Video sink node: each upstream frame is written; the file closes and the trailer is flushed when the graph run finishes. fourcc is a four-character codec name (e.g. mp4v); fps must match the source.
Module：Video I/O · Task type：video_writer
Ports
Inputs
| Port | Type | Required |
|---|---|---|
in | Image / cv::Mat | ✓ |
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） | output path (extension picks the container) | |
fourcc | string | "mp4v" | four-character codec id, e.g. mp4v / avc1 | |
fps | float | 30 | [1, 240] | frame rate; mismatch with the source speeds up/slows down playback |
is_color | bool | true | write color frames |
Example graph
A minimal runnable pipeline (read → process → write). Drag it into GraphStudio or open via --open; replace data/test.png with a real path.
{
"version": "2.0",
"tasks": [
{
"id": "read",
"type": "opencv_image_read",
"params": {
"file_path": "data/test.png"
}
},
{
"id": "node",
"type": "video_writer",
"params": {
"fourcc": "mp4v",
"fps": 30,
"is_color": true
}
},
{
"id": "save",
"type": "opencv_image_write",
"params": {
"file_path": "out_out.png"
}
}
],
"edges": [
{
"from": "read",
"from_port": "out",
"to": "node",
"to_port": "in"
},
{
"from": "node",
"from_port": "out",
"to": "save",
"to_port": "in"
}
]
}
Part of the GraphStudio node guide series; parameters reflect the latest release.