosing on-click changes only what the downloaded PPTX looks like when a human opens it in PowerPoint. It does not make the MP4 wait for a click.

Step 3: Author the deck with ppt-master, passing the resolved trigger

Invoke the installed ppt-master skill and follow its full workflow: source conversion, project init/import, the Strategist confirmation stage (fields a through h, MANDATORY, cannot be skipped), optional image acquisition, sequential page-by-page SVG authoring, svg_quality_checker.py, then the three-command export pipeline run one command at a time (total_md_split.py, finalize_svg.py, svg_to_pptx.py).

• Do not replace ppt-master with handwritten SVG, a local simplified generator, or a copied example deck whose content does not come from the paper.
• If ppt-master reaches a blocking confirmation gate and the user has not already approved defaults, stop and ask the user.
• If a machine dependency is missing, record the concrete missing dependency and stop. Do not silently degrade to a different slide-generation method.
• Pass $PAPER_ASSETS/assets/meta/narration.json sections (or the paper/PDF content directly) as the source content; do not invent claims absent from the paper.

Pass ppt-master's --animation-trigger flag exactly as resolve_ppt_trigger_handoff returned in Step 2:

python3 ${SKILL_DIR}/scripts/svg_to_pptx.py <project_path> \
  --animation-trigger <ppt_master_animation_trigger from Step 2>

If the deck should carry no entrance animation at all (-a none, ppt-master's own default), the --animation-trigger flag is irrelevant and may be omitted; the resolved value only matters once -a requests an actual entrance effect. Leave speaker notes enabled (ppt-master's default; do not pass --no-notes) so Step 4 can replace its raw Notes with pptx2video's canonical per-element protocol -- see the note on notes format below.

ppt-master Notes are not pptx2video's Notes protocol. ppt-master's markdown_to_plain_text() writes plain presenter-note paragraphs, not pptx2video's canonical ## [handle] semantic block grammar. pptx2video treats ordinary presenter notes as absent narration and falls back to a generic per-shape handle. Do not render an animated raw ppt-master PPTX directly. Step 4 first bootstraps the page-level narration into handle-addressed Notes and Alt Text.

Before invoking ppt-master, prepare title-slide utility assets when a paper2assets package exists:

python skills/paper2assets/scripts/fetch_logos.py \
  --outdir "$PAPER_ASSETS" --from-spec "$PAPER_ASSETS/assets/meta/paper_spec.md" || true
python skills/paper2assets/scripts/make_qr.py \
  --outdir "$PAPER_ASSETS" --from-metadata "$PAPER_ASSETS/assets/meta/metadata.json" || true

Skip fetch_logos.py when paper_spec.md is not available; do not invent logos. make_qr.py is best-effort and only uses paper_url, code_url, or the documented arxiv_id fallback from metadata.json. Add a requirement block to the ppt-master prompt covering restrained placement of these assets on slide 1 (right-side title area or lower-right safe zone), and instruct ppt-master to omit unavailable assets cleanly rather than leaving broken placeholders.

Confirm the export produced a PPTX at <project_path>/exports/<name>.pptx before continuing to Step 4.

Step 4: Prepare narration and bootstrap the editable protocol

Build a script.json from the shared narration.json so pptx2video's narration authority is explicit and does not depend on ppt-master's raw Notes text:

{
  "sections": [
    {"id": "problem", "heading": "Problem", "text": "..."},
    {"id": "method", "heading": "Method", "text": "..."}
  ]
}

assets/meta/narration.json from paper2assets already has this {"id", "heading", "text"} shape; it can be used directly as the bootstrap --script-json input provided its section count matches the PPTX slide count. The number of sections in this file must equal the number of slides in the deck exported in Step 3, in the same order; pptx2video rejects a section-count mismatch. When ppt-master's page-count resolution produced a different number of slides than narration.json has sections, reconcile the two before rendering: either regenerate the deck at the corrected page count, or edit the script.json copy so its section count and order match the delivered PPTX exactly. Do not truncate or duplicate sections to force a match.

