2 * Copyright (c) 2005 Edward Hervey <bilboed@bilboed.com>
3 * Copyright (C) 2010 Sebastian Dröge <sebastian.droege@collabora.co.uk>
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
15 * You should have received a copy of the GNU Library General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 * Boston, MA 02111-1307, USA.
22 * SECTION:element-imagefreeze
24 * The imagefreeze element generates a still frame video stream from
25 * the input. It duplicates the first frame with the framerate requested
26 * by downstream, allows seeking and answers queries.
29 * <title>Example launch line</title>
31 * gst-launch -v filesrc location=some.png ! decodebin2 ! imagefreeze ! autovideosink
32 * ]| This pipeline shows a still frame stream of a PNG file.
36 /* This is based on the imagefreeze element from PiTiVi:
37 * http://git.gnome.org/browse/pitivi/tree/pitivi/elements/imagefreeze.py
44 #include <gst/glib-compat-private.h>
46 #include "gstimagefreeze.h"
48 static void gst_image_freeze_finalize (GObject * object);
50 static void gst_image_freeze_reset (GstImageFreeze * self);
52 static GstStateChangeReturn gst_image_freeze_change_state (GstElement * element,
53 GstStateChange transition);
55 static GstFlowReturn gst_image_freeze_sink_chain (GstPad * pad,
56 GstObject * parent, GstBuffer * buffer);
57 static gboolean gst_image_freeze_sink_event (GstPad * pad, GstObject * parent,
59 static gboolean gst_image_freeze_sink_setcaps (GstImageFreeze * self,
61 static GstCaps *gst_image_freeze_sink_getcaps (GstImageFreeze * self,
63 static gboolean gst_image_freeze_sink_query (GstPad * pad, GstObject * parent,
65 static void gst_image_freeze_src_loop (GstPad * pad);
66 static gboolean gst_image_freeze_src_event (GstPad * pad, GstObject * parent,
68 static gboolean gst_image_freeze_src_query (GstPad * pad, GstObject * parent,
71 static GstStaticPadTemplate sink_pad_template = GST_STATIC_PAD_TEMPLATE ("sink",
74 GST_STATIC_CAPS ("video/x-raw"));
76 static GstStaticPadTemplate src_pad_template =
77 GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
78 GST_STATIC_CAPS ("video/x-raw"));
80 GST_DEBUG_CATEGORY_STATIC (gst_image_freeze_debug);
81 #define GST_CAT_DEFAULT gst_image_freeze_debug
83 #define gst_image_freeze_parent_class parent_class
84 G_DEFINE_TYPE (GstImageFreeze, gst_image_freeze, GST_TYPE_ELEMENT);
88 gst_image_freeze_class_init (GstImageFreezeClass * klass)
90 GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
91 GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);
93 gobject_class->finalize = gst_image_freeze_finalize;
95 gstelement_class->change_state =
96 GST_DEBUG_FUNCPTR (gst_image_freeze_change_state);
98 gst_element_class_set_details_simple (gstelement_class,
99 "Still frame stream generator",
101 "Generates a still frame stream from an image",
102 "Sebastian Dröge <sebastian.droege@collabora.co.uk>");
104 gst_element_class_add_pad_template (gstelement_class,
105 gst_static_pad_template_get (&sink_pad_template));
106 gst_element_class_add_pad_template (gstelement_class,
107 gst_static_pad_template_get (&src_pad_template));
111 gst_image_freeze_init (GstImageFreeze * self)
