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Diffstat (limited to 'v4l2-apps/libv4l2util/v4l2_driver.c')
-rw-r--r--v4l2-apps/libv4l2util/v4l2_driver.c804
1 files changed, 804 insertions, 0 deletions
diff --git a/v4l2-apps/libv4l2util/v4l2_driver.c b/v4l2-apps/libv4l2util/v4l2_driver.c
new file mode 100644
index 000000000..94f826968
--- /dev/null
+++ b/v4l2-apps/libv4l2util/v4l2_driver.c
@@ -0,0 +1,804 @@
+/*
+ Copyright (C) 2006 Mauro Carvalho Chehab <mchehab@infradead.org>
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <malloc.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <stdlib.h>
+
+#include "v4l2_driver.h"
+
+/****************************************************************************
+ Auxiliary routines
+ ****************************************************************************/
+static int xioctl (int fd, int request, void *arg)
+{
+ int r;
+
+ do r = ioctl (fd, request, arg);
+ while (-1 == r && EINTR == errno);
+
+ return r;
+}
+
+static void free_list(struct drv_list **list_ptr)
+{
+ struct drv_list *prev,*cur;
+
+ if (list_ptr==NULL)
+ return;
+
+ prev=*list_ptr;
+ if (prev==NULL)
+ return;
+
+ do {
+ cur=prev->next;
+ if (prev->curr)
+ free (prev->curr); // Free data
+ free (prev); // Free list
+ prev=cur;
+ } while (prev);
+
+ *list_ptr=NULL;
+}
+
+/****************************************************************************
+ Auxiliary Arrays to aid debug messages
+ ****************************************************************************/
+char *v4l2_field_names[] = {
+ [V4L2_FIELD_ANY] = "any",
+ [V4L2_FIELD_NONE] = "none",
+ [V4L2_FIELD_TOP] = "top",
+ [V4L2_FIELD_BOTTOM] = "bottom",
+ [V4L2_FIELD_INTERLACED] = "interlaced",
+ [V4L2_FIELD_SEQ_TB] = "seq-tb",
+ [V4L2_FIELD_SEQ_BT] = "seq-bt",
+ [V4L2_FIELD_ALTERNATE] = "alternate",
+};
+
+char *v4l2_type_names[] = {
+ [V4L2_BUF_TYPE_VIDEO_CAPTURE] = "video-cap",
+ [V4L2_BUF_TYPE_VIDEO_OVERLAY] = "video-over",
+ [V4L2_BUF_TYPE_VIDEO_OUTPUT] = "video-out",
+ [V4L2_BUF_TYPE_VBI_CAPTURE] = "vbi-cap",
+ [V4L2_BUF_TYPE_VBI_OUTPUT] = "vbi-out",
+ [V4L2_BUF_TYPE_SLICED_VBI_CAPTURE] = "sliced-vbi-cap",
+ [V4L2_BUF_TYPE_SLICED_VBI_OUTPUT] = "slicec-vbi-out",
+};
+
+static char *v4l2_memory_names[] = {
+ [V4L2_MEMORY_MMAP] = "mmap",
+ [V4L2_MEMORY_USERPTR] = "userptr",
+ [V4L2_MEMORY_OVERLAY] = "overlay",
+};
+
+#define ARRAY_SIZE(arr) (sizeof(arr)/sizeof(*arr))
+#define prt_names(a,arr) (((a)<ARRAY_SIZE(arr))?arr[a]:"unknown")
+
+char *prt_caps(uint32_t caps)
+{
+ static char s[4096]="";
+
+ if (V4L2_CAP_VIDEO_CAPTURE & caps)
+ strcat (s,"CAPTURE ");
