gstreamer/ext/pango/gsttextrender.c
2009-08-06 06:43:37 +02:00

678 lines
21 KiB
C

/* GStreamer
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
* Copyright (C) <2003> David Schleef <ds@schleef.org>
* Copyright (C) <2009> Young-Ho Cha <ganadist@gmail.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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:element-textrender
* @see_also: #GstTextOverlay
*
* This plugin renders text received on the text sink pad to a video
* buffer (retaining the alpha channel), so it can later be overlayed
* on top of video streams using other elements.
*
* The text can contain newline characters. (FIXME: What about text
* wrapping? It does not make sense in this context)
*
* <refsect2>
* <title>Example launch lines</title>
* |[
* gst-launch -v filesrc location=subtitles.srt ! subparse ! textrender ! xvimagesink
* ]|
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <gst/gst.h>
#include <gst/video/video.h>
#include "gsttextrender.h"
#include <string.h>
GST_DEBUG_CATEGORY_EXTERN (pango_debug);
#define GST_CAT_DEFAULT pango_debug
#define MINIMUM_OUTLINE_OFFSET 1.0
#define DEFAULT_PROP_VALIGNMENT GST_TEXT_RENDER_VALIGN_BASELINE
#define DEFAULT_PROP_HALIGNMENT GST_TEXT_RENDER_HALIGN_CENTER
#define DEFAULT_PROP_LINE_ALIGNMENT GST_TEXT_RENDER_LINE_ALIGN_CENTER
#define DEFAULT_PROP_XPAD 25
#define DEFAULT_PROP_YPAD 25
#define DEFAULT_RENDER_WIDTH 720
#define DEFAULT_RENDER_HEIGHT 576
enum
{
PROP_0,
PROP_HALIGNMENT,
PROP_VALIGNMENT,
PROP_LINE_ALIGNMENT,
PROP_XPAD,
PROP_YPAD,
PROP_FONT_DESC
};
static GstStaticPadTemplate src_template_factory =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("AYUV") ";" GST_VIDEO_CAPS_ARGB)
);
static GstStaticPadTemplate sink_template_factory =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("text/x-pango-markup; text/plain")
);
#define GST_TYPE_TEXT_RENDER_VALIGN (gst_text_render_valign_get_type())
static GType
gst_text_render_valign_get_type (void)
{
static GType text_render_valign_type = 0;
static const GEnumValue text_render_valign[] = {
{GST_TEXT_RENDER_VALIGN_BASELINE, "baseline", "baseline"},
{GST_TEXT_RENDER_VALIGN_BOTTOM, "bottom", "bottom"},
{GST_TEXT_RENDER_VALIGN_TOP, "top", "top"},
{0, NULL, NULL},
};
if (!text_render_valign_type) {
text_render_valign_type =
g_enum_register_static ("GstTextRenderVAlign", text_render_valign);
}
return text_render_valign_type;
}
#define GST_TYPE_TEXT_RENDER_HALIGN (gst_text_render_halign_get_type())
static GType
gst_text_render_halign_get_type (void)
{
static GType text_render_halign_type = 0;
static const GEnumValue text_render_halign[] = {
{GST_TEXT_RENDER_HALIGN_LEFT, "left", "left"},
{GST_TEXT_RENDER_HALIGN_CENTER, "center", "center"},
{GST_TEXT_RENDER_HALIGN_RIGHT, "right", "right"},
{0, NULL, NULL},
};
if (!text_render_halign_type) {
text_render_halign_type =
g_enum_register_static ("GstTextRenderHAlign", text_render_halign);
}
return text_render_halign_type;
}
#define GST_TYPE_TEXT_RENDER_LINE_ALIGN (gst_text_render_line_align_get_type())
static GType
gst_text_render_line_align_get_type (void)
{
static GType text_render_line_align_type = 0;
static const GEnumValue text_render_line_align[] = {
{GST_TEXT_RENDER_LINE_ALIGN_LEFT, "left", "left"},
{GST_TEXT_RENDER_LINE_ALIGN_CENTER, "center", "center"},
{GST_TEXT_RENDER_LINE_ALIGN_RIGHT, "right", "right"},
{0, NULL, NULL}
};
if (!text_render_line_align_type) {
text_render_line_align_type =
g_enum_register_static ("GstTextRenderLineAlign",
text_render_line_align);
}
return text_render_line_align_type;
}
static void gst_text_render_adjust_values_with_fontdesc (GstTextRender *