113 self->sinkpad = gst_pad_new_from_static_template (&sink_pad_template, "sink");
114 gst_pad_set_chain_function (self->sinkpad,
115 GST_DEBUG_FUNCPTR (gst_image_freeze_sink_chain));
116 gst_pad_set_event_function (self->sinkpad,
117 GST_DEBUG_FUNCPTR (gst_image_freeze_sink_event));
118 gst_pad_set_query_function (self->sinkpad,
119 GST_DEBUG_FUNCPTR (gst_image_freeze_sink_query));
120 GST_PAD_SET_PROXY_ALLOCATION (self->sinkpad);
121 gst_element_add_pad (GST_ELEMENT (self), self->sinkpad);
123 self->srcpad = gst_pad_new_from_static_template (&src_pad_template, "src");
124 gst_pad_set_event_function (self->srcpad,
125 GST_DEBUG_FUNCPTR (gst_image_freeze_src_event));
126 gst_pad_set_query_function (self->srcpad,
127 GST_DEBUG_FUNCPTR (gst_image_freeze_src_query));
128 gst_pad_use_fixed_caps (self->srcpad);
129 gst_element_add_pad (GST_ELEMENT (self), self->srcpad);
131 g_mutex_init (&self->lock);
133 gst_image_freeze_reset (self);
137 gst_image_freeze_finalize (GObject * object)
139 GstImageFreeze *self = GST_IMAGE_FREEZE (object);
141 gst_image_freeze_reset (self);
143 g_mutex_clear (&self->lock);
145 G_OBJECT_CLASS (parent_class)->finalize (object);
149 gst_image_freeze_reset (GstImageFreeze * self)
151 GST_DEBUG_OBJECT (self, "Resetting internal state");
153 g_mutex_lock (&self->lock);
154 gst_buffer_replace (&self->buffer, NULL);
156 gst_segment_init (&self->segment, GST_FORMAT_TIME);
157 self->need_segment = TRUE;
159 self->fps_n = self->fps_d = 0;
161 g_mutex_unlock (&self->lock);
163 g_atomic_int_set (&self->seeking, 0);
167 gst_image_freeze_sink_setcaps (GstImageFreeze * self, GstCaps * caps)
169 gboolean ret = FALSE;
172 GstCaps *othercaps, *intersection;
177 caps = gst_caps_make_writable (gst_caps_ref (caps));
179 GST_DEBUG_OBJECT (pad, "Setting caps: %" GST_PTR_FORMAT, caps);
181 s = gst_caps_get_structure (caps, 0);
183 /* 1. Remove framerate */
184 gst_structure_remove_field (s, "framerate");
185 gst_structure_set (s, "framerate", GST_TYPE_FRACTION_RANGE, 0, 1, G_MAXINT, 1,
188 /* 2. Intersect with template caps */
189 othercaps = (GstCaps *) gst_pad_get_pad_template_caps (pad);
190 intersection = gst_caps_intersect (caps, othercaps);
191 GST_DEBUG_OBJECT (pad, "Intersecting: %" GST_PTR_FORMAT, caps);
192 GST_DEBUG_OBJECT (pad, "with: %" GST_PTR_FORMAT, othercaps);
193 GST_DEBUG_OBJECT (pad, "gave: %" GST_PTR_FORMAT, intersection);
194 gst_caps_unref (caps);
196 intersection = othercaps = NULL;
198 /* 3. Intersect with downstream peer caps */
199 othercaps = gst_pad_peer_query_caps (self->srcpad, NULL);
201 intersection = gst_caps_intersect (caps, othercaps);
202 GST_DEBUG_OBJECT (pad, "Intersecting: %" GST_PTR_FORMAT, caps);
203 GST_DEBUG_OBJECT (pad, "with: %" GST_PTR_FORMAT, othercaps);
204 GST_DEBUG_OBJECT (pad, "gave: %" GST_PTR_FORMAT, intersection);
205 gst_caps_unref (othercaps);
206 gst_caps_unref (caps);
208 intersection = othercaps = NULL;
211 /* 4. For every candidate check if it's accepted downstream
212 * and fixate framerate to nearest 25/1 */
213 n = gst_caps_get_size (caps);
214 for (i = 0; i < n; i++) {
215 GstCaps *candidate = gst_caps_new_empty ();