+ if (V4L2_CAP_VIDEO_OUTPUT & caps)
+ strcat (s,"OUTPUT ");
+ if (V4L2_CAP_VIDEO_OVERLAY & caps)
+ strcat (s,"OVERLAY ");
+ if (V4L2_CAP_VBI_CAPTURE & caps)
+ strcat (s,"VBI_CAPTURE ");
+ if (V4L2_CAP_VBI_OUTPUT & caps)
+ strcat (s,"VBI_OUTPUT ");
+ if (V4L2_CAP_SLICED_VBI_CAPTURE & caps)
+ strcat (s,"SLICED_VBI_CAPTURE ");
+ if (V4L2_CAP_SLICED_VBI_OUTPUT & caps)
+ strcat (s,"SLICED_VBI_OUTPUT ");
+ if (V4L2_CAP_RDS_CAPTURE & caps)
+ strcat (s,"RDS_CAPTURE ");
+ if (V4L2_CAP_TUNER & caps)
+ strcat (s,"TUNER ");
+ if (V4L2_CAP_AUDIO & caps)
+ strcat (s,"AUDIO ");
+ if (V4L2_CAP_RADIO & caps)
+ strcat (s,"RADIO ");
+ if (V4L2_CAP_READWRITE & caps)
+ strcat (s,"READWRITE ");
+ if (V4L2_CAP_ASYNCIO & caps)
+ strcat (s,"ASYNCIO ");
+ if (V4L2_CAP_STREAMING & caps)
+ strcat (s,"STREAMING ");
+
+ return s;
+}
+
+static void prt_buf_info(char *name,struct v4l2_buffer *p)
+{
+ struct v4l2_timecode *tc=&p->timecode;
+
+ printf ("%s: %02ld:%02d:%02d.%08ld index=%d, type=%s, "
+ "bytesused=%d, flags=0x%08x, "
+ "field=%s, sequence=%d, memory=%s, offset=0x%08x, length=%d\n",
+ name, (p->timestamp.tv_sec/3600),
+ (int)(p->timestamp.tv_sec/60)%60,
+ (int)(p->timestamp.tv_sec%60),
+ p->timestamp.tv_usec,
+ p->index,
+ prt_names(p->type,v4l2_type_names),
+ p->bytesused,p->flags,
+ prt_names(p->field,v4l2_field_names),
+ p->sequence,
+ prt_names(p->memory,v4l2_memory_names),
+ p->m.offset,
+ p->length);
+ tc=&p->timecode;
+ printf ("\tTIMECODE: %02d:%02d:%02d type=%d, "
+ "flags=0x%08x, frames=%d, userbits=0x%08x\n",
+ tc->hours,tc->minutes,tc->seconds,
+ tc->type, tc->flags, tc->frames, *(uint32_t *) tc->userbits);
+}
+
+/****************************************************************************
+ Open V4L2 devices
+ ****************************************************************************/
+int v4l2_open (char *device, int debug, struct v4l2_driver *drv)
+{
+ int ret;
+
+ memset(drv,0,sizeof(*drv));
+
+ drv->debug=debug;
+
+ if ((drv->fd = open(device, O_RDWR )) < 0) {
+ return(-errno);
+ }
+
+ ret=xioctl(drv->fd,VIDIOC_QUERYCAP,(void *) &drv->cap);
+ if (!ret && drv->debug) {
+ printf ("driver=%s, card=%s, bus=%s, version=%d.%d.%d, "
+ "capabilities=%s\n",
+ drv->cap.driver,drv->cap.card,drv->cap.bus_info,
+ (drv->cap.version >> 16) & 0xff,
+ (drv->cap.version >> 8) & 0xff,
+ drv->cap.version & 0xff,
+ prt_caps(drv->cap.capabilities));
+
+
+ }
+ return ret;
+}
+
+
+/****************************************************************************
+ V4L2 Eumberations
+ ****************************************************************************/