render, PangoFontDescription * desc);
GST_BOILERPLATE (GstTextRender, gst_text_render, GstElement, GST_TYPE_ELEMENT);
static void gst_text_render_finalize (GObject * object);
static void gst_text_render_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec);
static void gst_text_render_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec);
static void
gst_text_render_base_init (gpointer g_class)
{
GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&src_template_factory));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&sink_template_factory));
gst_element_class_set_details_simple (element_class, "Text renderer",
"Filter/Editor/Video",
"Renders a text string to an image bitmap",
"David Schleef <ds@schleef.org>, "
"Ronald S. Bultje <rbultje@ronald.bitfreak.net>");
}
static void
gst_text_render_class_init (GstTextRenderClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
PangoFontMap *fontmap;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
parent_class = g_type_class_peek_parent (klass);
gobject_class->finalize = gst_text_render_finalize;
gobject_class->set_property = gst_text_render_set_property;
gobject_class->get_property = gst_text_render_get_property;
fontmap = pango_cairo_font_map_get_default ();
klass->pango_context =
pango_cairo_font_map_create_context (PANGO_CAIRO_FONT_MAP (fontmap));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_FONT_DESC,
g_param_spec_string ("font-desc", "font description",
"Pango font description of font "
"to be used for rendering. "
"See documentation of "
"pango_font_description_from_string"
" for syntax.", "", G_PARAM_WRITABLE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_VALIGNMENT,
g_param_spec_enum ("valignment", "vertical alignment",
"Vertical alignment of the text", GST_TYPE_TEXT_RENDER_VALIGN,
DEFAULT_PROP_VALIGNMENT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_HALIGNMENT,
g_param_spec_enum ("halignment", "horizontal alignment",
"Horizontal alignment of the text", GST_TYPE_TEXT_RENDER_HALIGN,
DEFAULT_PROP_HALIGNMENT, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_XPAD,
g_param_spec_int ("xpad", "horizontal paddding",
"Horizontal paddding when using left/right alignment", 0, G_MAXINT,
DEFAULT_PROP_XPAD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_YPAD,
g_param_spec_int ("ypad", "vertical padding",
"Vertical padding when using top/bottom alignment", 0, G_MAXINT,
DEFAULT_PROP_YPAD, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_LINE_ALIGNMENT,
g_param_spec_enum ("line-alignment", "line alignment",
"Alignment of text lines relative to each other.",
GST_TYPE_TEXT_RENDER_LINE_ALIGN, DEFAULT_PROP_LINE_ALIGNMENT,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
}
static void
gst_text_render_adjust_values_with_fontdesc (GstTextRender * render,
PangoFontDescription * desc)
{
gint font_size = pango_font_description_get_size (desc) / PANGO_SCALE;
render->shadow_offset = (double) (font_size) / 13.0;
render->outline_offset = (double) (font_size) / 15.0;
if (render->outline_offset < MINIMUM_OUTLINE_OFFSET)
render->outline_offset = MINIMUM_OUTLINE_OFFSET;
}
static void
gst_text_render_render_pangocairo (GstTextRender * render)
{
cairo_t *cr;
cairo_surface_t *surface;
cairo_t *cr_shadow;
cairo_surface_t *surface_shadow;
PangoRectangle ink_rect, logical_rect;
gint width, height;
pango_layout_get_pixel_extents (render->layout, &ink_rect, &logical_rect);
width = logical_rect.width + render->shadow_offset;
height = logical_rect.height + logical_rect.y + render->shadow_offset;
