/* GStreamer * Copyright (c) 2005 Edward Hervey * Copyright (C) 2010 Sebastian Dröge * Copyright (C) 2020 Sebastian Dröge * * 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-imagefreeze * @title: imagefreeze * * The imagefreeze element generates a still frame video stream from * the input. It duplicates the first frame with the framerate requested * by downstream, allows seeking and answers queries. * * ## Example launch line * |[ * gst-launch-1.0 -v filesrc location=some.png ! decodebin ! imagefreeze ! autovideosink * ]| This pipeline shows a still frame stream of a PNG file. * */ /* This is based on the imagefreeze element from PiTiVi: * http://git.gnome.org/browse/pitivi/tree/pitivi/elements/imagefreeze.py */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include "gstimagefreeze.h" #define DEFAULT_NUM_BUFFERS -1 #define DEFAULT_ALLOW_REPLACE FALSE #define DEFAULT_IS_LIVE FALSE enum { PROP_0, PROP_NUM_BUFFERS, PROP_ALLOW_REPLACE, PROP_IS_LIVE, }; static void gst_image_freeze_finalize (GObject * object); static void gst_image_freeze_reset (GstImageFreeze * self); static GstStateChangeReturn gst_image_freeze_change_state (GstElement * element, GstStateChange transition); static GstClock *gst_image_freeze_provide_clock (GstElement * element); static void gst_image_freeze_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec); static void gst_image_freeze_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec); static GstFlowReturn gst_image_freeze_sink_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer); static gboolean gst_image_freeze_sink_event (GstPad * pad, GstObject * parent, GstEvent * event); static gboolean gst_image_freeze_sink_setcaps (GstImageFreeze * self, GstCaps * caps); static GstCaps *gst_image_freeze_sink_getcaps (GstImageFreeze * self, GstCaps * filter); static gboolean gst_image_freeze_sink_query (GstPad * pad, GstObject * parent, GstQuery * query); static void gst_image_freeze_src_loop (GstPad * pad); static gboolean gst_image_freeze_src_event (GstPad * pad, GstObject * parent, GstEvent * event); static gboolean gst_image_freeze_src_query (GstPad * pad, GstObject * parent, GstQuery * query); static GstStaticPadTemplate sink_pad_template = GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS, GST_STATIC_CAPS ("video/x-raw(ANY)")); static GstStaticPadTemplate src_pad_template = GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS, GST_STATIC_CAPS ("video/x-raw(ANY)")); GST_DEBUG_CATEGORY_STATIC (gst_image_freeze_debug); #define GST_CAT_DEFAULT gst_image_freeze_debug #define gst_image_freeze_parent_class parent_class G_DEFINE_TYPE (GstImageFreeze, gst_image_freeze, GST_TYPE_ELEMENT); static void gst_image_freeze_class_init (GstImageFreezeClass * klass) { GObjectClass *gobject_class = G_OBJECT_CLASS (klass); GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass); gobject_class->finalize = gst_image_freeze_finalize; gobject_class->set_property = gst_image_freeze_set_property; gobject_class->get_property = gst_image_freeze_get_property; g_object_class_install_property (gobject_class, PROP_NUM_BUFFERS, g_param_spec_int ("num-buffers", "Number of buffers", "Number of buffers to output before sending EOS (-1 = unlimited)", -1, G_MAXINT, DEFAULT_NUM_BUFFERS, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_ALLOW_REPLACE, g_param_spec_boolean ("allow-replace", "Allow Replace", "Allow replacing the input buffer and always output the latest", DEFAULT_ALLOW_REPLACE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); /** * GstImageFreeze:is-live * * Selects whether the output stream should be a non-live stream based on * the segment configured via a %GST_EVENT_SEEK, or whether the output * stream should be a live stream with the negotiated framerate. * * Since: 1.18 */ g_object_class_install_property (gobject_class, PROP_IS_LIVE, g_param_spec_boolean ("is-live", "Is Live", "Whether to output a live video stream", DEFAULT_IS_LIVE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_image_freeze_change_state); gstelement_class->provide_clock = GST_DEBUG_FUNCPTR (gst_image_freeze_provide_clock); gst_element_class_set_static_metadata (gstelement_class, "Still frame stream generator", "Filter/Video", "Generates a still frame stream from an image", "Sebastian Dröge "); gst_element_class_add_static_pad_template (gstelement_class, &sink_pad_template); gst_element_class_add_static_pad_template (gstelement_class, &src_pad_template); } static void gst_image_freeze_init (GstImageFreeze * self) { self->sinkpad = gst_pad_new_from_static_template (&sink_pad_template, "sink"); gst_pad_set_chain_function (self->sinkpad, GST_DEBUG_FUNCPTR (gst_image_freeze_sink_chain)); gst_pad_set_event_function (self->sinkpad, GST_DEBUG_FUNCPTR (gst_image_freeze_sink_event)); gst_pad_set_query_function (self->sinkpad, GST_DEBUG_FUNCPTR (gst_image_freeze_sink_query)); GST_PAD_SET_PROXY_ALLOCATION (self->sinkpad); gst_element_add_pad (GST_ELEMENT (self), self->sinkpad); self->srcpad = gst_pad_new_from_static_template (&src_pad_template, "src"); gst_pad_set_event_function (self->srcpad, GST_DEBUG_FUNCPTR (gst_image_freeze_src_event)); gst_pad_set_query_function (self->srcpad, GST_DEBUG_FUNCPTR (gst_image_freeze_src_query)); gst_pad_use_fixed_caps (self->srcpad); gst_element_add_pad (GST_ELEMENT (self), self->srcpad); g_mutex_init (&self->lock); g_cond_init (&self->blocked_cond); self->num_buffers = DEFAULT_NUM_BUFFERS; self->allow_replace = DEFAULT_ALLOW_REPLACE; self->is_live = DEFAULT_IS_LIVE; gst_image_freeze_reset (self); } static void gst_image_freeze_finalize (GObject * object) { GstImageFreeze *self = GST_IMAGE_FREEZE (object); self->num_buffers = DEFAULT_NUM_BUFFERS; gst_image_freeze_reset (self); g_mutex_clear (&self->lock); g_cond_clear (&self->blocked_cond); G_OBJECT_CLASS (parent_class)->finalize (object); } static void gst_image_freeze_reset (GstImageFreeze * self) { GST_DEBUG_OBJECT (self, "Resetting internal state"); g_mutex_lock (&self->lock); gst_buffer_replace (&self->buffer, NULL); gst_caps_replace (&self->buffer_caps, NULL); gst_caps_replace (&self->current_caps, NULL); self->num_buffers_left = self->num_buffers; gst_segment_init (&self->segment, GST_FORMAT_TIME); self->need_segment = TRUE; self->flushing = TRUE; self->negotiated_framerate = FALSE; self->fps_n = self->fps_d = 0; self->offset = 0; self->seqnum = 0; g_mutex_unlock (&self->lock); } static gboolean gst_image_freeze_sink_setcaps (GstImageFreeze * self, GstCaps * caps) { gboolean ret = FALSE; GstStructure *s; gint fps_n, fps_d; GstCaps *othercaps, *intersection; guint i, n; GstPad *pad; pad = self->sinkpad; caps = gst_caps_copy (caps); /* If we already negotiated a framerate then only update for the * caps of the new buffer */ if (self->negotiated_framerate) { gst_caps_set_simple (caps, "framerate", GST_TYPE_FRACTION, self->fps_n, self->fps_d, NULL); GST_DEBUG_OBJECT (pad, "Setting caps %" GST_PTR_FORMAT, caps); gst_pad_set_caps (self->srcpad, caps); gst_caps_unref (caps); return TRUE; } /* Else negotiate a framerate with downstream */ GST_DEBUG_OBJECT (pad, "Setting caps: %" GST_PTR_FORMAT, caps); s = gst_caps_get_structure (caps, 0); /* 1. Remove framerate */ gst_structure_remove_field (s, "framerate"); gst_structure_set (s, "framerate", GST_TYPE_FRACTION_RANGE, 0, 1, G_MAXINT, 1, NULL); /* 2. Intersect with template caps */ othercaps = (GstCaps *) gst_pad_get_pad_template_caps (pad); intersection = gst_caps_intersect (caps, othercaps); GST_DEBUG_OBJECT (pad, "Intersecting: %" GST_PTR_FORMAT, caps); GST_DEBUG_OBJECT (pad, "with: %" GST_PTR_FORMAT, othercaps); GST_DEBUG_OBJECT (pad, "gave: %" GST_PTR_FORMAT, intersection); gst_caps_unref (caps); gst_caps_unref (othercaps); caps = intersection; intersection = othercaps = NULL; /* 3. Intersect with downstream peer caps */ othercaps = gst_pad_peer_query_caps (self->srcpad, caps); GST_DEBUG_OBJECT (pad, "Peer query resulted: %" GST_PTR_FORMAT, othercaps); gst_caps_unref (caps); caps = othercaps; othercaps = NULL; /* 4. For every candidate try to use it downstream with framerate as * near as possible to 25/1 */ n = gst_caps_get_size (caps); for (i = 0; i < n; i++) { GstCaps *candidate = gst_caps_new_empty (); GstStructure *s = gst_structure_copy (gst_caps_get_structure (caps, i)); GstCapsFeatures *f = gst_caps_features_copy (gst_caps_get_features (caps, i)); gst_caps_append_structure_full (candidate, s, f); if (gst_structure_has_field_typed (s, "framerate", GST_TYPE_FRACTION) || gst_structure_fixate_field_nearest_fraction (s, "framerate", 25, 1)) { gst_structure_get_fraction (s, "framerate", &fps_n, &fps_d); if (fps_d != 0) { gst_pad_set_caps (self->srcpad, candidate); g_mutex_lock (&self->lock); self->fps_n = fps_n; self->fps_d = fps_d; g_mutex_unlock (&self->lock); self->negotiated_framerate = TRUE; GST_DEBUG_OBJECT (pad, "Setting caps %" GST_PTR_FORMAT, candidate); ret = TRUE; gst_caps_unref (candidate); break; } else { GST_WARNING_OBJECT (pad, "Invalid caps with framerate %d/%d", fps_n, fps_d); } } gst_caps_unref (candidate); } if (!ret) GST_ERROR_OBJECT (pad, "No usable caps found"); gst_caps_unref (caps); return ret; } /* remove framerate in writable @caps */ static void gst_image_freeze_remove_fps (GstImageFreeze * self, GstCaps * caps) { gint i, n; n = gst_caps_get_size (caps); for (i = 0; i < n; i++) { GstStructure *s = gst_caps_get_structure (caps, i); gst_structure_remove_field (s, "framerate"); gst_structure_set (s, "framerate", GST_TYPE_FRACTION_RANGE, 0, 1, G_MAXINT, 1, NULL); } } static GstCaps * gst_image_freeze_sink_getcaps (GstImageFreeze * self, GstCaps * filter) { GstCaps *ret, *tmp, *templ; GstPad *pad; pad = self->sinkpad; if (filter) { filter = gst_caps_copy (filter); gst_image_freeze_remove_fps (self, filter); } templ = gst_pad_get_pad_template_caps (pad); tmp = gst_pad_peer_query_caps (self->srcpad, filter); if (tmp) { GST_LOG_OBJECT (self, "peer caps %" GST_PTR_FORMAT, tmp); ret = gst_caps_intersect (tmp, templ); gst_caps_unref (tmp); } else { GST_LOG_OBJECT (self, "going to copy"); ret = gst_caps_copy (templ); } if (templ) gst_caps_unref (templ); if (filter) gst_caps_unref (filter); ret = gst_caps_make_writable (ret); gst_image_freeze_remove_fps (self, ret); GST_LOG_OBJECT (pad, "Returning caps: %" GST_PTR_FORMAT, ret); return ret; } static gboolean gst_image_freeze_sink_query (GstPad * pad, GstObject * parent, GstQuery * query) { GstImageFreeze *self = GST_IMAGE_FREEZE (parent); gboolean ret; GST_LOG_OBJECT (pad, "Handling query of type '%s'", gst_query_type_get_name (GST_QUERY_TYPE (query))); switch (GST_QUERY_TYPE (query)) { case GST_QUERY_CAPS: { GstCaps *caps; gst_query_parse_caps (query, &caps); caps = gst_image_freeze_sink_getcaps (self, caps); gst_query_set_caps_result (query, caps); gst_caps_unref (caps); ret = TRUE; break; } default: ret = gst_pad_query_default (pad, parent, query); } return ret; } static gboolean gst_image_freeze_convert (GstImageFreeze * self, GstFormat src_format, gint64 src_value, GstFormat * dest_format, gint64 * dest_value) { gboolean ret = FALSE; if (src_format == *dest_format) { *dest_value = src_value; return TRUE; } if (src_value == -1) { *dest_value = -1; return TRUE; } switch (src_format) { case GST_FORMAT_DEFAULT:{ switch (*dest_format) { case GST_FORMAT_TIME: g_mutex_lock (&self->lock); if (self->fps_n == 0) *dest_value = -1; else *dest_value = gst_util_uint64_scale (src_value, GST_SECOND * self->fps_d, self->fps_n); g_mutex_unlock (&self->lock); ret = TRUE; break; default: break; } break; } case GST_FORMAT_TIME:{ switch (*dest_format) { case GST_FORMAT_DEFAULT: g_mutex_lock (&self->lock); *dest_value = gst_util_uint64_scale (src_value, self->fps_n, self->fps_d * GST_SECOND); g_mutex_unlock (&self->lock); ret = TRUE; break; default: break; } break; } default: break; } return ret; } static gboolean gst_image_freeze_src_query (GstPad * pad, GstObject * parent, GstQuery * query) { GstImageFreeze *self = GST_IMAGE_FREEZE (parent); gboolean ret = FALSE; GST_LOG_OBJECT (pad, "Handling query of type '%s'", gst_query_type_get_name (GST_QUERY_TYPE (query))); switch (GST_QUERY_TYPE (query)) { case GST_QUERY_CONVERT:{ GstFormat src_format, dest_format; gint64 src_value, dest_value; gst_query_parse_convert (query, &src_format, &src_value, &dest_format, &dest_value); ret = gst_image_freeze_convert (self, src_format, src_value, &dest_format, &dest_value); if (ret) gst_query_set_convert (query, src_format, src_value, dest_format, dest_value); break; } case GST_QUERY_POSITION:{ GstFormat format; gint64 position; gst_query_parse_position (query, &format, NULL); switch (format) { case GST_FORMAT_DEFAULT:{ g_mutex_lock (&self->lock); position = self->offset; g_mutex_unlock (&self->lock); ret = TRUE; break; } case GST_FORMAT_TIME:{ g_mutex_lock (&self->lock); position = self->segment.position; g_mutex_unlock (&self->lock); ret = TRUE; break; } default: break; } if (ret) { gst_query_set_position (query, format, position); GST_DEBUG_OBJECT (pad, "Returning position %" G_GINT64_FORMAT " in format %s", position, gst_format_get_name (format)); } else { GST_DEBUG_OBJECT (pad, "Position query failed"); } break; } case GST_QUERY_DURATION:{ GstFormat format; gint64 duration; gst_query_parse_duration (query, &format, NULL); switch (format) { case GST_FORMAT_TIME:{ g_mutex_lock (&self->lock); duration = self->segment.stop; g_mutex_unlock (&self->lock); ret = TRUE; break; } case GST_FORMAT_DEFAULT:{ g_mutex_lock (&self->lock); duration = self->segment.stop; if (duration != -1) duration = gst_util_uint64_scale (duration, self->fps_n, GST_SECOND * self->fps_d); g_mutex_unlock (&self->lock); ret = TRUE; break; } default: break; } if (ret) { gst_query_set_duration (query, format, duration); GST_DEBUG_OBJECT (pad, "Returning duration %" G_GINT64_FORMAT " in format %s", duration, gst_format_get_name (format)); } else { GST_DEBUG_OBJECT (pad, "Duration query failed"); } break; } case GST_QUERY_SEEKING:{ GstFormat format; gboolean seekable; gst_query_parse_seeking (query, &format, NULL, NULL, NULL); seekable = !self->is_live && (format == GST_FORMAT_TIME || format == GST_FORMAT_DEFAULT); gst_query_set_seeking (query, format, seekable, (seekable ? 0 : -1), -1); ret = TRUE; break; } case GST_QUERY_LATENCY: if (self->is_live) { /* If we run live, we output the buffer without any latency but allow * for at most one frame of latency. If downstream takes longer to * consume out frame we would skip ahead */ if (self->fps_n > 0 && self->fps_d > 0) gst_query_set_latency (query, TRUE, 0, gst_util_uint64_scale_ceil (GST_SECOND, self->fps_d, self->fps_n)); else gst_query_set_latency (query, TRUE, 0, GST_CLOCK_TIME_NONE); } else { /* If we don't run live, even if upstream is live, we never output any * buffers with latency but immediately generate buffers as fast as we * can according to the negotiated framerate */ gst_query_set_latency (query, FALSE, 0, GST_CLOCK_TIME_NONE); } ret = TRUE; break; default: ret = FALSE; break; } return ret; } static gboolean gst_image_freeze_sink_event (GstPad * pad, GstObject * parent, GstEvent * event) { GstImageFreeze *self = GST_IMAGE_FREEZE (parent); gboolean ret; GST_LOG_OBJECT (pad, "Got %s event", GST_EVENT_TYPE_NAME (event)); switch (GST_EVENT_TYPE (event)) { case GST_EVENT_CAPS: { GstCaps *caps; g_mutex_lock (&self->lock); gst_event_parse_caps (event, &caps); gst_caps_replace (&self->current_caps, caps); g_mutex_unlock (&self->lock); gst_event_unref (event); ret = TRUE; break; } case GST_EVENT_EOS: if (!self->buffer) { /* if we receive EOS before a buffer arrives, then let it pass */ GST_DEBUG_OBJECT (self, "EOS without input buffer, passing on"); ret = gst_pad_push_event (self->srcpad, event); break; } /* fall-through */ case GST_EVENT_SEGMENT: GST_DEBUG_OBJECT (pad, "Dropping event"); gst_event_unref (event); ret = TRUE; break; case GST_EVENT_FLUSH_START: gst_image_freeze_reset (self); /* fall through */ default: ret = gst_pad_push_event (self->srcpad, gst_event_ref (event)); if (GST_EVENT_IS_STICKY (event)) ret = TRUE; gst_event_unref (event); break; } return ret; } static gboolean gst_image_freeze_src_event (GstPad * pad, GstObject * parent, GstEvent * event) { GstImageFreeze *self = GST_IMAGE_FREEZE (parent); gboolean ret; GST_LOG_OBJECT (pad, "Got %s event", GST_EVENT_TYPE_NAME (event)); switch (GST_EVENT_TYPE (event)) { case GST_EVENT_NAVIGATION: case GST_EVENT_QOS: case GST_EVENT_LATENCY: case GST_EVENT_STEP: GST_DEBUG_OBJECT (pad, "Dropping event"); gst_event_unref (event); ret = TRUE; break; case GST_EVENT_SEEK:{ gdouble rate; GstFormat format; GstSeekFlags flags; GstSeekType start_type, stop_type; gint64 start, stop; gint64 last_stop; gboolean start_task; gboolean flush; guint32 seqnum; if (self->is_live) { GST_ERROR_OBJECT (pad, "Can't seek in live mode"); ret = FALSE; gst_event_unref (event); break; } seqnum = gst_event_get_seqnum (event); gst_event_parse_seek (event, &rate, &format, &flags, &start_type, &start, &stop_type, &stop); gst_event_unref (event); flush = ! !(flags & GST_SEEK_FLAG_FLUSH); if (format != GST_FORMAT_TIME && format != GST_FORMAT_DEFAULT) { GST_ERROR_OBJECT (pad, "Seek in invalid format: %s", gst_format_get_name (format)); ret = FALSE; break; } if (format == GST_FORMAT_DEFAULT) { format = GST_FORMAT_TIME; if (!gst_image_freeze_convert (self, GST_FORMAT_DEFAULT, start, &format, &start) || !gst_image_freeze_convert (self, GST_FORMAT_DEFAULT, stop, &format, &stop) || start == -1 || stop == -1) { GST_ERROR_OBJECT (pad, "Failed to convert seek from DEFAULT format into TIME format"); ret = FALSE; break; } } if (flush) { GstEvent *e; g_mutex_lock (&self->lock); self->flushing = TRUE; g_mutex_unlock (&self->lock); e = gst_event_new_flush_start (); gst_event_set_seqnum (e, seqnum); gst_pad_push_event (self->srcpad, e); } else { gst_pad_pause_task (self->srcpad); } GST_PAD_STREAM_LOCK (self->srcpad); g_mutex_lock (&self->lock); gst_segment_do_seek (&self->segment, rate, format, flags, start_type, start, stop_type, stop, NULL); self->need_segment = TRUE; last_stop = self->segment.position; start_task = self->buffer != NULL; self->flushing = FALSE; g_mutex_unlock (&self->lock); if (flush) { GstEvent *e; e = gst_event_new_flush_stop (TRUE); gst_event_set_seqnum (e, seqnum); gst_pad_push_event (self->srcpad, e); } if (flags & GST_SEEK_FLAG_SEGMENT) { GstMessage *m; m = gst_message_new_segment_start (GST_OBJECT (self), format, last_stop); gst_element_post_message (GST_ELEMENT (self), m); } self->seqnum = seqnum; GST_PAD_STREAM_UNLOCK (self->srcpad); GST_DEBUG_OBJECT (pad, "Seek successful"); if (start_task) { g_mutex_lock (&self->lock); if (self->buffer != NULL) gst_pad_start_task (self->srcpad, (GstTaskFunction) gst_image_freeze_src_loop, self->srcpad, NULL); g_mutex_unlock (&self->lock); } ret = TRUE; break; } case GST_EVENT_FLUSH_START: g_mutex_lock (&self->lock); self->flushing = TRUE; g_mutex_unlock (&self->lock); ret = gst_pad_push_event (self->sinkpad, event); break; case GST_EVENT_FLUSH_STOP: gst_image_freeze_reset (self); g_mutex_lock (&self->lock); self->flushing = FALSE; g_mutex_unlock (&self->lock); ret = gst_pad_push_event (self->sinkpad, event); break; default: ret = gst_pad_push_event (self->sinkpad, event); break; } return ret; } static void gst_image_freeze_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec) { GstImageFreeze *self; self = GST_IMAGE_FREEZE (object); switch (prop_id) { case PROP_NUM_BUFFERS: self->num_buffers = g_value_get_int (value); break; case PROP_ALLOW_REPLACE: self->allow_replace = g_value_get_boolean (value); break; case PROP_IS_LIVE: self->is_live = g_value_get_boolean (value); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_image_freeze_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec) { GstImageFreeze *self; self = GST_IMAGE_FREEZE (object); switch (prop_id) { case PROP_NUM_BUFFERS: g_value_set_int (value, self->num_buffers); break; case PROP_ALLOW_REPLACE: g_value_set_boolean (value, self->allow_replace); break; case PROP_IS_LIVE: g_value_set_boolean (value, self->is_live); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static GstFlowReturn gst_image_freeze_sink_chain (GstPad * pad, GstObject * parent, GstBuffer * buffer) { GstImageFreeze *self = GST_IMAGE_FREEZE (parent); GstFlowReturn flow_ret; g_mutex_lock (&self->lock); if (self->buffer && !self->allow_replace) { GST_DEBUG_OBJECT (pad, "Already have a buffer, dropping"); gst_buffer_unref (buffer); g_mutex_unlock (&self->lock); return GST_FLOW_EOS; } if (!self->current_caps) { GST_ERROR_OBJECT (pad, "Not negotiated yet"); g_mutex_unlock (&self->lock); return GST_FLOW_NOT_NEGOTIATED; } gst_buffer_replace (&self->buffer, buffer); if (!self->buffer_caps || !gst_caps_is_equal (self->buffer_caps, self->current_caps)) gst_pad_mark_reconfigure (self->srcpad); gst_caps_replace (&self->buffer_caps, self->current_caps); gst_buffer_unref (buffer); gst_pad_start_task (self->srcpad, (GstTaskFunction) gst_image_freeze_src_loop, self->srcpad, NULL); flow_ret = self->allow_replace ? GST_FLOW_OK : GST_FLOW_EOS; g_mutex_unlock (&self->lock); return flow_ret; } static void gst_image_freeze_src_loop (GstPad * pad) { GstImageFreeze *self = GST_IMAGE_FREEZE (GST_PAD_PARENT (pad)); GstBuffer *buffer; guint64 offset; GstClockTime timestamp, timestamp_end; guint64 cstart, cstop; gboolean in_seg, eos; GstFlowReturn flow_ret = GST_FLOW_OK; gboolean first = FALSE; g_mutex_lock (&self->lock); if (self->flushing) { GST_DEBUG_OBJECT (pad, "Flushing"); flow_ret = GST_FLOW_FLUSHING; g_mutex_unlock (&self->lock); goto pause_task; } else if (!self->buffer) { GST_ERROR_OBJECT (pad, "Have no buffer yet"); flow_ret = GST_FLOW_ERROR; g_mutex_unlock (&self->lock); goto pause_task; } g_assert (self->buffer); /* Take a new reference of the buffer here so we're guaranteed to have one * in all the following code even if it disappears while we temporarily * unlock the mutex */ buffer = gst_buffer_ref (self->buffer); if (gst_pad_check_reconfigure (self->srcpad)) { GstCaps *buffer_caps = gst_caps_ref (self->buffer_caps); g_mutex_unlock (&self->lock); if (!gst_image_freeze_sink_setcaps (self, buffer_caps)) { gst_caps_unref (buffer_caps); gst_buffer_unref (buffer); gst_pad_mark_reconfigure (self->srcpad); flow_ret = GST_FLOW_NOT_NEGOTIATED; goto pause_task; } gst_caps_unref (buffer_caps); g_mutex_lock (&self->lock); } /* normally we don't count buffers */ if (G_UNLIKELY (self->num_buffers_left >= 0)) { GST_DEBUG_OBJECT (pad, "Buffers left %d", self->num_buffers_left); if (self->num_buffers_left == 0) { flow_ret = GST_FLOW_EOS; gst_buffer_unref (buffer); g_mutex_unlock (&self->lock); goto pause_task; } else { self->num_buffers_left--; } } buffer = gst_buffer_make_writable (buffer); g_mutex_unlock (&self->lock); if (self->need_segment) { GstEvent *e; GST_DEBUG_OBJECT (pad, "Pushing SEGMENT event: %" GST_SEGMENT_FORMAT, &self->segment); e = gst_event_new_segment (&self->segment); if (self->seqnum) gst_event_set_seqnum (e, self->seqnum); g_mutex_lock (&self->lock); if (self->segment.rate >= 0) { self->offset = gst_util_uint64_scale (self->segment.start, self->fps_n, self->fps_d * GST_SECOND); } else { self->offset = gst_util_uint64_scale (self->segment.stop, self->fps_n, self->fps_d * GST_SECOND); } g_mutex_unlock (&self->lock); self->need_segment = FALSE; first = TRUE; gst_pad_push_event (self->srcpad, e); } g_mutex_lock (&self->lock); offset = self->offset; if (self->is_live) { GstClockTime base_time, clock_time; GstClockTimeDiff jitter; GstClockReturn clock_ret; GstClock *clock; /* Wait until the element went to PLAYING or flushing */ while (self->blocked && !self->flushing) g_cond_wait (&self->blocked_cond, &self->lock); if (self->flushing) { g_mutex_unlock (&self->lock); gst_buffer_unref (buffer); flow_ret = GST_FLOW_FLUSHING; goto pause_task; } /* Wait on the clock until the time for our current frame is reached */ clock = gst_element_get_clock (GST_ELEMENT (self)); base_time = gst_element_get_base_time (GST_ELEMENT (self)); if (self->fps_n != 0) { clock_time = base_time + gst_util_uint64_scale (offset, self->fps_d * GST_SECOND, self->fps_n); } else { clock_time = base_time; } self->clock_id = gst_clock_new_single_shot_id (clock, clock_time); g_mutex_unlock (&self->lock); GST_TRACE_OBJECT (self, "Waiting for %" GST_TIME_FORMAT ", now %" GST_TIME_FORMAT, GST_TIME_ARGS (clock_time), GST_TIME_ARGS (gst_clock_get_time (clock))); clock_ret = gst_clock_id_wait (self->clock_id, &jitter); GST_TRACE_OBJECT (self, "Waited for %" GST_TIME_FORMAT ", clock ret %d, jitter %" GST_STIME_FORMAT, GST_TIME_ARGS (clock_time), clock_ret, GST_STIME_ARGS (jitter)); g_mutex_lock (&self->lock); gst_clock_id_unref (self->clock_id); self->clock_id = NULL; gst_object_unref (clock); if (self->flushing || clock_ret == GST_CLOCK_UNSCHEDULED) { g_mutex_unlock (&self->lock); gst_buffer_unref (buffer); flow_ret = GST_FLOW_FLUSHING; goto pause_task; } /* If we were late, adjust our offset and jump ahead if needed */ if (self->fps_n != 0) { if (jitter > 0) { guint64 new_offset = gst_util_uint64_scale (clock_time + jitter - base_time, self->fps_n, self->fps_d * GST_SECOND); if (new_offset != offset) { GST_INFO_OBJECT (self, "Late by %" GST_TIME_FORMAT ", old offset %" G_GUINT64_FORMAT ", new offset %" G_GUINT64_FORMAT, GST_TIME_ARGS (jitter), offset, new_offset); self->offset = offset = new_offset; } } timestamp = gst_util_uint64_scale (offset, self->fps_d * GST_SECOND, self->fps_n); timestamp_end = gst_util_uint64_scale (offset + 1, self->fps_d * GST_SECOND, self->fps_n); } else { /* If we have no framerate then we output a single frame now */ if (jitter > 0) timestamp = jitter; else timestamp = 0; timestamp_end = GST_CLOCK_TIME_NONE; } } else { if (self->fps_n != 0) { timestamp = gst_util_uint64_scale (offset, self->fps_d * GST_SECOND, self->fps_n); timestamp_end = gst_util_uint64_scale (offset + 1, self->fps_d * GST_SECOND, self->fps_n); } else { timestamp = self->segment.start; timestamp_end = GST_CLOCK_TIME_NONE; } } eos = (self->fps_n == 0 && offset > 0) || (self->segment.rate >= 0 && self->segment.stop != -1 && timestamp > self->segment.stop) || (self->segment.rate < 0 && offset == 0) || (self->segment.rate < 0 && self->segment.start != -1 && timestamp_end < self->segment.start); if (self->fps_n == 0 && offset > 0) in_seg = FALSE; else in_seg = gst_segment_clip (&self->segment, GST_FORMAT_TIME, timestamp, timestamp_end, &cstart, &cstop); if (in_seg) { self->segment.position = cstart; if (self->segment.rate >= 0) self->segment.position = cstop; } if (self->segment.rate >= 0) self->offset++; else self->offset--; g_mutex_unlock (&self->lock); GST_DEBUG_OBJECT (pad, "Handling buffer with timestamp %" GST_TIME_FORMAT, GST_TIME_ARGS (timestamp)); if (in_seg) { GST_BUFFER_DTS (buffer) = GST_CLOCK_TIME_NONE; GST_BUFFER_PTS (buffer) = cstart; GST_BUFFER_DURATION (buffer) = cstop - cstart; GST_BUFFER_OFFSET (buffer) = offset; GST_BUFFER_OFFSET_END (buffer) = offset + 1; if (first) GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DISCONT); else GST_BUFFER_FLAG_UNSET (buffer, GST_BUFFER_FLAG_DISCONT); flow_ret = gst_pad_push (self->srcpad, buffer); GST_DEBUG_OBJECT (pad, "Pushing buffer resulted in %s", gst_flow_get_name (flow_ret)); if (flow_ret != GST_FLOW_OK) goto pause_task; } else { gst_buffer_unref (buffer); } if (eos) { flow_ret = GST_FLOW_EOS; goto pause_task; } return; pause_task: { const gchar *reason = gst_flow_get_name (flow_ret); GST_LOG_OBJECT (self, "pausing task, reason %s", reason); gst_pad_pause_task (pad); if (flow_ret == GST_FLOW_EOS) { if ((self->segment.flags & GST_SEEK_FLAG_SEGMENT)) { GstMessage *m; GstEvent *e; GST_DEBUG_OBJECT (pad, "Sending segment done at end of segment"); if (self->segment.rate >= 0) { m = gst_message_new_segment_done (GST_OBJECT_CAST (self), GST_FORMAT_TIME, self->segment.stop); e = gst_event_new_segment_done (GST_FORMAT_TIME, self->segment.stop); } else { m = gst_message_new_segment_done (GST_OBJECT_CAST (self), GST_FORMAT_TIME, self->segment.start); e = gst_event_new_segment_done (GST_FORMAT_TIME, self->segment.start); } gst_element_post_message (GST_ELEMENT_CAST (self), m); gst_pad_push_event (self->srcpad, e); } else { GstEvent *e = gst_event_new_eos (); GST_DEBUG_OBJECT (pad, "Sending EOS at end of segment"); if (self->seqnum) gst_event_set_seqnum (e, self->seqnum); gst_pad_push_event (self->srcpad, e); } } else if (flow_ret == GST_FLOW_NOT_LINKED || flow_ret < GST_FLOW_EOS) { GstEvent *e = gst_event_new_eos (); GST_ELEMENT_FLOW_ERROR (self, flow_ret); if (self->seqnum) gst_event_set_seqnum (e, self->seqnum); gst_pad_push_event (self->srcpad, e); } return; } } static GstStateChangeReturn gst_image_freeze_change_state (GstElement * element, GstStateChange transition) { GstImageFreeze *self = GST_IMAGE_FREEZE (element); GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS; gboolean no_preroll = FALSE; switch (transition) { case GST_STATE_CHANGE_READY_TO_PAUSED: gst_image_freeze_reset (self); g_mutex_lock (&self->lock); self->flushing = FALSE; self->blocked = TRUE; g_mutex_unlock (&self->lock); if (self->is_live) no_preroll = TRUE; break; case GST_STATE_CHANGE_PAUSED_TO_PLAYING: g_mutex_lock (&self->lock); self->blocked = FALSE; g_cond_signal (&self->blocked_cond); g_mutex_unlock (&self->lock); break; case GST_STATE_CHANGE_PAUSED_TO_READY: g_mutex_lock (&self->lock); self->flushing = TRUE; if (self->clock_id) { GST_DEBUG_OBJECT (self, "unlock clock wait"); gst_clock_id_unschedule (self->clock_id); } self->blocked = FALSE; g_cond_signal (&self->blocked_cond); g_mutex_unlock (&self->lock); gst_image_freeze_reset (self); gst_pad_stop_task (self->srcpad); break; default: break; } if (GST_ELEMENT_CLASS (parent_class)->change_state) ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition); switch (transition) { case GST_STATE_CHANGE_PLAYING_TO_PAUSED: g_mutex_lock (&self->lock); self->blocked = TRUE; g_mutex_unlock (&self->lock); if (self->is_live) no_preroll = TRUE; break; default: break; } if (no_preroll && ret == GST_STATE_CHANGE_SUCCESS) ret = GST_STATE_CHANGE_NO_PREROLL; return ret; } /* FIXME: GStreamer 2.0 */ static GstClock * gst_image_freeze_provide_clock (GstElement * element) { return gst_system_clock_obtain (); } static gboolean plugin_init (GstPlugin * plugin) { GST_DEBUG_CATEGORY_INIT (gst_image_freeze_debug, "imagefreeze", 0, "imagefreeze element"); if (!gst_element_register (plugin, "imagefreeze", GST_RANK_NONE, GST_TYPE_IMAGE_FREEZE)) return FALSE; return TRUE; } GST_PLUGIN_DEFINE (GST_VERSION_MAJOR, GST_VERSION_MINOR, imagefreeze, "Still frame stream generator", plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)