Local video capture

This code captures the video from a webcam (v4l2, cf doc/sflphone_video) and display it as a texture on an openGL window

src/video/COPYING

+		    GNU GENERAL PUBLIC LICENSE
+		       Version 2, June 1991
+
+ Copyright (C) 1989, 1991 Free Software Foundation, Inc.
+     51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
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+
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+Public License instead of this License.

src/video/README

+##############################################################
+Pour compiler: faire 'make'
+gcc gui-openGL/display.c -lglut -ljpeg -o stream_video
+make clean : to remove the .o files
+##############################################################
+
+
+##############################################################
+Executable: stream_video
+
+Lit le flux video de la webcam (device video0), et l'affiche avec openGL comme une texture.
+Driver: video4linux2
+##############################################################
+
+
+################################################################
+Raccourcis clavier:
+
+'q', 'Q' ou 'echap pour quitter l'application
+pad numérique:  1 - taille initiale (de la résolution supportée par la caméra)
+		2 - double la taille d'affichage
+		3 - triple la taille d'affichage  
+####################################################################

src/video/gui-openGL/display.c

+/*
+ *  Copyright (C) 2006-2007 Savoir-Faire Linux inc. 
+ *  Author: Emmanuel Milou <emmanuel.milou@savoirfairelinux.com
+ *  
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <GL/gl.h>
+#include <GL/glut.h>
+#include <jpeglib.h>
+#include <jerror.h>
+
+#include "../v4l2/capture_v4l2.c"
+
+unsigned char* pix;
+camera_v4l2* camera;
+// video resolution
+int RES_X;
+int RES_Y; 
+// window size
+int WIDTH = 512;
+int HEIGHT = 512;
+// texture size
+int x_t;
+int y_t;
+
+
+/*
+ * Sets up appropriate viewport coordinates for 2D
+ */
+void reshape(int w, int h)
+{
+	glViewport(0, 0, w, h);
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+	glOrtho(0, w, h, 0, -1, 1);
+	glMatrixMode(GL_MODELVIEW);
+	glLoadIdentity();
+}
+
+void makeQuad(){
+
+	// centrer la video dans la fenetre
+	int x1,y1,x2,y2,x3,y3,x4,y4;
+	x1 = (WIDTH - x_t) / 2;
+	y1 = (HEIGHT - y_t) / 2;
+	x2 = x_t + x1;
+	y2 = y1;
+	x3 = x2;
+	y3 = y1 + y_t;
+	x4 = x1;	
+	y4 = y3;
+
+	glBegin(GL_QUADS);
+
+	glTexCoord3i(0,0,0);
+        glVertex3i(x1,y1,0);
+        glTexCoord3i(1,0,0);
+        glVertex3i(x2,y2,0);
+        glTexCoord3i(1,1,0);
+        glVertex3i(x3,y3,0);
+        glTexCoord3i(0,1,0);
+        glVertex3i(x4,y4,0);
+
+
+
+
+	glEnd();
+}
+
+
+/*
+ *  display callback function
+ */
+void display(void){
+	
+	pix = v4l2_grab_data(camera);
+	
+	glClear(GL_COLOR_BUFFER_BIT);
+	makeQuad();
+	glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,RES_X,RES_Y,0,GL_RGB,GL_UNSIGNED_BYTE,pix);
+	glutSwapBuffers();
+
+}
+
+void keyboard(unsigned char c, int x, int y){
+	switch(c)
+	{
+	case 27:
+	case 'q':
+	case 'Q':
+		exit(1);
+		break;
+	case '1':
+		x_t = RES_X;
+		y_t = RES_Y;
+		break;
+	case '2':
+		x_t = RES_X*2;
+                y_t = RES_Y*2;
+                break;
+	case '3':
+                x_t = RES_X*3;
+                y_t = RES_Y*3;
+                break;
+	}
+}	
+
+
+void idle( void )
+{
+	glutPostRedisplay();
+}
+
+
+int main (int argc, char **argv) {
+	// init webcam
+	camera = v4l2_init_camera("/dev/video0");
+	// set video resolution
+	RES_X = camera->width;	
+	RES_Y = camera->height;	
+	// set texture resolution
+	x_t = RES_X;	
+	y_t = RES_Y;
+
+	glutInit (&argc, argv);
+	glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE) ;
+	glutInitWindowSize (WIDTH,HEIGHT);
+	glutInitWindowPosition (300,200);
+	glutCreateWindow ("SFLphone Video Prototype");
+	
+	// OpenGL texture paramaters
+	glEnable(GL_TEXTURE_2D);
+	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
+	//printf("Texture initialization done...........");
+	//glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,WIDTH,HEIGHT,0,GL_RGB,GL_UNSIGNED_BYTE,pix);
+
+	// Callback functions
+	glutDisplayFunc (display);	
+	glutReshapeFunc(reshape);
+	glutIdleFunc(idle);
+	glutKeyboardFunc(keyboard);	
+
+
+	glEnable(GL_DEPTH_TEST);
+
+	// main loop
+	glutMainLoop ();
+	//return 0;
+}

