gstreamer/sys/v4l2/gstv4l2src.c
Michael Olbrich 00ffe41e6a v4l2: Don't stop streaming when set_caps is called with unchanged caps
This can happen if other parts of the pipeline are reconfigured.
Stop streaming even for a short amount of time can be quite visible, so it
should be avoided if possible.

https://bugzilla.gnome.org/show_bug.cgi?id=700503
2013-05-20 11:13:18 +02:00

930 lines
26 KiB
C

/* GStreamer
*
* Copyright (C) 2001-2002 Ronald Bultje <rbultje@ronald.bitfreak.net>
* 2006 Edgard Lima <edgard.lima@indt.org.br>
*
* 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
*
* v4l2src can be used to capture video from v4l2 devices, like webcams and tv
* cards.
*
* <refsect2>
* <title>Example launch lines</title>
* |[
* 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.
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#undef HAVE_XVIDEO
#include <string.h>
#include <sys/time.h>
#include <unistd.h>
#include <gst/video/gstvideometa.h>
#include <gst/video/gstvideopool.h>
#include "gstv4l2src.h"
#include "gstv4l2colorbalance.h"
#include "gstv4l2tuner.h"
#ifdef HAVE_XVIDEO
#include "gstv4l2xoverlay.h"
#endif
#include "gstv4l2vidorient.h"
#include "gst/gst-i18n-plugin.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_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);
#ifdef HAVE_XVIDEO
GST_IMPLEMENT_V4L2_XOVERLAY_METHODS (GstV4l2Src, gst_v4l2src);
#endif
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);
#ifdef HAVE_XVIDEO
/* FIXME: does GstXOverlay for v4l2src make sense in a GStreamer context? */
G_IMPLEMENT_INTERFACE (GST_TYPE_X_OVERLAY,
gst_v4l2src_xoverlay_interface_init);
#endif
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));
static void gst_v4l2src_dispose (GObject * object);
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 gboolean gst_v4l2src_set_caps (GstBaseSrc * src, GstCaps * caps);
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_fill (GstPushSrc * src, GstBuffer * out);
static GstCaps *gst_v4l2src_fixate (GstBaseSrc * basesrc, GstCaps * caps);
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->dispose = gst_v4l2src_dispose;
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::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.
*
* Since: 0.10.32
*/
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@indt.org.br>, "
"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->set_caps = GST_DEBUG_FUNCPTR (gst_v4l2src_set_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->fixate = GST_DEBUG_FUNCPTR (gst_v4l2src_fixate);
basesrc_class->negotiate = GST_DEBUG_FUNCPTR (gst_v4l2src_negotiate);
basesrc_class->decide_allocation =
GST_DEBUG_FUNCPTR (gst_v4l2src_decide_allocation);
pushsrc_class->fill = GST_DEBUG_FUNCPTR (gst_v4l2src_fill);
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),
V4L2_BUF_TYPE_VIDEO_CAPTURE, DEFAULT_PROP_DEVICE,
gst_v4l2_get_input, gst_v4l2_set_input, NULL);
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_dispose (GObject * object)
{
GstV4l2Src *v4l2src = GST_V4L2SRC (object);
if (v4l2src->probed_caps) {
gst_caps_unref (v4l2src->probed_caps);
}
G_OBJECT_CLASS (parent_class)->dispose (object);
}
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) {
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
}
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) {
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
}
/* this function is a bit of a last resort */
static GstCaps *
gst_v4l2src_fixate (GstBaseSrc * basesrc, GstCaps * caps)
{
GstStructure *structure;
gint i;
GST_DEBUG_OBJECT (basesrc, "fixating caps %" GST_PTR_FORMAT, caps);
caps = gst_caps_make_writable (caps);
for (i = 0; i < gst_caps_get_size (caps); ++i) {
structure = gst_caps_get_structure (caps, i);
/* We are fixating to a resonable 320x200 resolution
and the maximum framerate resolution for that size */
gst_structure_fixate_field_nearest_int (structure, "width", 320);
gst_structure_fixate_field_nearest_int (structure, "height", 200);
gst_structure_fixate_field_nearest_fraction (structure, "framerate",
G_MAXINT, 1);
gst_structure_fixate_field (structure, "format");
}
GST_DEBUG_OBJECT (basesrc, "fixated caps %" GST_PTR_FORMAT, caps);
caps = GST_BASE_SRC_CLASS (parent_class)->fixate (basesrc, caps);
return caps;
}
static gboolean
gst_v4l2src_negotiate (GstBaseSrc * basesrc)
{
