V4L2 test added

Former-commit-id: eec49d94ffbb0e1be0639e9cbbebba5955c79f4d
This commit is contained in:
johan 2014-01-04 13:24:05 +01:00
parent eaa4b0bae5
commit e474c90fcd
7 changed files with 669 additions and 1 deletions

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@ -10,6 +10,9 @@ cmake_minimum_required(VERSION 2.8)
option (ENABLE_DISPMANX "Enable the RPi dispmanx grabber" ON)
message(STATUS "ENABLE_DISPMANX = " ${ENABLE_DISPMANX})
option (ENABLE_V4L2 "Enable the V4L2 grabber" ON)
message(STATUS "ENABLE_V4L2 = " ${ENABLE_V4L2})
# Createt the configuration file
# configure a header file to pass some of the CMake settings
# to the source code
@ -39,7 +42,7 @@ include_directories(${CMAKE_SOURCE_DIR}/include)
set(CMAKE_BUILD_TYPE "Release")
# enable C++11
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++0x -Wall")
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++0x -Wall -g")
# Configure the use of QT4
find_package(Qt4 COMPONENTS QtCore QtGui QtNetwork REQUIRED QUIET)

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@ -2,3 +2,6 @@
// Define to enable the dispmanx grabber
#cmakedefine ENABLE_DISPMANX
// Define to enable the v4l2 grabber
#cmakedefine ENABLE_V4L2

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@ -31,6 +31,10 @@ if (ENABLE_DISPMANX)
add_subdirectory(dispmanx2png)
endif (ENABLE_DISPMANX)
if (ENABLE_V4L2)
add_subdirectory(v4l2png)
endif (ENABLE_V4L2)
add_executable(test_blackborderdetector
TestBlackBorderDetector.cpp)
target_link_libraries(test_blackborderdetector

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@ -0,0 +1,17 @@
# find Qt4
find_package(Qt4 REQUIRED QtCore QtGui)
include_directories(${QT_INCLUDES})
add_executable(v4l_to_png
v4l2png.cpp
V4L2Grabber.h
V4L2Grabber.cpp)
target_link_libraries(v4l_to_png
getoptPlusPlus)
qt4_use_modules(v4l_to_png
Core
Gui)

