bytedeco/javacv

How to specify the screen for screen capturing in JavaCV

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#2324 opened on Mar 14, 2025

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help wantedquestion

Description

On Windows, I am using the following code for screen capturing. I would like to ask how I can specify which screen to capture in a multi-screen setup.


FFmpegFrameGrabber grabber = new FFmpegFrameGrabber("desktop");
grabber.setFormat("gdigrab");
grabber.setOption("draw_mouse", "0");
grabber.setOption("offset_x", "1920");
grabber.setOption("offset_y", "0");
grabber.setOption("framerate", "45");
grabber.setOption("hwaccel", "auto");
grabber.setOption("threads", "auto");
grabber.start();

Contributor guide

Tech stack
java
Domain
desktop
Issue type
research
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
under 1 hour
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
JavaJavaCV
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
75
Research direction
Check the JavaCV documentation for FFmpegFrameGrabber options related to specifying screen index. The user's code uses offset x and offset y, but the screen index might be set via the input filename (e.g., 'desktop' can be replaced with 'desktop:screen index') or via additional options. Look at the FFmpeg gdigrab documentation for how to enumerate screens.