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updated cap_libv4l.cpp to support CV_CAP_PROP_POS_MSEC, CV_CAP_PROP_POS_FRAMES and CV_CAP_PROP_FPS

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msandler 2015-05-09 05:32:07 -07:00 committed by blue
parent a31b29308f
commit 8e82bed459
1 changed files with 57 additions and 9 deletions
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66
modules/videoio/src/cap_libv4l.cpp
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@ -190,6 +190,10 @@ make & enjoy!
- PlayStation 3 Eye
- Logitech C920
- Odroid USB-CAM 720P
17th patch: May 9, 2015, Matt Sandler
added supported for CV_CAP_PROP_POS_MSEC, CV_CAP_PROP_POS_FRAMES, CV_CAP_PROP_FPS
*/
/*M///////////////////////////////////////////////////////////////////////////////////////
@ -333,6 +337,11 @@ typedef struct CvCaptureCAM_V4L
enum v4l2_buf_type type;
struct v4l2_queryctrl queryctrl;
struct timeval timestamp;
/** value set the buffer of V4L*/
int sequence;
/* V4L2 control variables */
v4l2_ctrl_range** v4l2_ctrl_ranges;
int v4l2_ctrl_count;
@ -1124,6 +1133,11 @@ static int read_frame_v4l2(CvCaptureCAM_V4L* capture) {
if (-1 == xioctl (capture->deviceHandle, VIDIOC_QBUF, &buf))
perror ("VIDIOC_QBUF");
//set timestamp in capture struct to be timestamp of most recent frame
/** where timestamps refer to the instant the field or frame was received by the driver, not the capture time*/
capture->timestamp = buf.timestamp; //printf( "timestamp update done \n");
capture->sequence = buf.sequence;
return 1;
}
@ -1237,16 +1251,16 @@ static int icvGrabFrameCAM_V4L(CvCaptureCAM_V4L* capture) {
} else
{
capture->mmaps[capture->bufferIndex].frame = capture->bufferIndex;
capture->mmaps[capture->bufferIndex].width = capture->captureWindow.width;
capture->mmaps[capture->bufferIndex].height = capture->captureWindow.height;
capture->mmaps[capture->bufferIndex].format = capture->imageProperties.palette;
capture->mmaps[capture->bufferIndex].frame = capture->bufferIndex;
capture->mmaps[capture->bufferIndex].width = capture->captureWindow.width;
capture->mmaps[capture->bufferIndex].height = capture->captureWindow.height;
capture->mmaps[capture->bufferIndex].format = capture->imageProperties.palette;
if (v4l1_ioctl (capture->deviceHandle, VIDIOCMCAPTURE,
&capture->mmaps[capture->bufferIndex]) == -1) {
/* capture is on the way, so just exit */
return 1;
}
if (v4l1_ioctl (capture->deviceHandle, VIDIOCMCAPTURE,
&capture->mmaps[capture->bufferIndex]) == -1) {
/* capture is on the way, so just exit */
return 1;
}
++capture->bufferIndex;
if (capture->bufferIndex == capture->memoryBuffer.frames) {
@ -1362,6 +1376,36 @@ static double icvGetPropertyCAM_V4L (CvCaptureCAM_V4L* capture,
}
}
return (property_id == CV_CAP_PROP_FRAME_WIDTH)?capture->form.fmt.pix.width:capture->form.fmt.pix.height;
case CV_CAP_PROP_POS_MSEC:
if (capture->FirstCapture) {
return 0;
} else {
//would be maximally numerically stable to cast to convert as bits, but would also be counterintuitive to decode
return 1000 * capture->timestamp.tv_sec + ((double) capture->timestamp.tv_usec) / 1000;
}
break;
case CV_CAP_PROP_POS_FRAMES:
return capture->sequence;
break;
case CV_CAP_PROP_FPS: {
struct v4l2_streamparm sp;
memset (&sp, 0, sizeof(struct v4l2_streamparm));
sp.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (xioctl (capture->deviceHandle, VIDIOC_G_PARM, &sp) < 0){
fprintf(stderr, "VIDEOIO ERROR: V4L: Unable to get camera FPS\n");
return (double) -1;
}
// this is the captureable, not per say what you'll get..
double framesPerSec = sp.parm.capture.timeperframe.denominator / (double) sp.parm.capture.timeperframe.numerator ;
return framesPerSec;
}
break;
case CV_CAP_PROP_MODE:
return capture->mode;
break;
@ -1507,13 +1551,17 @@ static int icvSetVideoSize( CvCaptureCAM_V4L* capture, int w, int h) {
xioctl (capture->deviceHandle, VIDIOC_S_FMT, &capture->form);
/* try to set framerate to 30 fps */
struct v4l2_streamparm setfps;
memset (&setfps, 0, sizeof(struct v4l2_streamparm));
setfps.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
setfps.parm.capture.timeperframe.numerator = 1;
setfps.parm.capture.timeperframe.denominator = 30;
xioctl (capture->deviceHandle, VIDIOC_S_PARM, &setfps);
/* we need to re-initialize some things, like buffers, because the size has
* changed */
capture->FirstCapture = 1;