216 GstStructure *s = gst_structure_copy (gst_caps_get_structure (caps, i));
218 gst_caps_append_structure (candidate, s);
219 if (gst_pad_peer_query_accept_caps (self->srcpad, candidate)) {
220 if (gst_structure_has_field_typed (s, "framerate", GST_TYPE_FRACTION) ||
221 gst_structure_fixate_field_nearest_fraction (s, "framerate", 25, 1)) {
222 gst_structure_get_fraction (s, "framerate", &fps_n, &fps_d);
224 g_mutex_lock (&self->lock);
227 g_mutex_unlock (&self->lock);
228 GST_DEBUG_OBJECT (pad, "Setting caps %" GST_PTR_FORMAT, candidate);
229 gst_pad_set_caps (self->srcpad, candidate);
230 gst_caps_unref (candidate);
234 GST_WARNING_OBJECT (pad, "Invalid caps with framerate %d/%d", fps_n,
239 gst_caps_unref (candidate);
244 GST_ERROR_OBJECT (pad, "No usable caps found");
246 gst_caps_unref (caps);
252 gst_image_freeze_sink_getcaps (GstImageFreeze * self, GstCaps * filter)
259 if (gst_pad_has_current_caps (pad)) {
260 ret = gst_pad_get_current_caps (pad);
261 gst_caps_replace (&ret, gst_caps_copy (ret));
262 gst_caps_unref (ret);
266 tmp = gst_pad_peer_query_caps (self->srcpad, filter);
268 ret = gst_caps_intersect (tmp, gst_pad_get_pad_template_caps (pad));
269 gst_caps_unref (tmp);
271 ret = gst_caps_copy (gst_pad_get_pad_template_caps (pad));
274 n = gst_caps_get_size (ret);
275 for (i = 0; i < n; i++) {
276 GstStructure *s = gst_caps_get_structure (ret, i);
278 gst_structure_remove_field (s, "framerate");
279 gst_structure_set (s, "framerate", GST_TYPE_FRACTION_RANGE, 0, 1, G_MAXINT,
284 GST_LOG_OBJECT (pad, "Returning caps: %" GST_PTR_FORMAT, ret);
290 gst_image_freeze_sink_query (GstPad * pad, GstObject * parent, GstQuery * query)
292 GstImageFreeze *self = GST_IMAGE_FREEZE (parent);
294 GstPad *peer = gst_pad_get_peer (self->srcpad);
296 GST_LOG_OBJECT (pad, "Handling query of type '%s'",
297 gst_query_type_get_name (GST_QUERY_TYPE (query)));
300 GST_INFO_OBJECT (pad, "No peer yet, dropping query");
303 switch (GST_QUERY_TYPE (query)) {
308 gst_query_parse_caps (query, &caps);
309 caps = gst_image_freeze_sink_getcaps (self, caps);
310 gst_query_set_caps_result (query, caps);
311 gst_caps_unref (caps);
316 ret = gst_pad_query_default (peer, parent, query);
318 gst_object_unref (peer);
325 gst_image_freeze_convert (GstImageFreeze * self,
326 GstFormat src_format, gint64 src_value,
327 GstFormat * dest_format, gint64 * dest_value)
329 gboolean ret = FALSE;
331 if (src_format == *dest_format) {
332 *dest_value = src_value;
336 if (src_value == -1) {
341 switch (src_format) {
342 case GST_FORMAT_DEFAULT:{
343 switch (*dest_format) {
344 case GST_FORMAT_TIME:
345 g_mutex_lock (&self->lock);
346 if (self->fps_n == 0)
350 gst_util_uint64_scale (src_value, GST_SECOND * self->fps_d,
352 g_mutex_unlock (&self->lock);
360 case GST_FORMAT_TIME:{
361 switch (*dest_format) {
362 case GST_FORMAT_DEFAULT:
363 g_mutex_lock (&self->lock);
365 gst_util_uint64_scale (src_value, self->fps_n,
366 self->fps_d * GST_SECOND);
367 g_mutex_unlock (&self->lock);
383 gst_image_freeze_src_query (GstPad * pad, GstObject * parent, GstQuery * query)
385 GstImageFreeze *self = GST_IMAGE_FREEZE (parent);