Bootstrap the ordinary animated deck once. This divides each slide's page-level narration across its animation targets and writes canonical handle-addressed Notes and Alt Text:

PPTX2VIDEO_WORK=$(mktemp -d)
PPTX2VIDEO_SOURCE="$PPTX2VIDEO_WORK/video-protocol-source.pptx"
PPTX2VIDEO_TMP="$PPTX2VIDEO_WORK/video-bundle"
python3 -m pptx2video bootstrap \
  "<project_path>/exports/<name>.pptx" \
  --script-json "$VIDEO_AUDIO/script.json" \
  --output "$PPTX2VIDEO_SOURCE"

Treat a non-zero bootstrap exit as blocking. Do not replace $PPTX2VIDEO_SOURCE with the raw ppt-master export in Step 5.

Step 5: Render through pptx2video, passing the same resolved trigger

Render the bootstrapped PPTX into the fresh output directory. Pass the page-level script only as --ids-from-script: this preserves the per-element narration written in Step 4 while fixing each slide's internal section_id. Do not use --script-json for this render; it would put the entire slide transcript on the first animation element while clearing the others.

python3 -m pptx2video render \
  "$PPTX2VIDEO_SOURCE" \
  "$PPTX2VIDEO_TMP" \
  --resolution 1080p \
  --ids-from-script "$VIDEO_AUDIO/script.json" \
  --animation-order-policy animation-pane \
  --click-group-policy <pptx2video_click_group_policy from Step 2> \
  --qa-mode strict

• --click-group-policy must be the exact value Step 2 resolved (normalize for on-click, preserve for after-previous). Never omit this flag and rely on pptx2video's own CLI default; the CLI default (normalize) silently overwrites a deliberately authored after-previous cascade into a click-driven deck, which is the opposite of what an explicit after-previous request means.
• --animation-order-policy animation-pane makes the run fully non-interactive and deterministic. pptx2video's own auto default only prompts when stdin is a TTY; in a non-interactive agent session with an actual ordering conflict it exits 3 without rendering. Passing animation-pane explicitly confirms "trust the deck's own Animation Pane order" up front so a real conflict never stalls the run silently.
• Do not pass --no-subtitles unless the user explicitly disabled captions; the default burns captions into video.mp4 while leaving video_no_subtitles.mp4 and the VTT/SRT sidecars intact.
• Do not pass --baseline-pptx / --narration-mode regenerate for a first render; those are for an explicit re-render of a previously delivered deck.

Do not add --no-qa. It does not exist on the top-level pptx2video render CLI. QA always runs and always writes assets/meta/reports/video_qa_report.json; --qa-mode only decides which findings fail the render. Under the strict mode this step passes, cli.py's own _render() raises SystemExit unless the checker reported passed, which blocks on every error and every non-exempt warning. Codes the checker exempts (currently audio_extra_files, an unreferenced MP3 left over from a previous run) stay visible in the report without blocking. A non-zero exit here is a blocking failure: fix the deck, script, or flags and rerun this exact command; do not relax --qa-mode and do not fall back to a private render path to force a result through.

On success, promote the fresh bundle into <video_outdir> without clobbering an existing manifest.json from a different paper2* skill sharing the same bundle root:

rsync -a --exclude=manifest.json "$PPTX2VIDEO_TMP"/ "$VIDEO_OUT"/

If $VIDEO_OUT/manifest.json already exists (written by paper2assets, paper2poster, or paper2blog sharing the same bundle root), merge $PPTX2VIDEO_TMP/manifest.json's video-specific fields into it by hand instead of overwriting; do not let a blind copy erase fields another paper2* skill wrote to the same manifest.json. Otherwise, copy pptx2video's manifest.json in as-is.

