gstreamer/gst-libs/gst/video/gstvideosink.c

149 lines
4.1 KiB
C

/*
* GStreamer Video sink.
*
* Copyright (C) <2003> Julien Moutte <julien@moutte.net>
*
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:gstvideosink
* @short_description: Base class for video sinks
*
* <refsect2>
* <para>
* Provides useful functions and a base class for video sinks.
* </para>
* <para>
* GstVideoSink will configure the default base sink to drop frames that
* arrive later than 20ms as this is considered the default threshold for
* observing out-of-sync frames.
* </para>
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstvideosink.h"
GST_DEBUG_CATEGORY_STATIC (video_sink_debug);
#define GST_CAT_DEFAULT video_sink_debug
static GstElementClass *parent_class = NULL;
/**
* gst_video_sink_center_rect:
* @src: the #GstVideoRectangle describing the source area
* @dst: the #GstVideoRectangle describing the destination area
* @result: a pointer to a #GstVideoRectangle which will receive the result area
* @scaling: a #gboolean indicating if scaling should be applied or not
*
* Takes @src rectangle and position it at the center of @dst rectangle with or
* without @scaling. It handles clipping if the @src rectangle is bigger than
* the @dst one and @scaling is set to FALSE.
*/
void
gst_video_sink_center_rect (GstVideoRectangle src, GstVideoRectangle dst,
GstVideoRectangle * result, gboolean scaling)
{
g_return_if_fail (result != NULL);
if (!scaling) {
result->w = MIN (src.w, dst.w);
result->h = MIN (src.h, dst.h);
result->x = (dst.w - result->w) / 2;
result->y = (dst.h - result->h) / 2;
} else {
gdouble src_ratio, dst_ratio;
src_ratio = (gdouble) src.w / src.h;
dst_ratio = (gdouble) dst.w / dst.h;
if (src_ratio > dst_ratio) {
result->w = dst.w;
result->h = dst.w / src_ratio;
result->x = 0;
result->y = (dst.h - result->h) / 2;
} else if (src_ratio < dst_ratio) {
result->w = dst.h * src_ratio;
result->h = dst.h;
result->x = (dst.w - result->w) / 2;
result->y = 0;
} else {
result->x = 0;
result->y = 0;
result->w = dst.w;
result->h = dst.h;
}
}
GST_DEBUG ("source is %dx%d dest is %dx%d, result is %dx%d with x,y %dx%d",
src.w, src.h, dst.w, dst.h, result->w, result->h, result->x, result->y);
}
/* Initing stuff */
static void
gst_video_sink_init (GstVideoSink * videosink)
{
videosink->width = 0;
videosink->height = 0;
/* 20ms is more than enough, 80-130ms is noticable */
gst_base_sink_set_max_lateness (GST_BASE_SINK (videosink), 20 * GST_MSECOND);
gst_base_sink_set_qos_enabled (GST_BASE_SINK (videosink), TRUE);
}
static void
gst_video_sink_class_init (GstVideoSinkClass * klass)
{
parent_class = g_type_class_peek_parent (klass);
}
static void
gst_video_sink_base_init (gpointer g_class)
{
GST_DEBUG_CATEGORY_INIT (video_sink_debug, "videosink", 0, "GstVideoSink");
}
/* Public methods */
GType
gst_video_sink_get_type (void)
{
static GType videosink_type = 0;
if (!videosink_type) {
static const GTypeInfo videosink_info = {
sizeof (GstVideoSinkClass),
gst_video_sink_base_init,
NULL,
(GClassInitFunc) gst_video_sink_class_init,
NULL,
NULL,
sizeof (GstVideoSink),
0,
(GInstanceInitFunc) gst_video_sink_init,
};
videosink_type = g_type_register_static (GST_TYPE_BASE_SINK,
"GstVideoSink", &videosink_info, 0);
}
return videosink_type;
}