gstreamer/subprojects/gst-editing-services/ges/ges-source.c
Thibault Saunier a342d14ba9 ges: Add support for sources reverse playback
It introduces a `reverse` property at the `nlesource` level which will
basically reverse playback of the clip.

We guarantee that outside that clip, the data flow looks like it was
playing forward as we add an 'identity' element with `single-segment=true`.

This start making use of the newly introduced concept of
`CHILD_PROP_FLAG_SET_ON_ALL_INSTANCES` as it is natural that
doing `source_clip.set_child_property("reverse", True)` will make
the whole clip go reverse, meaning that all the GESSource children
properties will be set. To set an individual source "reverse" child
property as the desired effect.

Fixes: https://gitlab.freedesktop.org/gstreamer/gst-editing-services/-/issues/24
Depends on: https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/451

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/918>
2024-04-18 00:19:31 +00:00

334 lines
9.3 KiB
C

/* GStreamer Editing Services
* Copyright (C) 2009 Edward Hervey <edward.hervey@collabora.co.uk>
* 2009 Nokia Corporation
*
* 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:gessource
* @title: GESSource
* @short_description: Base Class for single-media sources
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "ges-internal.h"
#include "ges/ges-meta-container.h"
#include "ges-track-element.h"
#include "ges-source.h"
#include "ges-layer.h"
#include "gstframepositioner.h"
struct _GESSourcePrivate
{
GstElement *topbin;
GstElement *first_converter;
GstElement *last_converter;
GstPad *ghostpad;
GList *sub_element_probes;
GMutex sub_element_lock;
gboolean is_rendering_smartly;
};
G_DEFINE_TYPE_WITH_PRIVATE (GESSource, ges_source, GES_TYPE_TRACK_ELEMENT);
/******************************
* Internal helper methods *
******************************/
static GstElement *
link_elements (GstElement * bin, GPtrArray * elements)
{
GstElement *element, *prev = NULL, *first = NULL;
gint i;
for (i = 0; i < elements->len; i++) {
element = elements->pdata[i];
if (!element)
continue;
gst_bin_add (GST_BIN (bin), element);
if (prev) {
if (!gst_element_link_pads_full (prev, "src", element, "sink",
GST_PAD_LINK_CHECK_NOTHING)) {
if (!gst_element_link (prev, element)) {
g_error ("Could not link %s and %s", GST_OBJECT_NAME (prev),
GST_OBJECT_NAME (element));
}
}
}
prev = element;
if (first == NULL)
first = element;
}
return prev;
}
typedef struct
{
GstPad *pad;
gulong probe_id;
} ProbeData;
static GstPadProbeReturn
pad_probe_cb (GstPad * pad, GstPadProbeInfo * info, gpointer user_data)
{
return GST_PAD_PROBE_OK;
}
static void
_release_probe_data (ProbeData * pdata)
{
gst_pad_remove_probe (pdata->pad, pdata->probe_id);
gst_object_unref (pdata->pad);
g_free (pdata);
}
static void
_no_more_pads_cb (GstElement * element, GESSource * self)
{
GESSourcePrivate *priv = self->priv;
GST_DEBUG_OBJECT (self,
"Unblocking after no more pads from sub_element %" GST_PTR_FORMAT,
element);
g_mutex_lock (&priv->sub_element_lock);
g_list_free_full (priv->sub_element_probes,
(GDestroyNotify) _release_probe_data);
priv->sub_element_probes = NULL;
g_mutex_unlock (&priv->sub_element_lock);
}
static void
_set_ghost_pad_target (GESSource * self, GstPad * srcpad, GstElement * element)
{
GstPadLinkReturn link_return;
GESSourcePrivate *priv = self->priv;
GESSourceClass *source_klass = GES_SOURCE_GET_CLASS (self);
gboolean use_converter = !!priv->first_converter;
if (source_klass->select_pad && !source_klass->select_pad (self, srcpad)) {
GST_INFO_OBJECT (self, "Ignoring pad %" GST_PTR_FORMAT, srcpad);
return;
}
if (use_converter && priv->is_rendering_smartly) {
GstPad *pad = gst_element_get_static_pad (priv->first_converter, "sink");
use_converter = gst_pad_can_link (srcpad, pad);
gst_object_unref (pad);
}
if (use_converter) {
GstPad *converter_src, *sinkpad;
converter_src = gst_element_get_static_pad (priv->last_converter, "src");
if (!gst_ghost_pad_set_target (GST_GHOST_PAD (priv->ghostpad),
converter_src)) {
GST_ERROR_OBJECT (self, "Could not set ghost target");
}
sinkpad = gst_element_get_static_pad (priv->first_converter, "sink");
link_return = gst_pad_link (srcpad, sinkpad);
#ifndef GST_DISABLE_GST_DEBUG
if (link_return != GST_PAD_LINK_OK) {
GstCaps *srccaps = NULL;
GstCaps *sinkcaps = NULL;
srccaps = gst_pad_query_caps (srcpad, NULL);
sinkcaps = gst_pad_query_caps (sinkpad, NULL);
GST_ERROR_OBJECT (element, "Could not link source with "
"conversion bin: %s (srcpad caps %" GST_PTR_FORMAT
