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gstreamer/gst/imagefreeze/gstimagefreeze.c
Seungha Yang 027940a416 imagefreeze: Response caps query from srcpad 
... and chain up to default query handler for unhandled query types.
Unhandled query shouldn't be returned with FALSE if there's no special needs.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/-/merge_requests/731>
2020-09-21 10:28:01 +03:00

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/* GStreamer
* Copyright (c) 2005 Edward Hervey <bilboed@bilboed.com>
* Copyright (C) 2010 Sebastian Dröge <sebastian.droege@collabora.co.uk>
* Copyright (C) 2020 Sebastian Dröge <sebastian@centricular.com>
*
* 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 <gst/glib-compat-private.h>
#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_query_caps (GstImageFreeze * self,
GstPad * pad, 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 <sebastian.droege@collabora.co.uk>");
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_query_caps (GstImageFreeze * self, GstPad * pad,
GstCaps * filter)
{
GstCaps *ret, *tmp, *templ;
GstPad *otherpad;
otherpad = (pad == self->srcpad) ? self->sinkpad : self->srcpad;
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 (otherpad, filter);
if (tmp) {
GST_LOG_OBJECT (otherpad, "peer caps %" GST_PTR_FORMAT, tmp);
ret = gst_caps_intersect (tmp, templ);
gst_caps_unref (tmp);
} else {
GST_LOG_OBJECT (otherpad, "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_query_caps (self, pad, 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;
case GST_QUERY_CAPS:
{
GstCaps *caps;
gst_query_parse_caps (query, &caps);
caps = gst_image_freeze_query_caps (self, pad, caps);
gst_query_set_caps_result (query, caps);
gst_caps_unref (caps);
ret = TRUE;
break;
}
default:
ret = gst_pad_query_default (pad, parent, query);
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;
clock = gst_element_get_clock (GST_ELEMENT (self));
/* Wait until the element went to PLAYING or flushing */
while ((!clock || self->blocked) && !self->flushing) {
g_cond_wait (&self->blocked_cond, &self->lock);
gst_clear_object (&clock);
clock = gst_element_get_clock (GST_ELEMENT (self));
}
if (self->flushing) {
g_mutex_unlock (&self->lock);
gst_buffer_unref (buffer);
flow_ret = GST_FLOW_FLUSHING;
gst_clear_object (&clock);
goto pause_task;
}
/* Wait on the clock until the time for our current frame is reached */
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)
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