gstreamer/sys/v4l2/v4l2src_calls.c
Tim-Philipp Müller a769e5e70a sys/v4l2/: When probing the formats and sizes a camera supports, make sure the best ones (highest resolution, prefere...
Original commit message from CVS:
* sys/v4l2/gstv4l2src.c:
* sys/v4l2/v4l2src_calls.c:
When probing the formats and sizes a camera supports, make
sure the best ones (highest resolution, prefered format)
end up at the beginning of the probed caps and the less
desirable ones at the end.  This is important because the
order within the caps matters for things like fixation and
negotiation, ie. what format is chosen in the end.
With recent kernels, the current probing code will end up
querying the supported sizes from lowest resolution to
highest resolution, adding them to the probed caps in that
order, resulting to v4l2src fixating to the lowest possible
resolution if downstream does not express a size preference.
Also make up a somewhat random ranking of prefered output
formats for the same reason. Fixes #485828.
2007-10-13 12:03:44 +00:00

1420 lines
42 KiB
C

/* GStreamer
*
* Copyright (C) 2002 Ronald Bultje <rbultje@ronald.bitfreak.net>
* 2006 Edgard Lima <edgard.lima@indt.org.br>
*
* v4l2src.c - system calls
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <string.h>
#include <errno.h>
#include "v4l2src_calls.h"
#include <sys/time.h>
#include <unistd.h>
#include "gstv4l2tuner.h"
GST_DEBUG_CATEGORY_EXTERN (v4l2src_debug);
#define GST_CAT_DEFAULT v4l2src_debug
/* lalala... */
#define GST_V4L2_SET_ACTIVE(element) (element)->buffer = GINT_TO_POINTER (-1)
#define GST_V4L2_SET_INACTIVE(element) (element)->buffer = NULL
#define DEBUG(format, args...) \
GST_CAT_DEBUG_OBJECT (\
v4l2src_debug, v4l2src, \
"V4L2SRC: " format, ##args)
/* On some systems MAP_FAILED seems to be missing */
#ifndef MAP_FAILED
#define MAP_FAILED ((caddr_t) -1)
#endif
#define GST_TYPE_V4L2_BUFFER (gst_v4l2_buffer_get_type())
#define GST_IS_V4L2_BUFFER(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_V4L2_BUFFER))
#define GST_V4L2_BUFFER(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_V4L2_BUFFER, GstV4l2Buffer))
static void
gst_v4l2_buffer_finalize (GstV4l2Buffer * buffer)
{
GstV4l2BufferPool *pool;
gboolean resuscitated = FALSE;
pool = buffer->pool;
GST_LOG ("finalizing buffer %d", buffer->vbuffer.index);
g_mutex_lock (pool->lock);
if (GST_BUFFER_SIZE (buffer) != 0)
/* BUFFER_SIZE is only set if the frame was dequeued */
pool->num_live_buffers--;
if (pool->running) {
if (ioctl (pool->video_fd, VIDIOC_QBUF, &buffer->vbuffer) < 0) {
GST_WARNING ("could not requeue buffer %d", buffer->vbuffer.index);
} else {
/* FIXME: check that the caps didn't change */
gst_buffer_ref (GST_BUFFER (buffer));
GST_BUFFER_SIZE (buffer) = 0;
pool->buffers[buffer->vbuffer.index] = buffer;
resuscitated = TRUE;
}
}
g_mutex_unlock (pool->lock);
if (!resuscitated) {
gst_mini_object_unref (GST_MINI_OBJECT (pool));
munmap (GST_BUFFER_DATA (buffer), buffer->vbuffer.length);
}
}
static void
gst_v4l2_buffer_init (GstV4l2Buffer * xvimage, gpointer g_class)
{
/* NOP */
}
static void
gst_v4l2_buffer_class_init (gpointer g_class, gpointer class_data)
{
GstMiniObjectClass *mini_object_class = GST_MINI_OBJECT_CLASS (g_class);
mini_object_class->finalize = (GstMiniObjectFinalizeFunction)
gst_v4l2_buffer_finalize;
}
static GType
gst_v4l2_buffer_get_type (void)
{
static GType _gst_v4l2_buffer_type;
if (G_UNLIKELY (_gst_v4l2_buffer_type == 0)) {
static const GTypeInfo v4l2_buffer_info = {
sizeof (GstBufferClass),
NULL,
NULL,
gst_v4l2_buffer_class_init,
NULL,
NULL,
sizeof (GstV4l2Buffer),
0,
(GInstanceInitFunc) gst_v4l2_buffer_init,
NULL
};
_gst_v4l2_buffer_type = g_type_register_static (GST_TYPE_BUFFER,
"GstV4l2Buffer", &v4l2_buffer_info, 0);
}
return _gst_v4l2_buffer_type;
}
static GstV4l2Buffer *
gst_v4l2_buffer_new (GstV4l2BufferPool * pool, guint index, GstCaps * caps)
{
GstV4l2Buffer *ret;
guint8 *data;
ret = (GstV4l2Buffer *) gst_mini_object_new (GST_TYPE_V4L2_BUFFER);
GST_LOG ("creating buffer %u, %p in pool %p", index, ret, pool);
ret->pool = pool;
gst_mini_object_ref (GST_MINI_OBJECT (pool));
memset (&ret->vbuffer, 0x00, sizeof (ret->vbuffer));
ret->vbuffer.index = index;
ret->vbuffer.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
ret->vbuffer.memory = V4L2_MEMORY_MMAP;
if (ioctl (pool->video_fd, VIDIOC_QUERYBUF, &ret->vbuffer) < 0)
goto querybuf_failed;
GST_LOG (" index: %u", ret->vbuffer.index);
GST_LOG (" type: %d", ret->vbuffer.type);
GST_LOG (" bytesused: %u", ret->vbuffer.bytesused);
GST_LOG (" flags: %08x", ret->vbuffer.flags);
GST_LOG (" field: %d", ret->vbuffer.field);
GST_LOG (" memory: %d", ret->vbuffer.memory);
if (ret->vbuffer.memory == V4L2_MEMORY_MMAP)
GST_LOG (" MMAP offset: %u", ret->vbuffer.m.offset);
