bytedeco/javacv

ScreenCapture on Windows using new FFmpegFrameGrabber("screen-capture-recorder");

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#31 opened on Aug 24, 2014

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enhancementhelp wanted

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Description

Apparently ffmpeg supports screen capture on Windows according to this: https://trac.ffmpeg.org/wiki/Capture/Desktop

Attempting to do so using:

        FrameGrabber grabber = new FFmpegFrameGrabber("screen-capture-recorder");// As well as FFmpegFrameGrabber("UScreenCapture");
        grabber.setFormat("dshow");
        grabber.setFrameRate(30);
        grabber.start();

Results in:

run:
Exception in thread "main" org.bytedeco.javacv.FrameGrabber$Exception: avformat_open_input() error -5: Could not open input "screen-capture-recorder". (Has setFormat() been called?)
    at org.bytedeco.javacv.FFmpegFrameGrabber.startUnsafe(FFmpegFrameGrabber.java:368)
    at org.bytedeco.javacv.FFmpegFrameGrabber.start(FFmpegFrameGrabber.java:318)
    at testarea.JavaCVDemo.main(JavaCVDemo.java:40)
[dshow @ 154dc160] Malformed dshow input string.
[dshow @ 154dc160] Malformed dshow input string.
Java Result: 1
BUILD SUCCESSFUL (total time: 9 seconds)

This may possibly have something to do with(maybe???): https://trac.ffmpeg.org/wiki/DirectShow#Specifyinginputframerate

This is here as a resource in case other people experience this error and wish to look into it, as well as a reminder to myself to do so in the future. If you find any solutions or fixes, please let me know.

Contributor guide

Research direction
Check the FFmpeg DirectShow documentation for correct input device naming. The error 'Malformed dshow input string' suggests the input string format is incorrect. Verify that the device name 'screen capture recorder' is available and try alternative names like 'UScreenCapture' or 'video=screen capture recorder'. Also ensure setFormat() is called before start().
Tech stack
java
Domain
desktop
Issue type
Bug
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.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Needs investigation
Prerequisites
JavaFFmpeg
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70