+int v4l2_enum_stds (struct v4l2_driver *drv)
+{
+ struct v4l2_standard *p=NULL;
+ struct drv_list *list;
+ int ok=0,ret,i;
+ v4l2_std_id id;
+
+ free_list(&drv->stds);
+
+ list=drv->stds=calloc(1,sizeof(*drv->stds));
+ assert (list!=NULL);
+
+ for (i=0; ok==0; i++) {
+ p=calloc(1,sizeof(*p));
+ assert (p);
+
+ p->index=i;
+ ok=xioctl(drv->fd,VIDIOC_ENUMSTD,p);
+ if (ok<0) {
+ ok=-errno;
+ free(p);
+ break;
+ }
+ if (drv->debug) {
+ printf ("STANDARD: index=%d, id=0x%08x, name=%s, fps=%.3f, "
+ "framelines=%d\n", p->index,
+ (unsigned int)p->id, p->name,
+ 1.*p->frameperiod.denominator/p->frameperiod.numerator,
+ p->framelines);
+ }
+ if (list->curr) {
+ list->next=calloc(1,sizeof(*list->next));
+ list=list->next;
+ assert (list!=NULL);
+ }
+ list->curr=p;
+ }
+ if (i>0 && ok==-EINVAL)
+ return 0;
+
+ return ok;
+}
+
+int v4l2_enum_input (struct v4l2_driver *drv)
+{
+ struct v4l2_input *p=NULL;
+ struct drv_list *list;
+ int ok=0,ret,i;
+ v4l2_std_id id;
+
+ free_list(&drv->inputs);
+
+ list=drv->inputs=calloc(1,sizeof(*drv->inputs));
+ assert (list!=NULL);
+
+ for (i=0; ok==0; i++) {
+ p=calloc(1,sizeof(*p));
+ assert (p);
+ p->index=i;
+ ok=xioctl(drv->fd,VIDIOC_ENUMINPUT,p);
+ if (ok<0) {
+ ok=errno;
+ free(p);
+ break;
+ }
+ if (drv->debug) {
+ printf ("INPUT: index=%d, name=%s, type=%d, audioset=%d, "
+ "tuner=%d, std=%08x, status=%d\n",
+ p->index,p->name,p->type,p->audioset, p->tuner,
+ (unsigned int)p->std, p->status);
+ }
+ if (list->curr) {
+ list->next=calloc(1,sizeof(*list->next));
+ list=list->next;
+ assert (list!=NULL);
+ }
+ list->curr=p;
+ }
+ if (i>0 && ok==-EINVAL)
+ return 0;
+ return ok;
+}
+
+int v4l2_enum_fmt (struct v4l2_driver *drv, enum v4l2_buf_type type)
+{
+ struct v4l2_fmtdesc *p=NULL;
+ struct v4l2_format fmt;
+ struct drv_list *list;
+ int ok=0,ret,i;
+ v4l2_std_id id;
+
+ free_list(&drv->fmt_caps);
+
+ list=drv->fmt_caps=calloc(1,sizeof(*drv->fmt_caps));
+ assert (list!=NULL);
+
+ for (i=0; ok==0; i++) {
+ p=calloc(1,sizeof(*p));
+ assert (p!=NULL);
+
+ p->index=i;
+ p->type =type;
+
+ ok=xioctl(drv->fd,VIDIOC_ENUM_FMT,p);
+ if (ok<0) {
+ ok=errno;
+ free(p);
+ break;
+ }
+ if (drv->debug) {
+ printf ("FORMAT: index=%d, type=%d, flags=%d, description='%s'\n\t"
+ "fourcc=%c%c%c%c\n",
+ p->index, p->type, p->flags,p->description,
+ p->pixelformat & 0xff,
+ (p->pixelformat >> 8) & 0xff,
+ (p->pixelformat >> 16) & 0xff,
+ (p->pixelformat >> 24) & 0xff
+ );
+ }
+ if (list->curr) {
+ list->next=calloc(1,sizeof(*list->next));
+ list=list->next;
+ assert (list!=NULL);
+ }
+ list->curr=p;
+ }
+ if (i>0 && ok==-EINVAL)