GST_LOG (" length: %u", ret->vbuffer.length);
GST_LOG (" input: %u", ret->vbuffer.input);
data = mmap (0, ret->vbuffer.length,
PROT_READ | PROT_WRITE, MAP_SHARED, pool->video_fd,
ret->vbuffer.m.offset);
if (data == MAP_FAILED)
goto mmap_failed;
GST_BUFFER_DATA (ret) = data;
GST_BUFFER_SIZE (ret) = ret->vbuffer.length;
GST_BUFFER_FLAG_SET (ret, GST_BUFFER_FLAG_READONLY);
gst_buffer_set_caps (GST_BUFFER (ret), caps);
return ret;
/* ERRORS */
querybuf_failed:
{
gint errnosave = errno;
GST_WARNING ("Failed QUERYBUF: %s", g_strerror (errnosave));
gst_buffer_unref (GST_BUFFER (ret));
errno = errnosave;
return NULL;
}
mmap_failed:
{
gint errnosave = errno;
GST_WARNING ("Failed to mmap: %s", g_strerror (errnosave));
gst_buffer_unref (GST_BUFFER (ret));
errno = errnosave;
return NULL;
}
}
#define GST_TYPE_V4L2_BUFFER_POOL (gst_v4l2_buffer_pool_get_type())
#define GST_IS_V4L2_BUFFER_POOL(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_V4L2_BUFFER_POOL))
#define GST_V4L2_BUFFER_POOL(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_V4L2_BUFFER_POOL, GstV4l2BufferPool))
static void
gst_v4l2_buffer_pool_finalize (GstV4l2BufferPool * pool)
{
g_mutex_free (pool->lock);
pool->lock = NULL;
if (pool->video_fd >= 0)
close (pool->video_fd);
if (pool->buffers)
g_free (pool->buffers);
pool->buffers = NULL;
}
static void
gst_v4l2_buffer_pool_init (GstV4l2BufferPool * pool, gpointer g_class)
{
pool->lock = g_mutex_new ();
pool->running = FALSE;
pool->num_live_buffers = 0;
}
static void
gst_v4l2_buffer_pool_class_init (gpointer g_class, gpointer class_data)
{
GstMiniObjectClass *mini_object_class = GST_MINI_OBJECT_CLASS (g_class);
mini_object_class->finalize = (GstMiniObjectFinalizeFunction)
gst_v4l2_buffer_pool_finalize;
}
static GType
gst_v4l2_buffer_pool_get_type (void)
{
static GType _gst_v4l2_buffer_pool_type;
if (G_UNLIKELY (_gst_v4l2_buffer_pool_type == 0)) {
static const GTypeInfo v4l2_buffer_pool_info = {
sizeof (GstBufferClass),
NULL,
NULL,
gst_v4l2_buffer_pool_class_init,
NULL,
NULL,
sizeof (GstV4l2BufferPool),
0,
(GInstanceInitFunc) gst_v4l2_buffer_pool_init,
NULL
};
_gst_v4l2_buffer_pool_type = g_type_register_static (GST_TYPE_MINI_OBJECT,
"GstV4l2BufferPool", &v4l2_buffer_pool_info, 0);
}
return _gst_v4l2_buffer_pool_type;
}
static GstV4l2BufferPool *
gst_v4l2_buffer_pool_new (GstV4l2Src * v4l2src, gint fd, gint num_buffers,
GstCaps * caps)
{
GstV4l2BufferPool *pool;
gint n;
pool = (GstV4l2BufferPool *) gst_mini_object_new (GST_TYPE_V4L2_BUFFER_POOL);
pool->video_fd = dup (fd);
if (pool->video_fd < 0)
goto dup_failed;
pool->buffer_count = num_buffers;
pool->buffers = g_new0 (GstV4l2Buffer *, num_buffers);
for (n = 0; n < num_buffers; n++) {
pool->buffers[n] = gst_v4l2_buffer_new (pool, n, caps);
if (!pool->buffers[n])
goto buffer_new_failed;
}
return pool;
/* ERRORS */
dup_failed:
{
gint errnosave = errno;
gst_mini_object_unref (GST_MINI_OBJECT (pool));
errno = errnosave;
return NULL;
}
buffer_new_failed:
{
gint errnosave = errno;
gst_mini_object_unref (GST_MINI_OBJECT (pool));
errno = errnosave;
return NULL;
}
}
static gboolean
gst_v4l2_buffer_pool_activate (GstV4l2BufferPool * pool, GstV4l2Src * v4l2src)
{
gint n;
g_mutex_lock (pool->lock);
for (n = 0; n < pool->buffer_count; n++) {
struct v4l2_buffer *buf;
buf = &pool->buffers[n]->vbuffer;
GST_LOG ("enqueue pool buffer %d", n);
if (ioctl (pool->video_fd, VIDIOC_QBUF, buf) < 0)
goto queue_failed;
}
pool->running = TRUE;
g_mutex_unlock (pool->lock);
return TRUE;
/* ERRORS */
queue_failed:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ,
(_("Could not enqueue buffers in device '%s'."),
v4l2src->v4l2object->videodev),
("enqueing buffer %d/%d failed: %s",
n, v4l2src->num_buffers, g_strerror (errno)));
g_mutex_unlock (pool->lock);
return FALSE;
}
}
static void
gst_v4l2_buffer_pool_destroy (GstV4l2BufferPool * pool)
{
gint n;
g_mutex_lock (pool->lock);
pool->running = FALSE;
g_mutex_unlock (pool->lock);
/* after this point, no more buffers will be queued or dequeued; no buffer
* from pool->buffers that is NULL will be set to a buffer, and no buffer that
* is not NULL will be pushed out. */
for (n = 0; n < pool->buffer_count; n++) {
GstBuffer *buf;
g_mutex_lock (pool->lock);
buf = GST_BUFFER (pool->buffers[n]);
g_mutex_unlock (pool->lock);
if (buf)
/* we own the ref if the buffer is in pool->buffers; drop it. */
gst_buffer_unref (buf);
}
gst_mini_object_unref (GST_MINI_OBJECT (pool));
}
/* complete made up ranking, the values themselves are meaningless */
#define YUV_BASE_RANK 1000
#define JPEG_BASE_RANK 500
#define DV_BASE_RANK 200
#define RGB_BASE_RANK 100
#define YUV_ODD_BASE_RANK 50
#define RGB_ODD_BASE_RANK 25
#define BAYER_BASE_RANK 15
#define GREY_BASE_RANK 5
static gint
