/* GStreamer * * Copyright (C) 2001-2002 Ronald Bultje * 2006 Edgard Lima * * 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. * * * 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 #endif #include #include #include #include #include #include "gstv4l2src.h" #include "gstv4l2colorbalance.h" #include "gstv4l2tuner.h" #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); 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)); 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, GstStructure * pref_s); 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::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 , " "Stefan Kost "); 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) { 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; } } } struct PreferedCapsInfo { gint width; gint height; gint fps_n; gint fps_d; }; 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 PreferedCapsInfo *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); } /* TODO Consider framerate */ static gint gst_v4l2src_fixed_caps_compare (GstStructure * a, GstStructure * b, struct PreferedCapsInfo *pref) { gint aw = G_MAXINT, ah = G_MAXINT, ad = G_MAXINT; gint bw = G_MAXINT, bh = G_MAXINT, bd = G_MAXINT; gst_v4l2_src_parse_fixed_struct (a, &aw, &ah, NULL, NULL); gst_v4l2_src_parse_fixed_struct (b, &bw, &bh, NULL, NULL); /* When both are smaller then pref, just append to the end */ if ((bw < pref->width || bh < pref->height) && (aw < pref->width || ah < pref->height)) return 1; /* If a is smaller then pref and not b, then a goes after b */ if (aw < pref->width || ah < pref->height) return 1; /* If b is smaller then pref and not a, then a goes before b */ if (bw < pref->width || bh < pref->height) return -1; /* Both are strictly larger then the preference, prefer the smallest */ ad = (aw - pref->width) * (ah - pref->height); bd = (bw - pref->width) * (bh - pref->height); return ad - bd; } 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); return gst_v4l2_object_set_format (obj, caps, error); } static GstCaps * gst_v4l2src_fixate (GstBaseSrc * basesrc, GstCaps * caps, GstStructure * pref_s) { /* Let's prefer a good resolutiion as of today's standard. */ struct PreferedCapsInfo pref = { 3840, 2160, 120, 1 }; 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); caps = gst_caps_make_writable (caps); /* We 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 (pref_s) { 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); } /* Sort the structures to get the caps that is nearest to our preferences, * first */ while ((s = gst_caps_steal_structure (caps, 0))) { gst_v4l2_src_fixate_struct_with_preference (s, &pref); caps_list = g_list_insert_sorted_with_data (caps_list, s, (GCompareDataFunc) gst_v4l2src_fixed_caps_compare, &pref); } while (caps_list) { s = caps_list->data; caps_list = g_list_delete_link (caps_list, caps_list); gst_caps_append_structure (caps, s); } 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); 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); if (GST_V4L2_IS_ACTIVE (obj)) { /* 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; } } else { if (gst_v4l2src_set_format (v4l2src, fcaps, &error)) 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; } gst_caps_unref (caps); GST_DEBUG_OBJECT (basesrc, "fixated caps %" GST_PTR_FORMAT, fcaps); return fcaps; } static gboolean gst_v4l2src_negotiate (GstBaseSrc * basesrc) { GstCaps *thiscaps; GstCaps *caps = NULL; GstCaps *peercaps = NULL; gboolean result = FALSE; /* 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)) { GstStructure *pref = NULL; if (peercaps && !gst_caps_is_any (peercaps)) pref = gst_caps_get_structure (peercaps, 0); caps = gst_v4l2src_fixate (basesrc, caps, pref); /* Fixating may fail as we now set the selected format */ if (!caps) { result = FALSE; goto done; } GST_DEBUG_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_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; 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); 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; caps = gst_caps_make_writable (caps); if (!(ret = gst_v4l2src_set_format (src, caps, &error))) gst_v4l2_error (src, &error); gst_caps_unref (caps); src->pending_set_fmt = FALSE; } else if (gst_buffer_pool_is_active (src->v4l2object->pool)) { /* 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, ¶ms); 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, ¶ms); else gst_query_add_allocation_param (query, allocator, ¶ms); 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); 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 (src->v4l2object->pool, TRUE)) goto activate_failed; } return ret; activate_failed: { GST_ELEMENT_ERROR (src, RESOURCE, SETTINGS, (_("Failed to allocate required memory.")), ("Buffer pool activation failed")); 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 */ 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)->max_latency; 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->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; 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; break; default: break; } return ret; } static GstFlowReturn gst_v4l2src_create (GstPushSrc * src, GstBuffer ** buf) { GstV4l2Src *v4l2src = GST_V4L2SRC (src); GstV4l2Object *obj = v4l2src->v4l2object; GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL_CAST (obj->pool); GstFlowReturn ret; GstClock *clock; GstClockTime abs_time, base_time, timestamp, duration; GstClockTime delay; GstMessage *qos_msg; 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)) goto alloc_failed; ret = gst_v4l2_buffer_pool_process (pool, buf); } while (ret == GST_V4L2_FLOW_CORRUPTED_BUFFER); 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)) { GTimeVal now; /* very large diff, fall back to system time */ g_get_current_time (&now); gstnow = GST_TIMEVAL_TO_TIME (now); } /* 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 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_INFO_OBJECT (src, "sync to %" GST_TIME_FORMAT " out ts %" GST_TIME_FORMAT, GST_TIME_ARGS (v4l2src->ctrl_time), GST_TIME_ARGS (timestamp)); /* 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++; GST_BUFFER_OFFSET_END (*buf) = 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) && (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; }