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@ -0,0 +1,531 @@
#include <iostream>
#include <cstdio>
#include <cassert>
#include <cstdlib>
#include <fcntl.h>
#include <unistd.h>
#include <cstring>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <linux/videodev2.h>
#include <QImage>
#include <QRgb>
#include "V4L2Grabber.h"
#define CLEAR(x) memset(&(x), 0, sizeof(x))
V4L2Grabber::V4L2Grabber() :
_deviceName("/dev/video0"),
_ioMethod(IO_METHOD_MMAP),
_fileDescriptor(-1),
_buffers()
{
}
V4L2Grabber::~V4L2Grabber()
{
}
void V4L2Grabber::start()
{
open_device();
init_device();
start_capturing();
int count = 100;
while (count-- > 0) {
for (;;) {
fd_set fds;
struct timeval tv;
int r;
FD_ZERO(&fds);
FD_SET(_fileDescriptor, &fds);
/* Timeout. */
tv.tv_sec = 2;
tv.tv_usec = 0;
r = select(_fileDescriptor + 1, &fds, NULL, NULL, &tv);
if (-1 == r)
{
if (EINTR == errno)
continue;
errno_exit("select");
}
if (0 == r)
{
fprintf(stderr, "select timeout\n");
exit(EXIT_FAILURE);
}
if (read_frame())
break;
/* EAGAIN - continue select loop. */
}
}
stop_capturing();
uninit_device();
close_device();
}
void V4L2Grabber::open_device()
{
struct stat st;
if (-1 == stat(_deviceName.c_str(), &st))
{
fprintf(stderr, "Cannot identify '%s': %d, %s\n", _deviceName.c_str(), errno, strerror(errno));
exit(EXIT_FAILURE);
}
if (!S_ISCHR(st.st_mode))
{
fprintf(stderr, "%s is no device\n", _deviceName.c_str());
exit(EXIT_FAILURE);
}
_fileDescriptor = open(_deviceName.c_str(), O_RDWR /* required */ | O_NONBLOCK, 0);
if (-1 == _fileDescriptor)
{
fprintf(stderr, "Cannot open '%s': %d, %s\n", _deviceName.c_str(), errno, strerror(errno));
exit(EXIT_FAILURE);
}
}
void V4L2Grabber::close_device()
{
if (-1 == close(_fileDescriptor))
errno_exit("close");
_fileDescriptor = -1;
}
void V4L2Grabber::init_read(unsigned int buffer_size)
{
_buffers.resize(1);
_buffers[0].length = buffer_size;
_buffers[0].start = malloc(buffer_size);
if (!_buffers[0].start) {
fprintf(stderr, "Out of memory\n");
exit(EXIT_FAILURE);
}
}
void V4L2Grabber::init_mmap()
{
struct v4l2_requestbuffers req;
CLEAR(req);
req.count = 4;
req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
req.memory = V4L2_MEMORY_MMAP;
if (-1 == xioctl(VIDIOC_REQBUFS, &req)) {
if (EINVAL == errno) {
fprintf(stderr, "%s does not support memory mapping\n", _deviceName.c_str());
exit(EXIT_FAILURE);
} else {
errno_exit("VIDIOC_REQBUFS");
}
}
if (req.count < 2) {
fprintf(stderr, "Insufficient buffer memory on %s\n", _deviceName.c_str());
exit(EXIT_FAILURE);
}
_buffers.resize(req.count);
for (size_t n_buffers = 0; n_buffers < req.count; ++n_buffers) {
struct v4l2_buffer buf;
CLEAR(buf);
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
buf.index = n_buffers;
if (-1 == xioctl(VIDIOC_QUERYBUF, &buf))
errno_exit("VIDIOC_QUERYBUF");
_buffers[n_buffers].length = buf.length;
_buffers[n_buffers].start =
mmap(NULL /* start anywhere */,
buf.length,
PROT_READ | PROT_WRITE /* required */,
MAP_SHARED /* recommended */,
_fileDescriptor, buf.m.offset);
if (MAP_FAILED == _buffers[n_buffers].start)
errno_exit("mmap");
}
}
void V4L2Grabber::init_userp(unsigned int buffer_size)
{
struct v4l2_requestbuffers req;
CLEAR(req);
req.count = 4;
req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
req.memory = V4L2_MEMORY_USERPTR;
if (-1 == xioctl(VIDIOC_REQBUFS, &req)) {
if (EINVAL == errno)
{
fprintf(stderr, "%s does not support user pointer i/o\n", _deviceName.c_str());
exit(EXIT_FAILURE);
} else {
errno_exit("VIDIOC_REQBUFS");
}
}
_buffers.resize(4);
for (size_t n_buffers = 0; n_buffers < 4; ++n_buffers) {
_buffers[n_buffers].length = buffer_size;
_buffers[n_buffers].start = malloc(buffer_size);
if (!_buffers[n_buffers].start) {
fprintf(stderr, "Out of memory\n");
exit(EXIT_FAILURE);
}
}
}
void V4L2Grabber::init_device()
{
struct v4l2_capability cap;
struct v4l2_cropcap cropcap;
struct v4l2_crop crop;
struct v4l2_format fmt;
if (-1 == xioctl(VIDIOC_QUERYCAP, &cap))
{
if (EINVAL == errno) {
fprintf(stderr, "%s is no V4L2 device\n", _deviceName.c_str());
exit(EXIT_FAILURE);
} else {
errno_exit("VIDIOC_QUERYCAP");
}
}
if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE))
{
fprintf(stderr, "%s is no video capture device\n", _deviceName.c_str());
exit(EXIT_FAILURE);
}
switch (_ioMethod) {
case IO_METHOD_READ:
if (!(cap.capabilities & V4L2_CAP_READWRITE))
{
fprintf(stderr, "%s does not support read i/o\n", _deviceName.c_str());
exit(EXIT_FAILURE);
}
break;
case IO_METHOD_MMAP:
case IO_METHOD_USERPTR:
if (!(cap.capabilities & V4L2_CAP_STREAMING))
{
fprintf(stderr, "%s does not support streaming i/o\n", _deviceName.c_str());
exit(EXIT_FAILURE);
}
break;
}
/* Select video input, video standard and tune here. */
CLEAR(cropcap);
cropcap.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (0 == xioctl(VIDIOC_CROPCAP, &cropcap)) {
crop.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
