grab_v4l_c.c

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/* Gnome gxsm - Gnome X Scanning Microscopy
 * universal STM/AFM/SARLS/SPALEED/... controlling and
 * data analysis software
 *
 * Gxsm Hardware Interface Plugin Name: grab_v4l.C
 * ===============================================
 * 
 * Copyright (C) 1999 The Free Software Foundation
 *
 * Authors: Percy Zahl <zahl@fkp.uni-hannover.de>
 * additional features: Andreas Klust <klust@fkp.uni-hannover.de>
 *
 * 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 2 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 */

/* irnore this module for docuscan
% PlugInModuleIgnore
 */


#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <glib.h>
#include <string.h>
#include <sys/types.h>

#include <unistd.h>
#include <linux/videodev.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>
#include <fcntl.h>
#include <signal.h>
#include <linux/types.h> 
#include <linux/videodev.h>
#include <errno.h>

/*
 * GXSM V4L Hardware Interface Class -- plain c module
 * ============================================================
 */

gint gxsm_v4l_open_video4l ();
gint gxsm_v4l_close_video4l ();
gint gxsm_v4l_maxwidth  ();
gint gxsm_v4l_maxheight ();
gint gxsm_v4l_win_width  ();
gint gxsm_v4l_win_height ();
gint gxsm_v4l_grab_video4l ();
gint gxsm_v4l_get_pixel (int *r, int *g, int *b);

int    video_dev_fd=0;
struct video_capability cap;
struct video_picture pic;
struct video_window win;
struct video_capture vicap;
struct video_channel vidcan;
struct video_mbuf vidbuf;
struct video_buffer buffer;
struct video_mmap mapbuf;
guchar *bigbuf;
guchar *buf;
int gray[3];
guchar  *src;


gint gxsm_v4l_open_video4l (){
//    struct v4l2_capability v4l2_cap;
//    struct v4l2_requestbuffers reqbuf;
    struct {
        void *start;
        size_t length;
    } *buffers;
    unsigned int i;
//-------------------------------------------------------------------
              /* OPEN VIDEO DEVICE */
//-------------------------------------------------------------------   
        
        video_dev_fd = open("/dev/video", O_RDWR );

        if (video_dev_fd<0){
                printf("ERROR: THERE IS NO CAMERA CONECTED\n");
                exit(-1);
        }

//--------------------------------------------------------------------
                /* VIDEO CAPABILITIES*/
//---------------------------------------------------------------------

        if (-1==ioctl(video_dev_fd,VIDIOCGCAP,&cap)){
                perror("ioctl VIDIOCGCAP");
                exit(-1);
        }
        printf("------------------------------------\n");
        printf("------------------------------------\n");
        printf("name      -> %s\n", cap.name);
        printf("type      -> %d\n", cap.type);
        printf("channels  -> %d\n", cap.channels);
        printf("audios    -> %d\n", cap.audios );
        printf("maxwidth  -> %d\n", cap.maxwidth );
        printf("maxheight -> %d\n", cap.maxheight);
        printf("minwidth  -> %d\n", cap.minwidth );
        printf("minheight -> %d\n", cap.minheight );
        printf("------------------------------------\n");

//---------------------------------------------------------------------
                /* FRAME GRABBERS DETECTION*/
//---------------------------------------------------------------------

        if (-1==ioctl(video_dev_fd,VIDIOCSFBUF,&buffer))
                printf ("Not a decteced frame grabber\n");
        else {
 
                if (-1==ioctl(video_dev_fd,VIDIOCGFBUF,&buffer)) {
                        perror ("ioctl VIDIOCGFBUF");
                        exit(-1);
                }
                printf("------------------------------------\n"); 
                printf ("add -> %d\n", buffer.base);
                printf ("height -> %d\n", buffer.height);
                printf ("width -> %d\n", buffer.width);
                printf ("depth -> %d\n", buffer.depth);
                printf ("BPL -> %d\n", buffer.bytesperline);
        }
        printf("------------------------------------\n");                                       

/*
        reqbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        reqbuf.memory = V4L2_MEMORY_MMAP;
        reqbuf.count = 20;

        if (-1 == ioctl (video_dev_fd, VIDIOC_REQBUFS, &reqbuf)) {
            if (errno == EINVAL)
                printf ("Video capturing or mmap-streaming is not supported\n");
            else
                perror ("ioctl VIDIOC_REQBUFS");