GstV4l2Src *v4l2src;
GstV4l2Object *obj;
GstCaps *thiscaps;
GstCaps *caps = NULL;
GstCaps *peercaps = NULL;
gboolean result = FALSE;
v4l2src = GST_V4L2SRC (basesrc);
obj = v4l2src->v4l2object;
/* We don't allow renegotiation, just return TRUE in that case */
if (GST_V4L2_IS_ACTIVE (obj))
return TRUE;
/* 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);
LOG_CAPS (basesrc, 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 */
peercaps = gst_pad_peer_query_caps (GST_BASE_SRC_PAD (basesrc), thiscaps);
GST_DEBUG_OBJECT (basesrc, "caps of peer: %" GST_PTR_FORMAT, peercaps);
LOG_CAPS (basesrc, peercaps);
if (peercaps && !gst_caps_is_any (peercaps)) {
GstCaps *icaps = NULL;
int i;
/* Prefer the first caps we are compatible with that the peer proposed */
for (i = 0; i < gst_caps_get_size (peercaps); i++) {
/* get intersection */
GstCaps *ipcaps = gst_caps_copy_nth (peercaps, i);
GST_DEBUG_OBJECT (basesrc, "peer: %" GST_PTR_FORMAT, ipcaps);
LOG_CAPS (basesrc, ipcaps);
icaps = gst_caps_intersect (thiscaps, ipcaps);
gst_caps_unref (ipcaps);
if (!gst_caps_is_empty (icaps))
break;
gst_caps_unref (icaps);
icaps = NULL;
}
GST_DEBUG_OBJECT (basesrc, "intersect: %" GST_PTR_FORMAT, icaps);
LOG_CAPS (basesrc, icaps);
if (icaps) {
/* If there are multiple intersections pick the one with the smallest
* resolution strictly bigger then the first peer caps */
if (gst_caps_get_size (icaps) > 1) {
GstStructure *s = gst_caps_get_structure (peercaps, 0);
int best = 0;
int twidth, theight;
int width = G_MAXINT, height = G_MAXINT;
if (gst_structure_get_int (s, "width", &twidth)
&& gst_structure_get_int (s, "height", &theight)) {
/* Walk the structure backwards to get the first entry of the
* smallest resolution bigger (or equal to) the preferred resolution)
*/
for (i = gst_caps_get_size (icaps) - 1; i >= 0; i--) {
GstStructure *is = gst_caps_get_structure (icaps, i);
int w, h;
if (gst_structure_get_int (is, "width", &w)
&& gst_structure_get_int (is, "height", &h)) {
if (w >= twidth && w <= width && h >= theight && h <= height) {
width = w;
height = h;
best = i;
}
}
}
}
caps = gst_caps_copy_nth (icaps, best);
gst_caps_unref (icaps);
} else {
caps = icaps;
}
}
gst_caps_unref (thiscaps);
} else {
/* no peer or peer have ANY caps, work with our own caps then */
caps = thiscaps;
}
if (peercaps)
gst_caps_unref (peercaps);
if (caps) {
caps = gst_caps_truncate (caps);
/* now fixate */
if (!gst_caps_is_empty (caps)) {
caps = gst_v4l2src_fixate (basesrc, caps);
GST_DEBUG_OBJECT (basesrc, "fixated to: %" GST_PTR_FORMAT, caps);
LOG_CAPS (basesrc, 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);
}
return result;
no_nego_needed:
{
GST_DEBUG_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;
GstCaps *ret;
GSList *walk;
GSList *formats;
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));
}
if (v4l2src->probed_caps)
return gst_caps_ref (v4l2src->probed_caps);
formats = gst_v4l2_object_get_format_list (obj);
ret = gst_caps_new_empty ();
for (walk = formats; walk; walk = walk->next) {
struct v4l2_fmtdesc *format;
GstStructure *template;
format = (struct v4l2_fmtdesc *) walk->data;
template = gst_v4l2_object_v4l2fourcc_to_structure (format->pixelformat);
if (template) {
GstCaps *tmp;
tmp =
gst_v4l2_object_probe_caps_for_format (obj,
format->pixelformat, template);
if (tmp)
gst_caps_append (ret, tmp);
gst_structure_free (template);
} else {
GST_DEBUG_OBJECT (v4l2src, "unknown format %u", format->pixelformat);
}
}
v4l2src->probed_caps = gst_caps_ref (ret);
GST_INFO_OBJECT (v4l2src, "probed caps: %" GST_PTR_FORMAT, ret);
return ret;
}
static gboolean
gst_v4l2src_set_caps (GstBaseSrc * src, GstCaps * caps)
{
GstV4l2Src *v4l2src;
GstV4l2Object *obj;
v4l2src = GST_V4L2SRC (src);
obj = v4l2src->v4l2object;
/* make sure the caps changed before doing anything */
if (gst_v4l2_object_caps_equal (obj, caps))
return TRUE;
/* 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_v4l2_object_set_format (obj, caps))
/* error already posted */
return FALSE;
return TRUE;
}
static gboolean
gst_v4l2src_decide_allocation (GstBaseSrc * bsrc, GstQuery * query)
{
GstV4l2Src *src;
GstV4l2Object *obj;
GstBufferPool *pool;
guint size, min, max;
gboolean update;
src = GST_V4L2SRC (bsrc);
obj = src->v4l2object;
if (gst_query_get_n_allocation_pools (query) > 0) {
gst_query_parse_nth_allocation_pool (query, 0, &pool, &size, &min, &max);
