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gstreamer/subprojects/gst-plugins-good/sys/v4l2/gstv4l2src.c
Haihua Hu 37e3a38ba9 v4l2src: need maintain the caps order in caps compare when fixate 
if the calculated "distance" of caps A and B from the preference are
equal, need to keep the original order instead of swap them

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6451>
2024-03-28 12:53:01 +00:00

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/* GStreamer
*
* Copyright (C) 2001-2002 Ronald Bultje <rbultje@ronald.bitfreak.net>
* 2006 Edgard Lima <edgard.lima@gmail.com>
*
* gstv4l2src.c: Video4Linux2 source element
*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:element-v4l2src
* @title: v4l2src
*
* v4l2src can be used to capture video from v4l2 devices, like webcams and tv
* cards.
*
* ## Example launch lines
* |[
* gst-launch-1.0 v4l2src ! xvimagesink
* ]| This pipeline shows the video captured from /dev/video0 tv card and for
* webcams.
* |[
* gst-launch-1.0 v4l2src ! jpegdec ! xvimagesink
* ]| This pipeline shows the video captured from a webcam that delivers jpeg
* images.
*
* Since 1.14, the use of libv4l2 has been disabled due to major bugs in the
* emulation layer. To enable usage of this library, set the environment
* variable GST_V4L2_USE_LIBV4L2=1.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <string.h>
#include <sys/time.h>
#include <unistd.h>
#include <gst/video/gstvideometa.h>
#include <gst/video/gstvideopool.h>
#include "gstv4l2elements.h"
#include "gstv4l2src.h"
#include "gstv4l2colorbalance.h"
#include "gstv4l2tuner.h"
#include "gstv4l2vidorient.h"
#include <glib/gi18n-lib.h>
GST_DEBUG_CATEGORY (v4l2src_debug);
#define GST_CAT_DEFAULT v4l2src_debug
#define DEFAULT_PROP_DEVICE "/dev/video0"
enum
{
PROP_0,
V4L2_STD_OBJECT_PROPS,
PROP_CROP_TOP,
PROP_CROP_LEFT,
PROP_CROP_BOTTOM,
PROP_CROP_RIGHT,
PROP_CROP_BOUNDS,
PROP_LAST
};
/* signals and args */
enum
{
SIGNAL_PRE_SET_FORMAT,
LAST_SIGNAL
};
static guint gst_v4l2_signals[LAST_SIGNAL] = { 0 };
GST_IMPLEMENT_V4L2_COLOR_BALANCE_METHODS (GstV4l2Src, gst_v4l2src);
GST_IMPLEMENT_V4L2_TUNER_METHODS (GstV4l2Src, gst_v4l2src);
GST_IMPLEMENT_V4L2_VIDORIENT_METHODS (GstV4l2Src, gst_v4l2src);
static void gst_v4l2src_uri_handler_init (gpointer g_iface,
gpointer iface_data);
#define gst_v4l2src_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (GstV4l2Src, gst_v4l2src, GST_TYPE_PUSH_SRC,
G_IMPLEMENT_INTERFACE (GST_TYPE_URI_HANDLER, gst_v4l2src_uri_handler_init);
G_IMPLEMENT_INTERFACE (GST_TYPE_TUNER, gst_v4l2src_tuner_interface_init);
G_IMPLEMENT_INTERFACE (GST_TYPE_COLOR_BALANCE,
gst_v4l2src_color_balance_interface_init);
G_IMPLEMENT_INTERFACE (GST_TYPE_VIDEO_ORIENTATION,
gst_v4l2src_video_orientation_interface_init));
GST_ELEMENT_REGISTER_DEFINE_WITH_CODE (v4l2src,
"v4l2src", GST_RANK_PRIMARY, GST_TYPE_V4L2SRC, v4l2_element_init (plugin));
struct PreferredCapsInfo
{
gint width;
gint height;
gint fps_n;
gint fps_d;
};
static void gst_v4l2src_finalize (GstV4l2Src * v4l2src);
/* element methods */
static GstStateChangeReturn gst_v4l2src_change_state (GstElement * element,
GstStateChange transition);
/* basesrc methods */
static gboolean gst_v4l2src_start (GstBaseSrc * src);
static gboolean gst_v4l2src_unlock (GstBaseSrc * src);
static gboolean gst_v4l2src_unlock_stop (GstBaseSrc * src);
static gboolean gst_v4l2src_stop (GstBaseSrc * src);
static GstCaps *gst_v4l2src_get_caps (GstBaseSrc * src, GstCaps * filter);
static gboolean gst_v4l2src_query (GstBaseSrc * bsrc, GstQuery * query);
static gboolean gst_v4l2src_decide_allocation (GstBaseSrc * src,
GstQuery * query);
static GstFlowReturn gst_v4l2src_create (GstPushSrc * src, GstBuffer ** out);
static GstCaps *gst_v4l2src_fixate (GstBaseSrc * basesrc, GstCaps * caps,
struct PreferredCapsInfo *pref);
static gboolean gst_v4l2src_negotiate (GstBaseSrc * basesrc);
static void gst_v4l2src_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_v4l2src_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static void
gst_v4l2src_class_init (GstV4l2SrcClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *element_class;
GstBaseSrcClass *basesrc_class;
GstPushSrcClass *pushsrc_class;
gobject_class = G_OBJECT_CLASS (klass);
element_class = GST_ELEMENT_CLASS (klass);
basesrc_class = GST_BASE_SRC_CLASS (klass);
pushsrc_class = GST_PUSH_SRC_CLASS (klass);
gobject_class->finalize = (GObjectFinalizeFunc) gst_v4l2src_finalize;
gobject_class->set_property = gst_v4l2src_set_property;
gobject_class->get_property = gst_v4l2src_get_property;
element_class->change_state = gst_v4l2src_change_state;
gst_v4l2_object_install_properties_helper (gobject_class,
DEFAULT_PROP_DEVICE);
/**
* GstV4l2Src:crop-top:
*
* Number of pixels to crop from the top edge of captured video
* stream
*
* Since: 1.22
*/
g_object_class_install_property (gobject_class, PROP_CROP_TOP,
g_param_spec_uint ("crop-top", "Crop top",
"Pixels to crop at top of video capture input",
0, G_MAXUINT, 0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstV4l2Src:crop-left:
*
* Number of pixels to crop from the left edge of captured video
* stream
*
* Since: 1.22
*/
g_object_class_install_property (gobject_class, PROP_CROP_LEFT,
g_param_spec_uint ("crop-left", "Crop left",
"Pixels to crop at left of video capture input",
0, G_MAXUINT, 0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstV4l2Src:crop-bottom:
*
* Number of pixels to crop from the bottom edge of captured video
* stream
*
* Since: 1.22
*/
g_object_class_install_property (gobject_class, PROP_CROP_BOTTOM,
g_param_spec_uint ("crop-bottom", "Crop bottom",
"Pixels to crop at bottom of video capture input",
0, G_MAXUINT, 0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstV4l2Src:crop-right:
*
* Number of pixels to crop from the right edge of captured video
* stream
*
* Since: 1.22
*/
g_object_class_install_property (gobject_class, PROP_CROP_RIGHT,
g_param_spec_uint ("crop-right", "Crop right",
"Pixels to crop at right of video capture input",
0, G_MAXUINT, 0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstV4l2Src:crop-bounds:
*
* Crop bounding region. All crop regions must lie within this region.