Step 6: Audit the final PPTX against the resolved trigger (MANDATORY gate)

This closes the loop the old protocol never checked: prove the delivered video.pptx's native p:timing tree actually carries the trigger this skill resolved in Step 2, rather than trusting that ppt-master's flag and pptx2video's flag each did the right thing.

python3 skills/paper2video/scripts/ppt_stage_validator.py audit-final-pptx-trigger \
  "$VIDEO_OUT/video.pptx" \
  --ppt-trigger <ppt_trigger from Step 2>

• on-click requires every non-With-Previous native row to be clickEffect; this is what gives a downloaded PPTX a continuous 1..N Animation Pane badge sequence.
• after-previous requires every non-With-Previous native row, including every row inside a preserved cascade, to be afterEffect; this is what makes the PPTX auto-play natively in PowerPoint. No numbered Pane is claimed or required for this choice.
• The audit raises if the delivered deck has no native p:timing animation on any slide at all, so a silently-dropped animation request fails loudly instead of passing by vacuity.

A non-zero exit here is a blocking failure, exactly like a failed video_qa_report.json in Step 5: it means ppt-master's --animation-trigger and pptx2video's --click-group-policy disagreed about the trigger, or one of them fell back to its own default instead of the value resolved in Step 2. Re-check the flags actually passed in Step 3 and Step 5 against Step 2's printed JSON, fix whichever command diverged, and re-render before reporting the video as done.

Step 7: Report

Tell the user the absolute paths of the deliverables:

• <video_outdir>/video.mp4 (burned-in subtitles)
• <video_outdir>/video_no_subtitles.mp4 (paper2reel source)
• <video_outdir>/video.pptx (editable deck, the same file the Step 6 audit verified)
• <video_outdir>/assets/meta/timeline.json and <video_outdir>/assets/meta/reports/video_qa_report.json

State explicitly which ppt_trigger was used and confirm Step 6's audit passed. Do not report the task done without having run and passed both Step 5's QA gate and Step 6's trigger audit.

Acceptance criteria

• Downloaded PPTX Animation Pane shows a continuous 1..N badge sequence when ppt_trigger=on-click was resolved and used.
• The rendered video auto-plays every phase in an order that matches the spoken narration, regardless of which ppt_trigger was used.
• When the user explicitly requested after-previous, the delivered PPTX still auto-plays natively in PowerPoint, without a claim of continuous native numbering.
• ppt_stage_validator.py audit-final-pptx-trigger exits 0 against the exact ppt_trigger resolved in Step 2.
• pptx2video render's own QA gate (video_qa_report.json) reported passed under --qa-mode strict: no errors, and no warnings outside the checker's own exempt list.

Key rules

• One route only. Every render goes through /pptx2video or the exact pptx2video render CLI command in Step 5; never a private pptx2video.<module> import, never a hand-rolled narration/timeline/QA substitute.
• One trigger decision. Step 2 resolves ppt_trigger exactly once per run; Step 3 and Step 5 both consume that same resolved JSON, never their own child-skill default.
• QA gate passing is not the finish line by itself. A passing video_qa_report.json proves pptx2video's own render was clean; it does not prove the trigger handoff held. Step 6's audit is the check that proves that, and it is mandatory before reporting completion.
• Do not degrade silently. A missing dependency, a blocked ppt-master confirmation gate, a failed QA report, or a failed trigger audit are all stop-and-fix conditions, never a reason to ship a simplified or unverified video.

Tools

scripts/
├── ppt_options_contract.py   # resolve-ppt-trigger CLI; also the shared PPT option/appearance contract
└── ppt_stage_validator.py    # audit-final-pptx-trigger CLI; also descriptive-option/export-flag audits

The generic render runtime is not owned or vendored by this skill. Install pptx2video and invoke it only through /pptx2video or python3 -m pptx2video {doctor,render,bootstrap}.

References

• references/pptx2video.md - the standalone renderer's install steps, the exact CLI flags this skill's Step 5 command relies on, and the pitfalls (PATH, --no-qa not existing, click-group-policy defaults) that make an almost-right invocation silently diverge from the protocol.
• references/script_json_schema.md - the script.json schema Step 4 passes to bootstrap and Step 5 passes only as --ids-from-script, including the handle-level elements form and TTS text gotchas.
• references/ppt_trigger_handoff.md - deep dive on the four-concept model, the native OOXML mechanics behind it, and the failure modes this skill's Step 2/Step 6 close.