gst_v4l2src_format_get_rank (guint32 fourcc)
{
switch (fourcc) {
case V4L2_PIX_FMT_MJPEG:
return JPEG_BASE_RANK;
case V4L2_PIX_FMT_JPEG:
return JPEG_BASE_RANK + 1;
case V4L2_PIX_FMT_RGB332:
case V4L2_PIX_FMT_RGB555:
case V4L2_PIX_FMT_RGB555X:
case V4L2_PIX_FMT_RGB565:
case V4L2_PIX_FMT_RGB565X:
return RGB_ODD_BASE_RANK;
case V4L2_PIX_FMT_RGB24:
case V4L2_PIX_FMT_BGR24:
return RGB_BASE_RANK - 1;
case V4L2_PIX_FMT_RGB32:
case V4L2_PIX_FMT_BGR32:
return RGB_BASE_RANK;
case V4L2_PIX_FMT_GREY: /* 8 Greyscale */
return GREY_BASE_RANK;
case V4L2_PIX_FMT_NV12: /* 12 Y/CbCr 4:2:0 */
case V4L2_PIX_FMT_NV21: /* 12 Y/CrCb 4:2:0 */
case V4L2_PIX_FMT_YYUV: /* 16 YUV 4:2:2 */
case V4L2_PIX_FMT_HI240: /* 8 8-bit color */
return YUV_ODD_BASE_RANK;
case V4L2_PIX_FMT_YVU410: /* YVU9, 9 bits per pixel */
return YUV_BASE_RANK + 3;
case V4L2_PIX_FMT_YUV410: /* YUV9, 9 bits per pixel */
return YUV_BASE_RANK + 2;
case V4L2_PIX_FMT_YUV420: /* I420, 12 bits per pixel */
return YUV_BASE_RANK + 7;
case V4L2_PIX_FMT_YUYV: /* YUY2, 16 bits per pixel */
return YUV_BASE_RANK + 10;
case V4L2_PIX_FMT_YVU420: /* YV12, 12 bits per pixel */
return YUV_BASE_RANK + 6;
case V4L2_PIX_FMT_UYVY: /* UYVY, 16 bits per pixel */
return YUV_BASE_RANK + 9;
case V4L2_PIX_FMT_Y41P: /* Y41P, 12 bits per pixel */
return YUV_BASE_RANK + 5;
case V4L2_PIX_FMT_YUV411P: /* Y41B, 12 bits per pixel */
return YUV_BASE_RANK + 4;
case V4L2_PIX_FMT_YUV422P: /* Y42B, 16 bits per pixel */
return YUV_BASE_RANK + 8;
case V4L2_PIX_FMT_DV:
return DV_BASE_RANK;
case V4L2_PIX_FMT_MPEG: /* MPEG */
case V4L2_PIX_FMT_WNVA: /* Winnov hw compres */
return 0;
case V4L2_PIX_FMT_SBGGR8:
return BAYER_BASE_RANK;
default:
break;
}
return 0;
}
static gint
gst_v4l2src_format_cmp_func (gconstpointer a, gconstpointer b)
{
guint32 pf1 = ((struct v4l2_fmtdesc *) a)->pixelformat;
guint32 pf2 = ((struct v4l2_fmtdesc *) b)->pixelformat;
if (pf1 == pf2)
return 0;
return gst_v4l2src_format_get_rank (pf2) - gst_v4l2src_format_get_rank (pf1);
}
/******************************************************
* gst_v4l2src_fill_format_list():
* create list of supported capture formats
* return value: TRUE on success, FALSE on error
******************************************************/
gboolean
gst_v4l2src_fill_format_list (GstV4l2Src * v4l2src)
{
gint n;
struct v4l2_fmtdesc *format;
GST_DEBUG_OBJECT (v4l2src, "getting src format enumerations");
/* format enumeration */
for (n = 0;; n++) {
format = g_new (struct v4l2_fmtdesc, 1);
format->index = n;
format->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (ioctl (v4l2src->v4l2object->video_fd, VIDIOC_ENUM_FMT, format) < 0) {
if (errno == EINVAL)
break; /* end of enumeration */
else
goto failed;
}
GST_LOG_OBJECT (v4l2src, "index: %u", format->index);
GST_LOG_OBJECT (v4l2src, "type: %d", format->type);
GST_LOG_OBJECT (v4l2src, "flags: %08x", format->flags);
GST_LOG_OBJECT (v4l2src, "description: '%s'", format->description);
GST_LOG_OBJECT (v4l2src, "pixelformat: %" GST_FOURCC_FORMAT,
GST_FOURCC_ARGS (format->pixelformat));
/* sort formats according to our preference; we do this, because caps
* are probed in the order the formats are in the list, and the order of
* formats in the final probed caps matters for things like fixation */
v4l2src->formats = g_slist_insert_sorted (v4l2src->formats, format,
(GCompareFunc) gst_v4l2src_format_cmp_func);
}
GST_DEBUG_OBJECT (v4l2src, "got %d format(s)", n);
return TRUE;
/* ERRORS */
failed:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, SETTINGS,
(_("Failed to enumerate possible video formats device '%s' can work with"), v4l2src->v4l2object->videodev), ("Failed to get number %d in pixelformat enumeration for %s. (%d - %s)", n, v4l2src->v4l2object->videodev, errno, g_strerror (errno)));
g_free (format);
return FALSE;
}
}
/******************************************************
* gst_v4l2src_clear_format_list():
* free list of supported capture formats
* return value: TRUE on success, FALSE on error
******************************************************/
gboolean
gst_v4l2src_clear_format_list (GstV4l2Src * v4l2src)
{
g_slist_foreach (v4l2src->formats, (GFunc) g_free, NULL);
g_slist_free (v4l2src->formats);
v4l2src->formats = NULL;
return TRUE;
}
/* The frame interval enumeration code first appeared in Linux 2.6.19. */
#ifdef VIDIOC_ENUM_FRAMEINTERVALS
static GstStructure *
gst_v4l2src_probe_caps_for_format_and_size (GstV4l2Src * v4l2src,
guint32 pixelformat,
guint32 width, guint32 height, const GstStructure * template)
{
GstCaps *ret;
gint fd = v4l2src->v4l2object->video_fd;
struct v4l2_frmivalenum ival;
guint32 num, denom;
GstStructure *s;
GValue rates = { 0, };
ret = gst_caps_new_empty ();
memset (&ival, 0, sizeof (struct v4l2_frmivalenum));