* The bounds are represented as a four element array, that descibes the
* [x, y, width, height] of the area.
*
* The size and position of the crop
* bounds will only be known, once the v4l2 device is opened and the
* input source selected. Applications can connect to the
* "notify::crop-bounds" signal to be notified when the bounding region is
* updated, and set an appropriate crop region.
*
* Since: 1.22
*/
g_object_class_install_property (gobject_class, PROP_CROP_BOUNDS,
gst_param_spec_array ("crop-bounds", "Crop bounds",
"The bounding region for crop rectangles ('<x, y, width, height>').",
g_param_spec_int ("rect-value", "Rectangle Value",
"One of x, y, width or height value.", G_MININT, G_MAXINT, -1,
G_PARAM_READABLE | G_PARAM_STATIC_STRINGS),
G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
/**
* GstV4l2Src::prepare-format:
* @v4l2src: the v4l2src instance
* @fd: the file descriptor of the current device
* @caps: the caps of the format being set
*
* This signal gets emitted before calling the v4l2 VIDIOC_S_FMT ioctl
* (set format). This allows for any custom configuration of the device to
* happen prior to the format being set.
* This is mostly useful for UVC H264 encoding cameras which need the H264
* Probe & Commit to happen prior to the normal Probe & Commit.
*/
gst_v4l2_signals[SIGNAL_PRE_SET_FORMAT] = g_signal_new ("prepare-format",
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
0, NULL, NULL, NULL, G_TYPE_NONE, 2, G_TYPE_INT, GST_TYPE_CAPS);
gst_element_class_set_static_metadata (element_class,
"Video (video4linux2) Source", "Source/Video",
"Reads frames from a Video4Linux2 device",
"Edgard Lima <edgard.lima@gmail.com>, "
"Stefan Kost <ensonic@users.sf.net>");
gst_element_class_add_pad_template
(element_class,
gst_pad_template_new ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
gst_v4l2_object_get_all_caps ()));
basesrc_class->get_caps = GST_DEBUG_FUNCPTR (gst_v4l2src_get_caps);
basesrc_class->start = GST_DEBUG_FUNCPTR (gst_v4l2src_start);
basesrc_class->unlock = GST_DEBUG_FUNCPTR (gst_v4l2src_unlock);
basesrc_class->unlock_stop = GST_DEBUG_FUNCPTR (gst_v4l2src_unlock_stop);
basesrc_class->stop = GST_DEBUG_FUNCPTR (gst_v4l2src_stop);
basesrc_class->query = GST_DEBUG_FUNCPTR (gst_v4l2src_query);
basesrc_class->negotiate = GST_DEBUG_FUNCPTR (gst_v4l2src_negotiate);
basesrc_class->decide_allocation =
GST_DEBUG_FUNCPTR (gst_v4l2src_decide_allocation);
pushsrc_class->create = GST_DEBUG_FUNCPTR (gst_v4l2src_create);
klass->v4l2_class_devices = NULL;
GST_DEBUG_CATEGORY_INIT (v4l2src_debug, "v4l2src", 0, "V4L2 source element");
}
static void
gst_v4l2src_init (GstV4l2Src * v4l2src)
{
/* fixme: give an update_fps_function */
v4l2src->v4l2object = gst_v4l2_object_new (GST_ELEMENT (v4l2src),
GST_OBJECT (GST_BASE_SRC_PAD (v4l2src)), V4L2_BUF_TYPE_VIDEO_CAPTURE,
DEFAULT_PROP_DEVICE, gst_v4l2_get_input, gst_v4l2_set_input, NULL);
/* Avoid the slow probes */
v4l2src->v4l2object->skip_try_fmt_probes = TRUE;
gst_base_src_set_format (GST_BASE_SRC (v4l2src), GST_FORMAT_TIME);
gst_base_src_set_live (GST_BASE_SRC (v4l2src), TRUE);
}
static void
gst_v4l2src_finalize (GstV4l2Src * v4l2src)
{
gst_v4l2_object_destroy (v4l2src->v4l2object);
G_OBJECT_CLASS (parent_class)->finalize ((GObject *) (v4l2src));
}
static void
gst_v4l2src_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec)
{
GstV4l2Src *v4l2src = GST_V4L2SRC (object);
if (!gst_v4l2_object_set_property_helper (v4l2src->v4l2object,
prop_id, value, pspec)) {
switch (prop_id) {
case PROP_CROP_TOP:
v4l2src->crop_top = g_value_get_uint (value);
break;
case PROP_CROP_LEFT:
v4l2src->crop_left = g_value_get_uint (value);
break;
case PROP_CROP_BOTTOM:
v4l2src->crop_bottom = g_value_get_uint (value);
break;
case PROP_CROP_RIGHT:
v4l2src->crop_right = g_value_get_uint (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
}
static void
gst_v4l2src_set_rect_value (GValue * value, struct v4l2_rect *rect)
{
GValue val = { 0 };
g_value_init (&val, G_TYPE_INT);
g_value_reset (value);
g_value_set_int (&val, rect->left);
gst_value_array_append_value (value, &val);
g_value_set_int (&val, rect->top);
gst_value_array_append_value (value, &val);
g_value_set_int (&val, rect->width);
gst_value_array_append_value (value, &val);
g_value_set_int (&val, rect->height);
gst_value_array_append_value (value, &val);
g_value_unset (&val);
}
static void
gst_v4l2src_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec)
{
GstV4l2Src *v4l2src = GST_V4L2SRC (object);
if (!gst_v4l2_object_get_property_helper (v4l2src->v4l2object,
prop_id, value, pspec)) {
switch (prop_id) {
case PROP_CROP_TOP:
g_value_set_uint (value, v4l2src->crop_top);
