CoreVideo

Introduction

CoreVideo integrates the Zoom Meeting SDK into OBS Studio with no screen capture or virtual camera required. It receives raw I420 video and 48 kHz PCM audio from any meeting participant, performs optional hardware-accelerated color conversion, and pushes frames into OBS as native sources.

The ZoomObsEngine child process hosts all SDK access in isolation, communicating with the plugin over JSON IPC (named pipes on Windows, Unix domain sockets on macOS/Linux) with frame data flowing through named shared memory. The plugin contains no Zoom SDK linkage.

Joining a meeting is driven by the built-in Zoom Control dock (or the TCP/OSC APIs). Once in a meeting, sources can follow a fixed participant, the active speaker, a ZoomISO-style spotlight slot, or the active screen share — and switch automatically with a configurable failover participant if the primary leaves.

A ZoomReconnectManager automatically re-joins after engine crashes, network drops, or unexpected disconnects, with exponential back-off and a cancel-at-any-time UI in the dock.

For Zoom App Marketplace compliance and attributed joins, ZoomOAuthManager uses the CoreVideo HTTPS broker to run Zoom Public Client OAuth with PKCE and receive a short-lived broker token through the bundled corevideo://oauth/callback helper. Before each join, the plugin refreshes OAuth tokens through the broker when needed, fetches the signed-in user's ZAK, and starts the Meeting SDK helper with the embedded Marketplace Public Client ID as AuthContext.publicAppKey. The plugin also exposes TCP and OSC control APIs for external production automation, including source assignment, meeting control, and ISO recording.

Features

Adding the App

CoreVideo is distributed as a fully installable Windows application — there is nothing to compile and no SDK to download. Installation takes a few minutes.

Adding CoreVideo to your Zoom account

In Zoom's terms, an app is added to your Zoom account the first time you authorize it. There are two equivalent ways to do that:

• From OBS (recommended): click Sign in with Zoom in the Zoom Control dock or Tools → Zoom Plugin Settings. Your browser opens Zoom's authorization page; review the requested permissions and click Allow. CoreVideo is added to your account automatically and the sign-in completes back in OBS.
• From the Zoom App Marketplace: open the Zoom App Marketplace, search for CoreVideo, open the listing, and click Add. After you click Allow on the permissions screen, install the Windows app (steps above) and sign in — the account authorization is already in place.

Either way, CoreVideo then appears under Zoom App Marketplace → Manage → Added Apps, where you can review or remove it at any time.

macOS: Apple Silicon beta

CoreVideo v0.1.45-beta.1 is available as a signed and notarized installer. Requires an Apple Silicon Mac (M1 or later). Use OBS Studio 32.2.1 or newer for this beta; the replacement package was built against OBS 32.2.1.

Download the macOS installer and SHA-256 checksum.

1. Close OBS and open the downloaded .pkg.
2. Install for your user account; no administrator password is needed.
3. Reopen OBS, sign in to Zoom, and join a meeting. Allow the requested permissions. The meeting host must grant recording permission before raw video and audio can start.

The original macOS downloads were replaced on September 6, 2026 after signature errors. Download the replacement installer if you previously downloaded this beta. The old ZIP was removed.

ISO recording requires a working FFmpeg executable configured in Zoom ISO Recorder; the macOS installer does not bundle it.

Talkback remains Windows-only. For your own screen, use OBS's native macOS Screen Capture source. Intel Macs are not supported by this package.

Sign in with Zoom

Use case: Authorize CoreVideo to join meetings and receive raw participant media on your behalf. You sign in once; CoreVideo refreshes the session automatically.

Prerequisites: A Zoom account and CoreVideo installed. You do not need a Zoom developer account, an SDK key, or any client secret — published builds use CoreVideo's hosted broker with OAuth 2.0 + PKCE.

1. Click "Sign in with Zoom"

In the Zoom Control dock, or via Tools → Zoom Plugin Settings.

2. Authorize in your browser

Your browser opens Zoom's consent screen. Approve access. CoreVideo registers its corevideo:// callback handler automatically the first time.

3. Done

The dock shows a connected status and token expiry. Tokens are stored locally on your machine (DPAPI-encrypted on Windows). CoreVideo never sees your Zoom password, and no client secret is stored in the app.

Requirements

Using CoreVideo

Each capability below lists what it's for and what you need before using it. For deeper technical detail, see the Architecture and Reference sections further down.