            //      exit (EXIT_FAILURE);
        }

        if (-1 == ioctl (video_dev_fd, VIDIOC_QUERYCAP, &v4l2_cap)) {
            if (errno == EINVAL)
                printf ("not supported request by kernel\n");
            else
                perror ("ioctl V4L2 VIDIOC_QUERYCAP");
        } else {
            printf("------------------------------------\n");
            printf("v4l2 driver    -> %s\n", v4l2_cap.driver);
            printf("v4l2 card      -> %s\n", v4l2_cap.card);
            printf("v4l2 bus info  -> %s\n", v4l2_cap.bus_info);
            printf("v4l2 driver    -> %s\n", v4l2_cap.driver);
            printf("v4l2 version   -> %06X\n", v4l2_cap.version);
            printf("v4l2 capabilities -> %X\n", v4l2_cap.capabilities);
            printf("---| V4L2_CAP_VIDEO_CAPTURE .. %s\n", v4l2_cap.capabilities&V4L2_CAP_VIDEO_CAPTURE ? "Yes":"No");
            printf("   | V4L2_CAP_VIDEO_OUTPUT ... %s\n", v4l2_cap.capabilities&V4L2_CAP_VIDEO_OUTPUT ? "Yes":"No");
            printf("   | V4L2_CAP_VIDEO_OVERLAY .. %s\n", v4l2_cap.capabilities&V4L2_CAP_VIDEO_OVERLAY ? "Yes":"No");
            printf("   | V4L2_CAP_VBI_CAPTURE .... %s\n", v4l2_cap.capabilities&V4L2_CAP_VBI_CAPTURE ? "Yes":"No");
            printf("   | V4L2_CAP_VBI_OUTPUT... .. %s\n", v4l2_cap.capabilities&V4L2_CAP_VBI_OUTPUT ? "Yes":"No");
            printf("   | V4L2_CAP_TUNER .......... %s\n", v4l2_cap.capabilities&V4L2_CAP_TUNER ? "Yes":"No");
            printf("   | V4L2_CAP_AUDIO .......... %s\n", v4l2_cap.capabilities&V4L2_CAP_AUDIO ? "Yes":"No");
            printf("   | V4L2_CAP_READWRITE ...... %s\n", v4l2_cap.capabilities&V4L2_CAP_READWRITE ? "Yes":"No");
            printf("   | V4L2_CAP_ASYNCIO ........ %s\n", v4l2_cap.capabilities&V4L2_CAP_ASYNCIO ? "Yes":"No");
            printf("   | V4L2_CAP_STREAMING ...... %s\n", v4l2_cap.capabilities&V4L2_CAP_STREAMING ? "Yes":"No");
            printf("------------------------------------\n");
        }
*/

        return 0;
}

gint gxsm_v4l_close_video4l (){
        close (video_dev_fd);
        video_dev_fd = 0;
        return 0;
}

inline gint gxsm_v4l_maxwidth  () { return cap.maxwidth; }
inline gint gxsm_v4l_maxheight () { return cap.maxheight; }

inline gint gxsm_v4l_win_width  () { return win.width; }
inline gint gxsm_v4l_win_height () { return win.height; }

gint gxsm_v4l_grab_video4l (){ 

        int frame;
        int i;

//-----------------------------------------------------------------------
                /* CAPTURE FRAME */
//-----------------------------------------------------------------------

/*
        win.x = 0;
        win.y = 0;
        win.width = COLS;
        win.height = ROWS;
        win.clipcount = 0;
        win.chromakey = 1;
        win.flags = VIDEO_CLIPMAP_SIZE;
        
        if (-1== ioctl(video_dev_fd, VIDIOCSWIN,&win)){
                perror ("ioctl VIDIOCSWIN");
                exit (-1);
        }
*/
        if (ioctl(video_dev_fd, VIDIOCGWIN, &win) < 0) {
                perror("ioctl VIDIOCGWIN");
                close (video_dev_fd);
                exit(1);
        }       

        fprintf(stderr, "V4L Window [%d x %d]...\n", win.width, win.height);

//---------------------------------------------------------------------
                /* IMAGE PROPERTIES*/
//---------------------------------------------------------------------

        pic.depth = 24;
        pic.palette = VIDEO_PALETTE_RGB24;
        pic.brightness = 100;
        pic.contrast = 30;
        pic.whiteness = 0;
        pic.colour = 0;
        pic.hue = 0;
        
        
        if (-1==ioctl( video_dev_fd, VIDIOCSPICT, &pic )){perror("ioctl VIDIOCSPICT");
                exit(-1);}
        
        ioctl( video_dev_fd, VIDIOCGPICT, &pic );

        printf("------------------------------------\n");
        printf("brightness -> %d \n", pic.brightness/256 );
        printf("hue -> %d\n", pic.hue/256);
        printf("colour -> %d\n", pic.colour/256 );
        printf("contrast -> %d \n", pic.contrast/256 );
        printf("whiteness -> %d\n", pic.whiteness/256 );
        printf("depth -> %d\n", pic.depth );
        printf("palette -> %d \n", pic.palette );
        printf("------------------------------------\n");

