cap_v4l.cpp 56 KB
Newer Older
wester committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
/* This is the contributed code:

File:             cvcap_v4l.cpp
Current Location: ../opencv-0.9.6/otherlibs/videoio

Original Version: 2003-03-12  Magnus Lundin lundin@mlu.mine.nu
Original Comments:

ML:This set of files adds support for firevre and usb cameras.
First it tries to install a firewire camera,
if that fails it tries a v4l/USB camera
It has been tested with the motempl sample program

First Patch:  August 24, 2004 Travis Wood   TravisOCV@tkwood.com
For Release:  OpenCV-Linux Beta4  opencv-0.9.6
Tested On:    LMLBT44 with 8 video inputs
Problems?     Post your questions at answers.opencv.org,
              Report bugs at code.opencv.org,
a  
Kai Westerkamp committed
19
              Submit your fixes at https://github.com/Itseez/opencv/
wester committed
20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211
Patched Comments:

TW: The cv cam utils that came with the initial release of OpenCV for LINUX Beta4
were not working.  I have rewritten them so they work for me. At the same time, trying
to keep the original code as ML wrote it as unchanged as possible.  No one likes to debug
someone elses code, so I resisted changes as much as possible.  I have tried to keep the
same "ideas" where applicable, that is, where I could figure out what the previous author
intended. Some areas I just could not help myself and had to "spiffy-it-up" my way.

These drivers should work with other V4L frame capture cards other then my bttv
driven frame capture card.

Re Written driver for standard V4L mode. Tested using LMLBT44 video capture card.
Standard bttv drivers are on the LMLBT44 with up to 8 Inputs.

This utility was written with the help of the document:
http://pages.cpsc.ucalgary.ca/~sayles/VFL_HowTo
as a general guide for interfacing into the V4l standard.

Made the index value passed for icvOpenCAM_V4L(index) be the number of the
video device source in the /dev tree. The -1 uses original /dev/video.

Index  Device
  0    /dev/video0
  1    /dev/video1
  2    /dev/video2
  3    /dev/video3
  ...
  7    /dev/video7
with
  -1   /dev/video

TW: You can select any video source, but this package was limited from the start to only
ONE camera opened at any ONE time.
This is an original program limitation.
If you are interested, I will make my version available to other OpenCV users.  The big
difference in mine is you may pass the camera number as part of the cv argument, but this
convention is non standard for current OpenCV calls and the camera number is not currently
passed into the called routine.

Second Patch:   August 28, 2004 Sfuncia Fabio fiblan@yahoo.it
For Release:  OpenCV-Linux Beta4 Opencv-0.9.6

FS: this patch fix not sequential index of device (unplugged device), and real numCameras.
    for -1 index (icvOpenCAM_V4L) i dont use /dev/video but real device available, because
    if /dev/video is a link to /dev/video0 and i unplugged device on /dev/video0, /dev/video
    is a bad link. I search the first available device with indexList.

Third Patch:   December 9, 2004 Frederic Devernay Frederic.Devernay@inria.fr
For Release:  OpenCV-Linux Beta4 Opencv-0.9.6

[FD] I modified the following:
 - handle YUV420P, YUV420, and YUV411P palettes (for many webcams) without using floating-point
 - cvGrabFrame should not wait for the end of the first frame, and should return quickly
   (see videoio doc)
 - cvRetrieveFrame should in turn wait for the end of frame capture, and should not
   trigger the capture of the next frame (the user choses when to do it using GrabFrame)
   To get the old behavior, re-call cvRetrieveFrame just after cvGrabFrame.
 - having global bufferIndex and FirstCapture variables makes the code non-reentrant
 (e.g. when using several cameras), put these in the CvCapture struct.
 - according to V4L HowTo, incrementing the buffer index must be done before VIDIOCMCAPTURE.
 - the VID_TYPE_SCALES stuff from V4L HowTo is wrong: image size can be changed
   even if the hardware does not support scaling (e.g. webcams can have several
   resolutions available). Just don't try to set the size at 640x480 if the hardware supports
   scaling: open with the default (probably best) image size, and let the user scale it
   using SetProperty.
 - image size can be changed by two subsequent calls to SetProperty (for width and height)
 - bug fix: if the image size changes, realloc the new image only when it is grabbed
 - issue errors only when necessary, fix error message formatting.

Fourth Patch: Sept 7, 2005 Csaba Kertesz sign@freemail.hu
For Release:  OpenCV-Linux Beta5 OpenCV-0.9.7

I modified the following:
  - Additional Video4Linux2 support :)
  - Use mmap functions (v4l2)
  - New methods are internal:
    try_palette_v4l2 -> rewrite try_palette for v4l2
    mainloop_v4l2, read_image_v4l2 -> this methods are moved from official v4l2 capture.c example
    try_init_v4l -> device v4l initialisation
    try_init_v4l2 -> device v4l2 initialisation
    autosetup_capture_mode_v4l -> autodetect capture modes for v4l
    autosetup_capture_mode_v4l2 -> autodetect capture modes for v4l2
  - Modifications are according with Video4Linux old codes
  - Video4Linux handling is automatically if it does not recognize a Video4Linux2 device
  - Tested successfully with Logitech Quickcam Express (V4L), Creative Vista (V4L) and Genius VideoCam Notebook (V4L2)
  - Correct source lines with compiler warning messages
  - Information message from v4l/v4l2 detection

Fifth Patch: Sept 7, 2005 Csaba Kertesz sign@freemail.hu
For Release:  OpenCV-Linux Beta5 OpenCV-0.9.7

I modified the following:
  - SN9C10x chip based webcams support
  - New methods are internal:
    bayer2rgb24, sonix_decompress -> decoder routines for SN9C10x decoding from Takafumi Mizuno <taka-qce@ls-a.jp> with his pleasure :)
  - Tested successfully with Genius VideoCam Notebook (V4L2)

Sixth Patch: Sept 10, 2005 Csaba Kertesz sign@freemail.hu
For Release:  OpenCV-Linux Beta5 OpenCV-0.9.7

I added the following:
  - Add capture control support (hue, saturation, brightness, contrast, gain)
  - Get and change V4L capture controls (hue, saturation, brightness, contrast)
  - New method is internal:
    icvSetControl -> set capture controls
  - Tested successfully with Creative Vista (V4L)

Seventh Patch: Sept 10, 2005 Csaba Kertesz sign@freemail.hu
For Release:  OpenCV-Linux Beta5 OpenCV-0.9.7

I added the following:
  - Detect, get and change V4L2 capture controls (hue, saturation, brightness, contrast, gain)
  - New methods are internal:
    v4l2_scan_controls_enumerate_menu, v4l2_scan_controls -> detect capture control intervals
  - Tested successfully with Genius VideoCam Notebook (V4L2)

8th patch: Jan 5, 2006, Olivier.Bornet@idiap.ch
Add support of V4L2_PIX_FMT_YUYV and V4L2_PIX_FMT_MJPEG.
With this patch, new webcams of Logitech, like QuickCam Fusion works.
Note: For use these webcams, look at the UVC driver at
http://linux-uvc.berlios.de/

9th patch: Mar 4, 2006, Olivier.Bornet@idiap.ch
- try V4L2 before V4L, because some devices are V4L2 by default,
  but they try to implement the V4L compatibility layer.
  So, I think this is better to support V4L2 before V4L.
- better separation between V4L2 and V4L initialization. (this was needed to support
  some drivers working, but not fully with V4L2. (so, we do not know when we
  need to switch from V4L2 to V4L.

10th patch: July 02, 2008, Mikhail Afanasyev fopencv@theamk.com
Fix reliability problems with high-resolution UVC cameras on linux
the symptoms were damaged image and 'Corrupt JPEG data: premature end of data segment' on stderr
- V4L_ABORT_BADJPEG detects JPEG warnings and turns them into errors, so bad images
  could be filtered out
- USE_TEMP_BUFFER fixes the main problem (improper buffer management) and
  prevents bad images in the first place

11th patch: April 2, 2013, Forrest Reiling forrest.reiling@gmail.com
Added v4l2 support for getting capture property CV_CAP_PROP_POS_MSEC.
Returns the millisecond timestamp of the last frame grabbed or 0 if no frames have been grabbed
Used to successfully synchonize 2 Logitech C310 USB webcams to within 16 ms of one another


make & enjoy!