Join a meeting from the Zoom Control dock

Use case: Connect OBS to a live Zoom meeting or webinar.

Prerequisites: Signed in with Zoom. The host should admit "OBS" (the default display name) from the waiting room, or allow guests.

Paste a Meeting ID or Zoom URL, an optional passcode, and a display name, then click Join. Toggle Join as Webinar for webinars. The status dot turns green when connected.

Add Zoom sources to a scene

Use case: Bring individual participants, the active screen share, a spotlight slot, or interpretation audio into OBS as native sources you can position, style, and mix.

Prerequisites: Signed in and joined to a meeting.

In OBS, click + under Sources and choose a CoreVideo source: Zoom Participant (video), Zoom Participant Audio, Zoom Screen Share, Zoom Spotlight, or Zoom Interpretation Audio. Pick a participant or slot in the source properties (see the Configuration Reference).

Active Speaker Director

Use case: Automatically switch a source to whoever is speaking, with broadcast-safe debounce so it doesn't cut on every cough.

Prerequisites: In a meeting with participants on camera.

Enable Follow active speaker on a Zoom Participant source, or use the dock's Director controls, and tune sensitivity and minimum hold time. Full algorithm: Active Speaker Mode.

Output Manager & profiles

Use case: See every source's assignment and feed health at a glance, and save/load named participant-to-source layouts between shows.

Prerequisites: CoreVideo sources added to your scene.

Open the Zoom Output Manager dock to assign participants, watch live thumbnails and health, and save/load profiles. See Output Profiles.

ISO recording

Use case: Record each assigned participant to a separate video/audio file (clean ISOs) for editing, while optionally recording the OBS program.

Prerequisites: In a meeting with assigned sources, and disk space for per-participant files.

Enable ISO recording from the dock. Details: Auto ISO Recording.

Auto-reconnect

Use case: Automatically re-join after a network drop or engine restart so a broadcast recovers on its own.

Prerequisites: None — on by default; a cancel button appears during recovery. See Auto-Reconnect.

External control (TCP / OSC)

Use case: Drive CoreVideo from production tools, scripts, or lighting/broadcast hardware.

Prerequisites: Enable the control server (optionally set a token). See the TCP and OSC reference.

Removing the App

Removing CoreVideo has two parts: de-authorizing it from your Zoom account, and uninstalling the software.

1. De-authorize CoreVideo in Zoom

Sign in to Zoom App Marketplace → Manage → Installed Apps, find CoreVideo, and click Remove. You can also click Disconnect in Tools → Zoom Plugin Settings first to clear the local session.

2. Uninstall the software

Close OBS, then remove CoreVideo from Windows Settings → Apps → Installed apps → CoreVideo → Uninstall (or run the bundled uninstaller). This removes the plugin and its Zoom runtime from OBS.

3. How your data is removed

CoreVideo stores your Zoom OAuth tokens locally on your machine (DPAPI-encrypted on Windows) inside the OBS plugin config directory. It does not upload or store your account data on any server — CoreVideo's hosted broker only performs the OAuth token exchange in transit and retains nothing about you.

• Clicking Disconnect (Tools → Zoom Plugin Settings) deletes the stored access and refresh tokens.
• To remove all local settings, delete the obs-zoom-plugin folder under your OBS plugin_config directory after uninstalling.
• De-authorizing in the Zoom Marketplace (step 1) invalidates the tokens server-side regardless.

See our Privacy Policy for full details on data handling.

Troubleshooting

Installer blocked by Windows SmartScreen

CoreVideo's beta installer (CoreVideo-Setup.exe) is not yet code-signed, so Windows SmartScreen will show "Windows protected your PC" the first time you run it. This is expected during the beta — it does not mean the download is unsafe, but you should still confirm you got the file from corevideo.io/download or the official GitHub Releases page.

certutil -hashfile CoreVideo-Setup.exe SHA256

Get-FileHash .\CoreVideo-Setup.exe -Algorithm SHA256

"No video frames" checklist

Work through these in order — each one rules out a different stage of the pipeline.

