diff -r 000000000000 -r 0e761a78d257 gst_plugins_base/ext/pango/gsttextrender.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gst_plugins_base/ext/pango/gsttextrender.c Thu Dec 17 08:53:32 2009 +0200 @@ -0,0 +1,382 @@ +/* GStreamer + * Copyright (C) <1999> Erik Walthinsen + * Copyright (C) <2003> David Schleef + * + * 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) + * + * + * Example pipeline: + * + * gst-launch -v filesrc location=subtitles.srt ! subparse ! textrender ! xvimagesink + * + * + * + */ + +#ifdef HAVE_CONFIG_H +#include +#endif + +#include +#include + +#include "gsttextrender.h" + +GST_DEBUG_CATEGORY_EXTERN (pango_debug); +#define GST_CAT_DEFAULT pango_debug + +static const GstElementDetails text_render_details = +GST_ELEMENT_DETAILS ("Text renderer", + "Filter/Editor/Video", + "Renders a text string to an image bitmap", + "David Schleef , " + "Ronald S. Bultje "); + +enum +{ + ARG_0, + ARG_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")) + ); + +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") + ); + +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_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 (element_class, &text_render_details); +} + +static void +gst_text_render_class_init (GstTextRenderClass * klass) +{ + GObjectClass *gobject_class; + GstElementClass *gstelement_class; + + 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; + + klass->pango_context = pango_ft2_get_context (72, 72); + g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_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)); +} + + +static void +resize_bitmap (GstTextRender * render, gint width, gint height) +{ + FT_Bitmap *bitmap = &render->bitmap; + gint pitch = (width | 3) + 1; + gint size = pitch * height; + + /* no need to keep reallocating; just keep the maximum size so far */ + if (size <= render->bitmap_buffer_size) { + bitmap->rows = height; + bitmap->width = width; + bitmap->pitch = pitch; + memset (bitmap->buffer, 0, render->bitmap_buffer_size); + return; + } + if (!bitmap->buffer) { + /* initialize */ + bitmap->pixel_mode = ft_pixel_mode_grays; + bitmap->num_grays = 256; + } + if (bitmap->buffer) + bitmap->buffer = g_realloc (bitmap->buffer, size); + else + bitmap->buffer = g_malloc (size); + bitmap->rows = height; + bitmap->width = width; + bitmap->pitch = pitch; + memset (bitmap->buffer, 0, size); + render->bitmap_buffer_size = size; +} + +static void +gst_text_render_render_text (GstTextRender * render) +{ + PangoRectangle ink_rect, logical_rect; + + pango_layout_get_pixel_extents (render->layout, &ink_rect, &logical_rect); + resize_bitmap (render, ink_rect.width, ink_rect.height + ink_rect.y); + pango_ft2_render_layout (&render->bitmap, render->layout, -ink_rect.x, 0); + render->baseline_y = ink_rect.y; +} + +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->bitmap.width && height >= render->bitmap.rows) { + render->width = width; + render->height = height; + ret = TRUE; + } + + 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->bitmap.width); + gst_structure_fixate_field_nearest_int (s, "height", render->bitmap.rows); + GST_DEBUG ("Fixated to %" GST_PTR_FORMAT, caps); + + gst_object_unref (render); +} + +static void +gst_text_renderer_bitmap_to_ayuv (GstTextRender * render, FT_Bitmap * bitmap, + guchar * pixbuf) +{ + int y; /* text bitmap coordinates */ + int rowinc, bit_rowinc; + guchar *p, *bitp; + guchar v; + + rowinc = render->width - bitmap->width; + bit_rowinc = bitmap->pitch - bitmap->width; + + bitp = bitmap->buffer; + p = pixbuf; + + for (y = 0; y < bitmap->rows; y++) { + int n; + + for (n = bitmap->width; n > 0; --n) { + v = *bitp; + if (v) { + p[0] = v; + p[1] = 255; + p[2] = 0x80; + p[3] = 0x80; + } + p += 4; + bitp++; + } + p += rowinc * 4; + bitp += bit_rowinc; + } +} + + +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; + + 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_text (render); + + caps = gst_caps_new_simple ("video/x-raw-yuv", "format", GST_TYPE_FOURCC, + GST_MAKE_FOURCC ('A', 'Y', 'U', 'V'), "width", G_TYPE_INT, + render->bitmap.width, "height", G_TYPE_INT, render->bitmap.rows, + "framerate", GST_TYPE_FRACTION, 1, 1, NULL); + + 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 AYUV 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); + + for (n = 0; n < render->width * render->height; n++) { + data[n * 4] = 0; + data[n * 4 + 1] = 0; + data[n * 4 + 2] = data[n * 4 + 3] = 128; + } + + if (render->bitmap.buffer) { + gst_text_renderer_bitmap_to_ayuv (render, &render->bitmap, data); + } + + 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->bitmap.buffer); + + 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->layout = + pango_layout_new (GST_TEXT_RENDER_GET_CLASS (render)->pango_context); + memset (&render->bitmap, 0, sizeof (render->bitmap)); +} + +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 ARG_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); + pango_font_description_free (desc); + gst_text_render_render_text (render); + GST_OBJECT_UNLOCK (render); + } else { + GST_WARNING ("font description parse failed: %s", + g_value_get_string (value)); + } + break; + } + + default: + break; + } +}