*/

/*M///////////////////////////////////////////////////////////////////////////////////////
//
//  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
//
//  By downloading, copying, installing or using the software you agree to this license.
//  If you do not agree to this license, do not download, install,
//  copy or use the software.
//
//
//                        Intel License Agreement
//                For Open Source Computer Vision Library
//
// Copyright (C) 2000, Intel Corporation, all rights reserved.
// Third party copyrights are property of their respective owners.
//
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
//
//   * Redistribution's of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
//
//   * Redistribution's in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
//     and/or other materials provided with the distribution.
//
//   * The name of Intel Corporation may not be used to endorse or promote products
//     derived from this software without specific prior written permission.
//
// This software is provided by the copyright holders and contributors "as is" and
// any express or implied warranties, including, but not limited to, the implied
// warranties of merchantability and fitness for a particular purpose are disclaimed.
// In no event shall the Intel Corporation or contributors be liable for any direct,
// indirect, incidental, special, exemplary, or consequential damages
// (including, but not limited to, procurement of substitute goods or services;
// loss of use, data, or profits; or business interruption) however caused
// and on any theory of liability, whether in contract, strict liability,
// or tort (including negligence or otherwise) arising in any way out of
// the use of this software, even if advised of the possibility of such damage.
//
//M*/

#include "precomp.hpp"

a  
Kai Westerkamp committed
212
#if !defined WIN32 && (defined HAVE_CAMV4L2 || defined HAVE_VIDEOIO)
wester committed
213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/mman.h>

#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <sys/stat.h>
#include <sys/ioctl.h>

#ifdef HAVE_CAMV4L2
#include <asm/types.h>          /* for videodev2.h */
#include <linux/videodev2.h>
#endif

#ifdef HAVE_VIDEOIO
// NetBSD compability layer with V4L2
#include <sys/videoio.h>
#endif

/* Defaults - If your board can do better, set it here.  Set for the most common type inputs. */
#define DEFAULT_V4L_WIDTH  640
#define DEFAULT_V4L_HEIGHT 480
#define DEFAULT_V4L_FPS 30

#define CHANNEL_NUMBER 1
#define MAX_CAMERAS 8


// default and maximum number of V4L buffers, not including last, 'special' buffer
#define MAX_V4L_BUFFERS 10
#define DEFAULT_V4L_BUFFERS 4

// if enabled, then bad JPEG warnings become errors and cause NULL returned instead of image
#define V4L_ABORT_BADJPEG

#define MAX_DEVICE_DRIVER_NAME 80

namespace cv {

/* Device Capture Objects */
/* V4L2 structure */
struct buffer
{
  void *  start;
  size_t  length;
};

static unsigned int n_buffers = 0;

struct CvCaptureCAM_V4L : public CvCapture
{
    int deviceHandle;
    int bufferIndex;
    int FirstCapture;

    char *memoryMap;
    IplImage frame;

   __u32 palette;
a  
Kai Westerkamp committed
278
   int index;
wester committed
279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373
   int width, height;
   __u32 fps;
   bool convert_rgb;
   bool frame_allocated;

   /* V4L2 variables */
   buffer buffers[MAX_V4L_BUFFERS + 1];
   v4l2_capability cap;
   v4l2_input inp;
   v4l2_format form;
   v4l2_crop crop;
   v4l2_cropcap cropcap;
   v4l2_requestbuffers req;
   v4l2_buf_type type;
   v4l2_queryctrl queryctrl;

   timeval timestamp;

   /* V4L2 control variables */
   Range focus, brightness, contrast, saturation, hue, gain, exposure;

   bool open(int _index);

   virtual double getProperty(int) const;
   virtual bool setProperty(int, double);
   virtual bool grabFrame();
   virtual IplImage* retrieveFrame(int);

   Range getRange(int property_id) const {
       switch (property_id) {
       case CV_CAP_PROP_BRIGHTNESS:
           return brightness;
       case CV_CAP_PROP_CONTRAST:
           return contrast;
       case CV_CAP_PROP_SATURATION:
           return saturation;
       case CV_CAP_PROP_HUE:
           return hue;
       case CV_CAP_PROP_GAIN:
           return gain;
       case CV_CAP_PROP_EXPOSURE:
           return exposure;
       case CV_CAP_PROP_FOCUS:
           return focus;
       case CV_CAP_PROP_AUTOFOCUS:
           return Range(0, 1);
       default:
           return Range(0, 255);
       }
   }

   virtual ~CvCaptureCAM_V4L();
};

static void icvCloseCAM_V4L( CvCaptureCAM_V4L* capture );

static bool icvGrabFrameCAM_V4L( CvCaptureCAM_V4L* capture );
static IplImage* icvRetrieveFrameCAM_V4L( CvCaptureCAM_V4L* capture, int );

static double icvGetPropertyCAM_V4L( const CvCaptureCAM_V4L* capture, int property_id );
static int    icvSetPropertyCAM_V4L( CvCaptureCAM_V4L* capture, int property_id, double value );

/***********************   Implementations  ***************************************/

static int numCameras = 0;
static int indexList = 0;

CvCaptureCAM_V4L::~CvCaptureCAM_V4L() {
    icvCloseCAM_V4L(this);
}

/* Simple test program: Find number of Video Sources available.
   Start from 0 and go to MAX_CAMERAS while checking for the device with that name.
   If it fails on the first attempt of /dev/video0, then check if /dev/video is valid.
   Returns the global numCameras with the correct value (we hope) */

static void icvInitCapture_V4L() {
   int deviceHandle;
   int CameraNumber;
   char deviceName[MAX_DEVICE_DRIVER_NAME];

   CameraNumber = 0;
   while(CameraNumber < MAX_CAMERAS) {
      /* Print the CameraNumber at the end of the string with a width of one character */
      sprintf(deviceName, "/dev/video%1d", CameraNumber);
      /* Test using an open to see if this new device name really does exists. */
      deviceHandle = open(deviceName, O_RDONLY);
      if (deviceHandle != -1) {
         /* This device does indeed exist - add it to the total so far */
    // add indexList
    indexList|=(1 << CameraNumber);
        numCameras++;
    }
    if (deviceHandle != -1)
      close(deviceHandle);
a  
Kai Westerkamp committed
374 375
      /* Set up to test the next /dev/video source in line */
      CameraNumber++;
wester committed
376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394
   } /* End while */

}; /* End icvInitCapture_V4L */

static bool try_palette_v4l2(CvCaptureCAM_V4L* capture)
{
  capture->form = v4l2_format();
  capture->form.type                = V4L2_BUF_TYPE_VIDEO_CAPTURE;
  capture->form.fmt.pix.pixelformat = capture->palette;
  capture->form.fmt.pix.field       = V4L2_FIELD_ANY;
  capture->form.fmt.pix.width       = capture->width;
  capture->form.fmt.pix.height      = capture->height;

  if (-1 == ioctl (capture->deviceHandle, VIDIOC_S_FMT, &capture->form))
      return false;

  return capture->palette == capture->form.fmt.pix.pixelformat;
}

a  
Kai Westerkamp committed
395
static int try_init_v4l2(CvCaptureCAM_V4L* capture, char *deviceName)
wester committed
396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465
{
  // Test device for V4L2 compability
  // Return value:
  // -1 then unable to open device
  //  0 then detected nothing
  //  1 then V4L2 device

  int deviceIndex;

  /* Open and test V4L2 device */
  capture->deviceHandle = open (deviceName, O_RDWR /* required */ | O_NONBLOCK, 0);
  if (-1 == capture->deviceHandle)
  {
#ifndef NDEBUG
    fprintf(stderr, "(DEBUG) try_init_v4l2 open \"%s\": %s\n", deviceName, strerror(errno));
#endif
    icvCloseCAM_V4L(capture);
    return -1;
  }

  capture->cap = v4l2_capability();
  if (-1 == ioctl (capture->deviceHandle, VIDIOC_QUERYCAP, &capture->cap))
  {
#ifndef NDEBUG
    fprintf(stderr, "(DEBUG) try_init_v4l2 VIDIOC_QUERYCAP \"%s\": %s\n", deviceName, strerror(errno));
#endif
    icvCloseCAM_V4L(capture);
    return 0;
  }