break;
case PROP_CROP_LEFT:
g_value_set_uint (value, v4l2src->crop_left);
break;
case PROP_CROP_BOTTOM:
g_value_set_uint (value, v4l2src->crop_bottom);
break;
case PROP_CROP_RIGHT:
g_value_set_uint (value, v4l2src->crop_right);
break;
case PROP_CROP_BOUNDS:
gst_v4l2src_set_rect_value (value, &v4l2src->crop_bounds);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
}
static gboolean
gst_vl42_src_fixate_fields (GQuark field_id, GValue * value, gpointer user_data)
{
GstStructure *s = user_data;
if (field_id == g_quark_from_string ("interlace-mode"))
return TRUE;
if (field_id == g_quark_from_string ("colorimetry"))
return TRUE;
gst_structure_fixate_field (s, g_quark_to_string (field_id));
return TRUE;
}
static void
gst_v4l2_src_fixate_struct_with_preference (GstStructure * s,
struct PreferredCapsInfo *pref)
{
if (gst_structure_has_field (s, "width"))
gst_structure_fixate_field_nearest_int (s, "width", pref->width);
if (gst_structure_has_field (s, "height"))
gst_structure_fixate_field_nearest_int (s, "height", pref->height);
if (gst_structure_has_field (s, "framerate"))
gst_structure_fixate_field_nearest_fraction (s, "framerate", pref->fps_n,
pref->fps_d);
/* Finally, fixate everything else except the interlace-mode and colorimetry
* which still need further negotiation as it wasn't probed */
gst_structure_map_in_place (s, gst_vl42_src_fixate_fields, s);
}
static void
gst_v4l2_src_parse_fixed_struct (GstStructure * s,
gint * width, gint * height, gint * fps_n, gint * fps_d)
{
if (gst_structure_has_field (s, "width") && width)
gst_structure_get_int (s, "width", width);
if (gst_structure_has_field (s, "height") && height)
gst_structure_get_int (s, "height", height);
if (gst_structure_has_field (s, "framerate") && fps_n && fps_d)
gst_structure_get_fraction (s, "framerate", fps_n, fps_d);
}
static gint
gst_v4l2src_fixed_caps_compare (GstCaps * caps_a, GstCaps * caps_b,
struct PreferredCapsInfo *pref)
{
GstStructure *a, *b;
gint aw = G_MAXINT, ah = G_MAXINT;
gint bw = G_MAXINT, bh = G_MAXINT;
gint a_fps_n = G_MAXINT, a_fps_d = 1;
gint b_fps_n = G_MAXINT, b_fps_d = 1;
gint a_distance, b_distance;
gint ret = 0;
a = gst_caps_get_structure (caps_a, 0);
b = gst_caps_get_structure (caps_b, 0);
gst_v4l2_src_parse_fixed_struct (a, &aw, &ah, &a_fps_n, &a_fps_d);
gst_v4l2_src_parse_fixed_struct (b, &bw, &bh, &b_fps_n, &b_fps_d);
// Sort first the one with closest framerate to preference. Note that any
// framerate lower then 1 frame per second will be considered the same. In
// practice this should be fine considering that these framerate only exists
// for still picture, in which case the resolution is most likely the key.
a_distance = ABS ((a_fps_n / a_fps_d) - (pref->fps_n / pref->fps_d));
b_distance = ABS ((b_fps_n / b_fps_d) - (pref->fps_n / pref->fps_d));
if (a_distance != b_distance)
return a_distance - b_distance;
// If same framerate, sort first the one with closest resolution to preference
a_distance = ABS (aw * ah - pref->width * pref->height);
b_distance = ABS (bw * bh - pref->width * pref->height);
/* If the distance are equivalent, maintain the order */
if (a_distance == b_distance)
ret = 1;
else
ret = a_distance - b_distance;
GST_TRACE ("Placing %" GST_PTR_FORMAT " %s %" GST_PTR_FORMAT,
caps_a, ret > 0 ? "after" : "before", caps_b);
return ret;
}
static gboolean
gst_v4l2src_do_source_crop (GstV4l2Src * v4l2src)
{
struct v4l2_rect def_crop;
if (v4l2src->apply_crop_settings)
return gst_v4l2_object_set_crop (v4l2src->v4l2object, &v4l2src->crop_rect);
/* If no crop setting is given, reset to the default. Resetting the default
* crop may fail if the device does not support cropping. This should not
* be considered an error. */
if (gst_v4l2_object_get_crop_default (v4l2src->v4l2object, &def_crop))
gst_v4l2_object_set_crop (v4l2src->v4l2object, &def_crop);
return TRUE;
}
static gboolean
gst_v4l2src_set_format (GstV4l2Src * v4l2src, GstCaps * caps,
GstV4l2Error * error)
{
GstV4l2Object *obj;
obj = v4l2src->v4l2object;
/* make sure we stop capturing and dealloc buffers */
if (!gst_v4l2_object_stop (obj))
return FALSE;
g_signal_emit (v4l2src, gst_v4l2_signals[SIGNAL_PRE_SET_FORMAT], 0,
v4l2src->v4l2object->video_fd, caps);
if (!gst_v4l2src_do_source_crop (v4l2src))
return FALSE;
return gst_v4l2_object_set_format (obj, caps, error);
}
static GstCaps *
gst_v4l2src_fixate (GstBaseSrc * basesrc, GstCaps * caps,
struct PreferredCapsInfo *pref)
{
GstV4l2Src *v4l2src = GST_V4L2SRC (basesrc);
GstV4l2Object *obj = v4l2src->v4l2object;
GList *caps_list = NULL;
GstStructure *s;
gint i = G_MAXINT;
GstV4l2Error error = GST_V4L2_ERROR_INIT;
GstCaps *fcaps = NULL;
