ext/pango/gsttextoverlay.c

   1
   2
   3
   4 #ifdef HAVE_CONFIG_H
   5 #include <config.h>
   6 #endif
   7 #include <gst/gst.h>
   8 #include "gsttextoverlay.h"
   9 /*#include "gsttexttestsrc.h"*/
  10 /*#include "gstsubparse.h"*/
  11 /*#include "SDL_blit.h"*/
  12
  13 static GstElementDetails textoverlay_details = {
  14     "Text Overlay",
  15     "Filter/Editor/Video",
  16     "Adds text strings on top of a video buffer",
  17     "Gustavo J. A. M. Carneiro <gjc@inescporto.pt>"
  18 };
  19
  20 enum {
  21     ARG_0,
  22     ARG_TEXT,
  23     ARG_VALIGN,
  24     ARG_HALIGN,
  25     ARG_X0,
  26     ARG_Y0,
  27     ARG_FONT_DESC,
  28 };
  29
  30
  31 GST_PAD_TEMPLATE_FACTORY(textoverlay_src_template_factory,
  32                          "src",
  33                          GST_PAD_SRC,
  34                          GST_PAD_ALWAYS,
  35                          GST_CAPS_NEW(
  36                              "textoverlay_src",
  37                              "video/x-raw-yuv",
  38                              "format",          GST_PROPS_LIST(
  39                                  GST_PROPS_FOURCC(GST_STR_FOURCC("I420"))
  40                                  ),
  41                              "width",           GST_PROPS_INT_RANGE(0, G_MAXINT),
  42                              "height",          GST_PROPS_INT_RANGE(0, G_MAXINT)
  43                              )
  44     )
  45
  46 GST_PAD_TEMPLATE_FACTORY(video_sink_template_factory,
  47                          "video_sink",
  48                          GST_PAD_SINK,
  49                          GST_PAD_ALWAYS,
  50                          GST_CAPS_NEW(
  51                              "video_sink",
  52                              "video/x-raw-yuv",
  53                              "format",          GST_PROPS_LIST(
  54                                  GST_PROPS_FOURCC(GST_STR_FOURCC("I420"))
  55                                  ),
  56                              "width",           GST_PROPS_INT_RANGE(0, G_MAXINT),
  57                              "height",          GST_PROPS_INT_RANGE(0, G_MAXINT)
  58                              )
  59     )
  60
  61 GST_PAD_TEMPLATE_FACTORY(text_sink_template_factory,
  62                          "text_sink",
  63                          GST_PAD_SINK,
  64                          GST_PAD_ALWAYS,
  65                          GST_CAPS_NEW(
  66                              "text_sink",
  67                              "text/x-pango-markup",
  68                              NULL
  69                              )
  70     )
  71
  72 static void                  gst_textoverlay_base_init (gpointer g_class);
  73 static void                  gst_textoverlay_class_init(GstTextOverlayClass *klass);
  74 static void                  gst_textoverlay_init(GstTextOverlay      *overlay);
  75 static void                  gst_textoverlay_set_property(GObject             *object,
  76                                                            guint                prop_id,
  77                                                            const GValue        *value,
  78                                                            GParamSpec          *pspec);
  79 static void                  gst_textoverlay_get_property(GObject             *object,
  80                                                            guint                prop_id,
  81                                                            GValue              *value,
  82                                                            GParamSpec          *pspec);
  83 static GstElementStateReturn gst_textoverlay_change_state(GstElement          *element);
  84 static void                  gst_textoverlay_finalize(GObject             *object);
  85
  86
  87 static GstElementClass *parent_class = NULL;
  88 /*static guint gst_textoverlay_signals[LAST_SIGNAL] = { 0 }; */
  89
  90
  91 GType
  92 gst_textoverlay_get_type(void)
  93 {
  94     static GType textoverlay_type = 0;
  95
  96     if (!textoverlay_type) {
  97         static const GTypeInfo textoverlay_info = {
  98             sizeof(GstTextOverlayClass),
  99             gst_textoverlay_base_init,
 100             NULL,
 101             (GClassInitFunc)gst_textoverlay_class_init,
 102             NULL,
 103             NULL,
 104             sizeof(GstTextOverlay),
 105             0,
 106             (GInstanceInitFunc)gst_textoverlay_init,
 107         };
 108         textoverlay_type = g_type_register_static(GST_TYPE_ELEMENT, "GstTextOverlay",