+ return 0;
+ return ok;
+}
+
+/****************************************************************************
+ Set routines - currently, it also checks results with Get
+ ****************************************************************************/
+int v4l2_setget_std (struct v4l2_driver *drv, enum v4l2_direction dir, v4l2_std_id *id)
+{
+ v4l2_std_id s_id=*id;
+ int ret=0;
+ char s[256];
+
+ if (dir & V4L2_SET) {
+ ret=xioctl(drv->fd,VIDIOC_S_STD,&s_id);
+ if (ret<0) {
+ ret=errno;
+
+ sprintf (s,"while trying to set STD to %08x",
+ (unsigned int) *id);
+ perror(s);
+ }
+ }
+
+ if (dir & V4L2_GET) {
+ ret=xioctl(drv->fd,VIDIOC_G_STD,&s_id);
+ if (ret<0) {
+ ret=errno;
+ perror ("while trying to get STD id");
+ }
+ }
+
+ if (dir == V4L2_SET_GET) {
+ if (*id & s_id) {
+ if (*id != s_id) {
+ printf ("Warning: Received a std subset (%08x"
+ " std) while trying to adjust to %08x\n",
+ (unsigned int) s_id,(unsigned int) *id);
+ }
+ } else {
+ fprintf (stderr,"Error: Received %08x std while trying"
+ " to adjust to %08x\n",
+ (unsigned int) s_id,(unsigned int) *id);
+ }
+ }
+ return ret;
+}
+
+int v4l2_setget_input (struct v4l2_driver *drv, enum v4l2_direction dir, struct v4l2_input *input)
+{
+ int ok=0,ret,i;
+ unsigned int inp=input->index;
+ char s[256];
+
+ if (dir & V4L2_SET) {
+ ret=xioctl(drv->fd,VIDIOC_S_INPUT,input);
+ if (ret<0) {
+ ret=errno;
+ sprintf (s,"while trying to set INPUT to %d\n", inp);
+ perror(s);
+ }
+ }
+
+ if (dir & V4L2_GET) {
+ ret=xioctl(drv->fd,VIDIOC_G_INPUT,input);
+ if (ret<0) {
+ perror ("while trying to get INPUT id\n");
+ }
+ }
+
+ if (dir & V4L2_SET_GET) {
+ if (input->index != inp) {
+ printf ("Input is different than expected (received %i, set %i)\n",
+ inp, input->index);
+ }
+ }
+
+ return ok;
+}
+
+int v4l2_gettryset_fmt_cap (struct v4l2_driver *drv, enum v4l2_direction dir,
+ struct v4l2_format *fmt,uint32_t width, uint32_t height,
+ uint32_t pixelformat, enum v4l2_field field)
+{
+ struct v4l2_pix_format *pix=&(fmt->fmt.pix);
+ int ret=0;
+
+ fmt->type=V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ if (dir == V4L2_GET) {
+ ret=xioctl(drv->fd,VIDIOC_G_FMT,fmt);
+ if (ret < 0) {
+ ret=errno;
+ perror("VIDIOC_G_FMT failed\n");
+ }
+ return ret;
+ } else if (dir & (~(V4L2_TRY|V4L2_SET)) ) {
+ perror ("Invalid direction\n");
+ return EINVAL;
+ }
+
+ if (dir & (V4L2_TRY|V4L2_SET)) {
+ pix->width = width;
+ pix->height = height;
+ pix->pixelformat = pixelformat;
+ pix->field = field;
+ /*
+ enum v4l2_colorspace colorspace;
+ */
+
+ if (dir & V4L2_TRY) {
+ ret=xioctl(drv->fd,VIDIOC_TRY_FMT,fmt);
