changed to a more OO style interface; dequeueBuffer() still blocks indefinitely

git-svn-id: svn://anubis/misc/WebcamTracker@124 bd8a9e45-a331-0410-811e-c64571078777
This commit is contained in:
josh 2009-08-08 04:36:25 +00:00
parent 5a72b568b9
commit 3f048de88d
2 changed files with 211 additions and 136 deletions

View File

@ -14,164 +14,226 @@ using namespace std;
int main(int argc, char * argv[])
{
WebcamTracker("/dev/video0");
WebcamTracker wt;
wt.open("/dev/video0");
wt.start();
}
WebcamTracker::WebcamTracker(const char * device)
WebcamTracker::WebcamTracker()
{
m_open = false;
m_fd = open(device, O_RDWR);
m_buffers = NULL;
m_lengths = NULL;
}
bool WebcamTracker::open(const char * device)
{
m_fd = ::open(device, O_RDWR);
if (m_fd >= 0)
{
m_open = true;
struct v4l2_capability cap;
int ret = ioctl(m_fd, VIDIOC_QUERYCAP, &cap);
if (ret != 0)
{
cerr << "VIDIOC_QUERYCAP ioctl failed: " << ret << endl;
perror("VIDIOC_QUERYCAP");
}
if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE))
else
{
cerr << "Warning: V4L2_CAP_VIDEO_CAPTURE not supported!" << endl;
if (cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)
{
m_open = true;
}
else
{
cerr << "Warning: V4L2_CAP_VIDEO_CAPTURE not supported!" << endl;
}
}
v4l2_requestbuffers reqbuf;
reqbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
reqbuf.count = 1;
reqbuf.memory = V4L2_MEMORY_MMAP;
ret = ioctl(m_fd, VIDIOC_REQBUFS, &reqbuf);
if (ret != 0)
{
cerr << "VIDIOC_REQBUFS ioctl failed: returned " << ret
<< ", errno " << errno;
if (errno == EBUSY)
cerr << " (EBUSY)";
if (errno == EINVAL)
cerr << " (EINVAL)";
cerr << endl;
}
struct v4l2_buffer buf;
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.index = 0;
ret = ioctl(m_fd, VIDIOC_QUERYBUF, &buf);
if (ret != 0)
{
cerr << "VIDIOC_QUERYBUF ioctl failed: returned " << ret
<< ", errno: " << errno;
if (errno == EINVAL)
cerr << " (EINVAL)";
cerr << endl;
}
m_vidbuflen = buf.length;
m_vidbuf = mmap(NULL, buf.length, PROT_READ | PROT_WRITE, MAP_SHARED,
m_fd, buf.m.offset);
if (m_vidbuf == MAP_FAILED)
{
cerr << "mmap() failed: errno " << errno;
if (errno == EBADF)
cerr << " (EBADF)";
if (errno == EACCES)
cerr << " (EACCES)";
if (errno == EINVAL)
cerr << " (EINVAL)";
if (errno == ENOMEM)
cerr << " (ENOMEM)";
cerr << endl;
}
v4l2_buffer qbuf;
qbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
qbuf.memory = V4L2_MEMORY_MMAP;
qbuf.index = 0;
ret = ioctl(m_fd, VIDIOC_QBUF, &qbuf);
if (ret != 0)
{
cerr << "VIDIOC_QBUF failed! errno = " << errno;
if (errno == EAGAIN)
cerr << " (EAGAIN)";
if (errno == EINVAL)
cerr << " (EINVAL)";
if (errno == ENOMEM)
cerr << " (ENOMEM)";
if (errno == EIO)
cerr << " (EIO)";
cerr << endl;
}
int type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
ret = ioctl(m_fd, VIDIOC_STREAMON, &type);
if (ret != 0)
{