1. Assignment mode is set. A newly added Zoom Participant / Spotlight / Screen Share source isn't subscribed to anything until you assign it — in the source properties or the Zoom Output Manager dock. An unassigned source shows the color-bar placeholder, not black.
2. The participant actually has their camera on and has been admitted from the waiting room (or the meeting allows guests). CoreVideo can only capture video a participant is sending.
3. Check requested vs. observed resolution in the Zoom Diagnostics dock. Open Docks → Zoom Diagnostics (or Tools → Zoom Diagnostics) and look at the Outputs table. If Observed stays blank or 0×0 while Requested shows a resolution, the subscription never came up — re-assign the source or click Refresh. If observed resolution is consistently lower than requested, that's usually a bandwidth or entitlement ceiling, not a bug.
4. Confirm the engine is actually running. Every meeting session launches zoom-runtime\ZoomObsEngine.exe as a child process of OBS — all Zoom SDK access happens there, not in the plugin DLL. If it isn't running (check Task Manager, or "Engine running" in a support bundle's summary.txt), the plugin never receives frames. Antivirus software occasionally quarantines or blocks a freshly-installed ZoomObsEngine.exe — check your antivirus's quarantine/history if it's missing.
5. Bandwidth and entitlements. Your Zoom account and app entitlements bound both quality and stream count: standard accounts are commonly limited to ~30 Mbps incoming video (roughly 4-6 Mbps per 1080p feed), while Enhanced Media / HBM can raise that to ~100 Mbps. If several 1080p feeds are requested at once on a standard account, expect some to negotiate down or fail — see Requirements.

Sign-in loop / browser doesn't return to OBS

"Sign in with Zoom" opens your browser to Zoom's consent screen and expects the browser to hand control back to CoreVideo afterward through the corevideo:// URL scheme. A few different things can break that handoff:

• The corevideo:// handler isn't registered yet. CoreVideo registers it automatically the first time you click Sign in with Zoom. If a browser prompt asks which app should open a corevideo:// link, choose CoreVideo (and "always allow" it) — if you dismiss or block that prompt, the callback has nowhere to go and the browser tab just sits there after you approve access in Zoom.
• The callback helper didn't launch. The last hop is a small helper binary, CoreVideoOAuthCallback.exe, which the OS launches for the corevideo://oauth/callback URL and which forwards it to the plugin's local control server as an oauth_callback command. If antivirus software or SmartScreen blocked that helper from running, sign-in will look like it hung after you approved access in the browser. Retry sign-in, and allow the helper if prompted.
• Admin-managed Zoom account. If your organization restricts Marketplace apps, the consent screen shows Request pre-approval instead of Allow — sign-in cannot complete until a Zoom admin approves CoreVideo. See Adding CoreVideo to your Zoom account for the pre-approval steps.
• Whatever the cause, re-running sign-in from Tools → Zoom Plugin Settings is safe and starts a fresh authorization attempt.

Firewall prompts for TCP 19870 / UDP 19871

It's safe to Allow access on Private networks if you plan to drive CoreVideo from an external control surface (Companion, a lighting console, a custom script) running on the same machine. If you don't use the TCP/OSC APIs, it's equally safe to Cancel or deny the prompt — Zoom capture, sources, and sign-in do not depend on either server; only external control does.

Zoom Diagnostics / Zoom Output Manager / other docks missing

Every CoreVideo dock — Zoom Control, Zoom Diagnostics, Zoom Output Manager, and Zoom ISO Recorder — can be re-shown from OBS's Docks menu once it has appeared at least once. The first time, or if you closed it permanently, use the matching item under the Tools menu instead (e.g. Tools → Zoom Diagnostics) — the Tools menu items create and show the dock even if OBS has never registered it in the Docks list before.

Plugin not loading

If OBS starts normally but none of the Zoom Control / Diagnostics / Output Manager / ISO Recorder menu items or docks appear at all, the plugin itself likely failed to load:

• Confirm OBS Studio is 30 or newer (Help → About). CoreVideo links against OBS 30's plugin API; older OBS builds cannot load it.
• Check the OBS log (Help → Log Files → View Current Log) for a module-load failure mentioning obs-zoom-plugin.dll. A missing-DLL style error there most often means a required file didn't get installed alongside OBS — reinstall with OBS fully closed (the installer refuses to proceed if obs64.exe is still running, but a stuck background process can slip past that check).
• Missing Visual C++ runtime, in rare cases. CoreVideo's Qt6 and plugin DLLs are built with the same MSVC toolchain as OBS Studio itself, so if OBS runs at all the runtime is normally already present. On an unusually minimal Windows install, installing the latest Microsoft Visual C++ x64 Redistributable is a reasonable thing to try if the log shows a generic DLL load failure.