  /* Query channels number */
  if (-1 == ioctl (capture->deviceHandle, VIDIOC_G_INPUT, &deviceIndex))
  {
#ifndef NDEBUG
    fprintf(stderr, "(DEBUG) try_init_v4l2 VIDIOC_G_INPUT \"%s\": %s\n", deviceName, strerror(errno));
#endif
    icvCloseCAM_V4L(capture);
    return 0;
  }

  /* Query information about current input */
  capture->inp = v4l2_input();
  capture->inp.index = deviceIndex;
  if (-1 == ioctl (capture->deviceHandle, VIDIOC_ENUMINPUT, &capture->inp))
  {
#ifndef NDEBUG
    fprintf(stderr, "(DEBUG) try_init_v4l2 VIDIOC_ENUMINPUT \"%s\": %s\n", deviceName, strerror(errno));
#endif
    icvCloseCAM_V4L(capture);
    return 0;
  }

  return 1;

}

static int autosetup_capture_mode_v4l2(CvCaptureCAM_V4L* capture) {
    __u32 try_order[] = {
            V4L2_PIX_FMT_BGR24,
            V4L2_PIX_FMT_YVU420,
            V4L2_PIX_FMT_YUV411P,
#ifdef HAVE_JPEG
            V4L2_PIX_FMT_MJPEG,
            V4L2_PIX_FMT_JPEG,
#endif
            V4L2_PIX_FMT_YUYV,
            V4L2_PIX_FMT_UYVY,
            V4L2_PIX_FMT_SN9C10X,
            V4L2_PIX_FMT_SBGGR8,
            V4L2_PIX_FMT_SGBRG8,
a  
Kai Westerkamp committed
466
            V4L2_PIX_FMT_RGB24
wester committed
467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514
    };

    for (size_t i = 0; i < sizeof(try_order) / sizeof(__u32); i++) {
        capture->palette = try_order[i];
        if (try_palette_v4l2(capture)) {
            return 0;
        }
    }

    fprintf(stderr,
            "VIDEOIO ERROR: V4L2: Pixel format of incoming image is unsupported by OpenCV\n");
    icvCloseCAM_V4L(capture);
    return -1;
}

static void v4l2_control_range(CvCaptureCAM_V4L* cap, __u32 id)
{
    cap->queryctrl= v4l2_queryctrl();
    cap->queryctrl.id = id;

    if(0 != ioctl(cap->deviceHandle, VIDIOC_QUERYCTRL, &cap->queryctrl))
    {
        if (errno != EINVAL)
            perror ("VIDIOC_QUERYCTRL");
        return;
    }

    if (cap->queryctrl.flags & V4L2_CTRL_FLAG_DISABLED)
        return;

    Range range(cap->queryctrl.minimum, cap->queryctrl.maximum);

    switch(cap->queryctrl.id) {
    case V4L2_CID_BRIGHTNESS:
        cap->brightness = range;
        break;
    case V4L2_CID_CONTRAST:
        cap->contrast = range;
        break;
    case V4L2_CID_SATURATION:
        cap->saturation = range;
        break;
    case V4L2_CID_HUE:
        cap->hue = range;
        break;
    case V4L2_CID_GAIN:
        cap->gain = range;
        break;
a  
Kai Westerkamp committed
515
    case V4L2_CID_EXPOSURE:
wester committed
516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588
        cap->exposure = range;
        break;
    case V4L2_CID_FOCUS_ABSOLUTE:
        cap->focus = range;
        break;
    }
}

static void v4l2_scan_controls(CvCaptureCAM_V4L* capture)
{

  __u32 ctrl_id;

  for (ctrl_id = V4L2_CID_BASE; ctrl_id < V4L2_CID_LASTP1; ctrl_id++)
  {
      v4l2_control_range(capture, ctrl_id);
  }

  for (ctrl_id = V4L2_CID_PRIVATE_BASE;;ctrl_id++)
  {
      v4l2_control_range(capture, ctrl_id);

      if (errno == EINVAL)
        break;
  }

  v4l2_control_range(capture, V4L2_CID_FOCUS_ABSOLUTE);
}

static int v4l2_set_fps(CvCaptureCAM_V4L* capture) {
    v4l2_streamparm setfps = v4l2_streamparm();
    setfps.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    setfps.parm.capture.timeperframe.numerator = 1;
    setfps.parm.capture.timeperframe.denominator = capture->fps;
    return ioctl (capture->deviceHandle, VIDIOC_S_PARM, &setfps);
}

static int v4l2_num_channels(__u32 palette) {
    switch(palette) {
    case V4L2_PIX_FMT_YVU420:
    case V4L2_PIX_FMT_MJPEG:
    case V4L2_PIX_FMT_JPEG:
        return 1;
    case V4L2_PIX_FMT_YUYV:
    case V4L2_PIX_FMT_UYVY:
        return 2;
    case V4L2_PIX_FMT_BGR24:
    case V4L2_PIX_FMT_RGB24:
        return 3;
    default:
        return 0;
    }
}

static void v4l2_create_frame(CvCaptureCAM_V4L *capture) {
    CvSize size(capture->form.fmt.pix.width, capture->form.fmt.pix.height);
    int channels = 3;

    if (!capture->convert_rgb) {
        channels = v4l2_num_channels(capture->palette);

        switch(capture->palette) {
        case V4L2_PIX_FMT_MJPEG:
        case V4L2_PIX_FMT_JPEG:
            size = CvSize(capture->buffers[capture->bufferIndex].length, 1);
            break;
        case V4L2_PIX_FMT_YVU420:
            size.height = size.height * 3 / 2; // "1.5" channels
            break;
        }
    }

    /* Set up Image data */
a  
Kai Westerkamp committed
589
    cvInitImageHeader(&capture->frame, size, IPL_DEPTH_8U, channels);
wester committed
590 591 592 593 594 595 596 597 598 599 600 601 602

    /* Allocate space for pixelformat we convert to.
     * If we do not convert frame is just points to the buffer
     */
    if(capture->convert_rgb) {
        capture->frame.imageData = (char*)cvAlloc(capture->frame.imageSize);
    }

    capture->frame_allocated = capture->convert_rgb;
}

static int _capture_V4L2 (CvCaptureCAM_V4L *capture)
{
a  
Kai Westerkamp committed
603 604 605 606
   char deviceName[MAX_DEVICE_DRIVER_NAME];
   /* Print the CameraNumber at the end of the string with a width of one character */
   sprintf(deviceName, "/dev/video%1d", capture->index);

wester committed
607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763
   if (try_init_v4l2(capture, deviceName) != 1) {
       /* init of the v4l2 device is not OK */
       return -1;
   }

   /* V4L2 control variables are zero (memset above) */

   /* Scan V4L2 controls */
   v4l2_scan_controls(capture);

   if ((capture->cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
      /* Nope. */
      fprintf( stderr, "VIDEOIO ERROR: V4L2: device %s is unable to capture video memory.\n",deviceName);
      icvCloseCAM_V4L(capture);
      return -1;
   }

   /* The following code sets the CHANNEL_NUMBER of the video input.  Some video sources
   have sub "Channel Numbers".  For a typical V4L TV capture card, this is usually 1.
   I myself am using a simple NTSC video input capture card that uses the value of 1.
   If you are not in North America or have a different video standard, you WILL have to change
   the following settings and recompile/reinstall.  This set of settings is based on
   the most commonly encountered input video source types (like my bttv card) */

   if(capture->inp.index > 0) {
       capture->inp = v4l2_input();
       capture->inp.index = CHANNEL_NUMBER;
       /* Set only channel number to CHANNEL_NUMBER */
       /* V4L2 have a status field from selected video mode */
       if (-1 == ioctl (capture->deviceHandle, VIDIOC_ENUMINPUT, &capture->inp))
       {
         fprintf (stderr, "VIDEOIO ERROR: V4L2: Aren't able to set channel number\n");
         icvCloseCAM_V4L (capture);
         return -1;
       }
   } /* End if */

