OmniVCam Virtual Cam

简体中文

OmniVCam is a Windows DirectShow virtual camera. It can output local media files, DirectShow capture devices, OBS virtual-camera shared memory, and built-in test cards as a camera device. OmniVCamController.exe is the WinForms controller used to play inputs, tune playback options, and run playout playlists.

The project contains two main parts:

• OmniVCam: the DirectShow virtual camera DLL. It handles decoding, filtering, A/V sync, and output.
• OmniVCamController: the controller UI. It connects to the virtual camera TCP control server, default 127.0.0.1:16999.

Features

• Play local media files and arbitrary FFmpeg inputs.
• Play DirectShow devices such as capture cards or OBS Virtual Camera, either through FFmpeg or the native <DSHOW> capture input.
• Native <DSHOW> capture configuration: enumerate devices and formats, select video/audio pins, configure Crossbar routes and analog-device property pages, use device timestamps, and request an audio buffer size.
• Read OBS virtual camera shared-memory input with <OBSVCAM>.
• Built-in test cards: <TESTCARD> and <TESTCARD2>.
• Per-input options such as seek_time, stream indexes, filters, queue settings, and input format.
• Manual playback controls: play/pause toggle, stop, reopen, seek, byte seek, progress drag, filters, display aspect, scale mode, and output time shift.
• Runtime changes for scale mode and display aspect during playback.
• Favorite inputs list for reusable input/options pairs.
• Multiple connection tabs, each with independent host/port, input settings, playlists, and favorites.
• Controller UI localization through standard .resx resources, currently English, Simplified Chinese, and Traditional Chinese.
• Playout window with separate scheduled and normal playlists.
• One-time and weekly scheduled playlist items with editable title, options, start/end behavior, and live Apply.
• Bumper items in normal playlist for interstitial content.
• Drag-and-drop support: drop files onto the input field or playlist.
• Built-in log viewer displaying FFmpeg log messages forwarded via TCP.
• Frame deliver block-time stats displayed in the position area.
• Optional now-playing XML output for vMix and other external tools.
• Automatic saving of UI settings, playlists, scheduled playlist, and favorite inputs to OmniVCamController.xml.

Install

1. Copy the release files to a fixed directory, for example D:\OmniVCam. Keep OmniVCam.dll, FFmpeg DLLs, config files, and the controller together.

2. Register the virtual camera DLL from an elevated command prompt:

   cd /d D:\OmniVCam
   regsvr32 OmniVCam.dll

3. Select OmniVCam Virtual Camera in OBS, vMix, conferencing software, or other camera clients.

To unregister:

cd /d D:\OmniVCam
regsvr32 /u OmniVCam.dll

Multiple Instances

OmniVCam supports up to 4 simultaneous virtual camera instances. Each instance has its own CLSID and reads its own config.ini via an environment variable:

Instance	Environment Variable	Config Path Example
OmniVCam	OMNI_VCAM_CONFIG	D:\OmniVCam\config.ini
OmniVCam2	OMNI_VCAM_CONFIG2	D:\OmniVCam2\config.ini
OmniVCam3	OMNI_VCAM_CONFIG3	D:\OmniVCam3\config.ini
OmniVCam4	OMNI_VCAM_CONFIG4	D:\OmniVCam4\config.ini

To run multiple instances, copy the DLL and config files into separate directories, set each environment variable to point to the corresponding config.ini, and register each DLL instance. Each instance exposes a distinct camera device name (e.g. OmniVCam Virtual Camera, OmniVCam2 Virtual Camera, etc.).

Controller Basics

Run OmniVCamController.exe. The default target is 127.0.0.1:16999; the port must match tcp_port in OmniVCam/config.ini.

Connection Tabs

The controller supports multiple connection tabs. Each tab maintains its own host, port, input settings, playlists, favorites, and log text. Use the + button to add a tab and the - button to remove one. Tab titles display the connection endpoint.

Main controls:

• Host / Port: TCP control endpoint.
• Input: the input to play. It can be a file path, URL, DirectShow input, or a special input such as <TESTCARD>, <TESTCARD2>, <OBSVCAM>, or <DSHOW>. A quick-select dropdown provides quick access to special inputs.
• Title: display title used by playlists and now-playing XML. If blank, the controller derives a title from the input.
• Options: FFmpeg/open-input options for the current input, for example seek_time=14,video_filter='bwdif=1'.
• Browse: select a local media file.
• Open: open/play the current Input with current Options.
• Play: play the current Input, or toggle Pause/Play while playback is active or paused.
• Stop: stop playback and stop playout.
• Reopen: reopen the current input.
• Ping: test the TCP connection.
• Video filter / Audio filter: set or cancel global filters.
• Auto deinterlace: automatically applies the selected deinterlace filter only when no video_filter is set and an interlaced frame is detected. Mixed progressive/interlaced streams are handled per frame: progressive frames bypass the auto filter, interlaced frames go through it.
• Deinterlace filter: automatic deinterlace filter, bwdif, yadif, or w3fdif.
• HW decode: set hardware decode mode: none, dxva2, d3d11va, cuda, or qsv.
• Video index / Audio index: select input stream indexes. -1 means auto.
• Seek seconds: seek by absolute seconds.
• Progress: drag to seek. With Byte seek enabled, the progress bar seeks by file byte percentage. Quick -5s / +5s buttons are available beside the progress bar.
• Shift us: output frame timing shift in microseconds.
• Scale mode: output scaling mode (letterbox, fill). Can be changed at runtime.
• Display AR: display aspect ratio (auto, 16:9, 4:3, 1:1). Can be changed at runtime.
• DirectShow / Camera: opens the native <DSHOW> capture setup dialog. It is enabled for the <DSHOW> input and writes the required options automatically.
• Open playout: open the separate playout window.
• Language: select Auto, English, Simplified Chinese, or Traditional Chinese. Restart the controller after changing this setting.

Native <DSHOW> Capture Input

<DSHOW> is the native DirectShow capture path. Unlike the format=dshow FFmpeg input, it builds a DirectShow graph in OmniVCam and sends captured frames through the normal video/audio filter and output pipeline. Compressed samples are copied into bounded real-time queues and decoded on dedicated worker threads, so codec work does not block the DirectShow sample callback.

1. Select <DSHOW> in Input, then choose DirectShow → Camera.
2. Select a video device and capture format. Audio is optional; it can come from the capture device or a separate audio device.
3. Optionally select video/audio Crossbar routes, open Crossbar/TV tuner/TV audio property pages on playback, use video/audio device timestamps, and request an audio buffer size.
4. Choose OK to fill Input, Title, and Options, or Open to apply and start playback immediately.

The controller enumerates compatible pins and formats and stores device names and pin IDs as UTF-8 Base64 options, so the generated options should normally be kept intact. <DSHOW> supports video-only, audio-only, and combined capture. Standard per-input options still apply, including video_filter, audio_filter, queue_left, queue_right, and queue_center.

For programmatic control, the native options are dshow_device_b64, dshow_pin_b64, dshow_format, dshow_audio_device_b64, dshow_audio_device_type (0 for a video-capture device, 1 for an audio device), dshow_audio_pin_b64, dshow_audio_format, dshow_xbar_video_in, dshow_xbar_video_out, dshow_xbar_audio_in, dshow_xbar_audio_out, dshow_crossbar_dialog, dshow_tv_tuner_dialog, dshow_tv_audio_dialog, dshow_use_video_device_timestamp, dshow_use_audio_device_timestamp, and dshow_audio_buffer_size (milliseconds). Device and pin values use UTF-8 Base64; omitted format/route values select the device default.

Log Viewer

The main window includes a log viewer panel on the left side that displays FFmpeg log messages forwarded from the virtual camera instance over TCP. Log output is auto-scrolling and capped at a maximum line count. Each connection tab preserves its own log text independently.

Drag and Drop

• Drag files onto the Input field to load them for playback.
• Drag files onto the Normal playlist or Scheduled playlist to add them as items.

Favorite Inputs

Favorite inputs are shown in the right half of the main window.

• Add current: add current Input, Title, and Options.
• Remove, Up, Down: edit list order.
• Single-click: load the favorite into the main input fields.
• Double-click: play the favorite immediately.

Playout Window

Click Open playout in the main window. The playout window contains two lists:

• Scheduled playlist: timed playout items.
• Normal playlist: fallback/continuous playlist.

Closing the playout window hides it. Closing the main controller exits the application.

Top controls:

• Start playout: start playout scheduling. The playout timer only runs while playout is started.
• Next: manually play the next normal playlist item. In Random mode it chooses a random item.
• Stop playout: stop playout, stop playback, and clear scheduled trigger marks.
• Save XML: save controller settings and both playlists to OmniVCamController.xml.
• Write now playing XML: enable or disable now-playing XML output.

Scheduled Playlist

Scheduled playlist columns:

• Status: Waiting, In window, Blocked, Playing, Ended, Error, etc.
• Title: item title.
• Duration: item duration. Unknown duration is shown as --:--:--.
• Schedule: one-time date/time or weekly days/time.
• End: explicit end time, or Next schedule when no end time is set.
• Start: start behavior.
• End action: behavior if media ends before the end time.
• Last triggered: last schedule-window start that triggered this item. Stop clears it.
• Path: input path/URL/device/special input.