Filing a bug

Still stuck? Open the Zoom Diagnostics dock (Docks → Zoom Diagnostics, or Tools → Zoom Diagnostics) and click Create Support Bundle. It writes a redacted bundle — SDK keys, secrets, OAuth tokens, and similar credentials are stripped before anything is written to disk — plus a matching .zip under %AppData%\obs-studio\plugin_config\obs-zoom-plugin\support-bundles\. Attach that .zip when you file a bug report, or contact CoreVideo Support for anything that isn't a clear bug.

Architecture: System Overview

All Zoom SDK access lives exclusively in ZoomObsEngine. The plugin communicates with it through ZoomEngineClient — a singleton that launches the engine process, owns the IPC channels, and distributes roster events and frame notifications to registered sources. The plugin contains no Zoom SDK headers or linkage.

Meeting joining is handled by the Zoom Control dock (ZoomDock) or the TCP/OSC APIs. On unexpected disconnects the ZoomReconnectManager automatically re-joins with exponential back-off. Sources each hold an AssignmentMode that controls which feed they subscribe to: a fixed participant, the active speaker, a spotlight slot, or the active screen share.

Architecture: Plugin Components

All Zoom SDK access lives in ZoomObsEngine. The plugin-side hierarchy centers on ZoomEngineClient (IPC singleton) and ZoomSource (reads frames from ShmRegion). New additions: ZoomDock (join UI), ZoomReconnectManager (auto-reconnect), and HwVideoPipeline (hardware I420→NV12).

Architecture: ZoomEngineClient

ZoomEngineClient is the plugin-side singleton that manages the entire engine process lifecycle. It launches ZoomObsEngine as a child process, connects the two IPC channels, runs a dedicated reader thread for incoming events, and dispatches per-source frame/audio callbacks. All Zoom SDK state (auth, meeting, roster, active speaker) is owned by the engine; the client tracks it locally by processing the event stream.

Lifecycle

Roster, Active Speaker, and Spotlight

The engine sends a participants event whenever the roster changes and an active_speaker event when the speaking participant changes. ZoomEngineClient updates its internal roster and active-speaker ID from these events, then fires all registered RosterCallback functions. ZoomSource instances react based on their AssignmentMode: active-speaker sources run the debounce algorithm; spotlight sources send a subscribe_spotlight command when spotlight slots change.

Deferred Join (Pending Until Authenticated)

Calls to join() before the engine has authenticated store the meeting credentials in m_join_pending / m_pending_* fields. When the auth_ok event arrives, send_join_locked() is called automatically so operators can trigger join at any time.

Monitor Thread

A dedicated monitor_loop() thread watches for engine health issues (stalled reader, unexpected process exit) and sets the state to Failed, which triggers ZoomReconnectManager if recovery is configured.

Architecture: IPC Engine

ZoomObsEngine runs as a separate process on all platforms. Control messages use newline-delimited JSON over platform IPC channels. Frame data flows through named shared memory to avoid copying large buffers. ZoomEngineClient in the plugin abstracts all IPC details.

Architecture: Video Pipeline

Architecture: Audio Pipeline

Audio processing now lives entirely in the engine process. The engine writes PCM chunks to a per-source shared memory region and sends an audio event. ZoomSource reads the chunk from m_audio_shm and pushes it to OBS. Stereo sources use an internal m_stereo_buf to interleave channels before output.

Architecture: Screen Share Pipeline

Screen share handling now lives entirely inside ZoomObsEngine. The engine's IMeetingShareCtrlEvent handler detects share-start events, attaches an IZoomSDKRenderer to the share source, and writes I420 frames to a dedicated shared memory region. The plugin receives frame events on the share source UUID and forwards them to OBS exactly like participant video.

Flow: Authentication

Published CoreVideo builds do not ship Meeting SDK secrets in the OBS plugin. After Zoom sign-in, the plugin refreshes OAuth tokens through the CoreVideo broker when needed, fetches the signed-in user's ZAK, and starts the helper with AuthContext.publicAppKey. The engine is not started on module load; it is launched the first time a join is requested.