ival.index = 0;
ival.pixel_format = pixelformat;
ival.width = width;
ival.height = height;
GST_LOG_OBJECT (v4l2src, "get frame interval for %ux%u, %" GST_FOURCC_FORMAT,
width, height, GST_FOURCC_ARGS (pixelformat));
/* keep in mind that v4l2 gives us frame intervals (durations); we invert the
* fraction to get framerate */
if (ioctl (fd, VIDIOC_ENUM_FRAMEINTERVALS, &ival) < 0)
goto enum_frameintervals_failed;
if (ival.type == V4L2_FRMIVAL_TYPE_DISCRETE) {
GValue rate = { 0, };
g_value_init (&rates, GST_TYPE_LIST);
g_value_init (&rate, GST_TYPE_FRACTION);
do {
num = ival.discrete.numerator;
denom = ival.discrete.denominator;
if (num > G_MAXINT || denom > G_MAXINT) {
/* let us hope we don't get here... */
num >>= 1;
denom >>= 1;
}
GST_LOG_OBJECT (v4l2src, "adding discrete framerate: %d/%d", denom, num);
/* swap to get the framerate */
gst_value_set_fraction (&rate, denom, num);
gst_value_list_append_value (&rates, &rate);
ival.index++;
} while (ioctl (fd, VIDIOC_ENUM_FRAMEINTERVALS, &ival) >= 0);
} else if (ival.type == V4L2_FRMIVAL_TYPE_STEPWISE) {
GValue min = { 0, };
GValue step = { 0, };
GValue max = { 0, };
gboolean added = FALSE;
guint32 minnum, mindenom;
guint32 maxnum, maxdenom;
g_value_init (&rates, GST_TYPE_LIST);
g_value_init (&min, GST_TYPE_FRACTION);
g_value_init (&step, GST_TYPE_FRACTION);
g_value_init (&max, GST_TYPE_FRACTION);
/* get the min */
minnum = ival.stepwise.min.numerator;
mindenom = ival.stepwise.min.denominator;
if (minnum > G_MAXINT || mindenom > G_MAXINT) {
minnum >>= 1;
mindenom >>= 1;
}
GST_LOG_OBJECT (v4l2src, "stepwise min frame interval: %d/%d", minnum,
mindenom);
gst_value_set_fraction (&min, minnum, mindenom);
/* get the max */
maxnum = ival.stepwise.max.numerator;
maxdenom = ival.stepwise.max.denominator;
if (maxnum > G_MAXINT || maxdenom > G_MAXINT) {
maxnum >>= 1;
maxdenom >>= 1;
}
GST_LOG_OBJECT (v4l2src, "stepwise max frame interval: %d/%d", maxnum,
maxdenom);
gst_value_set_fraction (&max, maxnum, maxdenom);
/* get the step */
num = ival.stepwise.step.numerator;
denom = ival.stepwise.step.denominator;
if (num > G_MAXINT || denom > G_MAXINT) {
num >>= 1;
denom >>= 1;
}
if (num == 0 || denom == 0) {
/* in this case we have a wrong fraction or no step, set the step to max
* so that we only add the min value in the loop below */
num = maxnum;
denom = maxdenom;
}
/* since we only have gst_value_fraction_subtract and not add, negate the
* numerator */
GST_LOG_OBJECT (v4l2src, "stepwise step frame interval: %d/%d", num, denom);
gst_value_set_fraction (&step, -num, denom);
while (gst_value_compare (&min, &max) <= 0) {
GValue rate = { 0, };
num = gst_value_get_fraction_numerator (&min);
denom = gst_value_get_fraction_denominator (&min);
GST_LOG_OBJECT (v4l2src, "adding stepwise framerate: %d/%d", denom, num);
/* invert to get the framerate */
g_value_init (&rate, GST_TYPE_FRACTION);
gst_value_set_fraction (&rate, denom, num);
gst_value_list_append_value (&rates, &rate);
added = TRUE;
/* we're actually adding because step was negated above. This is because
* there is no _add function... */
if (!gst_value_fraction_subtract (&min, &min, &step)) {
GST_WARNING_OBJECT (v4l2src, "could not step fraction!");
break;
}
}
if (!added) {
/* no range was added, make a default range */
GST_WARNING_OBJECT (v4l2src, "no range added, setting 0/1 to 100/1");
g_value_unset (&rates);
g_value_init (&rates, GST_TYPE_FRACTION_RANGE);
gst_value_set_fraction_range_full (&rates, 0, 1, 100, 1);
}
} else if (ival.type == V4L2_FRMIVAL_TYPE_CONTINUOUS) {
guint32 maxnum, maxdenom;
g_value_init (&rates, GST_TYPE_FRACTION_RANGE);
num = ival.stepwise.min.numerator;
denom = ival.stepwise.min.denominator;
if (num > G_MAXINT || denom > G_MAXINT) {
num >>= 1;
denom >>= 1;
}
maxnum = ival.stepwise.max.numerator;
maxdenom = ival.stepwise.max.denominator;
if (maxnum > G_MAXINT || maxdenom > G_MAXINT) {
maxnum >>= 1;
maxdenom >>= 1;
}
GST_LOG_OBJECT (v4l2src, "continuous frame interval %d/%d to %d/%d",
maxdenom, maxnum, denom, num);
gst_value_set_fraction_range_full (&rates, maxdenom, maxnum, denom, num);
} else {
goto unknown_type;
}
s = gst_structure_copy (template);
gst_structure_set (s, "width", G_TYPE_INT, (gint) width,
"height", G_TYPE_INT, (gint) height, NULL);
gst_structure_set_value (s, "framerate", &rates);
g_value_unset (&rates);
return s;
/* ERRORS */
enum_frameintervals_failed:
{
GST_DEBUG_OBJECT (v4l2src,
"Failed to enumerate frame sizes for %" GST_FOURCC_FORMAT "@%ux%u",
GST_FOURCC_ARGS (pixelformat), width, height);
return NULL;
}
unknown_type:
{
/* I don't see how this is actually an error */
GST_WARNING_OBJECT (v4l2src,
"Unknown frame interval type at %" GST_FOURCC_FORMAT "@%ux%u: %u",
GST_FOURCC_ARGS (pixelformat), width, height, ival.type);