GST_DEBUG_OBJECT (basesrc, "Fixating caps %" GST_PTR_FORMAT, caps);
GST_DEBUG_OBJECT (basesrc, "Preferred size %ix%i", pref->width, pref->height);
/* Sort the structures to get the caps that is nearest to our preferences,
* first. Use single struct caps for sorting so we preserve the features. */
for (i = 0; i < gst_caps_get_size (caps); i++) {
GstCaps *tmp = gst_caps_copy_nth (caps, i);
s = gst_caps_get_structure (tmp, 0);
gst_v4l2_src_fixate_struct_with_preference (s, pref);
caps_list = g_list_insert_sorted_with_data (caps_list, tmp,
(GCompareDataFunc) gst_v4l2src_fixed_caps_compare, pref);
}
gst_caps_unref (caps);
caps = gst_caps_new_empty ();
while (caps_list) {
GstCaps *tmp = caps_list->data;
caps_list = g_list_delete_link (caps_list, caps_list);
gst_caps_append (caps, tmp);
}
GST_DEBUG_OBJECT (basesrc, "sorted and normalized caps %" GST_PTR_FORMAT,
caps);
/* Each structure in the caps has been fixated, except for the
* interlace-mode and colorimetry. Now normalize the caps so we can
* enumerate the possibilities */
caps = gst_caps_normalize (caps);
/* try hard to avoid TRY_FMT since some UVC camera just crash when this
* is called at run-time. */
if (gst_v4l2_object_caps_is_subset (obj, caps)) {
fcaps = gst_v4l2_object_get_current_caps (obj);
GST_DEBUG_OBJECT (basesrc, "reuse current caps %" GST_PTR_FORMAT, fcaps);
goto out;
}
for (i = 0; i < gst_caps_get_size (caps); ++i) {
gst_v4l2_clear_error (&error);
if (fcaps)
gst_caps_unref (fcaps);
fcaps = gst_caps_copy_nth (caps, i);
/* Just check if the format is acceptable, once we know
* no buffers should be outstanding we try S_FMT.
*
* Basesrc will do an allocation query that
* should indirectly reclaim buffers, after that we can
* set the format and then configure our pool */
if (gst_v4l2_object_try_format (obj, fcaps, &error)) {
/* make sure the caps changed before doing anything */
if (gst_v4l2_object_caps_equal (obj, fcaps))
break;
v4l2src->renegotiation_adjust = v4l2src->offset + 1;
v4l2src->pending_set_fmt = TRUE;
break;
}
/* Only EIVAL make sense, report any other errors, this way we don't keep
* probing if the device got disconnected, or if it's firmware stopped
* responding */
if (error.error->code != GST_RESOURCE_ERROR_SETTINGS) {
i = G_MAXINT;
break;
}
}
if (i >= gst_caps_get_size (caps)) {
gst_v4l2_error (v4l2src, &error);
if (fcaps)
gst_caps_unref (fcaps);
gst_caps_unref (caps);
return NULL;
}
out:
gst_caps_unref (caps);
GST_DEBUG_OBJECT (basesrc, "fixated caps %" GST_PTR_FORMAT, fcaps);
return fcaps;
}
static gboolean
gst_v4l2src_query_preferred_dv_timings (GstV4l2Src * v4l2src,
struct PreferredCapsInfo *pref)
{
GstV4l2Object *obj = v4l2src->v4l2object;
struct v4l2_dv_timings dv_timings = { 0, };
const struct v4l2_bt_timings *bt = &dv_timings.bt;
gboolean not_streaming;
gint tot_width, tot_height;
gint gcd;
if (!gst_v4l2_query_dv_timings (obj, &dv_timings))
return FALSE;
pref->width = bt->width;
pref->height = bt->height;
tot_height = bt->height +
bt->vfrontporch + bt->vsync + bt->vbackporch +
bt->il_vfrontporch + bt->il_vsync + bt->il_vbackporch;
tot_width = bt->width + bt->hfrontporch + bt->hsync + bt->hbackporch;
pref->fps_n = bt->pixelclock;
pref->fps_d = tot_width * tot_height;
if (bt->interlaced)
pref->fps_d /= 2;
gcd = gst_util_greatest_common_divisor (pref->fps_n, pref->fps_d);
pref->fps_n /= gcd;
pref->fps_d /= gcd;
/* If are are not streaming (e.g. we received source-change event), lock the
* new timing immediatly so that TRY_FMT can properly work */
{
GstBufferPool *obj_pool = gst_v4l2_object_get_buffer_pool (obj);
not_streaming = !obj_pool || !GST_V4L2_BUFFER_POOL_IS_STREAMING (obj_pool);
if (obj_pool)
gst_object_unref (obj_pool);
}
if (not_streaming) {
gst_v4l2_set_dv_timings (obj, &dv_timings);
/* Setting a new DV timings invalidates the probed caps. */
gst_caps_replace (&obj->probed_caps, NULL);
}
GST_INFO_OBJECT (v4l2src, "Using DV Timings: %i x %i (%i/%i fps)",
pref->width, pref->height, pref->fps_n, pref->fps_d);
return TRUE;
}
static gboolean
gst_v4l2src_query_preferred_size (GstV4l2Src * v4l2src,
struct PreferredCapsInfo *pref)
{
struct v4l2_input in = { 0, };
if (!gst_v4l2_get_input (v4l2src->v4l2object, &in.index))
return FALSE;
if (!gst_v4l2_query_input (v4l2src->v4l2object, &in))
return FALSE;
GST_INFO_OBJECT (v4l2src, "Detect input %u as `%s`", in.index, in.name);
/* Notify signal status using WARNING/INFO messages */
if (in.status & (V4L2_IN_ST_NO_POWER | V4L2_IN_ST_NO_SIGNAL)) {
if (!v4l2src->no_signal)
/* note: taken from decklinksrc element */
GST_ELEMENT_WARNING (v4l2src, RESOURCE, READ, ("Signal lost"),
("No input source was detected - video frames invalid"));
