1 /* GStreamer |
|
2 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu> |
|
3 * Copyright (C) <2003> David Schleef <ds@schleef.org> |
|
4 * |
|
5 * This library is free software; you can redistribute it and/or |
|
6 * modify it under the terms of the GNU Library General Public |
|
7 * License as published by the Free Software Foundation; either |
|
8 * version 2 of the License, or (at your option) any later version. |
|
9 * |
|
10 * This library is distributed in the hope that it will be useful, |
|
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of |
|
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
|
13 * Library General Public License for more details. |
|
14 * |
|
15 * You should have received a copy of the GNU Library General Public |
|
16 * License along with this library; if not, write to the |
|
17 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
|
18 * Boston, MA 02111-1307, USA. |
|
19 */ |
|
20 |
|
21 |
|
22 /** |
|
23 * SECTION:element-textrender |
|
24 * @see_also: #GstTextOverlay |
|
25 * |
|
26 * <refsect2> |
|
27 * <para> |
|
28 * This plugin renders text received on the text sink pad to a video |
|
29 * buffer (retaining the alpha channel), so it can later be overlayed |
|
30 * on top of video streams using other elements. |
|
31 * </para> |
|
32 * <para> |
|
33 * The text can contain newline characters. (FIXME: What about text |
|
34 * wrapping? It does not make sense in this context) |
|
35 * </para> |
|
36 * <para> |
|
37 * Example pipeline: |
|
38 * <programlisting> |
|
39 * gst-launch -v filesrc location=subtitles.srt ! subparse ! textrender ! xvimagesink |
|
40 * </programlisting> |
|
41 * </para> |
|
42 * </refsect2> |
|
43 */ |
|
44 |
|
45 #ifdef HAVE_CONFIG_H |
|
46 #include <config.h> |
|
47 #endif |
|
48 |
|
49 #include <gst/gst.h> |
|
50 #include <gst/video/video.h> |
|
51 |
|
52 #include "gsttextrender.h" |
|
53 |
|
54 GST_DEBUG_CATEGORY_EXTERN (pango_debug); |
|
55 #define GST_CAT_DEFAULT pango_debug |
|
56 |
|
57 static const GstElementDetails text_render_details = |
|
58 GST_ELEMENT_DETAILS ("Text renderer", |
|
59 "Filter/Editor/Video", |
|
60 "Renders a text string to an image bitmap", |
|
61 "David Schleef <ds@schleef.org>, " |
|
62 "Ronald S. Bultje <rbultje@ronald.bitfreak.net>"); |
|
63 |
|
64 enum |
|
65 { |
|
66 ARG_0, |
|
67 ARG_FONT_DESC |
|
68 }; |
|
69 |
|
70 |
|
71 static GstStaticPadTemplate src_template_factory = |
|
72 GST_STATIC_PAD_TEMPLATE ("src", |
|
73 GST_PAD_SRC, |
|
74 GST_PAD_ALWAYS, |
|
75 GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("AYUV")) |
|
76 ); |
|
77 |
|
78 static GstStaticPadTemplate sink_template_factory = |
|
79 GST_STATIC_PAD_TEMPLATE ("sink", |
|
80 GST_PAD_SINK, |
|
81 GST_PAD_ALWAYS, |
|
82 GST_STATIC_CAPS ("text/x-pango-markup; text/plain") |
|
83 ); |
|
84 |
|
85 GST_BOILERPLATE (GstTextRender, gst_text_render, GstElement, GST_TYPE_ELEMENT) |
|
86 |
|
87 static void gst_text_render_finalize (GObject * object); |
|
88 static void gst_text_render_set_property (GObject * object, |
|
89 guint prop_id, const GValue * value, GParamSpec * pspec); |
|
90 |
|
91 static void gst_text_render_base_init (gpointer g_class) |
|
92 { |
|
93 GstElementClass *element_class = GST_ELEMENT_CLASS (g_class); |