 109                                                   &textoverlay_info, 0);
 110     }
 111     return textoverlay_type;
 112 }
 113
 114 static void
 115 gst_textoverlay_base_init (gpointer g_class)
 116 {
 117     GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
 118
 119     gst_element_class_add_pad_template (element_class, GST_PAD_TEMPLATE_GET (textoverlay_src_template_factory));
 120     gst_element_class_add_pad_template (element_class, GST_PAD_TEMPLATE_GET (video_sink_template_factory));
 121     gst_element_class_add_pad_template (element_class, GST_PAD_TEMPLATE_GET (text_sink_template_factory));
 122
 123     gst_element_class_set_details (element_class, &textoverlay_details);
 124 }
 125
 126 static void
 127 gst_textoverlay_class_init(GstTextOverlayClass *klass)
 128 {
 129     GObjectClass *gobject_class;
 130     GstElementClass *gstelement_class;
 131
 132     gobject_class = (GObjectClass*)klass;
 133     gstelement_class = (GstElementClass*)klass;
 134
 135     parent_class = g_type_class_peek_parent(klass);
 136
 137     gobject_class->finalize = gst_textoverlay_finalize;
 138     gobject_class->set_property = gst_textoverlay_set_property;
 139     gobject_class->get_property = gst_textoverlay_get_property;
 140
 141     gstelement_class->change_state = gst_textoverlay_change_state;
 142     klass->pango_context = pango_ft2_get_context(72, 72);
 143     g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_TEXT,
 144                                     g_param_spec_string("text", "text",
 145                                                         "Text to be display,"
 146                                                         " in pango markup format.",
 147                                                         "", G_PARAM_WRITABLE));
 148     g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_VALIGN,
 149                                     g_param_spec_string("valign", "vertical alignment",
 150                                                         "Vertical alignment of the text. "
 151                                                         "Can be either 'baseline', 'bottom', or 'top'",
 152                                                         "baseline", G_PARAM_WRITABLE));
 153     g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_HALIGN,
 154                                     g_param_spec_string("halign", "horizontal alignment",
 155                                                         "Horizontal alignment of the text. "
 156                                                         "Can be either 'left', 'right', or 'center'",
 157                                                         "center", G_PARAM_WRITABLE));
 158     g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_X0,
 159                                     g_param_spec_int("x0", "X position",
 160                                                      "Initial X position."
 161                                                      " Horizontal aligment takes this point"
 162                                                      " as reference.",
 163                                                      G_MININT, G_MAXINT, 0, G_PARAM_WRITABLE));
 164     g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_Y0,
 165                                     g_param_spec_int("y0", "Y position",
 166                                                      "Initial Y position."
 167                                                      " Vertical aligment takes this point"
 168                                                      " as reference.",
 169                                                      G_MININT, G_MAXINT, 0, G_PARAM_WRITABLE));
 170     g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_FONT_DESC,
 171                                     g_param_spec_string("font-desc", "font description",
 172                                                         "Pango font description of font "
 173                                                         "to be used for rendering. "
 174                                                         "See documentation of "
 175                                                         "pango_font_description_from_string"
 176                                                         " for syntax.",
 177                                                         "", G_PARAM_WRITABLE));
 178 }
 179
 180
 181 static void
 182 resize_bitmap(GstTextOverlay *overlay, int width, int height)
 183 {
 184     FT_Bitmap *bitmap = &overlay->bitmap;
