gstreamer/ext/cairo/gsttimeoverlay.c
2012-04-10 00:51:41 +01:00

316 lines
9.2 KiB
C

/* GStreamer
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
* Copyright (C) <2003> David Schleef <ds@schleef.org>
*
* 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:element-cairotimeoverlay
*
* cairotimeoverlay renders the buffer timestamp for each frame on top of
* the frame.
*
* <refsect2>
* <title>Example launch line</title>
* |[
* gst-launch videotestsrc ! cairotimeoverlay ! autovideosink
* ]|
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/math-compat.h>
#include <gsttimeoverlay.h>
#include <string.h>
#include <cairo.h>
#include <gst/video/video.h>
static GstStaticPadTemplate gst_cairo_time_overlay_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))
);
static GstStaticPadTemplate gst_cairo_time_overlay_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))
);
static GstBaseTransformClass *parent_class = NULL;
static void
gst_cairo_time_overlay_update_font_height (GstCairoTimeOverlay * timeoverlay)
{
gint width, height;
cairo_surface_t *font_surface;
cairo_t *font_cairo;
cairo_font_extents_t font_extents;
width = timeoverlay->width;
height = timeoverlay->height;
font_surface =
cairo_image_surface_create (CAIRO_FORMAT_ARGB32, width, height);
font_cairo = cairo_create (font_surface);
cairo_surface_destroy (font_surface);
font_surface = NULL;
cairo_select_font_face (font_cairo, "monospace", 0, 0);
cairo_set_font_size (font_cairo, 20);
cairo_font_extents (font_cairo, &font_extents);
timeoverlay->text_height = font_extents.height;
GST_DEBUG_OBJECT (timeoverlay, "font height is %f", font_extents.height);
cairo_destroy (font_cairo);
font_cairo = NULL;
}
static gboolean
gst_cairo_time_overlay_set_caps (GstBaseTransform * btrans, GstCaps * incaps,
GstCaps * outcaps)
{
GstCairoTimeOverlay *filter = GST_CAIRO_TIME_OVERLAY (btrans);
GstStructure *structure;
gboolean ret = FALSE;
structure = gst_caps_get_structure (incaps, 0);
if (gst_structure_get_int (structure, "width", &filter->width) &&
gst_structure_get_int (structure, "height", &filter->height)) {
gst_cairo_time_overlay_update_font_height (filter);
ret = TRUE;
}
return ret;
}
/* Useful macros */
#define GST_VIDEO_I420_Y_ROWSTRIDE(width) (GST_ROUND_UP_4(width))
#define GST_VIDEO_I420_U_ROWSTRIDE(width) (GST_ROUND_UP_8(width)/2)
#define GST_VIDEO_I420_V_ROWSTRIDE(width) ((GST_ROUND_UP_8(GST_VIDEO_I420_Y_ROWSTRIDE(width)))/2)
#define GST_VIDEO_I420_Y_OFFSET(w,h) (0)
#define GST_VIDEO_I420_U_OFFSET(w,h) (GST_VIDEO_I420_Y_OFFSET(w,h)+(GST_VIDEO_I420_Y_ROWSTRIDE(w)*GST_ROUND_UP_2(h)))
#define GST_VIDEO_I420_V_OFFSET(w,h) (GST_VIDEO_I420_U_OFFSET(w,h)+(GST_VIDEO_I420_U_ROWSTRIDE(w)*GST_ROUND_UP_2(h)/2))
#define GST_VIDEO_I420_SIZE(w,h) (GST_VIDEO_I420_V_OFFSET(w,h)+(GST_VIDEO_I420_V_ROWSTRIDE(w)*GST_ROUND_UP_2(h)/2))
static gboolean
gst_cairo_time_overlay_get_unit_size (GstBaseTransform * btrans, GstCaps * caps,
guint * size)
{
GstCairoTimeOverlay *filter;
GstStructure *structure;
gboolean ret = FALSE;
gint width, height;
filter = GST_CAIRO_TIME_OVERLAY (btrans);
structure = gst_caps_get_structure (caps, 0);
if (gst_structure_get_int (structure, "width", &width) &&
gst_structure_get_int (structure, "height", &height)) {
*size = GST_VIDEO_I420_SIZE (width, height);
ret = TRUE;
GST_DEBUG_OBJECT (filter, "our frame size is %d bytes (%dx%d)", *size,
width, height);
}
return ret;
}
static char *
gst_cairo_time_overlay_print_smpte_time (guint64 time)
{
int hours;
int minutes;
int seconds;
int ms;
double x;
x = rint (gst_util_guint64_to_gdouble (time + 500000) * 1e-6);
hours = floor (x / (60 * 60 * 1000));
x -= hours * 60 * 60 * 1000;
minutes = floor (x / (60 * 1000));
x -= minutes * 60 * 1000;
seconds = floor (x / (1000));
x -= seconds * 1000;
ms = rint (x);
return g_strdup_printf ("%02d:%02d:%02d.%03d", hours, minutes, seconds, ms);
}
static GstFlowReturn
gst_cairo_time_overlay_transform (GstBaseTransform * trans, GstBuffer * in,
GstBuffer * out)
{
GstCairoTimeOverlay *timeoverlay;
