Comments on: OpenCV More with cameras.

By: lokye

lokye — Tue, 29 Jun 2010 01:21:18 +0000

Thanks again for your help. Much appreciated

By: damiles

damiles — Mon, 28 Jun 2010 09:31:17 +0000

Ok the you want save each frames with correct name…

You only need open video and read each frame in bucle and save it in correct file name.

This can be a c example for get filename correctly with fixed number of characters:

#include “stdio.h”;

int main(){
int totalFrames=30;
int frameNum=0;
int numChars=4;
char parser[255];
char fileName[255];

//Create the file pattern with fixed number of characters
sprintf(parser, “FileName_%%.%dd.ext”,numChars);
printf(“%s\n”,parser);

//Main bucle for save each frame.
for(frameNum=0;frameNum sprintf(fileName, parser, frameNum);
printf("%s\n", fileName);
//Now we can save the frame with name "fileName"
/*
…
*/
}
return 0;
}

Regards.

By: lokye

lokye — Mon, 28 Jun 2010 08:50:24 +0000

Hi.
What i’m trying to do is to try and save all the frame in a single avi video and save those frames in .jpg format with the correct filenameeg “depthmap0000.jpg”, ” depthmap0001.jpg” etc.

Firstly, get the number of frames the avi video is holding.

Secondly, loop over the number of frames one by one, then save these frames into the folder with the correct name accordingly to whichever frame they belong to.

Can you like teach me cause i’m new to OpenCV.
Thank you very much for your respond above. That was quick. *smile*

By: damiles

damiles — Mon, 28 Jun 2010 08:38:22 +0000

There are another way to write avi with opencv, you can use videowriter class (C++): http://opencv.willowgarage.com/documentation/cpp/reading_and_writing_images_and_video.html#videowriter

Or with c: http://opencv.willowgarage.com/documentation/c/reading_and_writing_images_and_video.html#writeframe

You can see an example here:

CvSize imgSize;
imgSize.width = image->width;
imgSize.height = image->height;

double fps = cvGetCaptureProperty(
input,
CV_CAP_PROP_FPS
);

CvVideoWriter *writer = cvCreateVideoWriter(
“out.avi”,
CV_FOURCC(‘M’, ‘J’, ‘P’, ‘G’),
fps,
imgSize
);

IplImage* colourImage;
//Keep processing frames…
for (;;) {

//Get a frame from the input video.
colourImage = cvQueryFrame(input);
cvWriteFrame(writer, colourImage);

}

cvReleaseVideoWriter(&writer);
cvReleaseCapture(&input);

}

By: lokye

lokye — Mon, 28 Jun 2010 08:30:38 +0000

How do u save all the frames in a single video and save them with the correct filename like “pic_0001″, “pic_0002″??
Thanks for your help. Really appreciate it.

By: damiles

damiles — Tue, 22 Jun 2010 07:16:40 +0000

I don’t need test with directshow because i no need it at this moment, but in future i will need use it.

Directshow is not bad, is other way to capture images. As V4l or specific camera driver or similar…

By: doliharahap

doliharahap — Tue, 22 Jun 2010 06:37:11 +0000

Why don’t test with directshow??
Is it bad???

I’ve tried also this problem in Linux (Ubuntu). The result is the same.

Ok then, thank you very much for your responds.

By: damiles

damiles — Mon, 21 Jun 2010 10:12:07 +0000

Hi, i no use win… and don’t test with directshow, but yes, you can capture with any sdk and convert the frame to iplImage structure.

By: doliharahap

doliharahap — Mon, 21 Jun 2010 10:03:58 +0000

have you tried to use directshow sdk along with opencv?

i just wonder if i can capture the video using directshow and then manipulate the video using opencv..

is it possible?

By: doliharahap

doliharahap — Mon, 21 Jun 2010 08:40:33 +0000

Thanks for your quick reply,

how to check whether i get frame or not??
That i sure is i can display the video and i can manipulate the video that i get from the camera, but the problem is i only get grayscale video. If i use my webcam i get perfect video with color video.

i just searched and i get UYVY something which i don’t understand.