src/video/utils/convert.c

+/*
+ *      Copyright (C) 2006-2007 Savoir-Faire Linux inc.
+ *      Author: Emmanuel Milou <emmanuel.milou@savoirfairelinux.com
+ *        
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 3 of the License, or
+ *      (at your option) any later version.
+ *      
+ *      This program is distributed in the hope that it will be useful,
+ *      but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *      GNU General Public License for more details.
+ *      
+ *      You should have received a copy of the GNU General Public License
+ *      along with this program; if not, write to the Free Software
+ *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/videodev.h>
+
+
+#define CLIP 320
+#define RED_NULL 128
+#define BLUE_NULL 128
+#define LUN_MUL 256
+#define RED_MUL 512
+#define BLUE_MUL 512
+
+
+#define GREEN1_MUL  (-RED_MUL/2)
+#define GREEN2_MUL  (-BLUE_MUL/6)
+#define RED_ADD     (-RED_NULL  * RED_MUL)
+#define BLUE_ADD    (-BLUE_NULL * BLUE_MUL)
+#define GREEN1_ADD  (-RED_ADD/2)
+#define GREEN2_ADD  (-BLUE_ADD/6)
+
+/* lookup tables */
+static unsigned int  ng_yuv_gray[256];
+static unsigned int  ng_yuv_red[256];
+static unsigned int  ng_yuv_blue[256];
+static unsigned int  ng_yuv_g1[256];
+static unsigned int  ng_yuv_g2[256];
+static unsigned int  ng_clip[256 + 2 * CLIP];
+
+#define GRAY(val)               ng_yuv_gray[val]
+#define RED(gray,red)           ng_clip[ CLIP + gray + ng_yuv_red[red] ]
+#define GREEN(gray,red,blue)    ng_clip[ CLIP + gray + ng_yuv_g1[red] + \
+	ng_yuv_g2[blue] ]
+#define BLUE(gray,blue)         ng_clip[ CLIP + gray + ng_yuv_blue[blue] ]
+
+#define clip(x) ( (x)<0 ? 0 : ( (x)>255 ? 255 : (x) ) )
+/******************************************************************************/
+
+void YUV2RGB_init(void)
+{
+	int i;
+
+	/* init Lookup tables */
+	for (i = 0; i < 256; i++) {
+		ng_yuv_gray[i] = i * LUN_MUL >> 8;
+		ng_yuv_red[i]  = (RED_ADD    + i * RED_MUL)    >> 8;
+		ng_yuv_blue[i] = (BLUE_ADD   + i * BLUE_MUL)   >> 8;
+		ng_yuv_g1[i]   = (GREEN1_ADD + i * GREEN1_MUL) >> 8;
+		ng_yuv_g2[i]   = (GREEN2_ADD + i * GREEN2_MUL) >> 8;
+	}
+	for (i = 0; i < CLIP; i++)
+		ng_clip[i] = 0;
+	for (; i < CLIP + 256; i++)
+		ng_clip[i] = i - CLIP;
+	for (; i < 2 * CLIP + 256; i++)
+		ng_clip[i] = 255;
+}
+
+
+void write_rgb(unsigned char **out, int Y, int U, int V)
+{
+	int R,G,B;
+	R=(76284*Y+104595*V)>>16;
+	G=(76284*Y -25625*U-53281*V)>>16;
+	B=(76284*Y+132252*U)>>16;
+
+	*(*out)=clip(R);
+	*(*out+1)=clip(G);
+	*(*out+2)=clip(B);
+	*out+=3;
+}
+
+
+void yuv420_rgb (unsigned char *out, unsigned char *in, int width, int height)
+{
+	unsigned char *u,*u1,*v,*v1;
+	int Y=0,U=0,V=0,i,j;
+
+	u=in+width*height;
+	v=u+(width*height)/4;
+
+	for(i=0;i<height;i++) {
+		u1=u;
+		v1=v;
+		for(j=0;j<width;j++) {
+			Y=(*in++)-16;
+			if((j&1)==0) {
+				U=(*u++)-128;
+				V=(*v++)-128;
+			}
+			write_rgb(&out,Y,U,V);
+		}
+		if((i&1)==0) { u=u1; v=v1; }
+	}
+}
+
+void yuyv_rgb (unsigned char *out, unsigned char *in, int width, int height)
+{
+	unsigned char *u,*u1,*v,*v1;
+	int Y=0,U=0,V=0,i,j;
+
+	u=in+1; v=in+3;
+	for(i=0;i<width*height;i++) {
+		Y=(*in)-16;
+		U=(*u)-128;
+		V=(*v)-128;
+		write_rgb(&out,Y,U,V);
+		in+=2;
+		if((i&1)==1) { u+=4; v+=4; }
+	}
+}
+
+
+void format_conversion(int format, char* in, char* out, int width, int height){
+
+	YUV2RGB_init();
+
+	switch(format){
+		case V4L2_PIX_FMT_YUV420:
+			yuv420_rgb(out,in,width,height);
+			break;
+		case V4L2_PIX_FMT_YUYV:
+                        yuyv_rgb(out,in,width,height);
+                        break;
+	}
+}
+
+
+