Flow: Zoom OAuth PKCE

ZoomOAuthManager implements broker-backed OAuth 2.0 with PKCE (Proof Key for Code Exchange, S256) for user-level attributed meeting joins and Zoom App Marketplace compliance. The desktop plugin opens the broker start URL, receives a short-lived broker token through corevideo://oauth/callback, and never stores a Zoom app secret.

Setup (one-time per machine)

Authorization Flow

ZAK Fetch and publicAppKey SDK Auth (before each join)

Security Notes

Flow: Meeting Join & Capture

Joining is centralized in ZoomDock (or the TCP/OSC control APIs) — not in individual sources. Sources subscribe to the already-joined meeting.

Assignment Modes

Each ZoomSource has an AssignmentMode property that controls which feed it subscribes to. This is the ZoomISO 3.0 model: sources are reusable roles rather than fixed participant bindings.

Screen Share Workflow

To capture slides, demos, or a shared desktop, add a CoreVideo Screen Share source or set any CoreVideo Participant source to Assignment > Active screen share. The source follows Zoom's active share feed and shows a placeholder when no participant is sharing.

The Zoom Output Manager assignment menu also includes Screen share. When a share is active, the menu label includes the sharing participant name. The TCP list_outputs response for screen-share outputs includes the current sharing participant ID and display name.

{
  "assignment_mode": "screen_share",
  "screen_share_available": true,
  "screen_share_participant_id": 123456,
  "screen_share_participant_name": "Alex Rivera",
  "observed_width": 1920,
  "observed_height": 1080,
  "observed_fps": 30.0
}

Failover Participant

In Participant mode, a failover_participant_id (0 = disabled) can be configured alongside the primary participant. When the engine sends a participants event showing the primary ID has left, ZoomSource automatically re-subscribes to the failover ID. When the primary rejoins, it switches back.

Spotlight Tracking

In Spotlight Slot mode, the roster callback checks ParticipantInfo::spotlight_index on every roster update. The source sends a subscribe_spotlight(uuid, slot) to the engine, which resolves the participant in that slot and sets up the SDK renderer. This mirrors the ZoomISO "Spotlight 1/2/3" output model.

Active Speaker Mode

When Follow active speaker is enabled on a Zoom Participant source, the plugin continuously monitors who is speaking and switches the video subscription (and optionally the isolated audio feed) to the new speaker. A two-timer debounce prevents rapid camera cuts caused by brief interruptions.

The current build also includes a central Active Speaker Director in the Zoom Control dock and a dedicated CoreVideo Active Speaker OBS source. The director tracks the raw Zoom speaker, candidate speaker, directed speaker, last directed speaker, and manual take/release state. The dock also shows a plain-language status line for waiting, holding, candidate evaluation, and manual supersede states. The dedicated source follows the directed speaker and uses a two-slot handoff: the current participant stays visible while the next participant warms on a hidden slot, then the source cuts only after a valid frame is available.

Debounce Algorithm

Every time ZoomEngineClient dispatches a roster callback (triggered by an active_speaker or participants IPC event), the source runs on_active_speaker_changed(). Two independent timers must both be satisfied before a switch is committed:

• Sensitivity guard — the candidate speaker must hold the floor continuously for at least speaker_sensitivity_ms (default 500 ms). A new candidate resets this clock.
• Hold guard — after any switch, no further switch may occur for at least speaker_hold_ms (default 2 000 ms), regardless of who speaks.

The actual delay is max(hold_remain, sense_remain). If the delay is zero the switch fires immediately on the calling thread; otherwise a detached background thread sleeps for the delay and then posts a UI task via obs_queue_task(OBS_TASK_UI, …) to re-evaluate on the OBS UI thread.

Switch Sequence

Timing Parameters

The Zoom Control dock exposes these values through the Active Speaker Director controls. Operators can also manually take a participant to air and release that supersede when automatic direction should resume.

Safety Mechanisms

• Liveness flag — speaker_alive is a shared_ptr<atomic<bool>> captured by value in every in-flight lambda. When the source is destroyed, speaker_alive → false is stored before deletion. The deferred UI task checks the flag before touching ZoomSource, preventing use-after-free.
• Supersede logic — if a new candidate arrives while one is already pending, pending_speaker_id and candidate_since are updated to the newer speaker, restarting the sensitivity clock. Stale callbacks from the previous candidate see spk != pending_speaker_id and bail out silently.
• Final verification — immediately before calling do_speaker_switch(), the code re-checks ZoomParticipants::active_speaker_id() == spk so a switch never fires for a speaker who stopped talking during the hold period.
• UI-thread commitment — all state mutations (participant_id, last_switch_time, video subscription) happen on the OBS UI thread via obs_queue_task, avoiding data races with the properties panel.