return NULL;
}
}
#endif /* defined VIDIOC_ENUM_FRAMEINTERVALS */
GstCaps *
gst_v4l2src_probe_caps_for_format (GstV4l2Src * v4l2src, guint32 pixelformat,
const GstStructure * template)
{
GstCaps *ret;
GstStructure *tmp;
GList *results = NULL;
#ifdef VIDIOC_ENUM_FRAMESIZES
gint fd = v4l2src->v4l2object->video_fd;
struct v4l2_frmsizeenum size;
guint32 w, h;
ret = gst_caps_new_empty ();
memset (&size, 0, sizeof (struct v4l2_frmsizeenum));
size.index = 0;
size.pixel_format = pixelformat;
if (ioctl (fd, VIDIOC_ENUM_FRAMESIZES, &size) < 0)
goto enum_framesizes_failed;
if (size.type == V4L2_FRMSIZE_TYPE_DISCRETE) {
do {
w = MIN (size.discrete.width, G_MAXINT);
h = MIN (size.discrete.height, G_MAXINT);
tmp = gst_v4l2src_probe_caps_for_format_and_size (v4l2src, pixelformat,
w, h, template);
if (tmp)
results = g_list_prepend (results, tmp);
size.index++;
} while (ioctl (fd, VIDIOC_ENUM_FRAMESIZES, &size) >= 0);
} else if (size.type == V4L2_FRMSIZE_TYPE_STEPWISE) {
for (w = size.stepwise.min_width, h = size.stepwise.min_height;
w < size.stepwise.max_width && h < size.stepwise.max_height;
w += size.stepwise.step_width, h += size.stepwise.step_height) {
if (w == 0 || h == 0)
continue;
tmp = gst_v4l2src_probe_caps_for_format_and_size (v4l2src, pixelformat,
w, h, template);
if (tmp)
gst_caps_append_structure (ret, tmp);
}
} else if (size.type == V4L2_FRMSIZE_TYPE_CONTINUOUS) {
guint32 maxw, maxh;
w = MAX (size.stepwise.min_width, 1);
h = MAX (size.stepwise.min_height, 1);
maxw = MIN (size.stepwise.max_width, G_MAXINT);
maxh = MIN (size.stepwise.max_height, G_MAXINT);
tmp = gst_v4l2src_probe_caps_for_format_and_size (v4l2src, pixelformat,
w, h, template);
if (tmp) {
gst_structure_set (tmp, "width", GST_TYPE_INT_RANGE, (gint) w,
(gint) maxw, "height", GST_TYPE_INT_RANGE, (gint) h, (gint) maxh,
NULL);
gst_caps_append_structure (ret, tmp);
}
} else {
goto unknown_type;
}
/* we use an intermediary list to store the results of the probing because
* we probe from lowest resolution to highest resolution, but want the caps
* to contain the results in reverse order starting with the highest
* resolution, as order in caps matters for things like fixation. However,
* there's no gst_caps_prepend_structure(), so we use the list as helper to
* reverse the order */
while (results != NULL) {
gst_caps_append_structure (ret, GST_STRUCTURE (results->data));
results = g_list_delete_link (results, results);
}
return ret;
/* ERRORS */
enum_framesizes_failed:
{
/* I don't see how this is actually an error */
GST_DEBUG_OBJECT (v4l2src,
"Failed to enumerate frame sizes for pixelformat %" GST_FOURCC_FORMAT
" (%s)", GST_FOURCC_ARGS (pixelformat), g_strerror (errno));
goto default_frame_sizes;
}
unknown_type:
{
GST_WARNING_OBJECT (v4l2src,
"Unknown frame sizeenum type for pixelformat %" GST_FOURCC_FORMAT
": %u", GST_FOURCC_ARGS (pixelformat), size.type);
goto default_frame_sizes;
}
default_frame_sizes:
#endif /* defined VIDIOC_ENUM_FRAMESIZES */
{
gint min_w, max_w, min_h, max_h;
/* This code is for Linux < 2.6.19 */
if (!gst_v4l2src_get_size_limits (v4l2src, pixelformat, &min_w, &max_w,
&min_h, &max_h)) {
min_w = min_h = 1;
max_w = max_h = GST_V4L2_MAX_SIZE;
}
ret = gst_caps_new_empty ();
tmp = gst_structure_copy (template);
gst_structure_set (tmp,
"width", GST_TYPE_INT_RANGE, min_w, max_w,
"height", GST_TYPE_INT_RANGE, min_h, max_h,
"framerate", GST_TYPE_FRACTION_RANGE, (gint) 0, (gint) 1, (gint) 100,
(gint) 1, NULL);
gst_caps_append_structure (ret, tmp);
}
return ret;
}
/******************************************************
* gst_v4l2src_grab_frame ():
* grab a frame for capturing
* return value: The captured frame number or -1 on error.
******************************************************/
GstFlowReturn
gst_v4l2src_grab_frame (GstV4l2Src * v4l2src, GstBuffer ** buf)
{
#define NUM_TRIALS 50
struct v4l2_buffer buffer;
gint32 trials = NUM_TRIALS;
GstBuffer *pool_buffer;
gboolean need_copy;
memset (&buffer, 0x00, sizeof (buffer));
buffer.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buffer.memory = V4L2_MEMORY_MMAP;
while (ioctl (v4l2src->v4l2object->video_fd, VIDIOC_DQBUF, &buffer) < 0) {
GST_WARNING_OBJECT (v4l2src,
"problem grabbing frame %d (ix=%d), trials=%d, pool-ct=%d, buf.flags=%d",
buffer.sequence, buffer.index, trials,
GST_MINI_OBJECT_REFCOUNT (v4l2src->pool), buffer.flags);
/* if the sync() got interrupted, we can retry */
switch (errno) {
case EAGAIN:
GST_WARNING_OBJECT (v4l2src,
"Non-blocking I/O has been selected using O_NONBLOCK and"
" no buffer was in the outgoing queue. device %s",
v4l2src->v4l2object->videodev);
break;
case EINVAL:
goto einval;
case ENOMEM:
goto enomem;
case EIO:
GST_INFO_OBJECT (v4l2src,
"VIDIOC_DQBUF failed due to an internal error."