src/video/v4l2/capture_v4l2.c

+/*
+ *  Copyright (C) 2006-2007 Savoir-Faire Linux inc.
+ *  Author: Emmanuel Milou <emmanuel.milou@savoirfairelinux.com
+ *    
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *  
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ * 
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ **/
+
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <jpeglib.h>
+
+#include "capture_v4l2.h"
+#include "../utils/convert.c"
+
+#define DEVICE "/dev/video0"
+
+
+/******************************************************************/
+
+camera_v4l2* v4l2_init_camera( char* device_name ){
+
+	// initialization of the struct fields
+	camera_v4l2* webcam;
+	webcam = (camera_v4l2*)malloc(sizeof(camera_v4l2));
+
+	memset(&(webcam->cap),0,sizeof(webcam->cap));
+	memset(&(webcam->format),0,sizeof(webcam->format));
+
+	webcam->device = device_name;
+
+	printf("Checking device /dev/video0.......\n");
+	int n = query_camera(webcam);
+	webcam->addr = n;
+
+	if(n==0){	
+		printf("Failed - query_camera()\n");
+		return 0;
+	}
+
+	printf("Query webcam done....\n");
+
+	// we use the fmt.pix.sizeimage field of the v4l2_pix_format struct
+	// fmt.pix.sizeimage contains the total size of the buffer to hold a complete image, in bytes.
+	webcam->raw_data = malloc(webcam->format.fmt.pix.sizeimage);		
+	if (webcam->raw_data == NULL){
+		printf("Error, can't alloc memory for data buffer\n");
+		return 0;
+	}
+
+	// set the resolution of the camera
+	webcam->width = webcam->format.fmt.pix.width;
+	webcam->height = webcam->format.fmt.pix.height;
+
+	// memory allocation for the buffer that will contain the RGB information
+	// 3 values per pixels 
+	webcam->img_data = malloc(webcam->width*webcam->height*3*sizeof(unsigned char));
+	
+	if(webcam==NULL){
+                printf("INIT FAILED!\n");
+                return NULL;
+         }
+
+	info_device(webcam);
+
+	return webcam;
+}
+
+int query_camera(camera_v4l2* const camera){
+
+	int fd;
+
+	char* device = camera->device;
+	struct v4l2_capability* cap = &(camera->cap);
+	struct v4l2_format* format = &(camera->format);
+
+	// open the webcam device, like a file, return a file descriptor
+	fd = open(device, O_RDONLY);
+
+	if(fd < 0){
+		printf("error, can't open device %s\n", device);	
+		return 0;	
+	}
+
+	// fill the v4l2_capabilities struct by a ioctl call (control device)
+	// VIDIOC_QUERYCAP (V4L2 API Specification) 
+	if(ioctl(fd, VIDIOC_QUERYCAP,cap)==-1){
+		printf("error, can't query device's capabilities\n");
+		return 0;
+	}
+
+	format->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	if(ioctl(fd, VIDIOC_G_FMT, format)==-1){
+		printf("error, can't set the capture image format\n");
+		return 0;
+	}
+	format->fmt.pix.pixelformat = V4L2_PIX_FMT_YUV420;
+
+	// return the file descriptor of the device
+	return fd;
+}
+
+
+char* v4l2_grab_data(camera_v4l2* const camera){
+
+	int fd = camera->addr;	
+	int n = read( fd, 
+			camera->raw_data, 
+			camera->format.fmt.pix.sizeimage);
+	if(n==-1){
+		printf("Error, can't read the webcam\n");
+		return 0;
+	}
+	
+	// launch image format conversion
+	format_conversion(camera->format.fmt.pix.pixelformat, camera->raw_data, camera->img_data, camera->width, camera->height);	 