v4l2src->no_signal = TRUE;
} else if (v4l2src->no_signal) {
if (v4l2src->no_signal)
GST_ELEMENT_INFO (v4l2src, RESOURCE, READ,
("Signal recovered"), ("Input source detected"));
v4l2src->no_signal = FALSE;
}
if (in.capabilities & V4L2_IN_CAP_NATIVE_SIZE) {
GST_FIXME_OBJECT (v4l2src, "missing support for native video size");
return FALSE;
} else if (in.capabilities & V4L2_IN_CAP_DV_TIMINGS) {
return gst_v4l2src_query_preferred_dv_timings (v4l2src, pref);
} else if (in.capabilities & V4L2_IN_CAP_STD) {
GST_FIXME_OBJECT (v4l2src, "missing support for video standards");
return FALSE;
}
return FALSE;
}
static gboolean
gst_v4l2src_setup_source_crop (GstV4l2Src * v4l2src,
struct PreferredCapsInfo *pref)
{
gint cropped_width, cropped_height;
struct v4l2_rect *crop_bounds = &v4l2src->crop_bounds;
v4l2src->apply_crop_settings = FALSE;
if (!gst_v4l2_object_get_crop_bounds (v4l2src->v4l2object, crop_bounds))
return FALSE;
g_object_notify (G_OBJECT (v4l2src), "crop-bounds");
cropped_width = crop_bounds->width - v4l2src->crop_left - v4l2src->crop_right;
cropped_height =
crop_bounds->height - v4l2src->crop_top - v4l2src->crop_bottom;
if (v4l2src->crop_left < crop_bounds->left
|| v4l2src->crop_top < crop_bounds->top
|| cropped_width <= 0 || cropped_height <= 0) {
GST_WARNING_OBJECT (v4l2src, "Ignoring out of bounds crop region");
return FALSE;
}
if (cropped_width == crop_bounds->width
&& cropped_height == crop_bounds->height) {
GST_DEBUG_OBJECT (v4l2src,
"No cropping requested, keep current preferred size");
return FALSE;
}
v4l2src->crop_rect.left = v4l2src->crop_left;
v4l2src->crop_rect.top = v4l2src->crop_top;
v4l2src->crop_rect.width = cropped_width;
v4l2src->crop_rect.height = cropped_height;
v4l2src->apply_crop_settings = TRUE;
pref->width = cropped_width;
pref->height = cropped_height;
GST_INFO_OBJECT (v4l2src, "Updated preferred capture size to %i x %i",
pref->width, pref->height);
return TRUE;
}
static gboolean
gst_v4l2src_negotiate (GstBaseSrc * basesrc)
{
GstV4l2Src *v4l2src = GST_V4L2SRC (basesrc);
GstCaps *thiscaps;
GstCaps *caps = NULL;
GstCaps *peercaps = NULL;
gboolean result = FALSE;
/* Let's prefer a good resolution as of today's standard. */
struct PreferredCapsInfo pref = {
3840, 2160, 120, 1
};
gboolean have_pref;
/* For drivers that has DV timings or other default size query
* capabilities, we will prefer that resolution. This must happen before we
* probe the caps, as locking DV Timings or standards will change result of
* the caps enumeration. */
have_pref = gst_v4l2src_query_preferred_size (v4l2src, &pref);
have_pref |= gst_v4l2src_setup_source_crop (v4l2src, &pref);
/* first see what is possible on our source pad */
thiscaps = gst_pad_query_caps (GST_BASE_SRC_PAD (basesrc), NULL);
GST_DEBUG_OBJECT (basesrc, "caps of src: %" GST_PTR_FORMAT, thiscaps);
/* nothing or anything is allowed, we're done */
if (thiscaps == NULL || gst_caps_is_any (thiscaps))
goto no_nego_needed;
/* get the peer caps without a filter as we'll filter ourselves later on */
peercaps = gst_pad_peer_query_caps (GST_BASE_SRC_PAD (basesrc), NULL);
GST_DEBUG_OBJECT (basesrc, "caps of peer: %" GST_PTR_FORMAT, peercaps);
if (peercaps && !gst_caps_is_any (peercaps)) {
/* Prefer the first caps we are compatible with that the peer proposed */
caps = gst_caps_intersect_full (peercaps, thiscaps,
GST_CAPS_INTERSECT_FIRST);
GST_DEBUG_OBJECT (basesrc, "intersect: %" GST_PTR_FORMAT, caps);
gst_caps_unref (thiscaps);
} else {
/* no peer or peer have ANY caps, work with our own caps then */
caps = thiscaps;
}
if (caps) {
/* now fixate */
if (!gst_caps_is_empty (caps)) {
/* otherwise consider the first structure from peercaps to be a
* preference. This is useful for matching a reported native display,
* or simply to avoid transformation to happen downstream. */
if (!have_pref && peercaps && !gst_caps_is_any (peercaps)) {
GstStructure *pref_s = gst_caps_get_structure (peercaps, 0);
pref_s = gst_structure_copy (pref_s);
gst_v4l2_src_fixate_struct_with_preference (pref_s, &pref);
gst_v4l2_src_parse_fixed_struct (pref_s, &pref.width, &pref.height,
&pref.fps_n, &pref.fps_d);
gst_structure_free (pref_s);
}
caps = gst_v4l2src_fixate (basesrc, caps, &pref);
/* Fixating may fail as we now set the selected format */
if (!caps) {
result = FALSE;
goto done;
}
GST_INFO_OBJECT (basesrc, "fixated to: %" GST_PTR_FORMAT, caps);
if (gst_caps_is_any (caps)) {
/* hmm, still anything, so element can do anything and
* nego is not needed */
result = TRUE;
} else if (gst_caps_is_fixed (caps)) {
/* yay, fixed caps, use those then */
result = gst_base_src_set_caps (basesrc, caps);
}
}
gst_caps_unref (caps);
}
done:
if (peercaps)