   /* Find Window info */
   capture->form = v4l2_format();
   capture->form.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

   if (-1 == ioctl (capture->deviceHandle, VIDIOC_G_FMT, &capture->form)) {
       fprintf( stderr, "VIDEOIO ERROR: V4L2: Could not obtain specifics of capture window.\n\n");
       icvCloseCAM_V4L(capture);
       return -1;
   }

   if (autosetup_capture_mode_v4l2(capture) == -1)
       return -1;

   /* try to set framerate */
   v4l2_set_fps(capture);

   unsigned int min;

   /* Buggy driver paranoia. */
   min = capture->form.fmt.pix.width * 2;

   if (capture->form.fmt.pix.bytesperline < min)
       capture->form.fmt.pix.bytesperline = min;

   min = capture->form.fmt.pix.bytesperline * capture->form.fmt.pix.height;

   if (capture->form.fmt.pix.sizeimage < min)
       capture->form.fmt.pix.sizeimage = min;

   capture->req = v4l2_requestbuffers();

   unsigned int buffer_number = DEFAULT_V4L_BUFFERS;

   try_again:

   capture->req.count = buffer_number;
   capture->req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
   capture->req.memory = V4L2_MEMORY_MMAP;

   if (-1 == ioctl (capture->deviceHandle, VIDIOC_REQBUFS, &capture->req))
   {
       if (EINVAL == errno)
       {
         fprintf (stderr, "%s does not support memory mapping\n", deviceName);
       } else {
         perror ("VIDIOC_REQBUFS");
       }
       /* free capture, and returns an error code */
       icvCloseCAM_V4L (capture);
       return -1;
   }

   if (capture->req.count < buffer_number)
   {
       if (buffer_number == 1)
       {
           fprintf (stderr, "Insufficient buffer memory on %s\n", deviceName);

           /* free capture, and returns an error code */
           icvCloseCAM_V4L (capture);
           return -1;
       } else {
         buffer_number--;
     fprintf (stderr, "Insufficient buffer memory on %s -- decreaseing buffers\n", deviceName);

     goto try_again;
       }
   }

   for (n_buffers = 0; n_buffers < capture->req.count; ++n_buffers)
   {
       v4l2_buffer buf = v4l2_buffer();
       buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
       buf.memory = V4L2_MEMORY_MMAP;
       buf.index = n_buffers;

       if (-1 == ioctl (capture->deviceHandle, VIDIOC_QUERYBUF, &buf)) {
           perror ("VIDIOC_QUERYBUF");

           /* free capture, and returns an error code */
           icvCloseCAM_V4L (capture);
           return -1;
       }

       capture->buffers[n_buffers].length = buf.length;
       capture->buffers[n_buffers].start =
         mmap (NULL /* start anywhere */,
               buf.length,
               PROT_READ | PROT_WRITE /* required */,
               MAP_SHARED /* recommended */,
               capture->deviceHandle, buf.m.offset);

       if (MAP_FAILED == capture->buffers[n_buffers].start) {
           perror ("mmap");

           /* free capture, and returns an error code */
           icvCloseCAM_V4L (capture);
           return -1;
       }

       if (n_buffers == 0) {
     capture->buffers[MAX_V4L_BUFFERS].start = malloc( buf.length );
     capture->buffers[MAX_V4L_BUFFERS].length = buf.length;
       }
   }

   v4l2_create_frame(capture);

   // reinitialize buffers
   capture->FirstCapture = 1;

   return 1;
}; /* End _capture_V4L2 */

/**
 * some properties can not be changed while the device is in streaming mode.
 * this method closes and re-opens the device to re-start the stream.
 * this also causes buffers to be reallocated if the frame size was changed.
 */
static bool v4l2_reset( CvCaptureCAM_V4L* capture) {
a  
Kai Westerkamp committed
764
    int index = capture->index;
wester committed
765
    icvCloseCAM_V4L(capture);
a  
Kai Westerkamp committed
766
    capture->index = index;
wester committed
767 768 769 770 771 772
    return _capture_V4L2(capture) == 1;
}

bool CvCaptureCAM_V4L::open(int _index)
{
   int autoindex = 0;
a  
Kai Westerkamp committed
773 774

   index = -1; // set the capture to closed state
wester committed
775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798

   if (!numCameras)
      icvInitCapture_V4L(); /* Havent called icvInitCapture yet - do it now! */
   if (!numCameras)
     return false; /* Are there any /dev/video input sources? */

   //search index in indexList
   if ( (_index>-1) && ! ((1 << _index) & indexList) )
   {
     fprintf( stderr, "VIDEOIO ERROR: V4L: index %d is not correct!\n",_index);
     return false; /* Did someone ask for not correct video source number? */
   }

   /* Select camera, or rather, V4L video source */
   if (_index<0) { // Asking for the first device available
     for (; autoindex<MAX_CAMERAS;autoindex++)
    if (indexList & (1<<autoindex))
        break;
     if (autoindex==MAX_CAMERAS)
    return false;
     _index=autoindex;
     autoindex++;// i can recall icvOpenCAM_V4l with index=-1 for next camera
   }

a  
Kai Westerkamp committed
799 800 801 802 803 804
   index = _index;
   FirstCapture = 1;
   width = DEFAULT_V4L_WIDTH;
   height = DEFAULT_V4L_HEIGHT;
   fps = DEFAULT_V4L_FPS;
   convert_rgb = true;
wester committed
805

a  
Kai Westerkamp committed
806
   return _capture_V4L2(this) == 1;
wester committed
807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832
}

static int read_frame_v4l2(CvCaptureCAM_V4L* capture) {
    v4l2_buffer buf = v4l2_buffer();

    buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    buf.memory = V4L2_MEMORY_MMAP;

    if (-1 == ioctl (capture->deviceHandle, VIDIOC_DQBUF, &buf)) {
        switch (errno) {
        case EAGAIN:
            return 0;

        case EIO:
        if (!(buf.flags & (V4L2_BUF_FLAG_QUEUED | V4L2_BUF_FLAG_DONE)))
        {
          if (ioctl(capture->deviceHandle, VIDIOC_QBUF, &buf) == -1)
          {
            return 0;
          }
        }
        return 0;

        default:
            /* display the error and stop processing */
            perror ("VIDIOC_DQBUF");
a  
Kai Westerkamp committed
833
            return 1;
wester committed
834 835 836 837 838 839 840 841 842 843 844 845 846 847 848
        }
   }

   assert(buf.index < capture->req.count);

   memcpy(capture->buffers[MAX_V4L_BUFFERS].start,
      capture->buffers[buf.index].start,
      capture->buffers[MAX_V4L_BUFFERS].length );
   capture->bufferIndex = MAX_V4L_BUFFERS;
   //printf("got data in buff %d, len=%d, flags=0x%X, seq=%d, used=%d)\n",
   //	  buf.index, buf.length, buf.flags, buf.sequence, buf.bytesused);

   if (-1 == ioctl (capture->deviceHandle, VIDIOC_QBUF, &buf))
       perror ("VIDIOC_QBUF");

a  
Kai Westerkamp committed
849 850 851
   //set timestamp in capture struct to be timestamp of most recent frame
   capture->timestamp = buf.timestamp;

wester committed
852 853 854
   return 1;
}

a  
Kai Westerkamp committed
855
static void mainloop_v4l2(CvCaptureCAM_V4L* capture) {
wester committed
856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888
    unsigned int count;

    count = 1;

    while (count-- > 0) {
        for (;;) {
            fd_set fds;
            struct timeval tv;
            int r;

            FD_ZERO (&fds);
            FD_SET (capture->deviceHandle, &fds);

            /* Timeout. */
            tv.tv_sec = 10;
            tv.tv_usec = 0;

            r = select (capture->deviceHandle+1, &fds, NULL, NULL, &tv);

            if (-1 == r) {
                if (EINTR == errno)
                    continue;

                perror ("select");
            }

            if (0 == r) {
                fprintf (stderr, "select timeout\n");