386 gboolean ret = FALSE;
388 GST_LOG_OBJECT (pad, "Handling query of type '%s'",
389 gst_query_type_get_name (GST_QUERY_TYPE (query)));
391 switch (GST_QUERY_TYPE (query)) {
392 case GST_QUERY_CONVERT:{
393 GstFormat src_format, dest_format;
394 gint64 src_value, dest_value;
396 gst_query_parse_convert (query, &src_format, &src_value, &dest_format,
399 gst_image_freeze_convert (self, src_format, src_value, &dest_format,
402 gst_query_set_convert (query, src_format, src_value, dest_format,
406 case GST_QUERY_POSITION:{
410 gst_query_parse_position (query, &format, NULL);
412 case GST_FORMAT_DEFAULT:{
413 g_mutex_lock (&self->lock);
414 position = self->offset;
415 g_mutex_unlock (&self->lock);
419 case GST_FORMAT_TIME:{
420 g_mutex_lock (&self->lock);
421 position = self->segment.position;
422 g_mutex_unlock (&self->lock);
431 gst_query_set_position (query, format, position);
432 GST_DEBUG_OBJECT (pad,
433 "Returning position %" G_GINT64_FORMAT " in format %s", position,
434 gst_format_get_name (format));
436 GST_DEBUG_OBJECT (pad, "Position query failed");
440 case GST_QUERY_DURATION:{
444 gst_query_parse_duration (query, &format, NULL);
446 case GST_FORMAT_TIME:{
447 g_mutex_lock (&self->lock);
448 duration = self->segment.stop;
449 g_mutex_unlock (&self->lock);
453 case GST_FORMAT_DEFAULT:{
454 g_mutex_lock (&self->lock);
455 duration = self->segment.stop;
458 gst_util_uint64_scale (duration, self->fps_n,
459 GST_SECOND * self->fps_d);
460 g_mutex_unlock (&self->lock);
469 gst_query_set_duration (query, format, duration);
470 GST_DEBUG_OBJECT (pad,
471 "Returning duration %" G_GINT64_FORMAT " in format %s", duration,
472 gst_format_get_name (format));
474 GST_DEBUG_OBJECT (pad, "Duration query failed");
478 case GST_QUERY_SEEKING:{
482 gst_query_parse_seeking (query, &format, NULL, NULL, NULL);
483 seekable = (format == GST_FORMAT_TIME || format == GST_FORMAT_DEFAULT);
485 gst_query_set_seeking (query, format, seekable, (seekable ? 0 : -1), -1);
499 gst_image_freeze_sink_event (GstPad * pad, GstObject * parent, GstEvent * event)
501 GstImageFreeze *self = GST_IMAGE_FREEZE (parent);
504 GST_LOG_OBJECT (pad, "Got %s event", GST_EVENT_TYPE_NAME (event));
506 switch (GST_EVENT_TYPE (event)) {
511 gst_event_parse_caps (event, &caps);
512 gst_image_freeze_sink_setcaps (self, caps);
513 gst_event_unref (event);
519 /* if we receive EOS before a buffer arrives, then let it pass */
520 GST_DEBUG_OBJECT (self, "EOS without input buffer, passing on");
521 ret = gst_pad_push_event (self->srcpad, event);
525 case GST_EVENT_SEGMENT:
526 GST_DEBUG_OBJECT (pad, "Dropping event");
527 gst_event_unref (event);
530 case GST_EVENT_FLUSH_START:
531 gst_image_freeze_reset (self);
534 ret = gst_pad_push_event (self->srcpad, event);
542 gst_image_freeze_src_event (GstPad * pad, GstObject * parent, GstEvent * event)
544 GstImageFreeze *self = GST_IMAGE_FREEZE (parent);
547 GST_LOG_OBJECT (pad, "Got %s event", GST_EVENT_TYPE_NAME (event));
549 switch (GST_EVENT_TYPE (event)) {
550 case GST_EVENT_NAVIGATION:
552 case GST_EVENT_LATENCY:
554 GST_DEBUG_OBJECT (pad, "Dropping event");
555 gst_event_unref (event);