crop.c = cropcap.defrect; /* reset to default */
if (-1 == xioctl(VIDIOC_S_CROP, &crop)) {
switch (errno) {
case EINVAL:
/* Cropping not supported. */
break;
default:
/* Errors ignored. */
break;
}
}
} else {
/* Errors ignored. */
}
CLEAR(fmt);
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
/* Preserve original settings as set by v4l2-ctl for example */
if (-1 == xioctl(VIDIOC_G_FMT, &fmt))
{
errno_exit("VIDIOC_G_FMT");
}
// /* Buggy driver paranoia. */
// min = fmt.fmt.pix.width * 2;
// if (fmt.fmt.pix.bytesperline < min)
// fmt.fmt.pix.bytesperline = min;
// min = fmt.fmt.pix.bytesperline * fmt.fmt.pix.height;
// if (fmt.fmt.pix.sizeimage < min)
// fmt.fmt.pix.sizeimage = min;
switch (_ioMethod) {
case IO_METHOD_READ:
init_read(fmt.fmt.pix.sizeimage);
break;
case IO_METHOD_MMAP:
init_mmap();
break;
case IO_METHOD_USERPTR:
init_userp(fmt.fmt.pix.sizeimage);
break;
}
}
void V4L2Grabber::uninit_device()
{
switch (_ioMethod) {
case IO_METHOD_READ:
free(_buffers[0].start);
break;
case IO_METHOD_MMAP:
for (size_t i = 0; i < _buffers.size(); ++i)
if (-1 == munmap(_buffers[i].start, _buffers[i].length))
errno_exit("munmap");
break;
case IO_METHOD_USERPTR:
for (size_t i = 0; i < _buffers.size(); ++i)
free(_buffers[i].start);
break;
}
_buffers.resize(0);
}
void V4L2Grabber::start_capturing()
{
switch (_ioMethod) {
case IO_METHOD_READ:
/* Nothing to do. */
break;
case IO_METHOD_MMAP:
{
for (size_t i = 0; i < _buffers.size(); ++i) {
struct v4l2_buffer buf;
CLEAR(buf);
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
buf.index = i;
if (-1 == xioctl(VIDIOC_QBUF, &buf))
errno_exit("VIDIOC_QBUF");
}
v4l2_buf_type type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (-1 == xioctl(VIDIOC_STREAMON, &type))
errno_exit("VIDIOC_STREAMON");
break;
}
case IO_METHOD_USERPTR:
{
for (size_t i = 0; i < _buffers.size(); ++i) {
struct v4l2_buffer buf;
CLEAR(buf);
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_USERPTR;
buf.index = i;
buf.m.userptr = (unsigned long)_buffers[i].start;
buf.length = _buffers[i].length;
if (-1 == xioctl(VIDIOC_QBUF, &buf))
errno_exit("VIDIOC_QBUF");
}
v4l2_buf_type type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (-1 == xioctl(VIDIOC_STREAMON, &type))
errno_exit("VIDIOC_STREAMON");
break;
}
}
}
void V4L2Grabber::stop_capturing()
{
enum v4l2_buf_type type;
switch (_ioMethod) {
case IO_METHOD_READ:
/* Nothing to do. */
break;
case IO_METHOD_MMAP:
case IO_METHOD_USERPTR:
type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (-1 == xioctl(VIDIOC_STREAMOFF, &type))
errno_exit("VIDIOC_STREAMOFF");
break;
}
}
int V4L2Grabber::read_frame()
{
struct v4l2_buffer buf;
switch (_ioMethod) {
case IO_METHOD_READ:
if (-1 == read(_fileDescriptor, _buffers[0].start, _buffers[0].length)) {
switch (errno) {
case EAGAIN:
return 0;
case EIO:
/* Could ignore EIO, see spec. */
/* fall through */
default:
errno_exit("read");
}
}
process_image(_buffers[0].start, _buffers[0].length);
break;
case IO_METHOD_MMAP:
CLEAR(buf);
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_MMAP;
if (-1 == xioctl(VIDIOC_DQBUF, &buf)) {
switch (errno) {
case EAGAIN:
return 0;
case EIO:
/* Could ignore EIO, see spec. */
/* fall through */
default:
errno_exit("VIDIOC_DQBUF");
}
}
assert(buf.index < _buffers.size());
process_image(_buffers[buf.index].start, buf.bytesused);
if (-1 == xioctl(VIDIOC_QBUF, &buf))
errno_exit("VIDIOC_QBUF");
break;
case IO_METHOD_USERPTR:
CLEAR(buf);
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.memory = V4L2_MEMORY_USERPTR;
if (-1 == xioctl(VIDIOC_DQBUF, &buf)) {
switch (errno) {
case EAGAIN:
return 0;
case EIO:
/* Could ignore EIO, see spec. */
/* fall through */
default:
errno_exit("VIDIOC_DQBUF");
}
}
for (size_t i = 0; i < _buffers.size(); ++i)
if (buf.m.userptr == (unsigned long)_buffers[i].start
&& buf.length == _buffers[i].length)
break;
process_image((void *)buf.m.userptr, buf.bytesused);
if (-1 == xioctl(VIDIOC_QBUF, &buf))
errno_exit("VIDIOC_QBUF");
break;
}
return 1;
}
void V4L2Grabber::process_image(const void *p, int size)
{
if (size != 2*720*480)
{
std::cout << "Frame too small: " << size << "<" << (2*720*480) << std::endl;
return;
}
std::cout << "process image of size = " << size << std::endl;
const uint8_t * data = reinterpret_cast<const uint8_t *>(p);
QImage image(720, 480, QImage::Format_RGB888);
for (int y = 0; y < image.height(); ++y)
{
for (int x = 0; x < image.width(); ++x)
{
uint8_t value = data[(720 * y + x) * 2 + 1];
image.setPixel(x, y, qRgb(value, value, value));
}
}
image.save("/home/pi/screenshot.png");
}
int V4L2Grabber::xioctl(int request, void *arg)
{
int r;
do {
r = ioctl(_fileDescriptor, request, arg);
} while (-1 == r && EINTR == errno);
return r;
}
void V4L2Grabber::errno_exit(const char *s)
{
fprintf(stderr, "%s error %d, %s\n", s, errno, strerror(errno));
exit(EXIT_FAILURE);
}