                /* end the infinite loop */
                break;
            }

a  
Kai Westerkamp committed
889
            if (read_frame_v4l2 (capture))
wester committed
890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933
                break;
        }
    }
}

static bool icvGrabFrameCAM_V4L(CvCaptureCAM_V4L* capture) {
   if (capture->FirstCapture) {
      /* Some general initialization must take place the first time through */

      /* This is just a technicality, but all buffers must be filled up before any
         staggered SYNC is applied.  SO, filler up. (see V4L HowTo) */

      {

        for (capture->bufferIndex = 0;
             capture->bufferIndex < ((int)capture->req.count);
             ++capture->bufferIndex)
        {

          v4l2_buffer buf = v4l2_buffer();

          buf.type        = V4L2_BUF_TYPE_VIDEO_CAPTURE;
          buf.memory      = V4L2_MEMORY_MMAP;
          buf.index       = (unsigned long)capture->bufferIndex;

          if (-1 == ioctl (capture->deviceHandle, VIDIOC_QBUF, &buf)) {
              perror ("VIDIOC_QBUF");
              return false;
          }
        }

        /* enable the streaming */
        capture->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        if (-1 == ioctl (capture->deviceHandle, VIDIOC_STREAMON,
                          &capture->type)) {
            /* error enabling the stream */
            perror ("VIDIOC_STREAMON");
            return false;
        }
      }

#if defined(V4L_ABORT_BADJPEG)
        // skip first frame. it is often bad -- this is unnotied in traditional apps,
        //  but could be fatal if bad jpeg is enabled
a  
Kai Westerkamp committed
934
        mainloop_v4l2(capture);
wester committed
935 936 937 938 939 940
#endif

      /* preparation is ok */
      capture->FirstCapture = 0;
   }

a  
Kai Westerkamp committed
941
   mainloop_v4l2(capture);
wester committed
942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539

   return true;
}

/*
 * Turn a YUV4:2:0 block into an RGB block
 *
 * Video4Linux seems to use the blue, green, red channel
 * order convention-- rgb[0] is blue, rgb[1] is green, rgb[2] is red.
 *
 * Color space conversion coefficients taken from the excellent
 * http://www.inforamp.net/~poynton/ColorFAQ.html
 * In his terminology, this is a CCIR 601.1 YCbCr -> RGB.
 * Y values are given for all 4 pixels, but the U (Pb)
 * and V (Pr) are assumed constant over the 2x2 block.
 *
 * To avoid floating point arithmetic, the color conversion
 * coefficients are scaled into 16.16 fixed-point integers.
 * They were determined as follows:
 *
 *  double brightness = 1.0;  (0->black; 1->full scale)
 *  double saturation = 1.0;  (0->greyscale; 1->full color)
 *  double fixScale = brightness * 256 * 256;
 *  int rvScale = (int)(1.402 * saturation * fixScale);
 *  int guScale = (int)(-0.344136 * saturation * fixScale);
 *  int gvScale = (int)(-0.714136 * saturation * fixScale);
 *  int buScale = (int)(1.772 * saturation * fixScale);
 *  int yScale = (int)(fixScale);
 */

/* LIMIT: convert a 16.16 fixed-point value to a byte, with clipping. */
#define LIMIT(x) ((x)>0xffffff?0xff: ((x)<=0xffff?0:((x)>>16)))

static inline void
move_411_block(int yTL, int yTR, int yBL, int yBR, int u, int v,
               int /*rowPixels*/, unsigned char * rgb)
{
    const int rvScale = 91881;
    const int guScale = -22553;
    const int gvScale = -46801;
    const int buScale = 116129;
    const int yScale  = 65536;
    int r, g, b;

    g = guScale * u + gvScale * v;
//  if (force_rgb) {
//      r = buScale * u;
//      b = rvScale * v;
//  } else {
        r = rvScale * v;
        b = buScale * u;
//  }

    yTL *= yScale; yTR *= yScale;
    yBL *= yScale; yBR *= yScale;

    /* Write out top two first pixels */
    rgb[0] = LIMIT(b+yTL); rgb[1] = LIMIT(g+yTL);
    rgb[2] = LIMIT(r+yTL);

    rgb[3] = LIMIT(b+yTR); rgb[4] = LIMIT(g+yTR);
    rgb[5] = LIMIT(r+yTR);

    /* Write out top two last pixels */
    rgb += 6;
    rgb[0] = LIMIT(b+yBL); rgb[1] = LIMIT(g+yBL);
    rgb[2] = LIMIT(r+yBL);

    rgb[3] = LIMIT(b+yBR); rgb[4] = LIMIT(g+yBR);
    rgb[5] = LIMIT(r+yBR);
}

/* Converts from planar YUV420P to RGB24. */
static inline void
yuv420p_to_rgb24(int width, int height, uchar* src, uchar* dst)
{
    cvtColor(Mat(height * 3 / 2, width, CV_8U, src), Mat(height, width, CV_8UC3, dst),
             COLOR_YUV2BGR_YV12);
}

// Consider a YUV411P image of 8x2 pixels.
//
// A plane of Y values as before.
//
// A plane of U values    1       2
//                        3       4
//
// A plane of V values    1       2
//                        3       4
//
// The U1/V1 samples correspond to the ABCD pixels.
//     U2/V2 samples correspond to the EFGH pixels.
//
/* Converts from planar YUV411P to RGB24. */
/* [FD] untested... */
static void
yuv411p_to_rgb24(int width, int height,
           unsigned char *pIn0, unsigned char *pOut0)
{
    const int numpix = width * height;
    const int bytes = 24 >> 3;
    int i, j, y00, y01, y10, y11, u, v;
    unsigned char *pY = pIn0;
    unsigned char *pU = pY + numpix;
    unsigned char *pV = pU + numpix / 4;
    unsigned char *pOut = pOut0;

    for (j = 0; j <= height; j++) {
        for (i = 0; i <= width - 4; i += 4) {
            y00 = *pY;
            y01 = *(pY + 1);
            y10 = *(pY + 2);
            y11 = *(pY + 3);
            u = (*pU++) - 128;
            v = (*pV++) - 128;

            move_411_block(y00, y01, y10, y11, u, v,
                       width, pOut);

            pY += 4;
            pOut += 4 * bytes;

        }
    }
}

/* convert from 4:2:2 YUYV interlaced to RGB24 */
static void
yuyv_to_rgb24(int width, int height, unsigned char* src, unsigned char* dst) {
    cvtColor(Mat(height, width, CV_8UC2, src), Mat(height, width, CV_8UC3, dst),
             COLOR_YUV2BGR_YUYV);
}

static inline void
uyvy_to_rgb24 (int width, int height, unsigned char *src, unsigned char *dst)
{
    cvtColor(Mat(height, width, CV_8UC2, src), Mat(height, width, CV_8UC3, dst),
             COLOR_YUV2BGR_UYVY);
}
#ifdef HAVE_JPEG

/* convert from mjpeg to rgb24 */
static bool
mjpeg_to_rgb24(int width, int height, unsigned char* src, int length, IplImage* dst) {
    Mat temp = cvarrToMat(dst);
    imdecode(Mat(1, length, CV_8U, src), IMREAD_COLOR, &temp);
    return temp.data && temp.cols == width && temp.rows == height;
}