+
+
+	//return camera->raw_data;
+	return camera->img_data;
+}
+
+void v4l2_free_data(camera_v4l2* cam){
+
+	free(cam->device);
+	free(cam->raw_data);
+	free(cam->img_data);
+	free(cam);
+}
+
+void info_device(camera_v4l2* cam){
+	
+	int format = cam->format.fmt.pix.pixelformat;
+	
+	printf("****************** SPECS CAMERA ********************\n");
+        printf("Image resolution = %ix%i\n",cam->width,cam->height);
+        printf("Image size = %i bytes\n", cam->format.fmt.pix.sizeimage);
+        printf("Pixels format = ");
+	switch(format){
+		case V4L2_PIX_FMT_RGB332:
+                        printf("RGB332\n");
+                        break;
+                case V4L2_PIX_FMT_RGB555:
+                        printf("RGB555\n");
+                        break;
+                case V4L2_PIX_FMT_RGB565:
+                        printf("RGB565\n");
+                        break;
+                case V4L2_PIX_FMT_BGR24:
+                        printf("BGR24\n");
+                        break;
+                case V4L2_PIX_FMT_RGB24:
+                        printf("RGB24\n");
+                	break;
+		case V4L2_PIX_FMT_BGR32:
+                        printf("BGR32\n");
+                        break;
+                case V4L2_PIX_FMT_RGB32:
+                        printf("RGB32\n");
+                        break;
+                case V4L2_PIX_FMT_YUV410:
+                        printf("YUV410\n");
+                        break;
+                case V4L2_PIX_FMT_YUV420:
+                        printf("YUV420\n");
+                        break;
+                case V4L2_PIX_FMT_YUYV:
+                        printf("YUYV\n");
+                        break;
+                case V4L2_PIX_FMT_UYVY:
+                        printf("UYVY\n");
+                        break;
+                default:
+                        printf("TODO: Implement support for V4L2_PIX_FMT 0x%X\n",
+                                                format);
+                        exit(1);
+        }
+
+}
+

src/video/v4l2/capture_v4l2.h

+/*
+ *  Copyright (C) 2006-2007 Savoir-Faire Linux inc.
+ *  Author: Emmanuel Milou <emmanuel.milou@savoirfairelinux.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ **/
+
+#ifndef CAPTURE_V4L2_H
+#define CAPTURE_V4L2_H
+
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/videodev.h>
+
+/*********************************
+ * struct camera_v4l2
+ */
+
+ typedef struct {
+	char* device; 				//device name (/dev/video0 for the webcam)
+	struct v4l2_capability cap;		//info on the device's capture capability (ex: type, name, ...)
+	struct v4l2_format format;		//to handle multimedia data
+	char* raw_data;				//buffer for the captured data
+	int addr;				//file descriptor of the device
+	char* img_data;
+	int width;
+	int height;	
+}camera_v4l2;  
+
+/***********************************
+
+/***********************************
+ * Methods
+ */
+
+// initialization of a new camera_v4l2 struct
+camera_v4l2* v4l2_init_camera( char* device_name );
+
+// grab frames
+char* v4l2_grab_data(camera_v4l2* const camera);
+
+//free the allocated buffers
+void v4l2_free_data(camera_v4l2* camera);
+
+void info_device(camera_v4l2* camera);
+
+#endif