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@ -0,0 +1,62 @@
#pragma once
// stl includes
#include <string>
#include <vector>
/// Capture class for V4L2 devices
///
/// @see http://linuxtv.org/downloads/v4l-dvb-apis/capture-example.html
class V4L2Grabber
{
public:
V4L2Grabber();
virtual ~V4L2Grabber();
void start();
private:
void open_device();
void close_device();
void init_read(unsigned int buffer_size);
void init_mmap();
void init_userp(unsigned int buffer_size);
void init_device();
void uninit_device();
void start_capturing();
void stop_capturing();
int read_frame();
void process_image(const void *p, int size);
int xioctl(int request, void *arg);
void errno_exit(const char *s);
private:
enum io_method {
IO_METHOD_READ,
IO_METHOD_MMAP,
IO_METHOD_USERPTR
};
struct buffer {
void *start;
size_t length;
};
private:
const std::string _deviceName;
const io_method _ioMethod;
int _fileDescriptor;
std::vector<buffer> _buffers;
};

48
test/v4l2png/v4l2png.cpp Normal file
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@ -0,0 +1,48 @@
// STL includes
#include <csignal>
#include <iomanip>
// QT includes
#include <QImage>
// getoptPlusPLus includes
#include <getoptPlusPlus/getoptpp.h>
#include "V4L2Grabber.h"
using namespace vlofgren;
int main(int argc, char** argv)
{
try
{
// create the option parser and initialize all parameters
OptionsParser optionParser("Simple application to send a command to hyperion using the Json interface");
ParameterSet & parameters = optionParser.getParameters();
SwitchParameter<> & argHelp = parameters.add<SwitchParameter<> >('h', "help", "Show this help message and exit");
// parse all options
optionParser.parse(argc, const_cast<const char **>(argv));
// check if we need to display the usage. exit if we do.
if (argHelp.isSet())
{
optionParser.usage();
return 0;
}
}
catch (const std::runtime_error & e)
{
// An error occured. Display error and quit
std::cerr << e.what() << std::endl;
return 1;
}
V4L2Grabber grabber;
grabber.start();
return 0;
}