" Can also indicate temporary problems like signal loss."
" Note the driver might dequeue an (empty) buffer despite"
" returning an error, or even stop capturing."
" device %s", v4l2src->v4l2object->videodev);
/* have we de-queued a buffer ? */
if (!(buffer.flags & (V4L2_BUF_FLAG_QUEUED | V4L2_BUF_FLAG_DONE))) {
/* this fails
if ((buffer.index >= 0) && (buffer.index < v4l2src->breq.count)) {
GST_DEBUG_OBJECT (v4l2src, "reenqueing buffer (ix=%ld)", buffer.index);
gst_v4l2src_queue_frame (v4l2src, buffer.index);
}
else {
*/
GST_DEBUG_OBJECT (v4l2src, "reenqueing buffer");
/* FIXME: this is not a good idea, as drivers usualy return the buffer
* with index-number set to 0, thus the re-enque will fail unless it
* was incidentialy 0.
* We could try to re-enque all buffers without handling the ioctl
* return.
*/
/*
if (ioctl (v4l2src->v4l2object->video_fd, VIDIOC_QBUF, &buffer) < 0) {
goto qbuf_failed;
}
*/
/*} */
}
break;
case EINTR:
GST_WARNING_OBJECT (v4l2src,
"could not sync on a buffer on device %s",
v4l2src->v4l2object->videodev);
break;
default:
GST_WARNING_OBJECT (v4l2src,
"Grabbing frame got interrupted on %s. No expected reason.",
v4l2src->v4l2object->videodev);
break;
}
/* check nr. of attempts to capture */
if (--trials == -1) {
goto too_many_trials;
} else {
memset (&buffer, 0x00, sizeof (buffer));
buffer.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
buffer.memory = V4L2_MEMORY_MMAP;
}
}
g_mutex_lock (v4l2src->pool->lock);
pool_buffer = GST_BUFFER (v4l2src->pool->buffers[buffer.index]);
v4l2src->pool->buffers[buffer.index] = NULL;
v4l2src->pool->num_live_buffers++;
need_copy = v4l2src->pool->num_live_buffers == v4l2src->pool->buffer_count;
g_mutex_unlock (v4l2src->pool->lock);
/* this can change at every frame, esp. with jpeg */
GST_BUFFER_SIZE (pool_buffer) = buffer.bytesused;
GST_BUFFER_OFFSET (pool_buffer) = v4l2src->offset++;
GST_BUFFER_OFFSET_END (pool_buffer) = v4l2src->offset;
/* timestamps, LOCK to get clock and base time. */
{
GstClock *clock;
GstClockTime timestamp;
GST_OBJECT_LOCK (v4l2src);
if ((clock = GST_ELEMENT_CLOCK (v4l2src))) {
/* we have a clock, get base time and ref clock */
timestamp = GST_ELEMENT (v4l2src)->base_time;
gst_object_ref (clock);
} else {
/* no clock, can't set timestamps */
timestamp = GST_CLOCK_TIME_NONE;
}
GST_OBJECT_UNLOCK (v4l2src);
if (clock) {
/* the time now is the time of the clock minus the base time */
timestamp = gst_clock_get_time (clock) - timestamp;
gst_object_unref (clock);
}
/* FIXME: use the timestamp from the buffer itself! */
GST_BUFFER_TIMESTAMP (pool_buffer) = timestamp;
}
if (G_UNLIKELY (need_copy)) {
*buf = gst_buffer_copy (pool_buffer);
/* this will requeue */
gst_buffer_unref (pool_buffer);
} else {
*buf = pool_buffer;
}
GST_LOG_OBJECT (v4l2src, "grabbed frame %d (ix=%d), flags %08x, pool-ct=%d",
buffer.sequence, buffer.index, buffer.flags,
v4l2src->pool->num_live_buffers);
return GST_FLOW_OK;
/* ERRORS */
einval:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, FAILED,
(_("Failed trying to get video frames from device '%s'."),
v4l2src->v4l2object->videodev),
(_("The buffer type is not supported, or the index is out of bounds,"
" or no buffers have been allocated yet, or the userptr"
" or length are invalid. device %s"),
v4l2src->v4l2object->videodev));
return GST_FLOW_ERROR;
}
enomem:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, FAILED,
(_("Failed trying to get video frames from device '%s'. Not enough memory."), v4l2src->v4l2object->videodev), (_("insufficient memory to enqueue a user pointer buffer. device %s."), v4l2src->v4l2object->videodev));
return GST_FLOW_ERROR;
}
too_many_trials:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, FAILED,
(_("Failed trying to get video frames from device '%s'."),
v4l2src->v4l2object->videodev),
(_("Failed after %d tries. device %s. system error: %s"),
NUM_TRIALS, v4l2src->v4l2object->videodev, g_strerror (errno)));
return GST_FLOW_ERROR;
}
/*
qbuf_failed:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, WRITE,
(_("Could not exchange data with device '%s'."),
v4l2src->v4l2object->videodev),
("Error queueing buffer on device %s. system error: %s",
v4l2src->v4l2object->videodev, g_strerror (errno)));
return GST_FLOW_ERROR;
}
*/
}
/******************************************************
* gst_v4l2src_set_capture():
* set capture parameters
* return value: TRUE on success, FALSE on error
******************************************************/
gboolean
gst_v4l2src_set_capture (GstV4l2Src * v4l2src, guint32 pixelformat,
guint32 width, guint32 height, guint fps_n, guint fps_d)
{
gint fd = v4l2src->v4l2object->video_fd;
struct v4l2_format format;
struct v4l2_streamparm stream;
DEBUG ("Setting capture format to %dx%d, format %" GST_FOURCC_FORMAT,
width, height, GST_FOURCC_ARGS (pixelformat));
GST_V4L2_CHECK_OPEN (v4l2src->v4l2object);
GST_V4L2_CHECK_NOT_ACTIVE (v4l2src->v4l2object);
memset (&format, 0x00, sizeof (struct v4l2_format));
format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (ioctl (fd, VIDIOC_G_FMT, &format) < 0)