int width;
int height;
int b_width;
int stride_y, stride_u, stride_v;
char *string;
int i, j;
unsigned char *image;
cairo_text_extents_t extents;
guint8 *dest, *src;
cairo_surface_t *font_surface;
cairo_t *text_cairo;
GstFlowReturn ret = GST_FLOW_OK;
timeoverlay = GST_CAIRO_TIME_OVERLAY (trans);
gst_buffer_copy_metadata (out, in, GST_BUFFER_COPY_TIMESTAMPS);
src = GST_BUFFER_DATA (in);
dest = GST_BUFFER_DATA (out);
width = timeoverlay->width;
height = timeoverlay->height;
/* create surface for font rendering */
/* FIXME: preparation of the surface could also be done once when settings
* change */
image = g_malloc (4 * width * timeoverlay->text_height);
font_surface =
cairo_image_surface_create_for_data (image, CAIRO_FORMAT_ARGB32, width,
timeoverlay->text_height, width * 4);
text_cairo = cairo_create (font_surface);
cairo_surface_destroy (font_surface);
font_surface = NULL;
/* we draw a rectangle because the compositing on the buffer below
* doesn't do alpha */
cairo_save (text_cairo);
cairo_rectangle (text_cairo, 0, 0, width, timeoverlay->text_height);
cairo_set_source_rgba (text_cairo, 0, 0, 0, 1);
cairo_set_operator (text_cairo, CAIRO_OPERATOR_SOURCE);
cairo_fill (text_cairo);
cairo_restore (text_cairo);
string = gst_cairo_time_overlay_print_smpte_time (GST_BUFFER_TIMESTAMP (in));
cairo_save (text_cairo);
cairo_select_font_face (text_cairo, "monospace", 0, 0);
cairo_set_font_size (text_cairo, 20);
cairo_text_extents (text_cairo, string, &extents);
cairo_set_source_rgb (text_cairo, 1, 1, 1);
cairo_move_to (text_cairo, 0, timeoverlay->text_height - 2);
cairo_show_text (text_cairo, string);
g_free (string);
cairo_restore (text_cairo);
/* blend width; should retain a max text width so it doesn't jitter */
b_width = extents.width;
if (b_width > width)
b_width = width;
stride_y = GST_VIDEO_I420_Y_ROWSTRIDE (width);
stride_u = GST_VIDEO_I420_U_ROWSTRIDE (width);
stride_v = GST_VIDEO_I420_V_ROWSTRIDE (width);
memcpy (dest, src, GST_BUFFER_SIZE (in));
for (i = 0; i < timeoverlay->text_height; i++) {
for (j = 0; j < b_width; j++) {
((unsigned char *) dest)[i * stride_y + j] =
image[(i * width + j) * 4 + 0];
}
}
for (i = 0; i < timeoverlay->text_height / 2; i++) {
memset (dest + GST_VIDEO_I420_U_OFFSET (width, height) + i * stride_u, 128,
b_width / 2);
memset (dest + GST_VIDEO_I420_V_OFFSET (width, height) + i * stride_v, 128,
b_width / 2);
}
cairo_destroy (text_cairo);
text_cairo = NULL;
g_free (image);
return ret;
}
static void
gst_cairo_time_overlay_base_init (gpointer g_class)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
gst_element_class_set_static_metadata (element_class, "Time overlay",
"Filter/Editor/Video",
"Overlays the time on a video stream", "David Schleef <ds@schleef.org>");
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&gst_cairo_time_overlay_sink_template));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&gst_cairo_time_overlay_src_template));
}
static void
gst_cairo_time_overlay_class_init (gpointer klass, gpointer class_data)
{
GstBaseTransformClass *trans_class;
trans_class = (GstBaseTransformClass *) klass;
parent_class = g_type_class_peek_parent (klass);
trans_class->set_caps = GST_DEBUG_FUNCPTR (gst_cairo_time_overlay_set_caps);
trans_class->get_unit_size =
GST_DEBUG_FUNCPTR (gst_cairo_time_overlay_get_unit_size);
trans_class->transform = GST_DEBUG_FUNCPTR (gst_cairo_time_overlay_transform);
}
static void
gst_cairo_time_overlay_init (GTypeInstance * instance, gpointer g_class)
{
}
GType
gst_cairo_time_overlay_get_type (void)
{
static GType cairo_time_overlay_type = 0;
if (!cairo_time_overlay_type) {
static const GTypeInfo cairo_time_overlay_info = {
sizeof (GstCairoTimeOverlayClass),
gst_cairo_time_overlay_base_init,
NULL,
gst_cairo_time_overlay_class_init,
NULL,
NULL,
sizeof (GstCairoTimeOverlay),
0,
gst_cairo_time_overlay_init,
};
cairo_time_overlay_type = g_type_register_static (GST_TYPE_BASE_TRANSFORM,
"GstCairoTimeOverlay", &cairo_time_overlay_info, 0);
}
return cairo_time_overlay_type;
}