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author | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2020-03-04 10:21:39 +0100 |
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committer | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2020-04-14 10:31:49 +0200 |
commit | 54f38fcae536ea202ce7d6a359521492fba30c1f (patch) | |
tree | dd1a2b36d8de0b13702f2716526ad3b91650e090 /Documentation/media/uapi/v4l/v4l2grab.c.rst | |
parent | 5dfb8db56b273740a76e8687ee7efb4b2c0ec83b (diff) | |
download | linux-stable-54f38fcae536ea202ce7d6a359521492fba30c1f.tar.gz linux-stable-54f38fcae536ea202ce7d6a359521492fba30c1f.tar.bz2 linux-stable-54f38fcae536ea202ce7d6a359521492fba30c1f.zip |
media: docs: move uAPI book to userspace-api/media
Since 2017, there is an space reserved for userspace API,
created by changeset 1d596dee3862 ("docs: Create a user-space API guide").
As the media subsystem was one of the first subsystems to use
Sphinx, until this patch, we were keeping things on a separate
place.
Let's just use the new location, as having all uAPI altogether
will likely make things easier for developers.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Diffstat (limited to 'Documentation/media/uapi/v4l/v4l2grab.c.rst')
-rw-r--r-- | Documentation/media/uapi/v4l/v4l2grab.c.rst | 176 |
1 files changed, 0 insertions, 176 deletions
diff --git a/Documentation/media/uapi/v4l/v4l2grab.c.rst b/Documentation/media/uapi/v4l/v4l2grab.c.rst deleted file mode 100644 index e76c5fb7bd19..000000000000 --- a/Documentation/media/uapi/v4l/v4l2grab.c.rst +++ /dev/null @@ -1,176 +0,0 @@ -.. Permission is granted to copy, distribute and/or modify this -.. document under the terms of the GNU Free Documentation License, -.. Version 1.1 or any later version published by the Free Software -.. Foundation, with no Invariant Sections, no Front-Cover Texts -.. and no Back-Cover Texts. A copy of the license is included at -.. Documentation/media/uapi/fdl-appendix.rst. -.. -.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections - -file: media/v4l/v4l2grab.c -========================== - -.. code-block:: c - - /* V4L2 video picture grabber - Copyright (C) 2009 Mauro Carvalho Chehab <mchehab@kernel.org> - - 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 <stdio.h> - #include <stdlib.h> - #include <string.h> - #include <fcntl.h> - #include <errno.h> - #include <sys/ioctl.h> - #include <sys/types.h> - #include <sys/time.h> - #include <sys/mman.h> - #include <linux/videodev2.h> - #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); - 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; - 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; - } |