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35 lines
1.3 KiB
Markdown
35 lines
1.3 KiB
Markdown
# VidNumerator
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This is a tiny library that uses syscalls to efficiently determine which `/dev/videoN` devices
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are webcams and which are the additional metadata control handles.
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The list of strings returned are the full filepaths to valid devices.
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>[!IMPORTANT]
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>In order for this library to work properly, the executing user must have either root or video group privileges
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## Technical Details
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The library works by:
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1. Scanning `/dev` for files matching the pattern `video*`
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2. Using the `VIDIOC_QUERYCAP` ioctl to check if each device is a video capture device
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3. Filtering out non-capture devices (like metadata control handles)
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The core functionality is implemented through direct syscalls to the Linux kernel's V4L2 (Video4Linux2) API. The library uses the `VIDIOC_QUERYCAP` ioctl command to query device capabilities and determine if a device supports video capture.
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## Usage
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```go
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devices, err := vidnumerator.EnumeratedVideoDevices()
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if err != nil {
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// handle error
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}
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// devices will contain paths like "/dev/video0", "/dev/video2", etc.
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```
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## Implementation Notes
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- Uses direct syscalls via `golang.org/x/sys/unix`
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- Implements custom ioctl constants for V4L2 device querying
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- Checks for specific device capabilities (0x4200001) to identify capture devices
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