From a46dffd0ef5e40f0ef2373e3b2e990624de38674 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 30 Jun 2009 08:57:26 -0300 Subject: v4l2grab: Add an userspace application for webcam testing, using libv4l2 From: Mauro Carvalho Chehab During FISL 10 (Forum Internacional de Software Livre) and the first FudCon Latam (Fedora Users and Developers Conference), while preparing the V4L panel, I and Douglas noticed the need of a very simple application to be an example for developers to test their drivers and to write newer v4l2 applications. So, we come to the idea of creating a v4l2grab application that takes pictures from the webcam and saves them with the ppm format, using libv4l to work with all webcam models. This application uses the absolute minimum of V4L2 calls to take 640x480 pictures, and was tested with uvcvideo and vivi drivers. Signed-off-by: Mauro Carvalho Chehab --- v4l2-apps/test/Makefile | 7 +++ v4l2-apps/test/v4l2grab.c | 155 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 162 insertions(+) create mode 100644 v4l2-apps/test/v4l2grab.c (limited to 'v4l2-apps') diff --git a/v4l2-apps/test/Makefile b/v4l2-apps/test/Makefile index d118b9210..71eaa77cf 100644 --- a/v4l2-apps/test/Makefile +++ b/v4l2-apps/test/Makefile @@ -7,6 +7,7 @@ binaries = ioctl-test \ sliced-vbi-detect \ vbi-test \ v4lgrab \ + v4l2grab \ driver-test \ pixfmt-test \ stress-buffer \ @@ -24,9 +25,15 @@ install: ../libv4l2util/libv4l2util.a: ../libv4l2util/v4l2_driver.c ../libv4l2util/frequencies.c make -C ../libv4l2util libv4l2util.a +../libv4l/libv4l2/libv4l2.so: + make -C ../libv4l/ + driver-test: driver-test.o ../libv4l2util/libv4l2util.a pixfmt-test: pixfmt-test.o $(CC) $(LDFLAGS) $^ $(LOADLIBES) $(LDLIBS) -o $@ -lX11 +v4l2grab: v4l2grab.o + $(CC) $(LDFLAGS) $^ -o $@ ../libv4l/libv4l2/libv4l2.so + include ../Make.rules diff --git a/v4l2-apps/test/v4l2grab.c b/v4l2-apps/test/v4l2grab.c new file mode 100644 index 000000000..20692117e --- /dev/null +++ b/v4l2-apps/test/v4l2grab.c @@ -0,0 +1,155 @@ +/* V4L2 video picture grabber + Copyright (C) 2006 Mauro Carvalho Chehab + + 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 version 2 of the License. + + 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "../libv4l/include/libv4l2.h" + +#define CLEAR(x) memset(&(x), 0, sizeof(x)) + +struct buffer { + void *start; + size_t length; +}; + +static void xioctl(int fh, int request, void *arg) +{ + int r; + + do { + r = v4l2_ioctl(fh, request, arg); + } while (r == -1 && ((errno == EINTR) || (errno == EAGAIN))); + + if (r == -1) { + fprintf(stderr, "error %d, %s\n", errno, strerror(errno)); + exit(EXIT_FAILURE); + } +} + +int main(int argc, char **argv) +{ + struct v4l2_format fmt; + struct v4l2_buffer buf; + struct v4l2_requestbuffers req; + enum v4l2_buf_type type; + fd_set fds; + struct timeval tv; + int r, fd = -1; + unsigned int i, n_buffers; + char *dev_name = "/dev/video0"; + char out_name[256]; + FILE *fout; + struct buffer *buffers; + + fd = v4l2_open(dev_name, O_RDWR | O_NONBLOCK, 0); + if (fd < 0) { + perror("Cannot open device"); + exit(EXIT_FAILURE); + } + + CLEAR(fmt); + fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; + fmt.fmt.pix.width = 640; + fmt.fmt.pix.height = 480; + fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_RGB24; + fmt.fmt.pix.field = V4L2_FIELD_INTERLACED; + xioctl(fd, VIDIOC_S_FMT, &fmt); + + CLEAR(req); + req.count = 2; + req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; + req.memory = V4L2_MEMORY_MMAP; + xioctl(fd, VIDIOC_REQBUFS, &req); + + buffers = calloc(req.count, sizeof(*buffers)); + for (n_buffers = 0; n_buffers < req.count; ++n_buffers) { + CLEAR(buf); + + buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; + buf.memory = V4L2_MEMORY_MMAP; + buf.index = n_buffers; + + xioctl(fd, VIDIOC_QUERYBUF, &buf); + + buffers[n_buffers].length = buf.length; + buffers[n_buffers].start = v4l2_mmap(NULL, buf.length, + PROT_READ | PROT_WRITE, MAP_SHARED, + fd, buf.m.offset); + + if (MAP_FAILED == buffers[n_buffers].start) { + perror("mmap"); + exit(EXIT_FAILURE); + } + } + + for (i = 0; i < n_buffers; ++i) { + CLEAR(buf); + buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; + buf.memory = V4L2_MEMORY_MMAP; + buf.index = i; + xioctl(fd, VIDIOC_QBUF, &buf); + } + type = V4L2_BUF_TYPE_VIDEO_CAPTURE; + + xioctl(fd, VIDIOC_STREAMON, &type); + for (i = 0; i < 20; i++) { + do { + FD_ZERO(&fds); + FD_SET(fd, &fds); + + /* Timeout. */ + tv.tv_sec = 2; + tv.tv_usec = 0; + + r = select(fd + 1, &fds, NULL, NULL, &tv); + } while ((r == -1 && (errno = EINTR))); + if (r == -1) { + perror("select"); + return errno; + } + + CLEAR(buf); + buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; + buf.memory = V4L2_MEMORY_MMAP; + xioctl(fd, VIDIOC_DQBUF, &buf); + + sprintf(out_name, "out%03d.ppm", i); + fout = fopen(out_name, "w"); + if (!fout) { + perror("Cannot open image"); + exit(EXIT_FAILURE); + } + fprintf(fout, "P6\n%d %d 255\n", + fmt.fmt.pix.width, fmt.fmt.pix.height); + fwrite(buffers[buf.index].start, buf.bytesused, 1, fout); + fclose(fout); + + xioctl(fd, VIDIOC_QBUF, &buf); + } + + type = V4L2_BUF_TYPE_VIDEO_CAPTURE; + xioctl(fd, VIDIOC_STREAMOFF, &type); + for (i = 0; i < n_buffers; ++i) + v4l2_munmap(buffers[i].start, buffers[i].length); + v4l2_close(fd); + + return 0; +} -- cgit v1.2.3 From 24655815f5d1643d22194d5abbd46c1bd43669e9 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Thu, 2 Jul 2009 17:49:43 -0300 Subject: v4l2grab: Be sure that libv4l is properly converting to RGB24 From: Mauro Carvalho Chehab To be simple, there's no format conversion inside v4l2grab. It relies that libv4l will do the hard work of converting whatever input format into RGB24. Instead of just proceeding and writing wrong images, die if libv4l can't convert into RGB24. Signed-off-by: Mauro Carvalho Chehab --- v4l2-apps/test/v4l2grab.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'v4l2-apps') diff --git a/v4l2-apps/test/v4l2grab.c b/v4l2-apps/test/v4l2grab.c index 20692117e..153a0dd30 100644 --- a/v4l2-apps/test/v4l2grab.c +++ b/v4l2-apps/test/v4l2grab.c @@ -72,6 +72,13 @@ int main(int argc, char **argv) fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_RGB24; fmt.fmt.pix.field = V4L2_FIELD_INTERLACED; xioctl(fd, VIDIOC_S_FMT, &fmt); + if (fmt.fmt.pix.pixelformat != V4L2_PIX_FMT_RGB24) { + printf("Libv4l didn't accept RGB24 format. Can't proceed.\n"); + exit(EXIT_FAILURE); + } + if ((fmt.fmt.pix.width != 640) || (fmt.fmt.pix.height != 480)) + printf("Warning: driver is sending image at %dx%d\n", + fmt.fmt.pix.width, fmt.fmt.pix.height); CLEAR(req); req.count = 2; -- cgit v1.2.3