" sinkpad caps: %" GST_PTR_FORMAT ")",
gst_pad_link_get_name (link_return), srccaps, sinkcaps);
gst_caps_unref (srccaps);
gst_caps_unref (sinkcaps);
}
#endif
gst_object_unref (converter_src);
gst_object_unref (sinkpad);
} else {
if (!gst_ghost_pad_set_target (GST_GHOST_PAD (priv->ghostpad), srcpad))
GST_ERROR_OBJECT (self, "Could not set ghost target");
}
}
static void
_pad_added_cb (GstElement * element, GstPad * srcpad, GESSource * self)
{
GESSourcePrivate *priv = self->priv;
ProbeData *pdata = g_new0 (ProbeData, 1);
GST_LOG_OBJECT (self, "blocking sub_element srcpad %" GST_PTR_FORMAT, srcpad);
pdata->probe_id = gst_pad_add_probe (srcpad,
GST_PAD_PROBE_TYPE_BLOCK_DOWNSTREAM,
(GstPadProbeCallback) pad_probe_cb, NULL, NULL);
pdata->pad = gst_object_ref (srcpad);
g_mutex_lock (&priv->sub_element_lock);
priv->sub_element_probes = g_list_append (priv->sub_element_probes, pdata);
g_mutex_unlock (&priv->sub_element_lock);
_set_ghost_pad_target (self, srcpad, element);
}
/* @elements: (transfer-full) */
GstElement *
ges_source_create_topbin (GESSource * source, const gchar * bin_name,
GstElement * sub_element, GPtrArray * elements)
{
GstElement *last;
GstElement *bin;
GstPad *sub_srcpad;
GESSourcePrivate *priv = source->priv;
bin = gst_bin_new (bin_name);
if (!gst_bin_add (GST_BIN (bin), sub_element)) {
GST_ERROR_OBJECT (source, "Could not add sub element: %" GST_PTR_FORMAT,
sub_element);
gst_object_unref (bin);
return NULL;
}
priv->ghostpad = gst_object_ref (gst_ghost_pad_new_no_target ("src",
GST_PAD_SRC));
gst_pad_set_active (priv->ghostpad, TRUE);
gst_element_add_pad (bin, priv->ghostpad);
priv->topbin = gst_object_ref (bin);
last = link_elements (bin, elements);
if (last) {
gint i = 0;
while (!elements->pdata[i])
i++;
priv->first_converter = gst_object_ref (elements->pdata[i]);
priv->last_converter = gst_object_ref (last);
}
sub_srcpad = gst_element_get_static_pad (sub_element, "src");
if (sub_srcpad) {
_set_ghost_pad_target (source, sub_srcpad, sub_element);
gst_object_unref (sub_srcpad);
} else {
GST_INFO_OBJECT (source, "Waiting for pad added");
g_signal_connect (sub_element, "pad-added",
G_CALLBACK (_pad_added_cb), source);
g_signal_connect (sub_element, "no-more-pads",
G_CALLBACK (_no_more_pads_cb), source);
}
g_ptr_array_free (elements, TRUE);
return bin;
}
void
ges_source_set_rendering_smartly (GESSource * source,
gboolean is_rendering_smartly)
{
if (is_rendering_smartly) {
GESTrack *track = ges_track_element_get_track (GES_TRACK_ELEMENT (source));
if (track && ges_track_get_mixing (track)) {
GST_DEBUG_OBJECT (source, "Not rendering smartly as track is mixing!");
source->priv->is_rendering_smartly = FALSE;
return;
}
}
source->priv->is_rendering_smartly = is_rendering_smartly;
}
gboolean
ges_source_get_rendering_smartly (GESSource * source)
{
return source->priv->is_rendering_smartly;
}
static GstElement *
ges_source_create_nle_object (GESTrackElement * self)
{
GParamSpec *pspec;
GstElement *nleobject;
nleobject =
GES_TRACK_ELEMENT_CLASS (ges_source_parent_class)->create_gnl_object
(self);
if (!nleobject)
return NULL;
pspec =
g_object_class_find_property (G_OBJECT_GET_CLASS (nleobject), "reverse");
g_assert (pspec);
if (!ges_timeline_element_add_child_property_full (GES_TIMELINE_ELEMENT
(self), NULL, pspec, G_OBJECT (nleobject),
GES_TIMELINE_ELEMENT_CHILD_PROP_FLAG_SET_ON_ALL_INSTANCES))
GST_ERROR_OBJECT (self,
"Could not register the child property 'reverse' for %" GST_PTR_FORMAT,
nleobject);
g_param_spec_unref (pspec);
return nleobject;
}
static void
ges_source_dispose (GObject * object)
{
GESSourcePrivate *priv = GES_SOURCE (object)->priv;
gst_clear_object (&priv->first_converter);
gst_clear_object (&priv->last_converter);
gst_clear_object (&priv->topbin);
gst_clear_object (&priv->ghostpad);
g_list_free_full (priv->sub_element_probes,
(GDestroyNotify) _release_probe_data);
g_mutex_clear (&priv->sub_element_lock);
G_OBJECT_CLASS (ges_source_parent_class)->dispose (object);
}
static void
ges_source_class_init (GESSourceClass * klass)
{
GESTrackElementClass *track_class = GES_TRACK_ELEMENT_CLASS (klass);
GObjectClass *object_class = G_OBJECT_CLASS (klass);
track_class->nleobject_factorytype = "nlesource";
track_class->create_element = NULL;
track_class->create_gnl_object = ges_source_create_nle_object;
object_class->dispose = ges_source_dispose;
GES_TRACK_ELEMENT_CLASS_DEFAULT_HAS_INTERNAL_SOURCE (klass) = TRUE;
}
static void
ges_source_init (GESSource * self)
{
self->priv = ges_source_get_instance_private (self);
g_mutex_init (&self->priv->sub_element_lock);
}