Audio Isolation Interaction

When Isolate Audio is also enabled, every speaker switch triggers a new subscribe command to the engine with the updated participant ID and the isolate_audio flag, so the engine adjusts the audio feed to follow the same participant as the video.

UI Behaviour

Enabling active speaker mode in the Properties panel automatically disables the Participant dropdown (not relevant while following the speaker) and enables the Sensitivity and Hold sliders. The participant list still shows live roster entries with talking (●) and video ([video]) indicators, and updates when the Refresh button is pressed.

Director TCP Controls

The status payload includes numeric IDs and resolved participant objects for directed_speaker, raw_speaker, candidate_speaker, last_speaker, manual_speaker, and excluded_participants, plus a status value such as holding, candidate_pending, manual_supersede, or waiting_for_speaker. TCP subscribers receive speaker_director_changed when the directed, candidate, or manual speaker changes.

Auto-Reconnect

ZoomReconnectManager automatically re-joins the meeting after engine crashes, network drops, SDK errors, or host-ended meetings. It is configurable per-session and shows a live countdown in the Zoom Control dock.

Reconnect Policy

Recovery Triggers

Cancellation Safety

A monotonically increasing generation counter ensures stale timer wakeups never fire a retry that was already cancelled or superseded. Calling cancel() bumps the generation; the timer thread sees the mismatch and discards the pending retry. The dock, TCP recovery_cancel, and OSC /zoom/recovery/cancel entry points also stop the engine and clear the stored join session so a canceled retry loop cannot resurrect itself.

Explicit leave() calls set the m_user_leaving flag and call clear_session(), preventing any recovery attempt after a deliberate disconnect.

Zoom Control Dock

ZoomDock is a dockable Qt widget added to OBS on plugin load. Access it via Tools → Zoom Control or drag it to any dock position in OBS. It is the primary UI for meeting management.

CoreVideo runs as normal OBS UI: the Zoom Control dock manages meeting state and raw media while Zoom Participant sources render inside OBS scenes.

Meeting Control Bar

Session Persistence

The dock saves last_meeting_id, last_display_name, and last_was_webinar to the plugin settings file on each successful join. These values are restored and pre-filled in the dock on next OBS launch.

Recovery Panel

Shown automatically when MeetingState::Recovering. Displays:

• Recovery status message with attempt count
• Live countdown timer to next retry (refreshes every second)
• Cancel Recovery button — stops the engine, clears the stored join session, and cancels pending reconnect timers

Routing Section

The dock no longer embeds the full output table. Its routing section opens the dedicated Zoom Output Manager dock, which is the primary assignment surface for saving, loading, deleting profiles, and reviewing requested resolution, observed signal, frame rate, audio mode, audio role, screen-share state, and spotlight state.

Hardware Video Acceleration

When built with -DCOREVIDEO_HW_ACCEL=ON, each ZoomSource owns a HwVideoPipeline that converts incoming I420 frames to NV12 using FFmpeg hardware acceleration. This offloads color-space conversion from the CPU to the GPU/media engine.

A per-source hw_accel_override property (−1 = use global setting) allows different acceleration modes per source. HwVideoPipeline builds a dynamic FFmpeg filter graph on the first frame and rebuilds it automatically on resolution change. On any error it falls back to the CPU path and sets a m_broken flag to avoid repeated failures.

TCP Control API

Listens on 127.0.0.1:19870 (configurable). Each request and response is a single-line compact JSON terminated by \n. If a token is configured, every request must include "token":"<value>". Token comparison uses constant-time equality to prevent timing attacks.

Participant object

{ "id": 123, "name": "Alice", "has_video": true, "is_talking": false, "is_muted": false }

Output object

{ "source": "Zoom Participant 1", "participant_id": 123, "active_speaker": false,
  "assignment_mode": "participant", "video_resolution": "1080p",
  "observed_width": 1920, "observed_height": 1080, "observed_fps": 29.97,
  "isolate_audio": true, "audio_channels": "stereo" }

Meeting states

OSC Control API

Listens on 127.0.0.1:19871 UDP (configurable). Accepts standard OSC 1.0 datagrams. Replies are sent back to the originating host/port. Supported argument types: i (int32), f (float32), s (string), T / F (true/false booleans).