surface_shadow = cairo_image_surface_create (CAIRO_FORMAT_A8, width, height);
cr_shadow = cairo_create (surface_shadow);
/* clear shadow surface */
cairo_set_source_rgba (cr_shadow, 0.0, 0.0, 0.0, 0.0);
cairo_set_operator (cr_shadow, CAIRO_OPERATOR_CLEAR);
cairo_paint (cr_shadow);
cairo_set_operator (cr_shadow, CAIRO_OPERATOR_OVER);
cairo_set_source_rgb (cr_shadow, 0.0, 0.0, 0.0);
pango_cairo_update_layout (cr_shadow, render->layout);
/* draw shadow text */
cairo_save (cr_shadow);
cairo_set_source_rgba (cr_shadow, 0.0, 0.0, 0.0, 0.5);
cairo_translate (cr_shadow, render->shadow_offset, render->shadow_offset);
pango_cairo_show_layout (cr_shadow, render->layout);
cairo_restore (cr_shadow);
/* draw outline text */
cairo_save (cr_shadow);
cairo_set_line_width (cr_shadow, render->outline_offset);
pango_cairo_layout_path (cr_shadow, render->layout);
cairo_stroke (cr_shadow);
cairo_restore (cr_shadow);
cairo_destroy (cr_shadow);
render->text_image = g_realloc (render->text_image, 4 * width * height);
memset (render->text_image, 0, 4 * width * height);
surface = cairo_image_surface_create_for_data (render->text_image,
CAIRO_FORMAT_ARGB32, width, height, width * 4);
cr = cairo_create (surface);
/* set default color */
cairo_set_source_rgb (cr, 1.0, 1.0, 1.0);
/* draw text */
pango_cairo_update_layout (cr, render->layout);
pango_cairo_show_layout (cr, render->layout);
/* composite shadow with offset */
cairo_set_operator (cr, CAIRO_OPERATOR_DEST_OVER);
cairo_set_source_surface (cr, surface_shadow, 0.0, 0.0);
cairo_paint (cr);
cairo_destroy (cr);
cairo_surface_destroy (surface_shadow);
cairo_surface_destroy (surface);
render->image_width = width;
render->image_height = height;
}
static void
gst_text_render_check_argb (GstTextRender * render)
{
GstCaps *peer_caps;
peer_caps = gst_pad_get_allowed_caps (render->srcpad);
if (G_LIKELY (peer_caps)) {
guint i = 0, n = 0;
n = gst_caps_get_size (peer_caps);
GST_DEBUG_OBJECT (render, "peer allowed caps (%u structure(s)) are %"
GST_PTR_FORMAT, n, peer_caps);
/* Check if AYUV or ARGB is first */
for (i = 0; i < n; i++) {
GstStructure *s = gst_caps_get_structure (peer_caps, i);
if (gst_structure_has_name (s, "video/x-raw-rgb") &&
gst_structure_has_field (s, "alpha_mask")) {
render->use_ARGB = TRUE;
break;
} else if (gst_structure_has_name (s, "video/x-raw-yuv")) {
guint fourcc;
if (gst_structure_get_fourcc (s, "format", &fourcc) &&
fourcc == GST_MAKE_FOURCC ('A', 'Y', 'U', 'V')) {
render->use_ARGB = FALSE;
break;
}
}
}
gst_caps_unref (peer_caps);
}
}
static gboolean
gst_text_render_setcaps (GstPad * pad, GstCaps * caps)
{
GstTextRender *render = GST_TEXT_RENDER (gst_pad_get_parent (pad));
GstStructure *structure;
gboolean ret = FALSE;
gint width = 0, height = 0;
structure = gst_caps_get_structure (caps, 0);
gst_structure_get_int (structure, "width", &width);
gst_structure_get_int (structure, "height", &height);
GST_DEBUG ("Got caps %" GST_PTR_FORMAT, caps);
if (width >= render->image_width && height >= render->image_height) {
render->width = width;
render->height = height;
ret = TRUE;
}
gst_text_render_check_argb (render);
gst_object_unref (render);
return ret;
}
static void
gst_text_render_fixate_caps (GstPad * pad, GstCaps * caps)
{
GstTextRender *render = GST_TEXT_RENDER (gst_pad_get_parent (pad));
GstStructure *s = gst_caps_get_structure (caps, 0);
GST_DEBUG ("Fixating caps %" GST_PTR_FORMAT, caps);
gst_structure_fixate_field_nearest_int (s, "width", render->image_width);
gst_structure_fixate_field_nearest_int (s, "height", render->image_height);
GST_DEBUG ("Fixated to %" GST_PTR_FORMAT, caps);
gst_object_unref (render);