gst_caps_unref (peercaps);
return result;
no_nego_needed:
{
GST_INFO_OBJECT (basesrc, "no negotiation needed");
if (thiscaps)
gst_caps_unref (thiscaps);
return TRUE;
}
}
static GstCaps *
gst_v4l2src_get_caps (GstBaseSrc * src, GstCaps * filter)
{
GstV4l2Src *v4l2src;
GstV4l2Object *obj;
v4l2src = GST_V4L2SRC (src);
obj = v4l2src->v4l2object;
if (!GST_V4L2_IS_OPEN (obj)) {
return gst_pad_get_pad_template_caps (GST_BASE_SRC_PAD (v4l2src));
}
return gst_v4l2_object_get_caps (obj, filter);
}
static gboolean
gst_v4l2src_decide_allocation (GstBaseSrc * bsrc, GstQuery * query)
{
GstV4l2Src *src = GST_V4L2SRC (bsrc);
GstBufferPool *bpool = gst_v4l2_object_get_buffer_pool (src->v4l2object);
gboolean ret = TRUE;
if (src->pending_set_fmt) {
GstCaps *caps = gst_pad_get_current_caps (GST_BASE_SRC_PAD (bsrc));
GstV4l2Error error = GST_V4L2_ERROR_INIT;
/* Setting the format replaces the current pool */
gst_clear_object (&bpool);
caps = gst_caps_make_writable (caps);
ret = gst_v4l2src_set_format (src, caps, &error);
if (ret) {
GstV4l2BufferPool *pool;
bpool = gst_v4l2_object_get_buffer_pool (src->v4l2object);
pool = GST_V4L2_BUFFER_POOL (bpool);
gst_v4l2_buffer_pool_enable_resolution_change (pool);
} else {
gst_v4l2_error (src, &error);
}
gst_caps_unref (caps);
src->pending_set_fmt = FALSE;
} else if (gst_buffer_pool_is_active (bpool)) {
/* Trick basesrc into not deactivating the active pool. Renegotiating here
* would otherwise turn off and on the camera. */
GstAllocator *allocator;
GstAllocationParams params;
GstBufferPool *pool;
gst_base_src_get_allocator (bsrc, &allocator, &params);
pool = gst_base_src_get_buffer_pool (bsrc);
if (gst_query_get_n_allocation_params (query))
gst_query_set_nth_allocation_param (query, 0, allocator, &params);
else
gst_query_add_allocation_param (query, allocator, &params);
if (gst_query_get_n_allocation_pools (query))
gst_query_set_nth_allocation_pool (query, 0, pool,
src->v4l2object->info.size, 1, 0);
else
gst_query_add_allocation_pool (query, pool, src->v4l2object->info.size, 1,
0);
if (pool)
gst_object_unref (pool);
if (allocator)
gst_object_unref (allocator);
if (bpool)
gst_object_unref (bpool);
return GST_BASE_SRC_CLASS (parent_class)->decide_allocation (bsrc, query);
}
if (ret) {
ret = gst_v4l2_object_decide_allocation (src->v4l2object, query);
if (ret)
ret = GST_BASE_SRC_CLASS (parent_class)->decide_allocation (bsrc, query);
}
if (ret) {
if (!gst_buffer_pool_set_active (bpool, TRUE))
goto activate_failed;
}
if (bpool)
gst_object_unref (bpool);
return ret;
activate_failed:
{
GST_ELEMENT_ERROR (src, RESOURCE, SETTINGS,
(_("Failed to allocate required memory.")),
("Buffer pool activation failed"));
if (bpool)
gst_object_unref (bpool);
return FALSE;
}
}
static gboolean
gst_v4l2src_query (GstBaseSrc * bsrc, GstQuery * query)
{
GstV4l2Src *src;
GstV4l2Object *obj;
gboolean res = FALSE;
src = GST_V4L2SRC (bsrc);
obj = src->v4l2object;
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_LATENCY:{
GstClockTime min_latency, max_latency;
guint32 fps_n, fps_d;
guint num_buffers = 0;
/* device must be open */
if (!GST_V4L2_IS_OPEN (obj)) {
GST_WARNING_OBJECT (src,
"Can't give latency since device isn't open !");
goto done;
}
fps_n = GST_V4L2_FPS_N (obj);
fps_d = GST_V4L2_FPS_D (obj);
/* we must have a framerate */
if (fps_n <= 0 || fps_d <= 0) {
GST_WARNING_OBJECT (src,
"Can't give latency since framerate isn't fixated !");
goto done;
}
/* min latency is the time to capture one frame/field */
min_latency = gst_util_uint64_scale_int (GST_SECOND, fps_d, fps_n);
if (GST_VIDEO_INFO_INTERLACE_MODE (&obj->info) ==
GST_VIDEO_INTERLACE_MODE_ALTERNATE)
min_latency /= 2;
/* max latency is total duration of the frame buffer */
{
GstBufferPool *obj_pool = gst_v4l2_object_get_buffer_pool (obj);
if (obj_pool != NULL) {
num_buffers = GST_V4L2_BUFFER_POOL_CAST (obj_pool)->max_latency;
gst_object_unref (obj_pool);
}
}
if (num_buffers == 0)
max_latency = -1;
else
max_latency = num_buffers * min_latency;
GST_DEBUG_OBJECT (bsrc,
"report latency min %" GST_TIME_FORMAT " max %" GST_TIME_FORMAT,
GST_TIME_ARGS (min_latency), GST_TIME_ARGS (max_latency));
/* we are always live, the min latency is 1 frame and the max latency is
* the complete buffer of frames. */
gst_query_set_latency (query, TRUE, min_latency, max_latency);
res = TRUE;
break;
}
default:
res = GST_BASE_SRC_CLASS (parent_class)->query (bsrc, query);
break;
}
done:
return res;
}
/* start and stop are not symmetric -- start will open the device, but not start
* capture. it's setcaps that will start capture, which is called via basesrc's
* negotiate method. stop will both stop capture and close the device.