|
94 |
|
95 gst_element_class_add_pad_template (element_class, |
|
96 gst_static_pad_template_get (&src_template_factory)); |
|
97 gst_element_class_add_pad_template (element_class, |
|
98 gst_static_pad_template_get (&sink_template_factory)); |
|
99 |
|
100 gst_element_class_set_details (element_class, &text_render_details); |
|
101 } |
|
102 |
|
103 static void |
|
104 gst_text_render_class_init (GstTextRenderClass * klass) |
|
105 { |
|
106 GObjectClass *gobject_class; |
|
107 GstElementClass *gstelement_class; |
|
108 |
|
109 gobject_class = (GObjectClass *) klass; |
|
110 gstelement_class = (GstElementClass *) klass; |
|
111 |
|
112 parent_class = g_type_class_peek_parent (klass); |
|
113 |
|
114 gobject_class->finalize = gst_text_render_finalize; |
|
115 gobject_class->set_property = gst_text_render_set_property; |
|
116 |
|
117 klass->pango_context = pango_ft2_get_context (72, 72); |
|
118 g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_FONT_DESC, |
|
119 g_param_spec_string ("font-desc", "font description", |
|
120 "Pango font description of font " |
|
121 "to be used for rendering. " |
|
122 "See documentation of " |
|
123 "pango_font_description_from_string" |
|
124 " for syntax.", "", G_PARAM_WRITABLE)); |
|
125 } |
|
126 |
|
127 |
|
128 static void |
|
129 resize_bitmap (GstTextRender * render, gint width, gint height) |
|
130 { |
|
131 FT_Bitmap *bitmap = &render->bitmap; |
|
132 gint pitch = (width | 3) + 1; |
|
133 gint size = pitch * height; |
|
134 |
|
135 /* no need to keep reallocating; just keep the maximum size so far */ |
|
136 if (size <= render->bitmap_buffer_size) { |
|
137 bitmap->rows = height; |
|
138 bitmap->width = width; |
|
139 bitmap->pitch = pitch; |
|
140 memset (bitmap->buffer, 0, render->bitmap_buffer_size); |
|
141 return; |
|
142 } |
|
143 if (!bitmap->buffer) { |
|
144 /* initialize */ |
|
145 bitmap->pixel_mode = ft_pixel_mode_grays; |
|
146 bitmap->num_grays = 256; |
|
147 } |
|
148 if (bitmap->buffer) |
|
149 bitmap->buffer = g_realloc (bitmap->buffer, size); |
|
150 else |
|
151 bitmap->buffer = g_malloc (size); |
|
152 bitmap->rows = height; |
|
153 bitmap->width = width; |
|
154 bitmap->pitch = pitch; |
|
155 memset (bitmap->buffer, 0, size); |
|
156 render->bitmap_buffer_size = size; |
|
157 } |
|
158 |
|
159 static void |
|
160 gst_text_render_render_text (GstTextRender * render) |
|
161 { |
|
162 PangoRectangle ink_rect, logical_rect; |
|
163 |
|
164 pango_layout_get_pixel_extents (render->layout, &ink_rect, &logical_rect); |
|
165 resize_bitmap (render, ink_rect.width, ink_rect.height + ink_rect.y); |
|
166 pango_ft2_render_layout (&render->bitmap, render->layout, -ink_rect.x, 0); |
|
167 render->baseline_y = ink_rect.y; |
|
168 } |
|
169 |
|
170 static gboolean |
|
171 gst_text_render_setcaps (GstPad * pad, GstCaps * caps) |
|
172 { |
|
173 GstTextRender *render = GST_TEXT_RENDER (gst_pad_get_parent (pad)); |
|
174 GstStructure *structure; |
|
175 gboolean ret = FALSE; |
|
176 gint width = 0, height = 0; |
|
177 |
|
178 structure = gst_caps_get_structure (caps, 0); |
|
179 gst_structure_get_int (structure, "width", &width); |
|
180 gst_structure_get_int (structure, "height", &height); |
|
181 |
|
182 GST_DEBUG ("Got caps %" GST_PTR_FORMAT, caps); |