Scheduled item controls:

• Add current: add current main Input as a scheduled item.
• Add files: add one or more media files as scheduled items.
• Add folder: recursively add media files from a folder.
• Apply: write the current scheduled settings into the selected scheduled item. This also works while the item is playing.
• Remove, Up, Down: edit list order.
• Refresh durations: probe durations for scheduled items only.

Scheduled settings:

• Schedule type: One-time or Weekly.
• One-time start: full date and time for one-time items.
• Weekly time: time of day for weekly items.
• Days: weekly day mask.
• Input title: title used for scheduled items. If blank, it falls back to main Title, then input-derived title.
• Input options: options used for scheduled items. If blank, it falls back to main Options.
• Use end time: enable explicit end time.
• End time: for one-time items this is date/time; for weekly items only the time of day is meaningful.
• If media ends early:
  • Replay until end: replay the same item until the end time.
  • Wait until end: do not play another item until the end time.
  • Continue immediately: leave the scheduled item immediately.
• At scheduled time:
  • Start immediately: cut in when this task becomes active, including over another scheduled item if this window starts later.
  • Wait current item: wait while another item is playing; the scheduler rechecks every tick.

Scheduling behavior:

• The scheduler uses time windows, not a one-second exact trigger. If the PC stalls for several seconds, a task can still start as long as current time is inside its window.
• With Use end time, the window is start -> end.
• Without Use end time, the window is start -> next scheduled task start. If no next task exists, the window is open-ended.
• A later Start immediately scheduled task can cut into the currently playing scheduled task.
• Stop playout clears all Last triggered marks, so restarting playout can trigger tasks that are still inside their windows.

Normal Playlist

Normal playlist controls:

• Add current: add current main Input to the normal playlist. This supports arbitrary input, not only files.
• Add files: add media files.
• Add folder: recursively add media files from a folder.
• Add bumper: add a file marked as Bumper. Bumpers serve as interstitial content between normal playlist items during playout.
• Remove, Up, Down: edit list order.
• Set title: apply the main Title field to selected normal items.
• Set options: apply the playout Input options field to selected normal items.
• Load / Save file: load or save .ovcpl playlist files.
• Refresh durations: probe durations for normal items only.
• Mode: Sequential or Random.
• Normal auto next: when enabled, normal playlist advances on ended/error or known duration reached.
• Start at: optional legacy time-of-day start for normal playlist start.

Duration is not probed automatically when adding or loading items. Click Refresh durations when durations are needed.

When scheduled playback finishes, the controller returns to the normal playlist if it has items. If no normal items exist, playback remains stopped/ended.

Now-Playing XML

When Write now playing XML is checked, the controller writes an XML file beside the controller executable. With a single connection tab the file is:

OmniVCamNowPlaying.xml

With multiple connection tabs, each tab writes its own file named by host and port:

OmniVCamNowPlaying-{host}-{port}.xml

For example OmniVCamNowPlaying-127.0.0.1-16999.xml.

The file is updated from STATUS polling and on stop. It can be imported by tools such as vMix.

Example:

<NowPlaying>
  <Title>Program title</Title>
  <Path>D:\media\program.mp4</Path>
  <PositionSeconds>123</PositionSeconds>
  <Position>00:02:03</Position>
  <DurationSeconds>3600</DurationSeconds>
  <Duration>01:00:00</Duration>
  <Status>Playing</Status>
</NowPlaying>

Uncheck Write now playing XML to stop writing this file. Existing XML files are not deleted automatically.

Common Inputs And Options

Options are parsed as FFmpeg open-input options plus OmniVCam-specific options. Multiple options are separated by commas.

Use case	Input	Options
OBS shared-memory input	<OBSVCAM>	queue_left=1,queue_right=5
Test card 1	<TESTCARD>	empty
Test card 2	<TESTCARD2>	empty
Native DirectShow capture	<DSHOW>	Configure with DirectShow → Camera; for example add video_filter='bwdif=1',audio_filter='loudnorm' as needed
Play file and seek to 14 seconds	D:\example.mp4	seek_time=14
Play file with filters/indexes	D:\tv.ts	video_filter='bwdif=1',audio_filter='loudnorm',video_index=0,audio_index=1
OBS Virtual Camera device	video=OBS Virtual Camera	format=dshow,rtbufsize=1G,queue_left=5,queue_right=20
Capture card 1080p60 YUY2	video=U4 4K60	format=dshow,rtbufsize=1G,queue_left=1,queue_right=5,video_size=1920x1080,framerate=60,pixel_format=yuyv422
Capture card 1080p120 MJPEG	video=U4 4K60	format=dshow,rtbufsize=1G,queue_left=1,queue_right=10,video_size=1920x1080,framerate=120,vcodec=mjpeg

Supported OmniVCam-specific options include:

• video_filter: per-input video filter.
• audio_filter: per-input audio filter.
• auto_deinterlace: optional per-input automatic deinterlace override, 1 or 0.
• auto_deinterlace_filter: optional per-input automatic deinterlace filter override, bwdif, yadif, or w3fdif.
• video_index / audio_index: input stream indexes.
• seek_time: seek after opening input.
• queue_left / queue_right / queue_center: frame queue tuning.
• probesize / analyzeduration: FFmpeg probing options.
• format: input format, for example dshow.
• vcodec / acodec / scodec / dcodec: decoder selection.

format=dshow remains available for FFmpeg's DirectShow demuxer. Prefer <DSHOW> when you want the controller to select native-device pins, formats, audio sources, Crossbar routes, or device timestamp settings.