}
static void
gst_text_renderer_image_to_ayuv (GstTextRender * render, guchar * pixbuf,
int xpos, int ypos, int stride)
{
int y; /* text bitmap coordinates */
guchar *p, *bitp;
guchar a, r, g, b;
int width, height;
width = render->image_width;
height = render->image_height;
bitp = render->text_image;
for (y = 0; y < height; y++) {
int n;
p = pixbuf + ypos * stride + xpos;
for (n = 0; n < width; n++) {
b = *bitp++;
g = *bitp++;
r = *bitp++;
a = *bitp++;
*p++ = a;
*p++ = CLAMP ((int) (((19595 * r) >> 16) + ((38470 * g) >> 16) +
((7471 * b) >> 16)), 0, 255);
*p++ = CLAMP ((int) (-((11059 * r) >> 16) - ((21709 * g) >> 16) +
((32768 * b) >> 16) + 128), 0, 255);
*p++ = CLAMP ((int) (((32768 * r) >> 16) - ((27439 * g) >> 16) -
((5329 * b) >> 16) + 128), 0, 255);
}
}
}
static void
gst_text_renderer_image_to_argb (GstTextRender * render, guchar * pixbuf,
int xpos, int ypos, int stride)
{
int i;
guchar *p, *bitp;
int width, height;
width = render->image_width;
height = render->image_height;
bitp = render->text_image;
for (i = 0; i < height; i++) {
p = pixbuf + ypos * stride + xpos;
memcpy (p, bitp, width * 4);
bitp += width * 4;
}
}
static GstFlowReturn
gst_text_render_chain (GstPad * pad, GstBuffer * inbuf)
{
GstTextRender *render;
GstFlowReturn ret;
GstBuffer *outbuf;
GstCaps *caps = NULL;
guint8 *data = GST_BUFFER_DATA (inbuf);
guint size = GST_BUFFER_SIZE (inbuf);
gint n;
gint xpos, ypos;
render = GST_TEXT_RENDER (gst_pad_get_parent (pad));
/* somehow pango barfs over "\0" buffers... */
while (size > 0 &&
(data[size - 1] == '\r' ||
data[size - 1] == '\n' || data[size - 1] == '\0')) {
size--;
}
/* render text */
GST_DEBUG ("rendering '%*s'", size, data);
pango_layout_set_markup (render->layout, (gchar *) data, size);
gst_text_render_render_pangocairo (render);
gst_text_render_check_argb (render);
if (!render->use_ARGB) {
caps =
gst_video_format_new_caps (GST_VIDEO_FORMAT_AYUV, render->width,
render->height, 1, 1, 1, 1);
} else {
caps =
gst_video_format_new_caps (GST_VIDEO_FORMAT_ARGB, render->width,
render->height, 1, 1, 1, 1);
}
if (!gst_pad_set_caps (render->srcpad, caps)) {
gst_caps_unref (caps);
GST_ELEMENT_ERROR (render, CORE, NEGOTIATION, (NULL), (NULL));
ret = GST_FLOW_ERROR;
goto done;
}
GST_DEBUG ("Allocating buffer WxH = %dx%d", render->width, render->height);
ret =
gst_pad_alloc_buffer_and_set_caps (render->srcpad, GST_BUFFER_OFFSET_NONE,
render->width * render->height * 4, caps, &outbuf);
if (ret != GST_FLOW_OK)
goto done;
gst_buffer_copy_metadata (outbuf, inbuf, GST_BUFFER_COPY_TIMESTAMPS);
data = GST_BUFFER_DATA (outbuf);
if (render->use_ARGB) {
for (n = 0; n < render->width * render->height; n++) {
data[n * 4] = 0;
data[n * 4 + 1] = data[n * 4 + 2] = data[n * 4 + 3] = 0;
}
} else {
for (n = 0; n < render->width * render->height; n++) {
data[n * 4] = data[n * 4 + 1] = 0;
data[n * 4 + 2] = data[n * 4 + 3] = 128;
}
}
switch (render->halign) {
case GST_TEXT_RENDER_HALIGN_LEFT:
xpos = render->xpad;
break;
case GST_TEXT_RENDER_HALIGN_CENTER:
xpos = (render->width - render->image_width) / 2;
break;
case GST_TEXT_RENDER_HALIGN_RIGHT:
xpos = render->width - render->image_width - render->xpad;
break;
default:
xpos = 0;
}
switch (render->valign) {
case GST_TEXT_RENDER_VALIGN_BOTTOM:
ypos = render->height - render->image_height - render->ypad;
break;
case GST_TEXT_RENDER_VALIGN_BASELINE:
ypos = render->height - (render->image_height + render->ypad);
break;
case GST_TEXT_RENDER_VALIGN_TOP:
ypos = render->ypad;
break;
default:
ypos = render->ypad;
break;
}
if (render->text_image) {
if (render->use_ARGB) {