*/
static gboolean
gst_v4l2src_start (GstBaseSrc * src)
{
GstV4l2Src *v4l2src = GST_V4L2SRC (src);
v4l2src->offset = 0;
v4l2src->next_offset_same = FALSE;
v4l2src->renegotiation_adjust = 0;
/* activate settings for first frame */
v4l2src->ctrl_time = 0;
gst_object_sync_values (GST_OBJECT (src), v4l2src->ctrl_time);
v4l2src->has_bad_timestamp = FALSE;
v4l2src->last_timestamp = 0;
return TRUE;
}
static gboolean
gst_v4l2src_unlock (GstBaseSrc * src)
{
GstV4l2Src *v4l2src = GST_V4L2SRC (src);
return gst_v4l2_object_unlock (v4l2src->v4l2object);
}
static gboolean
gst_v4l2src_unlock_stop (GstBaseSrc * src)
{
GstV4l2Src *v4l2src = GST_V4L2SRC (src);
v4l2src->last_timestamp = 0;
return gst_v4l2_object_unlock_stop (v4l2src->v4l2object);
}
static gboolean
gst_v4l2src_stop (GstBaseSrc * src)
{
GstV4l2Src *v4l2src = GST_V4L2SRC (src);
GstV4l2Object *obj = v4l2src->v4l2object;
if (GST_V4L2_IS_ACTIVE (obj)) {
if (!gst_v4l2_object_stop (obj))
return FALSE;
}
v4l2src->pending_set_fmt = FALSE;
return TRUE;
}
static GstStateChangeReturn
gst_v4l2src_change_state (GstElement * element, GstStateChange transition)
{
GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
GstV4l2Src *v4l2src = GST_V4L2SRC (element);
GstV4l2Object *obj = v4l2src->v4l2object;
GstV4l2Error error = GST_V4L2_ERROR_INIT;
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
/* open the device */
if (!gst_v4l2_object_open (obj, &error)) {
gst_v4l2_error (v4l2src, &error);
return GST_STATE_CHANGE_FAILURE;
}
break;
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
switch (transition) {
case GST_STATE_CHANGE_READY_TO_NULL:
/* close the device */
if (!gst_v4l2_object_close (obj))
return GST_STATE_CHANGE_FAILURE;
break;
default:
break;
}
return ret;
}
static gboolean
gst_v4l2src_handle_resolution_change (GstV4l2Src * v4l2src)
{
GST_INFO_OBJECT (v4l2src, "Resolution change detected.");
/* It is required to always cycle through streamoff, we also need to
* streamoff in order to allow locking a new DV_TIMING which will
* influence the output of TRY_FMT */
gst_v4l2src_stop (GST_BASE_SRC (v4l2src));
/* Force renegotiation */
v4l2src->renegotiation_adjust = v4l2src->offset + 1;
v4l2src->pending_set_fmt = TRUE;
return gst_base_src_negotiate (GST_BASE_SRC (v4l2src));
}
static GstFlowReturn
gst_v4l2src_create (GstPushSrc * src, GstBuffer ** buf)
{
GstV4l2Src *v4l2src = GST_V4L2SRC (src);
GstV4l2Object *obj = v4l2src->v4l2object;
GstFlowReturn ret;
GstClock *clock;
GstClockTime abs_time, base_time, timestamp, duration;
GstClockTime delay;
GstMessage *qos_msg;
gboolean half_frame;
do {
ret = GST_BASE_SRC_CLASS (parent_class)->alloc (GST_BASE_SRC (src), 0,
obj->info.size, buf);
if (G_UNLIKELY (ret != GST_FLOW_OK)) {
if (ret == GST_V4L2_FLOW_RESOLUTION_CHANGE) {
if (!gst_v4l2src_handle_resolution_change (v4l2src)) {
ret = GST_FLOW_NOT_NEGOTIATED;
goto error;
}
continue;
}
goto alloc_failed;
}
{
GstV4l2BufferPool *obj_pool =
GST_V4L2_BUFFER_POOL_CAST (gst_v4l2_object_get_buffer_pool (obj));
ret = gst_v4l2_buffer_pool_process (obj_pool, buf, NULL);
if (obj_pool)
gst_object_unref (obj_pool);
if (G_UNLIKELY (ret == GST_V4L2_FLOW_RESOLUTION_CHANGE)) {
if (!gst_v4l2src_handle_resolution_change (v4l2src)) {
ret = GST_FLOW_NOT_NEGOTIATED;
goto error;
}
}
}
} while (ret == GST_V4L2_FLOW_CORRUPTED_BUFFER ||
ret == GST_V4L2_FLOW_RESOLUTION_CHANGE);
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto error;
timestamp = GST_BUFFER_TIMESTAMP (*buf);
duration = obj->duration;
/* timestamps, LOCK to get clock and base time. */
/* FIXME: element clock and base_time is rarely changing */
GST_OBJECT_LOCK (v4l2src);
if ((clock = GST_ELEMENT_CLOCK (v4l2src))) {
/* we have a clock, get base time and ref clock */
base_time = GST_ELEMENT (v4l2src)->base_time;
gst_object_ref (clock);
} else {
/* no clock, can't set timestamps */
base_time = GST_CLOCK_TIME_NONE;
}
GST_OBJECT_UNLOCK (v4l2src);
/* sample pipeline clock */
if (clock) {
abs_time = gst_clock_get_time (clock);
gst_object_unref (clock);
} else {
abs_time = GST_CLOCK_TIME_NONE;
}
retry:
if (!v4l2src->has_bad_timestamp && timestamp != GST_CLOCK_TIME_NONE) {
struct timespec now;
GstClockTime gstnow;
/* v4l2 specs say to use the system time although many drivers switched to
* the more desirable monotonic time. We first try to use the monotonic time
* and see how that goes */
clock_gettime (CLOCK_MONOTONIC, &now);
gstnow = GST_TIMESPEC_TO_TIME (now);
if (timestamp > gstnow || (gstnow - timestamp) > (10 * GST_SECOND)) {
/* very large diff, fall back to system time */
gstnow = g_get_real_time () * GST_USECOND;
}
/* Detect buggy drivers here, and stop using their timestamp. Failing any
* of these condition would imply a very buggy driver:
* - Timestamp in the future
* - Timestamp is going backward compare to last seen timestamp
* - Timestamp is jumping forward for less then a frame duration
* - Delay is bigger then the actual timestamp
* */
if (timestamp > gstnow) {
GST_WARNING_OBJECT (v4l2src,
"Timestamp in the future detected, ignoring driver timestamps");
v4l2src->has_bad_timestamp = TRUE;
goto retry;
}
if (v4l2src->last_timestamp > timestamp) {
GST_WARNING_OBJECT (v4l2src,
"Timestamp going backward, ignoring driver timestamps");
