如何在OpenCV中设置相机FPS？ CV_CAP_PROP_FPS是假的 [英] How to set camera FPS in OpenCV? CV_CAP_PROP_FPS is a fake

问题描述

如何设定相机FPS？

可能是
cvSetCaptureProperty（cameraCapture，CV_CAP_PROP_FPS，30）;
？

May be cvSetCaptureProperty(cameraCapture, CV_CAP_PROP_FPS, 30); ?

但返回
HIGHGUI错误：V4L2：无法获取属性（5） - 参数无效

But it's return HIGHGUI ERROR: V4L2: Unable to get property (5) - Invalid argument

因为没有在highgui / cap_v4l.cpp

Because there is no implementation in highgui/cap_v4l.cpp

static int icvSetPropertyCAM_V4L( CvCaptureCAM_V4L* capture,
                                  int property_id, double value ){
    static int width = 0, height = 0;
    int retval;

    /* initialization */
    retval = 0;

    /* two subsequent calls setting WIDTH and HEIGHT will change
       the video size */
    /* the first one will return an error, though. */

    switch (property_id) {
    case CV_CAP_PROP_FRAME_WIDTH:
        width = cvRound(value);
        if(width !=0 && height != 0) {
            retval = icvSetVideoSize( capture, width, height);
            width = height = 0;
        }
        break;
    case CV_CAP_PROP_FRAME_HEIGHT:
        height = cvRound(value);
        if(width !=0 && height != 0) {
            retval = icvSetVideoSize( capture, width, height);
            width = height = 0;
        }
        break;
    case CV_CAP_PROP_BRIGHTNESS:
    case CV_CAP_PROP_CONTRAST:
    case CV_CAP_PROP_SATURATION:
    case CV_CAP_PROP_HUE:
    case CV_CAP_PROP_GAIN:
    case CV_CAP_PROP_EXPOSURE:
        retval = icvSetControl(capture, property_id, value);
        break;
    default:
        fprintf(stderr,
                "HIGHGUI ERROR: V4L: setting property #%d is not supported\n",
                property_id);
    }

    /* return the the status */
    return retval;
}

如何解决？

推荐答案

我不知道这是否仍然有效，但前一段时间，像一年半，我遇到了确切的问题。我与OpenCV的开发人员联系，他告诉我，改变捕获的一些属性的访问和能力尚未实现，其他一些只是为某些类型的相机工作。我终于看了一下 libdc1394 （在Linux中工作），并做了一些功能，将libdc1394检索的数据转换为IplImages从OpenCV。这不是一个艰巨的任务。

I don't know if that's still valid, but some time ago, something like one year and a half, I encountered that exactly problem. I contacted with a developer of OpenCV and he told me that the access and ability to change some of the properties of a capture weren't implemented yet and some other just worked for certain kinds of camera. I finally took a look to libdc1394 (working in linux) and made some functions that converted the data retrieved by libdc1394 to IplImages from OpenCV. It wasn't a such a tough task.

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