#endif

/*
 * BAYER2RGB24 ROUTINE TAKEN FROM:
 *
 * Sonix SN9C10x based webcam basic I/F routines
 * Takafumi Mizuno <taka-qce@ls-a.jp>
 *
 */
static void bayer2rgb24(long int WIDTH, long int HEIGHT, unsigned char *src, unsigned char *dst)
{
    long int i;
    unsigned char *rawpt, *scanpt;
    long int size;

    rawpt = src;
    scanpt = dst;
    size = WIDTH*HEIGHT;

    for ( i = 0; i < size; i++ ) {
  if ( (i/WIDTH) % 2 == 0 ) {
      if ( (i % 2) == 0 ) {
    /* B */
    if ( (i > WIDTH) && ((i % WIDTH) > 0) ) {
        *scanpt++ = (*(rawpt-WIDTH-1)+*(rawpt-WIDTH+1)+
         *(rawpt+WIDTH-1)+*(rawpt+WIDTH+1))/4;  /* R */
        *scanpt++ = (*(rawpt-1)+*(rawpt+1)+
         *(rawpt+WIDTH)+*(rawpt-WIDTH))/4;      /* G */
        *scanpt++ = *rawpt;                                     /* B */
    } else {
        /* first line or left column */
        *scanpt++ = *(rawpt+WIDTH+1);           /* R */
        *scanpt++ = (*(rawpt+1)+*(rawpt+WIDTH))/2;      /* G */
        *scanpt++ = *rawpt;                             /* B */
    }
      } else {
    /* (B)G */
    if ( (i > WIDTH) && ((i % WIDTH) < (WIDTH-1)) ) {
        *scanpt++ = (*(rawpt+WIDTH)+*(rawpt-WIDTH))/2;  /* R */
        *scanpt++ = *rawpt;                                     /* G */
        *scanpt++ = (*(rawpt-1)+*(rawpt+1))/2;          /* B */
    } else {
        /* first line or right column */
        *scanpt++ = *(rawpt+WIDTH);     /* R */
        *scanpt++ = *rawpt;             /* G */
        *scanpt++ = *(rawpt-1); /* B */
    }
      }
  } else {
      if ( (i % 2) == 0 ) {
    /* G(R) */
    if ( (i < (WIDTH*(HEIGHT-1))) && ((i % WIDTH) > 0) ) {
        *scanpt++ = (*(rawpt-1)+*(rawpt+1))/2;          /* R */
        *scanpt++ = *rawpt;                                     /* G */
        *scanpt++ = (*(rawpt+WIDTH)+*(rawpt-WIDTH))/2;  /* B */
    } else {
        /* bottom line or left column */
        *scanpt++ = *(rawpt+1);         /* R */
        *scanpt++ = *rawpt;                     /* G */
        *scanpt++ = *(rawpt-WIDTH);             /* B */
    }
      } else {
    /* R */
    if ( i < (WIDTH*(HEIGHT-1)) && ((i % WIDTH) < (WIDTH-1)) ) {
        *scanpt++ = *rawpt;                                     /* R */
        *scanpt++ = (*(rawpt-1)+*(rawpt+1)+
         *(rawpt-WIDTH)+*(rawpt+WIDTH))/4;      /* G */
        *scanpt++ = (*(rawpt-WIDTH-1)+*(rawpt-WIDTH+1)+
         *(rawpt+WIDTH-1)+*(rawpt+WIDTH+1))/4;  /* B */
    } else {
        /* bottom line or right column */
        *scanpt++ = *rawpt;                             /* R */
        *scanpt++ = (*(rawpt-1)+*(rawpt-WIDTH))/2;      /* G */
        *scanpt++ = *(rawpt-WIDTH-1);           /* B */
    }
      }
  }
  rawpt++;
    }

}

// SGBRG to RGB24
// for some reason, red and blue needs to be swapped
// at least for  046d:092f Logitech, Inc. QuickCam Express Plus to work
//see: http://www.siliconimaging.com/RGB%20Bayer.htm
//and 4.6 at http://tldp.org/HOWTO/html_single/libdc1394-HOWTO/
static void sgbrg2rgb24(long int WIDTH, long int HEIGHT, unsigned char *src, unsigned char *dst)
{
    long int i;
    unsigned char *rawpt, *scanpt;
    long int size;

    rawpt = src;
    scanpt = dst;
    size = WIDTH*HEIGHT;

    for ( i = 0; i < size; i++ )
    {
        if ( (i/WIDTH) % 2 == 0 ) //even row
        {
            if ( (i % 2) == 0 ) //even pixel
            {
                if ( (i > WIDTH) && ((i % WIDTH) > 0) )
                {
                    *scanpt++ = (*(rawpt-1)+*(rawpt+1))/2;       /* R */
                    *scanpt++ = *(rawpt);                        /* G */
                    *scanpt++ = (*(rawpt-WIDTH) + *(rawpt+WIDTH))/2;      /* B */
                } else
                {
                  /* first line or left column */

                  *scanpt++ = *(rawpt+1);           /* R */
                  *scanpt++ = *(rawpt);             /* G */
                  *scanpt++ =  *(rawpt+WIDTH);      /* B */
                }
            } else //odd pixel
            {
                if ( (i > WIDTH) && ((i % WIDTH) < (WIDTH-1)) )
                {
                    *scanpt++ = *(rawpt);       /* R */
                    *scanpt++ = (*(rawpt-1)+*(rawpt+1)+*(rawpt-WIDTH)+*(rawpt+WIDTH))/4; /* G */
                    *scanpt++ = (*(rawpt-WIDTH-1) + *(rawpt-WIDTH+1) + *(rawpt+WIDTH-1) + *(rawpt+WIDTH+1))/4;      /* B */
                } else
                {
                    /* first line or right column */

                    *scanpt++ = *(rawpt);       /* R */
                    *scanpt++ = (*(rawpt-1)+*(rawpt+WIDTH))/2; /* G */
                    *scanpt++ = *(rawpt+WIDTH-1);      /* B */
                }
            }
        } else
        { //odd row
            if ( (i % 2) == 0 ) //even pixel
            {
                if ( (i < (WIDTH*(HEIGHT-1))) && ((i % WIDTH) > 0) )
                {
                    *scanpt++ =  (*(rawpt-WIDTH-1)+*(rawpt-WIDTH+1)+*(rawpt+WIDTH-1)+*(rawpt+WIDTH+1))/4;          /* R */
                    *scanpt++ =  (*(rawpt-1)+*(rawpt+1)+*(rawpt-WIDTH)+*(rawpt+WIDTH))/4;      /* G */
                    *scanpt++ =  *(rawpt); /* B */
                } else
                {
                    /* bottom line or left column */

                    *scanpt++ =  *(rawpt-WIDTH+1);          /* R */
                    *scanpt++ =  (*(rawpt+1)+*(rawpt-WIDTH))/2;      /* G */
                    *scanpt++ =  *(rawpt); /* B */
                }
            } else
            { //odd pixel
                if ( i < (WIDTH*(HEIGHT-1)) && ((i % WIDTH) < (WIDTH-1)) )
                {
                    *scanpt++ = (*(rawpt-WIDTH)+*(rawpt+WIDTH))/2;  /* R */
                    *scanpt++ = *(rawpt);      /* G */
                    *scanpt++ = (*(rawpt-1)+*(rawpt+1))/2; /* B */
                } else
                {
                    /* bottom line or right column */

                    *scanpt++ = (*(rawpt-WIDTH));  /* R */
                    *scanpt++ = *(rawpt);      /* G */
                    *scanpt++ = (*(rawpt-1)); /* B */
                }
            }
        }
        rawpt++;
    }
}

static inline void
rgb24_to_rgb24 (int width, int height, unsigned char *src, unsigned char *dst)
{
    cvtColor(Mat(height, width, CV_8UC3, src), Mat(height, width, CV_8UC3, dst), COLOR_RGB2BGR);
}

#define CLAMP(x)        ((x)<0?0:((x)>255)?255:(x))

typedef struct {
  int is_abs;
  int len;
  int val;
} code_table_t;


/* local storage */
static code_table_t table[256];
static int init_done = 0;


/*
  sonix_decompress_init
  =====================
    pre-calculates a locally stored table for efficient huffman-decoding.

  Each entry at index x in the table represents the codeword
  present at the MSB of byte x.