To list DirectShow capture formats with FFmpeg:

ffmpeg -list_options true -f dshow -i video="U4 4K60"

Example screenshot:

Test Cards

<TESTCARD> shows a square and moving circles. It is useful for checking dropped frames and motion continuity.

<TESTCARD2> shows a square and rotating lines. It is useful for checking motion continuity and rotational line loss.

Controller

Configuration Files

Controller state is saved to:

OmniVCamController.xml

This file stores controller settings, favorite inputs, normal playlist, scheduled playlist, and now-playing XML output preference. It also stores the controller UI language in the root uiCulture attribute when a language is selected explicitly.

OmniVCam/config.ini is read by the virtual camera instance. Common keys include:

• hw_decode: default hardware decode mode.
• tcp_port: TCP control port, default 16999.
• scale_mode: output scaling mode, letterbox or fill.
• display_aspect: output display aspect ratio, auto or a ratio such as 16:9.
• auto_deinterlace: automatic deinterlace default, 1 enabled and 0 disabled. It only takes effect when no global or per-input video filter is set.
• auto_deinterlace_filter: automatic deinterlace filter, bwdif, yadif, or w3fdif; default is bwdif.
• log_level: FFmpeg log level.
• video_frame_buffer / audio_frame_buffer: output frame buffering.
• packet_queue_size: packet queue size.
• timeout: input timeout in microseconds.
• use_fixed_frame_interval: usually 1 for OBS compatibility.
• ajust_start_time_if_delay_over: output timing correction threshold.
• av_max_offset_time: max A/V timestamp offset in microseconds.

Restart the host application or reload the virtual camera instance after changing config.ini.

TCP Control Protocol

The virtual camera accepts line-based TCP commands. Default port: 16999.

Supported commands include:

• PING: returns OK PONG.
• STATUS: returns seconds, duration, size, state, scale_mode, display_aspect, input, deliver_ns, deliver_avg_ns, and controller_connected.
• DURATION <input>[\toptions]: probe input duration.
• PLAY <input>[\toptions]: play input.
• PAUSE: pause output without closing the input.
• RESUME: resume paused output.
• STOP: stop playback.
• REOPEN: reopen current input.
• SET_FILTER <filter>: set/cancel global video filter.
• SET_AUDIO_FILTER <filter>: set/cancel global audio filter.
• SET_HW_DECODE <none|dxva2|d3d11va|cuda|qsv>: set hardware decode.
• SET_SCALE_MODE <letterbox|fill|stretch|fit|keep_aspect|fullscreen>: set output scale mode at runtime.
• SET_DISPLAY_ASPECT <auto|num:den>: set display aspect ratio at runtime.
• SET_AUTO_DEINTERLACE <0|1> [bwdif|yadif|w3fdif]: set automatic deinterlace behavior at runtime.
• SET_INDEX video=<n> audio=<n>: set stream indexes.
• SET_SHIFT <microseconds>: set output timing shift.
• DSHOW_DEVICES: list native DirectShow video and audio devices for the controller.
• DSHOW_FORMATS <type> <device-moniker>: list native capture formats for a device (type is 0 for video capture or 1 for audio capture).
• DSHOW_CROSSBAR <device-moniker>: list available Crossbar routes and TV-tuner/TV-audio capabilities.
• SEEK <seconds>: seek by seconds.
• SEEK_BYTE_PERCENT <0-10000>: seek by byte percentage; 10000 means 100%.

Build

Solution: OmniVCam.sln.

• OmniVCam: C/C++ DirectShow DLL, Visual Studio 2022 / v143, supports Win32 and x64.
• OmniVCamController: C# WinForms application targeting .NET Framework 4.8, AnyCPU.

Dependency conventions:

• deps/include: DirectShow Base Classes headers.
• deps/lib/x86 and deps/lib/x64: DirectShow Base Classes libraries.
• ffmpeg_deps/include and ffmpeg_deps/lib: FFmpeg development files when building the native DLL.

A release package must include the virtual camera DLL, required FFmpeg runtime DLLs, config.ini, and OmniVCamController.exe.