//-----------------------------------------------------------------------
                /* MAPPING BUFFER */
//------------------------------------------------------------------------


        if (-1==ioctl(video_dev_fd,VIDIOCGMBUF,&vidbuf)){
                perror("ioctl VIDIOCGMBUF"); 
                exit(-1);
        }
        
        printf("------------------------------------\n");
        printf("size  -> %d\n",vidbuf.size);
        printf("frames -> %d\n",vidbuf.frames);
        printf("offsets -> %d\n",vidbuf.offsets);
        printf("------------------------------------\n");

        bigbuf = (guchar *)mmap(0,vidbuf.size, PROT_READ | PROT_WRITE, MAP_SHARED, video_dev_fd, 0);


        mapbuf.width  = win.width;
        mapbuf.height = win.height;
        mapbuf.format = VIDEO_PALETTE_RGB24;


//----------------------------------------------------------------------
                    /* SET BUFFERS*/
//----------------------------------------------------------------------                 

        for(frame=0; frame<vidbuf.frames;frame++){                                      // turn on both of the buffers
                mapbuf.frame = frame;                                                   // to start capture process.
                if (ioctl(video_dev_fd,VIDIOCMCAPTURE, &mapbuf)<0){                             // Now they can store images.
                        perror("VIDIOCMCAPTURE");
                        exit(-1);}
                }
        
        frame = 0;

    
//---------------------------------------------------------------------
                       /* CAPTURING*/
//---------------------------------------------------------------------         

        while (1){
                i = -1;
                while(i<0){
        
                        i= ioctl(video_dev_fd,VIDIOCSYNC, &frame);                              // Wait until the actual buffer
                        if(i < 0 && errno == EINTR) continue;                           // is full. When it happends 
                        if (i < 0) {                                                    // it start to capture to       
                                perror ("VIDIOCSYNC");                                  // the other buffer.
                                exit(-1);
                        }
                }
                break;
        }


        buf = bigbuf + vidbuf.offsets[frame];
        mapbuf.frame = frame;
                                                
        if (ioctl(video_dev_fd,VIDIOCMCAPTURE, &mapbuf)<0) {
                perror("VIDIOCMCAPTURE");               // Turn on the buffer that
                exit(-1);
        }                                                               // was being used.

        frame++;


        if (frame>=vidbuf.frames) frame=0;

        src = buf;

        return 0;
}

#define READ_VIDEO_PIXEL(buf, format, depth, r, g, b)                   \
{                                                                       \
        switch (format)                                                 \
        {                                                               \
                case VIDEO_PALETTE_GREY:                                \
                        switch (depth)                                  \
                        {                                               \
                                case 4:                                 \
                                case 6:                                 \
                                case 8:                                 \
                                        (r) = (g) = (b) = (*buf++ << 8);\
                                        break;                          \
                                                                        \
                                case 16:                                \
                                        (r) = (g) = (b) =               \
                                                *((unsigned short *) buf);      \
                                        buf += 2;                       \
                                        break;                          \
                        }                                               \
                        break;                                          \
                                                                        \
                                                                        \
                case VIDEO_PALETTE_RGB565:                              \
                {                                                       \
                        unsigned short tmp = *(unsigned short *)buf;    \
                        (r) = tmp&0xF800;                               \
                        (g) = (tmp<<5)&0xFC00;                          \
                        (b) = (tmp<<11)&0xF800;                         \
                        buf += 2;                                       \
                }                                                       \
                break;                                                  \
                                                                        \
                case VIDEO_PALETTE_RGB555:                              \
                        (r) = (buf[0]&0xF8)<<8;                         \
                        (g) = ((buf[0] << 5 | buf[1] >> 3)&0xF8)<<8;    \
                        (b) = ((buf[1] << 2 ) & 0xF8)<<8;               \
                        buf += 2;                                       \
                        break;                                          \
                                                                        \
                case VIDEO_PALETTE_RGB24:                               \
                        (r) = buf[0] << 8; (g) = buf[1] << 8;           \
                        (b) = buf[2] << 8;                              \
                        buf += 3;                                       \
                        break;                                          \
                                                                        \
                default:                                                \
                        fprintf(stderr,                                 \
                                "Format %d not yet supported\n",        \
                                format);                                \
        }                                                               \
}                                               

inline gint gxsm_v4l_get_pixel (int *r, int *g, int *b){
        READ_VIDEO_PIXEL(src, pic.palette, pic.depth, *r, *g, *b);
        return (*r + *g + *b);
}

---