*/
static void sonix_decompress_init(void)
{
  int i;
  int is_abs, val, len;

  for (i = 0; i < 256; i++) {
    is_abs = 0;
    val = 0;
    len = 0;
    if ((i & 0x80) == 0) {
      /* code 0 */
      val = 0;
      len = 1;
    }
    else if ((i & 0xE0) == 0x80) {
      /* code 100 */
      val = +4;
      len = 3;
    }
    else if ((i & 0xE0) == 0xA0) {
      /* code 101 */
      val = -4;
      len = 3;
    }
    else if ((i & 0xF0) == 0xD0) {
      /* code 1101 */
      val = +11;
      len = 4;
    }
    else if ((i & 0xF0) == 0xF0) {
      /* code 1111 */
      val = -11;
      len = 4;
    }
    else if ((i & 0xF8) == 0xC8) {
      /* code 11001 */
      val = +20;
      len = 5;
    }
    else if ((i & 0xFC) == 0xC0) {
      /* code 110000 */
      val = -20;
      len = 6;
    }
    else if ((i & 0xFC) == 0xC4) {
      /* code 110001xx: unknown */
      val = 0;
      len = 8;
    }
    else if ((i & 0xF0) == 0xE0) {
      /* code 1110xxxx */
      is_abs = 1;
      val = (i & 0x0F) << 4;
      len = 8;
    }
    table[i].is_abs = is_abs;
    table[i].val = val;
    table[i].len = len;
  }

  init_done = 1;
}


/*
  sonix_decompress
  ================
    decompresses an image encoded by a SN9C101 camera controller chip.

  IN    width
    height
    inp         pointer to compressed frame (with header already stripped)
  OUT   outp    pointer to decompressed frame

  Returns 0 if the operation was successful.
  Returns <0 if operation failed.

*/
static int sonix_decompress(int width, int height, unsigned char *inp, unsigned char *outp)
{
  int row, col;
  int val;
  int bitpos;
  unsigned char code;
  unsigned char *addr;

  if (!init_done) {
    /* do sonix_decompress_init first! */
    return -1;
  }

  bitpos = 0;
  for (row = 0; row < height; row++) {

    col = 0;



    /* first two pixels in first two rows are stored as raw 8-bit */
    if (row < 2) {
      addr = inp + (bitpos >> 3);
      code = (addr[0] << (bitpos & 7)) | (addr[1] >> (8 - (bitpos & 7)));
      bitpos += 8;
      *outp++ = code;

      addr = inp + (bitpos >> 3);
      code = (addr[0] << (bitpos & 7)) | (addr[1] >> (8 - (bitpos & 7)));
      bitpos += 8;
      *outp++ = code;

      col += 2;
    }

    while (col < width) {
      /* get bitcode from bitstream */
      addr = inp + (bitpos >> 3);
      code = (addr[0] << (bitpos & 7)) | (addr[1] >> (8 - (bitpos & 7)));

      /* update bit position */
      bitpos += table[code].len;

      /* calculate pixel value */
      val = table[code].val;
      if (!table[code].is_abs) {
        /* value is relative to top and left pixel */
        if (col < 2) {
          /* left column: relative to top pixel */
          val += outp[-2*width];
        }
        else if (row < 2) {
          /* top row: relative to left pixel */
          val += outp[-2];
        }
        else {
          /* main area: average of left pixel and top pixel */
          val += (outp[-2] + outp[-2*width]) / 2;
        }
      }

      /* store pixel */
      *outp++ = CLAMP(val);
      col++;
    }
  }

  return 0;
}

static IplImage* icvRetrieveFrameCAM_V4L( CvCaptureCAM_V4L* capture, int) {
    /* Now get what has already been captured as a IplImage return */
    // we need memory iff convert_rgb is true
    bool recreate_frame = capture->frame_allocated != capture->convert_rgb;

    if (!capture->convert_rgb) {
        // for mjpeg streams the size might change in between, so we have to change the header
        recreate_frame += capture->frame.imageSize != (int)capture->buffers[capture->bufferIndex].length;
    }

    if(recreate_frame) {
        // printf("realloc %d %zu\n", capture->frame.imageSize, capture->buffers[capture->bufferIndex].length);
        if(capture->frame_allocated)
            cvFree(&capture->frame.imageData);
        v4l2_create_frame(capture);
    }

    if(!capture->convert_rgb) {
        capture->frame.imageData = (char*)capture->buffers[capture->bufferIndex].start;
        return &capture->frame;
    }

    switch (capture->palette)
    {
    case V4L2_PIX_FMT_BGR24:
        memcpy((char *)capture->frame.imageData,
               (char *)capture->buffers[capture->bufferIndex].start,
               capture->frame.imageSize);
        break;

    case V4L2_PIX_FMT_YVU420:
        yuv420p_to_rgb24(capture->form.fmt.pix.width,
                 capture->form.fmt.pix.height,
                 (unsigned char*)(capture->buffers[capture->bufferIndex].start),
                 (unsigned char*)capture->frame.imageData);
        break;

    case V4L2_PIX_FMT_YUV411P:
        yuv411p_to_rgb24(capture->form.fmt.pix.width,
                 capture->form.fmt.pix.height,
                 (unsigned char*)(capture->buffers[capture->bufferIndex].start),
                 (unsigned char*)capture->frame.imageData);
        break;
#ifdef HAVE_JPEG
    case V4L2_PIX_FMT_MJPEG:
    case V4L2_PIX_FMT_JPEG:
        if (!mjpeg_to_rgb24(capture->form.fmt.pix.width,
                    capture->form.fmt.pix.height,
                    (unsigned char*)(capture->buffers[capture->bufferIndex]
                             .start),
                    capture->buffers[capture->bufferIndex].length,
                    &capture->frame))
          return 0;
        break;
#endif

    case V4L2_PIX_FMT_YUYV:
        yuyv_to_rgb24(capture->form.fmt.pix.width,
                  capture->form.fmt.pix.height,
                  (unsigned char*)(capture->buffers[capture->bufferIndex].start),
                  (unsigned char*)capture->frame.imageData);
        break;
    case V4L2_PIX_FMT_UYVY:
        uyvy_to_rgb24(capture->form.fmt.pix.width,
                  capture->form.fmt.pix.height,
                  (unsigned char*)(capture->buffers[capture->bufferIndex].start),
                  (unsigned char*)capture->frame.imageData);
        break;
    case V4L2_PIX_FMT_SBGGR8:
        bayer2rgb24(capture->form.fmt.pix.width,
                capture->form.fmt.pix.height,
                (unsigned char*)capture->buffers[capture->bufferIndex].start,
                (unsigned char*)capture->frame.imageData);
        break;

    case V4L2_PIX_FMT_SN9C10X:
        sonix_decompress_init();
        sonix_decompress(capture->form.fmt.pix.width,
                 capture->form.fmt.pix.height,
                 (unsigned char*)capture->buffers[capture->bufferIndex].start,
                 (unsigned char*)capture->buffers[(capture->bufferIndex+1) % capture->req.count].start);

        bayer2rgb24(capture->form.fmt.pix.width,
                capture->form.fmt.pix.height,
                (unsigned char*)capture->buffers[(capture->bufferIndex+1) % capture->req.count].start,
                (unsigned char*)capture->frame.imageData);
        break;

    case V4L2_PIX_FMT_SGBRG8:
        sgbrg2rgb24(capture->form.fmt.pix.width,
                capture->form.fmt.pix.height,
                (unsigned char*)capture->buffers[(capture->bufferIndex+1) % capture->req.count].start,
                (unsigned char*)capture->frame.imageData);
        break;
    case V4L2_PIX_FMT_RGB24:
        rgb24_to_rgb24(capture->form.fmt.pix.width,
                capture->form.fmt.pix.height,
                (unsigned char*)capture->buffers[(capture->bufferIndex+1) % capture->req.count].start,
                (unsigned char*)capture->frame.imageData);
        break;
    }

a  
Kai Westerkamp committed
1540
    return(&capture->frame);
wester committed
1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555
}

static inline __u32 capPropertyToV4L2(int prop) {
    switch (prop) {
    case CV_CAP_PROP_BRIGHTNESS:
        return V4L2_CID_BRIGHTNESS;
    case CV_CAP_PROP_CONTRAST:
        return V4L2_CID_CONTRAST;
    case CV_CAP_PROP_SATURATION:
        return V4L2_CID_SATURATION;
    case CV_CAP_PROP_HUE:
        return V4L2_CID_HUE;
    case CV_CAP_PROP_GAIN:
        return V4L2_CID_GAIN;
    case CV_CAP_PROP_EXPOSURE:
a  
Kai Westerkamp committed
1556
        return V4L2_CID_EXPOSURE;
wester committed
1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755
    case CV_CAP_PROP_AUTOFOCUS:
        return V4L2_CID_FOCUS_AUTO;
    case CV_CAP_PROP_FOCUS:
        return V4L2_CID_FOCUS_ABSOLUTE;
    default:
        return -1;
    }
}

