Video source node: the executor drives it frame by frame — each execute() outputs the next frame on out, with teardown at stream end. api_preference forces a decode backend (automatic by default; FFMPEG is the most common).
Module：Video I/O · Task type：video_reader
Ports
Inputs
None.
Outputs
| Port | Type | Required |
|---|---|---|
out | cv::Mat | ✓ |
Parameters
| 参数 | 类型 | 默认值 | 范围 / 选项 | 说明 |
|---|---|---|---|---|
file_path | string | （空） | video path; relative paths probe the graph directory | |
api_preference | enum | 0 | DEFAULT / FFMPEG | decode backend: DEFAULT (auto) / FFMPEG |
Notes
- Frame semantics are executor-driven: one GraphStudio execution = one frame; use embedded SDK execution or a script loop for batch transcoding.
Part of the GraphStudio node guide series; parameters reflect the latest release.