That simple app reads data from SDR device using libv4l2 and writes
it in float format to standard output. Stream is converted to
complex float format by libv4l.
sdr-fetch is based of v4l2grab v4l2 test app.
Signed-off-by: Antti Palosaari <cr...@iki.fi>
---
contrib/test/Makefile.am | 6 +-
contrib/test/sdr_fetch.c | 221 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 226 insertions(+), 1 deletion(-)
create mode 100644 contrib/test/sdr_fetch.c
diff --git a/contrib/test/Makefile.am b/contrib/test/Makefile.am
index 80c7665..3332b63 100644
--- a/contrib/test/Makefile.am
+++ b/contrib/test/Makefile.am
@@ -7,7 +7,8 @@ noinst_PROGRAMS = \
v4l2grab \
driver-test \
stress-buffer \
- capture-example
+ capture-example \
+ sdr-fetch
if HAVE_X11
noinst_PROGRAMS += pixfmt-test
@@ -45,6 +46,9 @@ stress_buffer_SOURCES = stress-buffer.c
capture_example_SOURCES = capture-example.c
+sdr_fetch_SOURCES = sdr_fetch.c
+sdr_fetch_LDADD = ../../lib/libv4l2/libv4l2.la
../../lib/libv4lconvert/libv4lconvert.la
+
ioctl-test.c: ioctl-test.h
sync-with-kernel:
diff --git a/contrib/test/sdr_fetch.c b/contrib/test/sdr_fetch.c
new file mode 100644
index 0000000..477d11e
--- /dev/null
+++ b/contrib/test/sdr_fetch.c
@@ -0,0 +1,221 @@
+/*
+ * SDR fetch
+ *
+ * Copyright (C) 2013 Antti Palosaari <cr...@iki.fi>
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <signal.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/mman.h>
+#include <argp.h>
+#include <linux/videodev2.h>
+#include "../../lib/include/libv4l2.h"
+
+/* signal handler to stop app */
+static int running;
+
+void signal_handler(int sig)
+{
+ running = 0;
+ return;
+}
+
+#define CLEAR(x) memset(&(x), 0, sizeof(x))
+
+struct buffer {
+ void *start;
+ size_t length;
+};
+
+static void xioctl(int fh, unsigned long int request, void *arg)
+{
+ int ret;
+
+ do {
+ ret = v4l2_ioctl(fh, request, arg);
+ } while (ret == -1 && ((errno == EINTR) || (errno == EAGAIN)));
+ if (ret == -1) {
+ fprintf(stderr, "error %d, %s\n", errno, strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+}
+
+static int stream(char *dev_name)
+{
+ struct v4l2_format fmt;
+ struct v4l2_buffer buf;
+ struct v4l2_requestbuffers req;
+ enum v4l2_buf_type type;
+ struct buffer *buffers;
+ struct timeval tv;
+ fd_set fds;
+ int ret, i, buffers_count, fd = -1;
+
+ fd = v4l2_open(dev_name, O_RDWR | O_NONBLOCK, 0);
+ if (fd < 0) {
+ perror("Cannot open device");
+ exit(EXIT_FAILURE);
+ }
+
+ /* ask float format from libv4l2 */
+ CLEAR(fmt);
+ fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_SDR_FLOAT;
+ xioctl(fd, VIDIOC_S_FMT, &fmt);
+ if (fmt.fmt.pix.pixelformat != V4L2_PIX_FMT_SDR_FLOAT) {
+ perror("Libv4l didn't accept FLOAT format");
+ exit(EXIT_FAILURE);
+ }
+
+ /* request buffers */
+ CLEAR(req);
+ req.count = 8;
+ req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ req.memory = V4L2_MEMORY_MMAP;
+ xioctl(fd, VIDIOC_REQBUFS, &req);
+
+ buffers = calloc(req.count, sizeof(*buffers));
+
+ /* v4l2_mmap buffers */
+ for (buffers_count = 0; buffers_count < req.count; buffers_count++) {
+ CLEAR(buf);
+ buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ buf.memory = V4L2_MEMORY_MMAP;
+ buf.index = buffers_count;
+ xioctl(fd, VIDIOC_QUERYBUF, &buf);
+
+ buffers[buffers_count].length = buf.length;
+ buffers[buffers_count].start = v4l2_mmap(NULL, buf.length,
+ PROT_READ | PROT_WRITE, MAP_SHARED,
+ fd, buf.m.offset);
+
+ if (buffers[buffers_count].start == MAP_FAILED) {
+ perror("mmap");
+ exit(EXIT_FAILURE);
+ }
+ }
+
+ /* enqueue all memory mapped buffers */
+ for (i = 0; i < buffers_count; i++) {
+ CLEAR(buf);
+ buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ buf.memory = V4L2_MEMORY_MMAP;
+ buf.index = i;
+ xioctl(fd, VIDIOC_QBUF, &buf);
+ }
+
+ /* start streaming */
+ type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ xioctl(fd, VIDIOC_STREAMON, &type);
+
+ /* data streaming */
+ while (running) {
+ /* wait data arrives from device */
+ do {
+ FD_ZERO(&fds);
+ FD_SET(fd, &fds);
+
+ /* timeout */
+ tv.tv_sec = 2;
+ tv.tv_usec = 0;
+
+ ret = select(fd + 1, &fds, NULL, NULL, &tv);
+ } while ((ret == -1 && (errno == EINTR)));
+ if (ret == -1) {
+ perror("select");
+ return errno;
+ }
+
+ CLEAR(buf);
+ buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ buf.memory = V4L2_MEMORY_MMAP;
+ xioctl(fd, VIDIOC_DQBUF, &buf);
+
+ /* write data to standard output */
+ fwrite(buffers[buf.index].start, buf.bytesused, 1, stdout);
+
+ xioctl(fd, VIDIOC_QBUF, &buf);
+ }
+
+ /* stop streaming */
+ type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ xioctl(fd, VIDIOC_STREAMOFF, &type);
+
+ /* v4l2_munmap buffers */
+ for (i = buffers_count - 1; i >= 0; i--)
+ v4l2_munmap(buffers[i].start, buffers[i].length);
+
+ free(buffers);
+
+ v4l2_close(fd);
+
+ return 0;
+}
+
+const char *argp_program_version = "SDR fetch version " V4L_UTILS_VERSION;
+const char *argp_program_bug_address = "Antti Palosaari <cr...@iki.fi>";
+
+static const char doc[] =
+ "\n"
+ "Reads data from SDR device using libv4l2 and writes it in float format
to standard output\n";
+
+static const struct argp_option options[] = {
+ {"device", 'd', "DEV", 0, "SDR device (default:
/dev/video0)", 0},
+ { 0, 0, 0, 0, 0, 0 }
+};
+
+/* Static vars to store the parameters */
+static char *dev_name = "/dev/video0";
+
+static error_t parse_opt(int k, char *arg, struct argp_state *state)
+{
+ switch (k) {
+ case 'd':
+ dev_name = arg;
+ break;
+ default:
+ return ARGP_ERR_UNKNOWN;
+ }
+ return 0;
+}
+
+static struct argp argp = {
+ .options = options,
+ .parser = parse_opt,
+ .doc = doc,
+};
+
+int main(int argc, char **argv)
+{
+ /* arguments */
+ argp_parse(&argp, argc, argv, 0, 0, 0);
+
+ /* signal handler */
+ running = 1;
+ signal(SIGQUIT, signal_handler);
+ signal(SIGINT, signal_handler);
+
+ return stream(dev_name);
+}
--
1.8.4.2
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