v4l2src->has_bad_timestamp = TRUE;
goto retry;
}
delay = gstnow - timestamp;
if (delay > timestamp) {
GST_WARNING_OBJECT (v4l2src,
"Timestamp does not correlate with any clock, ignoring driver timestamps");
v4l2src->has_bad_timestamp = TRUE;
goto retry;
}
/* Save last timestamp for sanity checks */
v4l2src->last_timestamp = timestamp;
GST_DEBUG_OBJECT (v4l2src, "ts: %" GST_TIME_FORMAT " now %" GST_TIME_FORMAT
" delay %" GST_TIME_FORMAT, GST_TIME_ARGS (timestamp),
GST_TIME_ARGS (gstnow), GST_TIME_ARGS (delay));
} else {
/* we assume 1 frame/field latency otherwise */
if (GST_CLOCK_TIME_IS_VALID (duration))
delay = duration;
else
delay = 0;
}
/* set buffer metadata */
if (G_LIKELY (abs_time != GST_CLOCK_TIME_NONE)) {
/* the time now is the time of the clock minus the base time */
timestamp = abs_time - base_time;
/* adjust for delay in the device */
if (timestamp > delay)
timestamp -= delay;
else
timestamp = 0;
} else {
timestamp = GST_CLOCK_TIME_NONE;
}
/* activate settings for next frame */
if (GST_CLOCK_TIME_IS_VALID (duration)) {
v4l2src->ctrl_time += duration;
} else {
/* this is not very good (as it should be the next timestamp),
* still good enough for linear fades (as long as it is not -1)
*/
v4l2src->ctrl_time = timestamp;
}
gst_object_sync_values (GST_OBJECT (src), v4l2src->ctrl_time);
GST_LOG_OBJECT (src, "sync to %" GST_TIME_FORMAT " out ts %" GST_TIME_FORMAT,
GST_TIME_ARGS (v4l2src->ctrl_time), GST_TIME_ARGS (timestamp));
if (v4l2src->next_offset_same &&
GST_BUFFER_OFFSET_IS_VALID (*buf) &&
GST_BUFFER_OFFSET (*buf) != v4l2src->offset) {
/* Probably had a lost field then, best to forget about last field. */
GST_WARNING_OBJECT (v4l2src,
"lost field detected - ts: %" GST_TIME_FORMAT,
GST_TIME_ARGS (timestamp));
v4l2src->next_offset_same = FALSE;
}
half_frame = (GST_BUFFER_FLAG_IS_SET (*buf, GST_VIDEO_BUFFER_FLAG_ONEFIELD));
if (half_frame)
v4l2src->next_offset_same = !v4l2src->next_offset_same;
/* use generated offset values only if there are not already valid ones
* set by the v4l2 device */
if (!GST_BUFFER_OFFSET_IS_VALID (*buf)
|| !GST_BUFFER_OFFSET_END_IS_VALID (*buf)
|| GST_BUFFER_OFFSET (*buf) <=
(v4l2src->offset - v4l2src->renegotiation_adjust)) {
GST_BUFFER_OFFSET (*buf) = v4l2src->offset;
GST_BUFFER_OFFSET_END (*buf) = v4l2src->offset + 1;
if (!half_frame || !v4l2src->next_offset_same)
v4l2src->offset++;
} else {
/* adjust raw v4l2 device sequence, will restart at null in case of renegotiation
* (streamoff/streamon) */
GST_BUFFER_OFFSET (*buf) += v4l2src->renegotiation_adjust;
GST_BUFFER_OFFSET_END (*buf) += v4l2src->renegotiation_adjust;
/* check for frame loss with given (from v4l2 device) buffer offset */
if ((v4l2src->offset != 0)
&& (!half_frame || v4l2src->next_offset_same)
&& (GST_BUFFER_OFFSET (*buf) != (v4l2src->offset + 1))) {
guint64 lost_frame_count = GST_BUFFER_OFFSET (*buf) - v4l2src->offset - 1;
GST_WARNING_OBJECT (v4l2src,
"lost frames detected: count = %" G_GUINT64_FORMAT " - ts: %"
GST_TIME_FORMAT, lost_frame_count, GST_TIME_ARGS (timestamp));
qos_msg = gst_message_new_qos (GST_OBJECT_CAST (v4l2src), TRUE,
GST_CLOCK_TIME_NONE, GST_CLOCK_TIME_NONE, timestamp,
GST_CLOCK_TIME_IS_VALID (duration) ? lost_frame_count *
duration : GST_CLOCK_TIME_NONE);
gst_element_post_message (GST_ELEMENT_CAST (v4l2src), qos_msg);
}
v4l2src->offset = GST_BUFFER_OFFSET (*buf);
}
GST_BUFFER_TIMESTAMP (*buf) = timestamp;
GST_BUFFER_DURATION (*buf) = duration;
return ret;
/* ERROR */
alloc_failed:
{
if (ret != GST_FLOW_FLUSHING)
GST_ELEMENT_ERROR (src, RESOURCE, NO_SPACE_LEFT,
("Failed to allocate a buffer"), (NULL));
return ret;
}
error:
{
gst_buffer_replace (buf, NULL);
if (ret == GST_V4L2_FLOW_LAST_BUFFER) {
GST_ELEMENT_ERROR (src, RESOURCE, FAILED,
("Driver returned a buffer with no payload, this most likely "
"indicate a bug in the driver."), (NULL));
ret = GST_FLOW_ERROR;
} else {
GST_DEBUG_OBJECT (src, "error processing buffer %d (%s)", ret,
gst_flow_get_name (ret));
}
return ret;
}
}
/* GstURIHandler interface */
static GstURIType
gst_v4l2src_uri_get_type (GType type)
{
return GST_URI_SRC;
}
static const gchar *const *
gst_v4l2src_uri_get_protocols (GType type)
{
static const gchar *protocols[] = { "v4l2", NULL };
return protocols;
}
static gchar *
gst_v4l2src_uri_get_uri (GstURIHandler * handler)
{
GstV4l2Src *v4l2src = GST_V4L2SRC (handler);
if (v4l2src->v4l2object->videodev != NULL) {
return g_strdup_printf ("v4l2://%s", v4l2src->v4l2object->videodev);
}
return g_strdup ("v4l2://");
}
static gboolean
gst_v4l2src_uri_set_uri (GstURIHandler * handler, const gchar * uri,
GError ** error)
{
GstV4l2Src *v4l2src = GST_V4L2SRC (handler);
const gchar *device = DEFAULT_PROP_DEVICE;
if (strcmp (uri, "v4l2://") != 0) {
device = uri + 7;
}
g_object_set (v4l2src, "device", device, NULL);
return TRUE;
}
static void
gst_v4l2src_uri_handler_init (gpointer g_iface, gpointer iface_data)
{
GstURIHandlerInterface *iface = (GstURIHandlerInterface *) g_iface;
iface->get_type = gst_v4l2src_uri_get_type;
iface->get_protocols = gst_v4l2src_uri_get_protocols;
iface->get_uri = gst_v4l2src_uri_get_uri;
iface->set_uri = gst_v4l2src_uri_set_uri;
}
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