cerr << "VIDIOC_STREAMON ioctl failed! errno = " << errno;
if (errno == EINVAL)
cerr << " (EINVAL)";
cerr << endl;
}
struct v4l2_buffer querybuf;
querybuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
querybuf.index = 0;
ret = ioctl(m_fd, VIDIOC_QUERYBUF, &querybuf);
if (ret != 0)
{
cerr << "VIDIOC_QUERYBUF ioctl failed: returned " << ret
<< ", errno: " << errno;
if (errno == EINVAL)
cerr << " (EINVAL)";
cerr << endl;
}
if (querybuf.flags & V4L2_BUF_FLAG_DONE)
{
cout << "buf done" << endl;
}
v4l2_buffer dqbuf;
dqbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
dqbuf.memory = V4L2_MEMORY_MMAP;
ret = ioctl(m_fd, VIDIOC_DQBUF, &dqbuf);
if (ret != 0)
{
cerr << "VIDIOC_DQBUF failed! errno = " << errno;
if (errno == EAGAIN)
cerr << " (EAGAIN)";
if (errno == EINVAL)
cerr << " (EINVAL)";
if (errno == ENOMEM)
cerr << " (ENOMEM)";
if (errno == EIO)
cerr << " (EIO)";
cerr << endl;
}
}
else
{
cerr << "Could not open device '" << device << "'" << endl;
}
return m_open;
}
void WebcamTracker::start()
{
requestBuffers(20);
for (int i = 0; i < m_numbufs; i++)
{
mapBuffer(i);
queueBuffer(i);
}
beginStreaming();
v4l2_buffer buf;
dequeueBuffer(&buf);
endStreaming();
}
void WebcamTracker::requestBuffers(int num)
{
m_numbufs = 0;
v4l2_requestbuffers reqbuf;
reqbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
reqbuf.count = num;
reqbuf.memory = V4L2_MEMORY_MMAP;
int ret = ioctl(m_fd, VIDIOC_REQBUFS, &reqbuf);
if (ret != 0)
{
cerr << "VIDIOC_REQBUFS ioctl failed: returned " << ret
<< ", errno " << errno;
if (errno == EBUSY)
cerr << " (EBUSY)";
if (errno == EINVAL)
cerr << " (EINVAL)";
cerr << endl;
}
else
{
m_numbufs = reqbuf.count;
cout << "Got " << m_numbufs << " buffers" << endl;
m_buffers = new void *[m_numbufs];
m_lengths = new int[m_numbufs];
}
}
void WebcamTracker::mapBuffer(int i)
{
struct v4l2_buffer buf;
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buf.index = i;
int ret = ioctl(m_fd, VIDIOC_QUERYBUF, &buf);
if (ret != 0)
{
cerr << "VIDIOC_QUERYBUF ioctl failed: returned " << ret
<< ", errno: " << errno;
if (errno == EINVAL)
cerr << " (EINVAL)";
cerr << endl;
}
m_buffers[i] = mmap(NULL, buf.length, PROT_READ | PROT_WRITE,
MAP_SHARED, m_fd, buf.m.offset);
m_lengths[i] = buf.length;
if (m_buffers[i] == MAP_FAILED)
{
cerr << "mmap() failed: errno " << errno;
if (errno == EBADF)
cerr << " (EBADF)";
if (errno == EACCES)
cerr << " (EACCES)";
if (errno == EINVAL)
cerr << " (EINVAL)";
if (errno == ENOMEM)
cerr << " (ENOMEM)";
cerr << endl;
}
}
void WebcamTracker::queueBuffer(int i)
{
v4l2_buffer qbuf;
qbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
qbuf.memory = V4L2_MEMORY_MMAP;
qbuf.index = i;
int ret = ioctl(m_fd, VIDIOC_QBUF, &qbuf);
if (ret != 0)
{
cerr << "VIDIOC_QBUF failed! errno = " << errno;
if (errno == EAGAIN)
cerr << " (EAGAIN)";
if (errno == EINVAL)