goto get_fmt_failed;
format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
format.fmt.pix.width = width;
format.fmt.pix.height = height;
format.fmt.pix.pixelformat = pixelformat;
/* request whole frames; change when gstreamer supports interlaced video */
format.fmt.pix.field = V4L2_FIELD_INTERLACED;
if (ioctl (fd, VIDIOC_S_FMT, &format) < 0)
goto set_fmt_failed;
if (format.fmt.pix.width != width || format.fmt.pix.height != height)
goto invalid_dimensions;
if (format.fmt.pix.pixelformat != pixelformat)
goto invalid_pixelformat;
memset (&stream, 0x00, sizeof (struct v4l2_streamparm));
stream.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (ioctl (fd, VIDIOC_G_PARM, &stream) < 0) {
GST_ELEMENT_WARNING (v4l2src, RESOURCE, SETTINGS,
(_("Could not get parameters on device '%s'"),
v4l2src->v4l2object->videodev), GST_ERROR_SYSTEM);
} else { /* seems no point in SET, if can't get GET */
/* Note: V4L2 gives us the frame interval, we need the frame rate */
stream.parm.capture.timeperframe.numerator = fps_d;
stream.parm.capture.timeperframe.denominator = fps_n;
if (ioctl (fd, VIDIOC_S_PARM, &stream) < 0) {
GST_ELEMENT_WARNING (v4l2src, RESOURCE, SETTINGS,
(_("Could not set parameters on device '%s'"),
v4l2src->v4l2object->videodev), GST_ERROR_SYSTEM);
/* FIXME: better test for fraction equality */
if (stream.parm.capture.timeperframe.numerator != fps_d
|| stream.parm.capture.timeperframe.denominator != fps_n)
goto invalid_framerate;
}
v4l2src->fps_d = fps_d;
v4l2src->fps_n = fps_n;
}
return TRUE;
/* ERRORS */
get_fmt_failed:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, SETTINGS,
(_("Device '%s' does not support video capture"),
v4l2src->v4l2object->videodev),
("Call to G_FMT failed: (%s)", g_strerror (errno)));
return FALSE;
}
set_fmt_failed:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, SETTINGS,
(_("Device '%s' cannot capture at %dx%d"),
v4l2src->v4l2object->videodev, width, height),
("Call to S_FMT failed for %" GST_FOURCC_FORMAT " @ %dx%d: %s",
GST_FOURCC_ARGS (pixelformat), width, height, g_strerror (errno)));
return FALSE;
}
invalid_dimensions:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, SETTINGS,
(_("Device '%s' cannot capture at %dx%d"),
v4l2src->v4l2object->videodev, width, height),
("Tried to capture at %dx%d, but device returned size %dx%d",
width, height, format.fmt.pix.width, format.fmt.pix.height));
return FALSE;
}
invalid_pixelformat:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, SETTINGS,
(_("Device '%s' cannot capture in the specified format"),
v4l2src->v4l2object->videodev),
("Tried to capture in %" GST_FOURCC_FORMAT
", but device returned format" " %" GST_FOURCC_FORMAT,
GST_FOURCC_ARGS (pixelformat),
GST_FOURCC_ARGS (format.fmt.pix.pixelformat)));
return FALSE;
}
invalid_framerate:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, SETTINGS,
(_("Device '%s' cannot capture at %d/%d frames per second"),
v4l2src->v4l2object->videodev, fps_n, fps_d),
("Tried to capture at %d/%d fps, but device returned %d/%d fps",
fps_n, fps_d, stream.parm.capture.timeperframe.denominator,
stream.parm.capture.timeperframe.numerator));
return FALSE;
}
}
/******************************************************
* gst_v4l2src_capture_init():
* initialize the capture system
* return value: TRUE on success, FALSE on error
******************************************************/
gboolean
gst_v4l2src_capture_init (GstV4l2Src * v4l2src, GstCaps * caps)
{
gint fd = v4l2src->v4l2object->video_fd;
struct v4l2_requestbuffers breq;
memset (&breq, 0, sizeof (struct v4l2_requestbuffers));
GST_DEBUG_OBJECT (v4l2src, "initializing the capture system");
GST_V4L2_CHECK_OPEN (v4l2src->v4l2object);
GST_V4L2_CHECK_NOT_ACTIVE (v4l2src->v4l2object);
if (v4l2src->v4l2object->vcap.capabilities & V4L2_CAP_STREAMING) {
GST_DEBUG_OBJECT (v4l2src, "STREAMING, requesting %d MMAP CAPTURE buffers",
v4l2src->num_buffers);
breq.count = v4l2src->num_buffers;
breq.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
breq.memory = V4L2_MEMORY_MMAP;
if (ioctl (fd, VIDIOC_REQBUFS, &breq) < 0)
goto reqbufs_failed;
GST_LOG_OBJECT (v4l2src, " count: %u", breq.count);
GST_LOG_OBJECT (v4l2src, " type: %d", breq.type);
GST_LOG_OBJECT (v4l2src, " memory: %d", breq.memory);
if (breq.count < GST_V4L2_MIN_BUFFERS)
goto no_buffers;
if (v4l2src->num_buffers != breq.count) {
GST_WARNING_OBJECT (v4l2src, "using %u buffers instead", breq.count);
v4l2src->num_buffers = breq.count;
g_object_notify (G_OBJECT (v4l2src), "queue-size");
}
/* Map the buffers */
GST_LOG_OBJECT (v4l2src, "initiating buffer pool");
if (!(v4l2src->pool = gst_v4l2_buffer_pool_new (v4l2src, fd,
v4l2src->num_buffers, caps)))
goto buffer_pool_new_failed;
GST_INFO_OBJECT (v4l2src, "capturing buffers via mmap()");
v4l2src->use_mmap = TRUE;
} else if (v4l2src->v4l2object->vcap.capabilities & V4L2_CAP_READWRITE) {
GST_INFO_OBJECT (v4l2src, "capturing buffers via read()");
v4l2src->use_mmap = FALSE;
v4l2src->pool = NULL;
} else {
goto no_supported_capture_method;
}