+ if (ret < 0) {
+ perror("VIDIOC_TRY_FMT failed\n");
+ }
+ }
+
+ if (dir & V4L2_SET) {
+ ret=xioctl(drv->fd,VIDIOC_S_FMT,fmt);
+ if (ret < 0) {
+ perror("VIDIOC_S_FMT failed\n");
+ }
+ drv->sizeimage=pix->sizeimage;
+ }
+
+ if (pix->pixelformat != pixelformat) {
+ fprintf(stderr,"Error: asked for format %d, received %d",pixelformat,
+ pix->pixelformat);
+ }
+
+ if (pix->width != width) {
+ fprintf(stderr,"Error: asked for format %d, received %d\n",width,
+ pix->width);
+ }
+
+ if (pix->height != height) {
+ fprintf(stderr,"Error: asked for format %d, received %d\n",height,
+ pix->height);
+ }
+
+ if (pix->bytesperline == 0 ) {
+ fprintf(stderr,"Error: bytesperline = 0\n");
+ }
+
+ if (pix->sizeimage == 0 ) {
+ fprintf(stderr,"Error: sizeimage = 0\n");
+ }
+ }
+
+ if (drv->debug)
+ printf( "FMT SET: %dx%d, fourcc=%c%c%c%c, %d bytes/line,"
+ " %d bytes/frame, colorspace=0x%08x\n",
+ pix->width,pix->height,
+ pix->pixelformat & 0xff,
+ (pix->pixelformat >> 8) & 0xff,
+ (pix->pixelformat >> 16) & 0xff,
+ (pix->pixelformat >> 24) & 0xff,
+ pix->bytesperline,
+ pix->sizeimage,
+ pix->colorspace);
+
+ return 0;
+}
+
+/****************************************************************************
+ Get routines
+ ****************************************************************************/
+int v4l2_get_parm (struct v4l2_driver *drv)
+{
+ int ret;
+ struct v4l2_captureparm *c;
+
+ drv->parm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ if ((ret=xioctl(drv->fd,VIDIOC_G_PARM,&drv->parm))>=0) {
+ c=&drv->parm.parm.capture;
+ printf ("PARM: capability=%d, capturemode=%d, %.3f fps "
+ "ext=%x, readbuf=%d\n",
+ c->capability,
+ c->capturemode,
+ c->timeperframe.denominator*1./c->timeperframe.numerator,
+ c->extendedmode, c->readbuffers);
+ } else {
+ ret=errno;
+
+ perror ("VIDIOC_G_PARM");
+ }
+
+ return ret;
+}
+
+/****************************************************************************
+ Queue and stream control
+ ****************************************************************************/
+
+int v4l2_free_bufs(struct v4l2_driver *drv)
+{
+ unsigned int i;
+
+ if (!drv->n_bufs)
+ return 0;
+
+ /* Requests the driver to free all buffers */
+ drv->reqbuf.count = 0;
+ drv->reqbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ drv->reqbuf.memory = V4L2_MEMORY_MMAP;
+
+ /* stop capture */
+ if (xioctl(drv->fd,VIDIOC_STREAMOFF,&drv->reqbuf.type)<0)
+ return errno;
+
+ sleep (1); // FIXME: Should check if all buffers are stopped
+
+/* V4L2 API says REQBUFS with count=0 should be used to release buffer.
+ However, video-buf.c doesn't implement it.