cerr << " (EINVAL)";
if (errno == ENOMEM)
cerr << " (ENOMEM)";
if (errno == EIO)
cerr << " (EIO)";
cerr << endl;
}
}
void WebcamTracker::beginStreaming()
{
int type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
int ret = ioctl(m_fd, VIDIOC_STREAMON, &type);
if (ret != 0)
{
cerr << "VIDIOC_STREAMON ioctl failed! errno = " << errno;
if (errno == EINVAL)
cerr << " (EINVAL)";
cerr << endl;
}
}
void WebcamTracker::endStreaming()
{
int type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
int ret = ioctl(m_fd, VIDIOC_STREAMOFF, &type);
if (ret != 0)
{
cerr << "VIDIOC_STREAMOFF ioctl failed! errno = " << errno;
if (errno == EINVAL)
cerr << " (EINVAL)";
cerr << endl;
}
}
void WebcamTracker::dequeueBuffer(v4l2_buffer * dqbuf)
{
dqbuf->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
dqbuf->memory = V4L2_MEMORY_MMAP;
int ret = ioctl(m_fd, VIDIOC_DQBUF, dqbuf);
if (ret != 0)
{
cerr << "VIDIOC_DQBUF failed! errno = " << errno;
if (errno == EAGAIN)
cerr << " (EAGAIN)";
if (errno == EINVAL)
cerr << " (EINVAL)";
if (errno == ENOMEM)
cerr << " (ENOMEM)";
if (errno == EIO)
cerr << " (EIO)";
cerr << endl;
}
}
void WebcamTracker::unmapBuffer(int i)
{
munmap(m_buffers[i], m_lengths[i]);
}
void WebcamTracker::freeBuffers()
{
v4l2_requestbuffers reqbuf;
reqbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
reqbuf.count = 0;
reqbuf.memory = V4L2_MEMORY_MMAP;
int ret = ioctl(m_fd, VIDIOC_REQBUFS, &reqbuf);
if (ret != 0)
{
cerr << "~WebcamTracker(): VIDIOC_REQBUFS ioctl failed: "
<< ret << endl;
if (errno == EBUSY)
cerr << "EBUSY" << endl;
if (errno == EINVAL)
cerr << "EINVAL" << endl;
}
}
WebcamTracker::~WebcamTracker()
{
if (m_open)
{
munmap(m_vidbuf, m_vidbuflen);
v4l2_requestbuffers reqbuf;
reqbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
reqbuf.count = 0;
reqbuf.memory = V4L2_MEMORY_MMAP;
int ret = ioctl(m_fd, VIDIOC_REQBUFS, &reqbuf);
if (ret != 0)
if (m_buffers)
{
cerr << "~WebcamTracker(): VIDIOC_REQBUFS ioctl failed: "
<< ret << endl;
if (errno == EBUSY)
cerr << "EBUSY" << endl;
if (errno == EINVAL)
cerr << "EINVAL" << endl;
for (int i = 0; i < m_numbufs; i++)
{
unmapBuffer(i);
}
delete m_buffers;
delete m_lengths;
freeBuffers();
}
close(m_fd);
}

View File

@ -6,16 +6,29 @@
#include <sys/ioctl.h> /* ioctl() */
#include <libv4lconvert.h>
#include <iostream>
#include <vector>
class WebcamTracker
{
public:
WebcamTracker(const char * device);
WebcamTracker();
~WebcamTracker();
bool open(const char * device);
void start();
protected:
void * m_vidbuf;
int m_vidbuflen;
void requestBuffers(int num);
void mapBuffer(int i);
void queueBuffer(int i);
void beginStreaming();
void endStreaming();
void dequeueBuffer(v4l2_buffer * dqbuf);
void unmapBuffer(int i);
void freeBuffers();
bool m_open;
int m_fd;
int m_numbufs;
void ** m_buffers;
int * m_lengths;
};