GST_V4L2_SET_ACTIVE (v4l2src->v4l2object);
return TRUE;
/* ERRORS */
reqbufs_failed:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ,
(_("Could not get buffers from device '%s'."),
v4l2src->v4l2object->videodev),
("error requesting %d buffers: %s",
v4l2src->num_buffers, g_strerror (errno)));
return FALSE;
}
no_buffers:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ,
(_("Could not get enough buffers from device '%s'."),
v4l2src->v4l2object->videodev),
("we received %d from device '%s', we want at least %d",
breq.count, v4l2src->v4l2object->videodev, GST_V4L2_MIN_BUFFERS));
return FALSE;
}
buffer_pool_new_failed:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ,
(_("Could not map buffers from device '%s'"),
v4l2src->v4l2object->videodev),
("Failed to create buffer pool: %s", g_strerror (errno)));
return FALSE;
}
no_supported_capture_method:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ,
(_("The driver of device '%s' does not support any known capture "
"method."), v4l2src->v4l2object->videodev), (NULL));
return FALSE;
}
}
/******************************************************
* gst_v4l2src_capture_start():
* start streaming capture
* return value: TRUE on success, FALSE on error
******************************************************/
gboolean
gst_v4l2src_capture_start (GstV4l2Src * v4l2src)
{
gint type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
gint fd = v4l2src->v4l2object->video_fd;
GST_DEBUG_OBJECT (v4l2src, "starting the capturing");
//GST_V4L2_CHECK_OPEN (v4l2src->v4l2object);
GST_V4L2_CHECK_ACTIVE (v4l2src->v4l2object);
v4l2src->quit = FALSE;
if (v4l2src->use_mmap) {
if (!gst_v4l2_buffer_pool_activate (v4l2src->pool, v4l2src))
goto pool_activate_failed;
if (ioctl (fd, VIDIOC_STREAMON, &type) < 0)
goto streamon_failed;
}
v4l2src->is_capturing = TRUE;
return TRUE;
/* ERRORS */
pool_activate_failed:
{
/* already errored */
return FALSE;
}
streamon_failed:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, OPEN_READ,
(_("Error starting streaming capture from device '%s'."),
v4l2src->v4l2object->videodev), GST_ERROR_SYSTEM);
return FALSE;
}
}
/******************************************************
* gst_v4l2src_capture_stop():
* stop streaming capture
* return value: TRUE on success, FALSE on error
******************************************************/
gboolean
gst_v4l2src_capture_stop (GstV4l2Src * v4l2src)
{
gint type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
GST_DEBUG_OBJECT (v4l2src, "stopping capturing");
if (!GST_V4L2_IS_OPEN (v4l2src->v4l2object)) {
goto done;
}
if (!GST_V4L2_IS_ACTIVE (v4l2src->v4l2object)) {
goto done;
}
if (v4l2src->use_mmap) {
/* we actually need to sync on all queued buffers but not
* on the non-queued ones */
if (ioctl (v4l2src->v4l2object->video_fd, VIDIOC_STREAMOFF, &type) < 0)
goto streamoff_failed;
}
done:
/* make an optional pending wait stop */
v4l2src->quit = TRUE;
v4l2src->is_capturing = FALSE;
return TRUE;
/* ERRORS */
streamoff_failed:
{
GST_ELEMENT_ERROR (v4l2src, RESOURCE, CLOSE,
(_("Error stopping streaming capture from device '%s'."),
v4l2src->v4l2object->videodev), GST_ERROR_SYSTEM);
return FALSE;
}
}
/******************************************************
* gst_v4l2src_capture_deinit():
* deinitialize the capture system
* return value: TRUE on success, FALSE on error
******************************************************/
gboolean
gst_v4l2src_capture_deinit (GstV4l2Src * v4l2src)
{
GST_DEBUG_OBJECT (v4l2src, "deinitting capture system");
if (!GST_V4L2_IS_OPEN (v4l2src->v4l2object)) {
return TRUE;
}
if (!GST_V4L2_IS_ACTIVE (v4l2src->v4l2object)) {
return TRUE;
}
if (v4l2src->pool) {
gst_v4l2_buffer_pool_destroy (v4l2src->pool);
v4l2src->pool = NULL;
}
GST_V4L2_SET_INACTIVE (v4l2src->v4l2object);
return TRUE;
}
/*
*/
gboolean
gst_v4l2src_get_size_limits (GstV4l2Src * v4l2src,
guint32 pixelformat, gint * min_w, gint * max_w, gint * min_h, gint * max_h)
{
struct v4l2_format fmt;
GST_LOG_OBJECT (v4l2src,
"getting size limits with format %" GST_FOURCC_FORMAT,
GST_FOURCC_ARGS (pixelformat));
/* get size delimiters */
memset (&fmt, 0, sizeof (fmt));
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
fmt.fmt.pix.width = 0;
fmt.fmt.pix.height = 0;
fmt.fmt.pix.pixelformat = pixelformat;
fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
if (ioctl (v4l2src->v4l2object->video_fd, VIDIOC_TRY_FMT, &fmt) < 0) {
GST_DEBUG_OBJECT (v4l2src, "failed to get min size: %s",
g_strerror (errno));
return FALSE;
}
if (min_w)
*min_w = fmt.fmt.pix.width;
if (min_h)
*min_h = fmt.fmt.pix.height;
GST_LOG_OBJECT (v4l2src,
"got min size %dx%d", fmt.fmt.pix.width, fmt.fmt.pix.height);
fmt.fmt.pix.width = GST_V4L2_MAX_SIZE;
fmt.fmt.pix.height = GST_V4L2_MAX_SIZE;
if (ioctl (v4l2src->v4l2object->video_fd, VIDIOC_TRY_FMT, &fmt) < 0) {
GST_DEBUG_OBJECT (v4l2src, "failed to get max size: %s",
g_strerror (errno));
return FALSE;
}
if (max_w)
*max_w = fmt.fmt.pix.width;
if (max_h)
*max_h = fmt.fmt.pix.height;
GST_LOG_OBJECT (v4l2src,
"got max size %dx%d", fmt.fmt.pix.width, fmt.fmt.pix.height);
return TRUE;
}