558 case GST_EVENT_SEEK:{
562 GstSeekType start_type, stop_type;
568 gst_event_parse_seek (event, &rate, &format, &flags, &start_type, &start,
570 gst_event_unref (event);
572 flush = ! !(flags & GST_SEEK_FLAG_FLUSH);
574 if (format != GST_FORMAT_TIME && format != GST_FORMAT_DEFAULT) {
575 GST_ERROR_OBJECT (pad, "Seek in invalid format: %s",
576 gst_format_get_name (format));
581 if (format == GST_FORMAT_DEFAULT) {
582 format = GST_FORMAT_TIME;
583 if (!gst_image_freeze_convert (self, GST_FORMAT_DEFAULT, start, &format,
585 || !gst_image_freeze_convert (self, GST_FORMAT_DEFAULT, stop,
587 || start == -1 || stop == -1) {
588 GST_ERROR_OBJECT (pad,
589 "Failed to convert seek from DEFAULT format into TIME format");
598 g_atomic_int_set (&self->seeking, 1);
599 e = gst_event_new_flush_start ();
600 gst_pad_push_event (self->srcpad, e);
602 gst_pad_pause_task (self->srcpad);
605 GST_PAD_STREAM_LOCK (self->srcpad);
607 g_mutex_lock (&self->lock);
609 gst_segment_do_seek (&self->segment, rate, format, flags, start_type,
610 start, stop_type, stop, NULL);
611 self->need_segment = TRUE;
612 last_stop = self->segment.position;
614 start_task = self->buffer != NULL;
615 g_mutex_unlock (&self->lock);
620 e = gst_event_new_flush_stop (TRUE);
621 gst_pad_push_event (self->srcpad, e);
622 g_atomic_int_set (&self->seeking, 0);
625 if (flags & GST_SEEK_FLAG_SEGMENT) {
628 m = gst_message_new_segment_start (GST_OBJECT (self),
630 gst_element_post_message (GST_ELEMENT (self), m);
633 GST_PAD_STREAM_UNLOCK (self->srcpad);
635 GST_DEBUG_OBJECT (pad, "Seek successful");
638 g_mutex_lock (&self->lock);
640 if (self->buffer != NULL)
641 gst_pad_start_task (self->srcpad,
642 (GstTaskFunction) gst_image_freeze_src_loop, self->srcpad);
644 g_mutex_unlock (&self->lock);
650 case GST_EVENT_FLUSH_START:
651 gst_image_freeze_reset (self);
654 ret = gst_pad_push_event (self->sinkpad, event);
662 gst_image_freeze_sink_chain (GstPad * pad, GstObject * parent,
665 GstImageFreeze *self = GST_IMAGE_FREEZE (parent);
667 g_mutex_lock (&self->lock);
669 GST_DEBUG_OBJECT (pad, "Already have a buffer, dropping");
670 gst_buffer_unref (buffer);
671 g_mutex_unlock (&self->lock);
675 self->buffer = buffer;
677 gst_pad_start_task (self->srcpad, (GstTaskFunction) gst_image_freeze_src_loop,
679 g_mutex_unlock (&self->lock);
684 gst_image_freeze_src_loop (GstPad * pad)
686 GstImageFreeze *self = GST_IMAGE_FREEZE (GST_PAD_PARENT (pad));
689 GstClockTime timestamp, timestamp_end;
690 guint64 cstart, cstop;
691 gboolean in_seg, eos;
693 g_mutex_lock (&self->lock);
695 GST_ERROR_OBJECT (pad, "Have no buffer yet");
696 g_mutex_unlock (&self->lock);
697 gst_pad_pause_task (self->srcpad);
700 buffer = gst_buffer_ref (self->buffer);
701 buffer = gst_buffer_make_writable (buffer);
702 g_mutex_unlock (&self->lock);
704 if (self->need_segment) {
707 GST_DEBUG_OBJECT (pad, "Pushing NEWSEGMENT event: %" GST_SEGMENT_FORMAT,
709 e = gst_event_new_segment (&self->segment);
711 g_mutex_lock (&self->lock);
712 if (self->segment.rate >= 0) {
714 gst_util_uint64_scale (self->segment.start, self->fps_n,
715 self->fps_d * GST_SECOND);