|
183 |
|
184 if (width >= render->bitmap.width && height >= render->bitmap.rows) { |
|
185 render->width = width; |
|
186 render->height = height; |
|
187 ret = TRUE; |
|
188 } |
|
189 |
|
190 gst_object_unref (render); |
|
191 return ret; |
|
192 } |
|
193 |
|
194 static void |
|
195 gst_text_render_fixate_caps (GstPad * pad, GstCaps * caps) |
|
196 { |
|
197 GstTextRender *render = GST_TEXT_RENDER (gst_pad_get_parent (pad)); |
|
198 GstStructure *s = gst_caps_get_structure (caps, 0); |
|
199 |
|
200 GST_DEBUG ("Fixating caps %" GST_PTR_FORMAT, caps); |
|
201 gst_structure_fixate_field_nearest_int (s, "width", render->bitmap.width); |
|
202 gst_structure_fixate_field_nearest_int (s, "height", render->bitmap.rows); |
|
203 GST_DEBUG ("Fixated to %" GST_PTR_FORMAT, caps); |
|
204 |
|
205 gst_object_unref (render); |
|
206 } |
|
207 |
|
208 static void |
|
209 gst_text_renderer_bitmap_to_ayuv (GstTextRender * render, FT_Bitmap * bitmap, |
|
210 guchar * pixbuf) |
|
211 { |
|
212 int y; /* text bitmap coordinates */ |
|
213 int rowinc, bit_rowinc; |
|
214 guchar *p, *bitp; |
|
215 guchar v; |
|
216 |
|
217 rowinc = render->width - bitmap->width; |
|
218 bit_rowinc = bitmap->pitch - bitmap->width; |
|
219 |
|
220 bitp = bitmap->buffer; |
|
221 p = pixbuf; |
|
222 |
|
223 for (y = 0; y < bitmap->rows; y++) { |
|
224 int n; |
|
225 |
|
226 for (n = bitmap->width; n > 0; --n) { |
|
227 v = *bitp; |
|
228 if (v) { |
|
229 p[0] = v; |
|
230 p[1] = 255; |
|
231 p[2] = 0x80; |
|
232 p[3] = 0x80; |
|
233 } |
|
234 p += 4; |
|
235 bitp++; |
|
236 } |
|
237 p += rowinc * 4; |
|
238 bitp += bit_rowinc; |
|
239 } |
|
240 } |
|
241 |
|
242 |
|
243 static GstFlowReturn |
|
244 gst_text_render_chain (GstPad * pad, GstBuffer * inbuf) |
|
245 { |
|
246 GstTextRender *render; |
|
247 GstFlowReturn ret; |
|
248 GstBuffer *outbuf; |
|
249 GstCaps *caps = NULL; |
|
250 guint8 *data = GST_BUFFER_DATA (inbuf); |
|
251 guint size = GST_BUFFER_SIZE (inbuf); |
|
252 gint n; |
|
253 |
|
254 render = GST_TEXT_RENDER (gst_pad_get_parent (pad)); |
|
255 |
|
256 /* somehow pango barfs over "\0" buffers... */ |
|
257 while (size > 0 && |
|
258 (data[size - 1] == '\r' || |
|
259 data[size - 1] == '\n' || data[size - 1] == '\0')) { |
|
260 size--; |
|
261 } |
|
262 |
|
263 /* render text */ |
|
264 GST_DEBUG ("rendering '%*s'", size, data); |
|
265 pango_layout_set_markup (render->layout, (gchar *) data, size); |
|
266 gst_text_render_render_text (render); |
|
267 |
|
268 caps = gst_caps_new_simple ("video/x-raw-yuv", "format", GST_TYPE_FOURCC, |
|
269 GST_MAKE_FOURCC ('A', 'Y', 'U', 'V'), "width", G_TYPE_INT, |
|
270 render->bitmap.width, "height", G_TYPE_INT, render->bitmap.rows, |
|
271 "framerate", GST_TYPE_FRACTION, 1, 1, NULL); |
|
272 |
|
273 if (!gst_pad_set_caps (render->srcpad, caps)) { |
|
274 gst_caps_unref (caps); |
|
275 GST_ELEMENT_ERROR (render, CORE, NEGOTIATION, (NULL), (NULL)); |
|
276 ret = GST_FLOW_ERROR; |
|
277 goto done; |
|
278 } |
|
279 |
|
280 GST_DEBUG ("Allocating AYUV buffer WxH = %dx%d", render->width, |
|
281 render->height); |
|
282 ret = |
|
283 gst_pad_alloc_buffer_and_set_caps (render->srcpad, GST_BUFFER_OFFSET_NONE, |
|
284 render->width * render->height * 4, caps, &outbuf); |