gst_text_renderer_image_to_argb (render, data, xpos, ypos,
render->width * 4);
} else {
gst_text_renderer_image_to_ayuv (render, data, xpos, ypos,
render->width * 4);
}
}
ret = gst_pad_push (render->srcpad, outbuf);
done:
if (caps)
gst_caps_unref (caps);
gst_buffer_unref (inbuf);
gst_object_unref (render);
return ret;
}
static void
gst_text_render_finalize (GObject * object)
{
GstTextRender *render = GST_TEXT_RENDER (object);
g_free (render->text_image);
if (render->layout)
g_object_unref (render->layout);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static void
gst_text_render_init (GstTextRender * render, GstTextRenderClass * klass)
{
GstPadTemplate *template;
/* sink */
template = gst_static_pad_template_get (&sink_template_factory);
render->sinkpad = gst_pad_new_from_template (template, "sink");
gst_object_unref (template);
gst_pad_set_chain_function (render->sinkpad,
GST_DEBUG_FUNCPTR (gst_text_render_chain));
gst_element_add_pad (GST_ELEMENT (render), render->sinkpad);
/* source */
template = gst_static_pad_template_get (&src_template_factory);
render->srcpad = gst_pad_new_from_template (template, "src");
gst_object_unref (template);
gst_pad_set_fixatecaps_function (render->srcpad,
GST_DEBUG_FUNCPTR (gst_text_render_fixate_caps));
gst_pad_set_setcaps_function (render->srcpad,
GST_DEBUG_FUNCPTR (gst_text_render_setcaps));
gst_element_add_pad (GST_ELEMENT (render), render->srcpad);
render->line_align = DEFAULT_PROP_LINE_ALIGNMENT;
render->layout =
pango_layout_new (GST_TEXT_RENDER_GET_CLASS (render)->pango_context);
pango_layout_set_alignment (render->layout,
(PangoAlignment) render->line_align);
render->halign = DEFAULT_PROP_HALIGNMENT;
render->valign = DEFAULT_PROP_VALIGNMENT;
render->xpad = DEFAULT_PROP_XPAD;
render->ypad = DEFAULT_PROP_YPAD;
render->width = DEFAULT_RENDER_WIDTH;
render->height = DEFAULT_RENDER_HEIGHT;
render->use_ARGB = FALSE;
}
static void
gst_text_render_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstTextRender *render = GST_TEXT_RENDER (object);
switch (prop_id) {
case PROP_VALIGNMENT:
render->valign = g_value_get_enum (value);
break;
case PROP_HALIGNMENT:
render->halign = g_value_get_enum (value);
break;
case PROP_LINE_ALIGNMENT:
render->line_align = g_value_get_enum (value);
pango_layout_set_alignment (render->layout,
(PangoAlignment) render->line_align);
break;
case PROP_XPAD:
render->xpad = g_value_get_int (value);
break;
case PROP_YPAD:
render->ypad = g_value_get_int (value);
break;
case PROP_FONT_DESC:
{
PangoFontDescription *desc;
desc = pango_font_description_from_string (g_value_get_string (value));
if (desc) {
GST_LOG ("font description set: %s", g_value_get_string (value));
GST_OBJECT_LOCK (render);
pango_layout_set_font_description (render->layout, desc);
gst_text_render_adjust_values_with_fontdesc (render, desc);
pango_font_description_free (desc);
gst_text_render_render_pangocairo (render);
GST_OBJECT_UNLOCK (render);
} else {
GST_WARNING ("font description parse failed: %s",
g_value_get_string (value));
}
break;
}
default:
break;
}
}
static void
gst_text_render_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstTextRender *render = GST_TEXT_RENDER (object);
switch (prop_id) {
case PROP_VALIGNMENT:
g_value_set_enum (value, render->valign);
break;
case PROP_HALIGNMENT:
g_value_set_enum (value, render->halign);
break;
case PROP_LINE_ALIGNMENT:
g_value_set_enum (value, render->line_align);
break;
case PROP_XPAD:
g_value_set_int (value, render->xpad);
break;
case PROP_YPAD:
g_value_set_int (value, render->ypad);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}