+ */
+#if 0
+ if (xioctl(drv->fd,VIDIOC_REQBUFS,&drv->reqbuf)<0) {
+ perror("reqbufs while freeing buffers");
+ return errno;
+ }
+#endif
+
+ if (drv->reqbuf.count != 0) {
+ fprintf(stderr,"REQBUFS returned %d buffers while asking for freeing it!\n",
+ drv->reqbuf.count);
+ }
+
+ for (i = 0; i < drv->n_bufs; i++) {
+ if (drv->bufs[i].length)
+ munmap(drv->bufs[i].start, drv->bufs[i].length);
+ if (drv->v4l2_bufs[i])
+ free (drv->v4l2_bufs[i]);
+ }
+
+ free(drv->v4l2_bufs);
+ free(drv->bufs);
+
+ drv->v4l2_bufs=NULL;
+ drv->bufs=NULL;
+ drv->n_bufs=0;
+
+ return 0;
+}
+
+int v4l2_mmap_bufs(struct v4l2_driver *drv, unsigned int num_buffers)
+{
+ /* Frees previous allocations, if required */
+ v4l2_free_bufs(drv);
+
+ if (drv->sizeimage==0) {
+ fprintf(stderr,"Image size is zero! Can't proceed\n");
+ return -1;
+ }
+ /* Requests the specified number of buffers */
+ drv->reqbuf.count = num_buffers;
+ drv->reqbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ drv->reqbuf.memory = V4L2_MEMORY_MMAP;
+
+ if (xioctl(drv->fd,VIDIOC_REQBUFS,&drv->reqbuf)<0) {
+ perror("reqbufs");
+ return errno;
+ }
+
+ if (drv->debug)
+ printf ("REQBUFS: count=%d, type=%s, memory=%s\n",
+ drv->reqbuf.count,
+ prt_names(drv->reqbuf.type,v4l2_type_names),
+ prt_names(drv->reqbuf.memory,v4l2_memory_names));
+
+ /* Allocates the required number of buffers */
+ drv->v4l2_bufs=calloc(drv->reqbuf.count, sizeof(*drv->v4l2_bufs));
+ assert(drv->v4l2_bufs!=NULL);
+ drv->bufs=calloc(drv->reqbuf.count, sizeof(*drv->bufs));
+ assert(drv->bufs!=NULL);
+
+ for (drv->n_bufs = 0; drv->n_bufs < drv->reqbuf.count; drv->n_bufs++) {
+ struct v4l2_buffer *p;
+ struct v4l2_timecode *tc;
+
+ /* Requests kernel buffers to be mmapped */
+ p=drv->v4l2_bufs[drv->n_bufs]=calloc(1,sizeof(*p));
+ assert (p!=NULL);
+ p->index = drv->n_bufs;
+ p->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ p->memory = V4L2_MEMORY_MMAP;
+ if (xioctl(drv->fd,VIDIOC_QUERYBUF,p)<0) {
+ int ret=errno;
+ perror("querybuf");
+
+ free (drv->v4l2_bufs[drv->n_bufs]);
+
+ v4l2_free_bufs(drv);
+ return ret;
+ }
+
+ if (drv->debug)
+ prt_buf_info("QUERYBUF",p);
+
+ if (drv->sizeimage != p->length) {
+ if (drv->sizeimage < p->length) {
+ fprintf (stderr, "QUERYBUF: ERROR: VIDIOC_S_FMT said buffer should have %d size, but received %d from QUERYBUF!\n",
+ drv->sizeimage, p->length);
+ } else {
+ fprintf (stderr, "QUERYBUF: Expecting %d size, received %d buff length\n",
+ drv->sizeimage, p->length);
+ }
+ }
+
+ drv->bufs[drv->n_bufs].length = p->length;
+ drv->bufs[drv->n_bufs].start = mmap (NULL, /* start anywhere */
+ p->length,
+ PROT_READ | PROT_WRITE, /* required */
+ MAP_SHARED, /* recommended */
+ drv->fd, p->m.offset);
+
+
+ if (MAP_FAILED == drv->bufs[drv->n_bufs].start) {
+ perror("mmap");
+
+ free (drv->v4l2_bufs[drv->n_bufs]);
+ v4l2_free_bufs(drv);
+ return errno;
+ }
+ }
+
+ return 0;
+}
+
+int v4l2_rcvbuf(struct v4l2_driver *drv, v4l2_recebe_buffer *rec_buf)
+{
+ int ret;
+
+ struct v4l2_buffer buf;
+ memset (&buf, 0, sizeof(buf));
+
+ buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ buf.memory = V4L2_MEMORY_MMAP;
+
+ if (-1 == xioctl (drv->fd, VIDIOC_DQBUF, &buf)) {
+ switch (errno) {
+ case EAGAIN:
+ return 0;
+
+ case EIO:
+ /* Could ignore EIO, see spec. */
+
+ /* fall through */
+
+ default:
+ perror ("dqbuf");
+ return errno;
+ }
+ }
+ prt_buf_info("DQBUF",&buf);
+
+ assert (buf.index < drv->n_bufs);
+
+ ret = rec_buf (&buf,&drv->bufs[buf.index]);
+
+ if (ret) {
+ v4l2_free_bufs(drv);
+ return ret;
+ }
+
+ if (-1 == xioctl (drv->fd, VIDIOC_QBUF, &buf)) {
+ perror ("qbuf");
+ return errno;
+ }
+ return 0;
+}
+
+
+int v4l2_start_streaming(struct v4l2_driver *drv)
+{
+ uint32_t i;
+ struct v4l2_buffer buf;
+
+ if (drv->debug)
+ printf("Activating %d queues\n", drv->n_bufs);
+ for (i = 0; i < drv->n_bufs; i++) {
+ int res;
+
+ memset(&buf, 0, sizeof(buf));
+ buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ buf.memory = V4L2_MEMORY_MMAP;
+ buf.index = i;
+
+ res = xioctl (drv->fd, VIDIOC_QBUF, &buf);
+
+ if (!res)
+ prt_buf_info("QBUF",&buf);
+ else {
+ perror("qbuf");
+ return errno;
+ }
+ }
+
+ /* Activates stream */
+ if (drv->debug)
+ printf("Enabling streaming\n");
+
+ if (xioctl(drv->fd,VIDIOC_STREAMON,&drv->reqbuf.type)<0)
+ return errno;
+
+ return 0;
+}
+
+int v4l2_stop_streaming(struct v4l2_driver *drv)
+{
+ v4l2_free_bufs(drv);
+
+ return 0;
+}
+
+/****************************************************************************
+ Close V4L2, disallocating all structs
+ ****************************************************************************/
+int v4l2_close (struct v4l2_driver *drv)
+{
+ v4l2_free_bufs(drv);
+
+ free_list(&drv->stds);
+ free_list(&drv->inputs);
+ free_list(&drv->fmt_caps);
+
+ return (close(drv->fd));
+}
+
+/****************************************************************************
+ Get/Set frequency
+ ****************************************************************************/
+
+int v4l2_getset_freq (struct v4l2_driver *drv, enum v4l2_direction dir,
+ double *freq)
+{
+ struct v4l2_tuner tun;
+ struct v4l2_frequency frq;
+ double d = 62500;
+ unsigned int counter;
+
+ memset(&tun, 0, sizeof(tun));
+
+ if (-1 == xioctl (drv->fd, VIDIOC_G_TUNER, &tun)) {
+ perror ("g_tuner");
+ printf("Assuming 62.5 kHz step\n");
+ } else {
+ if (tun.capability & V4L2_TUNER_CAP_LOW)
+ d=62.5;
+ }
+
+ if (drv->debug) {
+ if (tun.capability & V4L2_TUNER_CAP_LOW)
+ printf("62.5 Hz step\n");
+ else
+ printf("62.5 kHz step\n");
+ }
+
+ memset(&frq, 0, sizeof(frq));
+
+ frq.type = V4L2_TUNER_ANALOG_TV;
+
+ if (dir & V4L2_GET) {
+ if (-1 == xioctl (drv->fd, VIDIOC_G_FREQUENCY, &frq)) {
+ perror ("s_frequency");
+ return errno;
+ }
+ *freq = frq.frequency * d;
+ if (drv->debug)
+ printf("board is at freq %4.3f MHz (%d)\n",
+ *freq/1000000, frq.frequency);
+ } else {
+ frq.frequency = (uint32_t)(((*freq)+d/2) / d);
+
+ if (-1 == xioctl (drv->fd, VIDIOC_S_FREQUENCY, &frq)) {
+ perror ("s_frequency");
+ return errno;
+ }
+ if (drv->debug)
+ printf("board set to freq %4.3f MHz (%d)\n",
+ *freq/1000000, frq.frequency);
+
+ }
+ return 0;
+}