|
285 |
|
286 if (ret != GST_FLOW_OK) |
|
287 goto done; |
|
288 |
|
289 gst_buffer_copy_metadata (outbuf, inbuf, GST_BUFFER_COPY_TIMESTAMPS); |
|
290 data = GST_BUFFER_DATA (outbuf); |
|
291 |
|
292 for (n = 0; n < render->width * render->height; n++) { |
|
293 data[n * 4] = 0; |
|
294 data[n * 4 + 1] = 0; |
|
295 data[n * 4 + 2] = data[n * 4 + 3] = 128; |
|
296 } |
|
297 |
|
298 if (render->bitmap.buffer) { |
|
299 gst_text_renderer_bitmap_to_ayuv (render, &render->bitmap, data); |
|
300 } |
|
301 |
|
302 ret = gst_pad_push (render->srcpad, outbuf); |
|
303 |
|
304 done: |
|
305 if (caps) |
|
306 gst_caps_unref (caps); |
|
307 gst_buffer_unref (inbuf); |
|
308 gst_object_unref (render); |
|
309 return ret; |
|
310 } |
|
311 |
|
312 static void |
|
313 gst_text_render_finalize (GObject * object) |
|
314 { |
|
315 GstTextRender *render = GST_TEXT_RENDER (object); |
|
316 |
|
317 g_free (render->bitmap.buffer); |
|
318 |
|
319 if (render->layout) |
|
320 g_object_unref (render->layout); |
|
321 |
|
322 G_OBJECT_CLASS (parent_class)->finalize (object); |
|
323 } |
|
324 |
|
325 static void |
|
326 gst_text_render_init (GstTextRender * render, GstTextRenderClass * klass) |
|
327 { |
|
328 GstPadTemplate *template; |
|
329 |
|
330 /* sink */ |
|
331 template = gst_static_pad_template_get (&sink_template_factory); |
|
332 render->sinkpad = gst_pad_new_from_template (template, "sink"); |
|
333 gst_object_unref (template); |
|
334 gst_pad_set_chain_function (render->sinkpad, |
|
335 GST_DEBUG_FUNCPTR (gst_text_render_chain)); |
|
336 gst_element_add_pad (GST_ELEMENT (render), render->sinkpad); |
|
337 |
|
338 /* source */ |
|
339 template = gst_static_pad_template_get (&src_template_factory); |
|
340 render->srcpad = gst_pad_new_from_template (template, "src"); |
|
341 gst_object_unref (template); |
|
342 gst_pad_set_fixatecaps_function (render->srcpad, |
|
343 GST_DEBUG_FUNCPTR (gst_text_render_fixate_caps)); |
|
344 gst_pad_set_setcaps_function (render->srcpad, |
|
345 GST_DEBUG_FUNCPTR (gst_text_render_setcaps)); |
|
346 gst_element_add_pad (GST_ELEMENT (render), render->srcpad); |
|
347 |
|
348 render->layout = |
|
349 pango_layout_new (GST_TEXT_RENDER_GET_CLASS (render)->pango_context); |
|
350 memset (&render->bitmap, 0, sizeof (render->bitmap)); |
|
351 } |
|
352 |
|
353 static void |
|
354 gst_text_render_set_property (GObject * object, guint prop_id, |
|
355 const GValue * value, GParamSpec * pspec) |
|
356 { |
|
357 GstTextRender *render = GST_TEXT_RENDER (object); |
|
358 |
|
359 switch (prop_id) { |
|
360 case ARG_FONT_DESC: |
|
361 { |
|
362 PangoFontDescription *desc; |
|
363 |
|
364 desc = pango_font_description_from_string (g_value_get_string (value)); |
|
365 if (desc) { |
|
366 GST_LOG ("font description set: %s", g_value_get_string (value)); |
|
367 GST_OBJECT_LOCK (render); |
|
368 pango_layout_set_font_description (render->layout, desc); |
|
369 pango_font_description_free (desc); |
|
370 gst_text_render_render_text (render); |
|
371 GST_OBJECT_UNLOCK (render); |
|
372 } else { |
|
373 GST_WARNING ("font description parse failed: %s", |
|
374 g_value_get_string (value)); |
|
375 } |
|
376 break; |
|
377 } |
|
378 |
|
379 default: |
|
380 break; |
|
381 } |
|
382 } |
|