update = TRUE;
} else {
pool = NULL;
min = max = 0;
size = 0;
update = FALSE;
}
GST_DEBUG_OBJECT (src, "allocation: size:%u min:%u max:%u pool:%"
GST_PTR_FORMAT, size, min, max, pool);
if (min != 0) {
/* if there is a min-buffers suggestion, use it. We add 1 because we need 1
* buffer extra to capture while the other two buffers are downstream */
min += 1;
} else {
min = 2;
}
/* select a pool */
switch (obj->mode) {
case GST_V4L2_IO_RW:
if (pool == NULL) {
/* no downstream pool, use our own then */
GST_DEBUG_OBJECT (src,
"read/write mode: no downstream pool, using our own");
pool = GST_BUFFER_POOL_CAST (obj->pool);
size = obj->sizeimage;
} else {
/* in READ/WRITE mode, prefer a downstream pool because our own pool
* doesn't help much, we have to write to it as well */
GST_DEBUG_OBJECT (src, "read/write mode: using downstream pool");
/* use the bigest size, when we use our own pool we can't really do any
* other size than what the hardware gives us but for downstream pools
* we can try */
size = MAX (size, obj->sizeimage);
}
break;
case GST_V4L2_IO_MMAP:
case GST_V4L2_IO_USERPTR:
case GST_V4L2_IO_DMABUF:
/* in streaming mode, prefer our own pool */
pool = GST_BUFFER_POOL_CAST (obj->pool);
size = obj->sizeimage;
GST_DEBUG_OBJECT (src,
"streaming mode: using our own pool %" GST_PTR_FORMAT, pool);
break;
case GST_V4L2_IO_AUTO:
default:
GST_WARNING_OBJECT (src, "unhandled mode");
break;
}
if (pool) {
GstStructure *config;
GstCaps *caps;
config = gst_buffer_pool_get_config (pool);
gst_buffer_pool_config_get_params (config, &caps, NULL, NULL, NULL);
gst_buffer_pool_config_set_params (config, caps, size, min, max);
/* if downstream supports video metadata, add this to the pool config */
if (gst_query_find_allocation_meta (query, GST_VIDEO_META_API_TYPE, NULL)) {
GST_DEBUG_OBJECT (pool, "activate Video Meta");
gst_buffer_pool_config_add_option (config,
GST_BUFFER_POOL_OPTION_VIDEO_META);
}
gst_buffer_pool_set_config (pool, config);
}
if (update)
gst_query_set_nth_allocation_pool (query, 0, pool, size, min, max);
else
gst_query_add_allocation_pool (query, pool, size, min, max);
return GST_BASE_SRC_CLASS (parent_class)->decide_allocation (bsrc, query);
}
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 */
min_latency = gst_util_uint64_scale_int (GST_SECOND, fps_d, fps_n);
/* max latency is total duration of the frame buffer */
if (obj->pool != NULL)
num_buffers = GST_V4L2_BUFFER_POOL_CAST (obj->pool)->num_buffers;
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;
/* activate settings for first frame */
v4l2src->ctrl_time = 0;
gst_object_sync_values (GST_OBJECT (src), v4l2src->ctrl_time);
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);
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;
}
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;
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
/* open the device */
if (!gst_v4l2_object_open (obj))
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;
if (v4l2src->probed_caps) {
gst_caps_unref (v4l2src->probed_caps);
v4l2src->probed_caps = NULL;
}
break;
default:
break;
}
return ret;
}
static GstFlowReturn
gst_v4l2src_fill (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;
ret =
gst_v4l2_buffer_pool_process (GST_V4L2_BUFFER_POOL_CAST (obj->pool), buf);
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;
}
if (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 (gstnow < timestamp && (timestamp - gstnow) > (10 * GST_SECOND)) {
GTimeVal now;
/* very large diff, fall back to system time */
g_get_current_time (&now);
gstnow = GST_TIMEVAL_TO_TIME (now);
}
if (gstnow > timestamp) {
delay = gstnow - timestamp;
} else {
delay = 0;
}
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 latency otherwise */
if (GST_CLOCK_TIME_IS_VALID (duration))
delay = duration;
else
delay = 0;
}
/* set buffer metadata */
GST_BUFFER_OFFSET (buf) = v4l2src->offset++;
GST_BUFFER_OFFSET_END (buf) = v4l2src->offset;
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_INFO_OBJECT (src, "sync to %" GST_TIME_FORMAT " out ts %" GST_TIME_FORMAT,
GST_TIME_ARGS (v4l2src->ctrl_time), GST_TIME_ARGS (timestamp));
GST_BUFFER_TIMESTAMP (buf) = timestamp;
GST_BUFFER_DURATION (buf) = duration;
return ret;
/* ERROR */
error:
{
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;
}