Incoming Addresses

Reply Addresses (sent by plugin)

Output Profiles

The ZoomOutputProfile namespace persists named output configurations as JSON files under the OBS plugin config directory:

obs-studio/plugin_config/obs-zoom-plugin/profiles/<name>.json

Each profile stores all current output assignments (source name, participant ID, active speaker flag, audio isolation, audio mode). Use the Zoom Output Manager dock (or OBS → Tools to focus it) to save, load, and delete profiles interactively, or call the ZoomOutputProfile API directly from code.

The Output Manager mirrors the dock assignment controls and remains useful for named profile save/load workflows.

Profile JSON format

[
  {
    "source": "Zoom Participant 1",
    "display_name": "Camera A",
    "participant_id": 123,
    "active_speaker": false,
    "isolate_audio": true,
    "audio_channels": "stereo"
  }
]

IPC Protocol Reference

All messages are UTF-8 JSON terminated by \n. Frame data is transferred through named shared memory (prefix ZoomObsPlugin_).

Plugin → Engine

Engine → Plugin

Configuration

Settings Dialog (Tools → Zoom Plugin Settings)

Published builds use the embedded CoreVideo broker — end users do not enter SDK keys, secrets, or JWT tokens.

OAuth Settings

Control & Network

Meeting Control Dock

Zoom Participant Source Properties

Each Zoom Participant source keeps its own assignment mode, audio routing, requested resolution, and failover behavior.

Zoom Participant Audio Source

Zoom Interpretation Audio Source

Auto ISO Recording

CoreVideo can record assigned participant media as separate ISO files while optionally starting the main OBS program recording. ISO recording is owned by the OBS plugin process: the engine remains minimal and only publishes raw I420 video and PCM audio through the existing IPC and shared-memory path.

OBS ISO Recorder Panel

Open Tools → Zoom ISO Recorder to manage ISO recording from a separate OBS dock. The panel lets operators choose an output folder, set or test the FFmpeg executable, choose whether to also control OBS program recording, start/stop ISO recording, and monitor active ISO sessions with source, participant, resolution, frame counts, audio chunk counts, and output file paths. Recently completed sessions remain visible after stop so operators can confirm completed MP4/WAV outputs before opening the folder.

The panel uses the same ZoomIsoRecorder backend as the TCP and OSC APIs and persists its folder, FFmpeg path, and program-recording toggle in OBS global settings. If a selected hardware encoder is unavailable in the FFmpeg build, CoreVideo falls back to libx264 when available and reports the requested encoder, actual encoder, and fallback state in the panel and TCP status payload.

Assignments resolve the participant IDs. Each assigned Zoom source can feed an FFmpeg writer for video/audio ISO files while OBS continues to own the program output.

Start Recording

{
  "cmd": "iso_recording_start",
  "output_dir": "C:/Recordings/CoreVideo",
  "ffmpeg_path": "ffmpeg",
  "record_program": true
}

Check Status

{ "cmd": "iso_recording_status" }

Stop Recording

{ "cmd": "iso_recording_stop" }

OSC Controls

See the Core Plugin Functionality guide for complete TCP examples, OSC examples, troubleshooting notes, and the plugin media pipeline diagrams.

Modern UI (Phase 1)

CoreVideo applies its own scoped Qt stylesheet and custom widgets to the plugin UI, giving it a consistent dark-theme appearance without interfering with OBS's global QApplication stylesheet.

CoreVideo Stylesheet (cv-style.h)

Applied widget-level via cv_stylesheet(). Covers group boxes, buttons (with role variants), line edits, combo boxes, tables, and scroll bars.

CvStatusDot

A QWidget subclass that draws a coloured status indicator using QPainter rather than a Unicode bullet character. In transitional states (Joining, Leaving, Recovering) a QTimer drives a sinusoidal pulse glow animation.

CvBanner

A compact QFrame-derived notice strip. Supports three kinds: Info (blue), Warning (amber), Error (red). An optional underlined action button on the right emits actionClicked(). Used in ZoomDock as a first-run prompt to configure SDK credentials.