static double icvGetPropertyCAM_V4L (const CvCaptureCAM_V4L* capture,
                                     int property_id ) {
  {
      v4l2_format form;
      form.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
      if (-1 == ioctl (capture->deviceHandle, VIDIOC_G_FMT, &form)) {
          /* display an error message, and return an error code */
          perror ("VIDIOC_G_FMT");
          return -1;
      }

      switch (property_id) {
      case CV_CAP_PROP_FRAME_WIDTH:
          return form.fmt.pix.width;
      case CV_CAP_PROP_FRAME_HEIGHT:
          return form.fmt.pix.height;
      case CV_CAP_PROP_FOURCC:
      case CV_CAP_PROP_MODE:
          return capture->palette;
      case CV_CAP_PROP_FORMAT:
          return CV_MAKETYPE(CV_8U, capture->frame.nChannels);
      case CV_CAP_PROP_CONVERT_RGB:
          return capture->convert_rgb;
      }

      if(property_id == CV_CAP_PROP_FPS) {
          v4l2_streamparm sp = v4l2_streamparm();
          sp.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
          if (ioctl(capture->deviceHandle, VIDIOC_G_PARM, &sp) < 0){
              fprintf(stderr, "VIDEOIO ERROR: V4L: Unable to get camera FPS\n");
              return -1;
          }

          return sp.parm.capture.timeperframe.denominator / (double)sp.parm.capture.timeperframe.numerator;
      }

      /* initialize the control structure */

      if(property_id == CV_CAP_PROP_POS_MSEC) {
          if (capture->FirstCapture) {
            return 0;
          } else {
            return 1000 * capture->timestamp.tv_sec + ((double) capture->timestamp.tv_usec) / 1000;
          }
      }

      __u32 v4l2id = capPropertyToV4L2(property_id);

      if(v4l2id == __u32(-1)) {
          fprintf(stderr,
                  "VIDEOIO ERROR: V4L2: getting property #%d is not supported\n",
                  property_id);
          return -1;
      }

      v4l2_control control = {v4l2id, 0};

      if (-1 == ioctl (capture->deviceHandle, VIDIOC_G_CTRL,
                        &control)) {

          fprintf( stderr, "VIDEOIO ERROR: V4L2: ");
          switch (property_id) {
          case CV_CAP_PROP_BRIGHTNESS:
              fprintf (stderr, "Brightness");
              break;
          case CV_CAP_PROP_CONTRAST:
              fprintf (stderr, "Contrast");
              break;
          case CV_CAP_PROP_SATURATION:
              fprintf (stderr, "Saturation");
              break;
          case CV_CAP_PROP_HUE:
              fprintf (stderr, "Hue");
              break;
          case CV_CAP_PROP_GAIN:
              fprintf (stderr, "Gain");
              break;
          case CV_CAP_PROP_EXPOSURE:
              fprintf (stderr, "Exposure");
              break;
          case CV_CAP_PROP_AUTOFOCUS:
              fprintf (stderr, "Autofocus");
              break;
          case CV_CAP_PROP_FOCUS:
              fprintf (stderr, "Focus");
              break;
          }
          fprintf (stderr, " is not supported by your device\n");

          return -1;
      }

      /* get the min/max values */
      Range range = capture->getRange(property_id);

      /* all was OK, so convert to 0.0 - 1.0 range, and return the value */
      return ((double)control.value - range.start) / range.size();

  }
};

static bool icvSetControl (CvCaptureCAM_V4L* capture,
                          int property_id, double value) {

  /* limitation of the input value */
  if (value < 0.0) {
    value = 0.0;
  } else if (value > 1.0) {
    value = 1.0;
  }

    /* initialisations */
    __u32 v4l2id = capPropertyToV4L2(property_id);

    if(v4l2id == __u32(-1)) {
        fprintf(stderr,
                "VIDEOIO ERROR: V4L2: setting property #%d is not supported\n",
                property_id);
        return -1;
    }

    /* get the min/max values */
    Range range = capture->getRange(property_id);

    /* scale the value we want to set */
    value = value * range.size() + range.start;

    /* set which control we want to set */
    v4l2_control control = {v4l2id, int(value)};

    /* The driver may clamp the value or return ERANGE, ignored here */
    if (-1 == ioctl(capture->deviceHandle, VIDIOC_S_CTRL, &control) && errno != ERANGE) {
        perror ("VIDIOC_S_CTRL");
        return false;
    }

    /* all was OK */
    return true;
}

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

    /* two subsequent calls setting WIDTH and HEIGHT will change
       the video size */

    switch (property_id) {
    case CV_CAP_PROP_FRAME_WIDTH:
        width = cvRound(value);
        if(width !=0 && height != 0) {
            capture->width = width;
            capture->height = height;
            retval = v4l2_reset(capture);
            width = height = 0;
        }
        break;
    case CV_CAP_PROP_FRAME_HEIGHT:
        height = cvRound(value);
        if(width !=0 && height != 0) {
            capture->width = width;
            capture->height = height;
            retval = v4l2_reset(capture);
            width = height = 0;
        }
        break;
    case CV_CAP_PROP_FPS:
        capture->fps = value;
        retval = v4l2_reset(capture);
        break;
    case CV_CAP_PROP_CONVERT_RGB:
        // returns "0" for formats we do not know how to map to IplImage
        possible = v4l2_num_channels(capture->palette);
        capture->convert_rgb = bool(value) && possible;
        retval = possible || !bool(value);
        break;
    default:
        retval = icvSetControl(capture, property_id, value);
        break;
    }

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

static void icvCloseCAM_V4L( CvCaptureCAM_V4L* capture ){
   /* Deallocate space - Hopefully, no leaks */

a  
Kai Westerkamp committed
1756
   if (capture->index > -1)
wester committed
1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781
   {
       if (capture->deviceHandle != -1)
       {
           capture->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
           if (-1 == ioctl(capture->deviceHandle, VIDIOC_STREAMOFF, &capture->type)) {
               perror ("Unable to stop the stream");
       }

       for (unsigned int n_buffers_ = 0; n_buffers_ < capture->req.count; ++n_buffers_)
       {
           if (-1 == munmap (capture->buffers[n_buffers_].start, capture->buffers[n_buffers_].length)) {
               perror ("munmap");
           }
       }

       if (capture->buffers[MAX_V4L_BUFFERS].start)
       {
           free(capture->buffers[MAX_V4L_BUFFERS].start);
           capture->buffers[MAX_V4L_BUFFERS].start = 0;
       }
     }

     if (capture->deviceHandle != -1)
       close(capture->deviceHandle);

a  
Kai Westerkamp committed
1782
     if (capture->frame.imageData)
wester committed
1783 1784
         cvFree(&capture->frame.imageData);

a  
Kai Westerkamp committed
1785
     capture->index = -1; // flag that the capture is closed
wester committed
1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822
   }
};

bool CvCaptureCAM_V4L::grabFrame()
{
    return icvGrabFrameCAM_V4L( this );
}

IplImage* CvCaptureCAM_V4L::retrieveFrame(int)
{
    return icvRetrieveFrameCAM_V4L( this, 0 );
}

double CvCaptureCAM_V4L::getProperty( int propId ) const
{
    return icvGetPropertyCAM_V4L( this, propId );
}

bool CvCaptureCAM_V4L::setProperty( int propId, double value )
{
    return icvSetPropertyCAM_V4L( this, propId, value );
}

} // end namespace cv

CvCapture* cvCreateCameraCapture_V4L( int index )
{
    cv::CvCaptureCAM_V4L* capture = new cv::CvCaptureCAM_V4L();

    if(capture->open(index))
        return capture;

    delete capture;
    return NULL;
}

#endif