718 gst_util_uint64_scale (self->segment.stop, self->fps_n,
719 self->fps_d * GST_SECOND);
721 g_mutex_unlock (&self->lock);
723 self->need_segment = FALSE;
725 gst_pad_push_event (self->srcpad, e);
728 g_mutex_lock (&self->lock);
729 offset = self->offset;
731 if (self->fps_n != 0) {
733 gst_util_uint64_scale (offset, self->fps_d * GST_SECOND, self->fps_n);
735 gst_util_uint64_scale (offset + 1, self->fps_d * GST_SECOND,
738 timestamp = self->segment.start;
739 timestamp_end = GST_CLOCK_TIME_NONE;
742 eos = (self->fps_n == 0 && offset > 0) ||
743 (self->segment.rate >= 0 && self->segment.stop != -1
744 && timestamp > self->segment.stop) || (self->segment.rate < 0
745 && offset == 0) || (self->segment.rate < 0
746 && self->segment.start != -1 && timestamp_end < self->segment.start);
748 if (self->fps_n == 0 && offset > 0)
752 gst_segment_clip (&self->segment, GST_FORMAT_TIME, timestamp,
753 timestamp_end, &cstart, &cstop);
756 self->segment.position = cstart;
758 if (self->segment.rate >= 0)
762 g_mutex_unlock (&self->lock);
764 GST_DEBUG_OBJECT (pad, "Handling buffer with timestamp %" GST_TIME_FORMAT,
765 GST_TIME_ARGS (timestamp));
770 GST_BUFFER_TIMESTAMP (buffer) = cstart;
771 GST_BUFFER_DURATION (buffer) = cstop - cstart;
772 GST_BUFFER_OFFSET (buffer) = offset;
773 GST_BUFFER_OFFSET_END (buffer) = offset + 1;
774 ret = gst_pad_push (self->srcpad, buffer);
775 GST_DEBUG_OBJECT (pad, "Pushing buffer resulted in %s",
776 gst_flow_get_name (ret));
777 if (ret != GST_FLOW_OK)
778 gst_pad_pause_task (self->srcpad);
780 gst_buffer_unref (buffer);
784 if ((self->segment.flags & GST_SEEK_FLAG_SEGMENT)) {
787 GST_DEBUG_OBJECT (pad, "Sending segment done at end of segment");
788 if (self->segment.rate >= 0)
789 m = gst_message_new_segment_done (GST_OBJECT_CAST (self),
790 GST_FORMAT_TIME, self->segment.stop);
792 m = gst_message_new_segment_done (GST_OBJECT_CAST (self),
793 GST_FORMAT_TIME, self->segment.start);
794 gst_element_post_message (GST_ELEMENT_CAST (self), m);
796 GST_DEBUG_OBJECT (pad, "Sending EOS at end of segment");
797 gst_pad_push_event (self->srcpad, gst_event_new_eos ());
799 gst_pad_pause_task (self->srcpad);
803 static GstStateChangeReturn
804 gst_image_freeze_change_state (GstElement * element, GstStateChange transition)
806 GstImageFreeze *self = GST_IMAGE_FREEZE (element);
807 GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
809 switch (transition) {
810 case GST_STATE_CHANGE_READY_TO_PAUSED:
811 gst_image_freeze_reset (self);
813 case GST_STATE_CHANGE_PAUSED_TO_READY:
814 gst_pad_stop_task (self->srcpad);
815 gst_image_freeze_reset (self);
821 if (GST_ELEMENT_CLASS (parent_class)->change_state)
822 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
824 switch (transition) {
833 plugin_init (GstPlugin * plugin)
835 GST_DEBUG_CATEGORY_INIT (gst_image_freeze_debug, "imagefreeze", 0,
836 "imagefreeze element");
838 if (!gst_element_register (plugin, "imagefreeze", GST_RANK_NONE,
839 GST_TYPE_IMAGE_FREEZE))
845 GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
848 "Still frame stream generator",
849 plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)