 185     int        pitch = (width|3) + 1;
 186     int        size = pitch*height;
 187
 188     /* no need to keep reallocating; just keep the maximum size so far */
 189     if (size <= overlay->bitmap_buffer_size) {
 190         bitmap->rows = height;
 191         bitmap->width = width;
 192         bitmap->pitch = pitch;
 193         memset(bitmap->buffer, 0, overlay->bitmap_buffer_size);
 194         return;
 195     }
 196     if (!bitmap->buffer) {
 197         /* initialize */
 198         bitmap->pixel_mode = ft_pixel_mode_grays;
 199         bitmap->num_grays = 256;
 200     }
 201     if (bitmap->buffer)
 202         bitmap->buffer = g_realloc(bitmap->buffer, size);
 203     else
 204         bitmap->buffer = g_malloc(size);
 205     bitmap->rows = height;
 206     bitmap->width = width;
 207     bitmap->pitch = pitch;
 208     memset(bitmap->buffer, 0, size);
 209     overlay->bitmap_buffer_size = size;
 210 }
 211
 212 static void
 213 render_text(GstTextOverlay *overlay)
 214 {
 215     PangoRectangle ink_rect, logical_rect;
 216
 217     pango_layout_get_pixel_extents(overlay->layout, &ink_rect, &logical_rect);
 218     resize_bitmap(overlay, ink_rect.width, ink_rect.height + ink_rect.y);
 219     pango_ft2_render_layout(&overlay->bitmap, overlay->layout, 0, 0);
 220     overlay->baseline_y = ink_rect.y;
 221 }
 222
 223 /* static GstPadLinkReturn */
 224 /* gst_textoverlay_text_sinkconnect (GstPad *pad, GstCaps *caps) */
 225 /* { */
 226 /*     return GST_PAD_LINK_DONE; */
 227 /* } */
 228
 229
 230 static GstPadLinkReturn
 231 gst_textoverlay_video_sinkconnect(GstPad *pad, GstCaps *caps)
 232 {
 233     GstTextOverlay *overlay;
 234
 235     overlay = GST_TEXTOVERLAY(gst_pad_get_parent(pad));
 236
 237     if (!GST_CAPS_IS_FIXED(caps))
 238         return GST_PAD_LINK_DELAYED;
 239
 240     overlay->width = overlay->height = 0;
 241     gst_caps_get_int(caps, "width", &overlay->width);
 242     gst_caps_get_int(caps, "height", &overlay->height);
 243
 244     return gst_pad_try_set_caps(overlay->srcpad, caps);
 245 }
 246
 247
 248 static void
 249 gst_text_overlay_blit_yuv420(GstTextOverlay *overlay, FT_Bitmap *bitmap,
 250                              guchar *pixbuf, int x0, int y0)
 251 {
 252     int y;                      /* text bitmap coordinates */
 253     int x1, y1;                 /* video buffer coordinates */
 254     int rowinc, bit_rowinc, uv_rowinc;
 255     guchar *p, *bitp, *u_p;
 256     int video_width = overlay->width, video_height = overlay->height;
 257     int bitmap_x0 = x0 < 1? -(x0 - 1) : 1; /* 1 pixel border */
 258     int bitmap_y0 = y0 < 1? -(y0 - 1) : 1; /* 1 pixel border */
 259     int bitmap_width = bitmap->width - bitmap_x0;
 260     int bitmap_height = bitmap->rows - bitmap_y0;
 261     int u_plane_size;
 262     int skip_y, skip_x;
 263     guchar v;
 264
 265     if (x0 + bitmap_x0 + bitmap_width > video_width - 1) /* 1 pixel border */
 266         bitmap_width -= x0 + bitmap_x0 + bitmap_width - video_width + 1;
 267     if (y0 + bitmap_y0 + bitmap_height > video_height - 1) /* 1 pixel border */
 268         bitmap_height -= y0 + bitmap_y0 + bitmap_height - video_height + 1;
 269
 270     rowinc = video_width - bitmap_width;
 271     uv_rowinc = video_width / 2 - bitmap_width / 2;
 272     bit_rowinc = bitmap->pitch - bitmap_width;
 273     u_plane_size = (video_width / 2)*(video_height / 2);
 274
 275     y1 = y0 + bitmap_y0;
 276     x1 = x0 + bitmap_x0;
 277     p = pixbuf + video_width*y1 + x1;
 278     bitp = bitmap->buffer + bitmap->pitch*bitmap_y0 + bitmap_x0;
 279     for (y = bitmap_y0; y < bitmap_height; y++){
 280       int n;
 281       for(n=bitmap_width; n>0; --n){
 282         v = *bitp;
 283         if (v) {
 284           p[-1] = CLAMP(p[-1] - v, 0, 255);
 285           p[ 1] = CLAMP(p[ 1] - v, 0, 255);
 286           p[-video_width] = CLAMP(p[-video_width] - v, 0, 255);
 287           p[ video_width] = CLAMP(p[ video_width] - v, 0, 255);
 288         }
 289         p++;
 290         bitp++;
 291       }
 292       p += rowinc;
 293       bitp += bit_rowinc;
 294     }
 295
 296     y = bitmap_y0;
 297     y1 = y0 + bitmap_y0;
 298     x1 = x0 + bitmap_x0;
 299     bitp = bitmap->buffer + bitmap->pitch*bitmap_y0 + bitmap_x0;
 300     p = pixbuf + video_width*y1 + x1;
 301     u_p = pixbuf + video_width*video_height + (video_width >> 1)*(y1 >> 1) + (x1 >> 1);
 302     skip_y = 0;
 303     skip_x = 0;
 304
 305     for ( ; y < bitmap_height; y++){
 306       int n;
 307       x1 = x0 + bitmap_x0;
 308       skip_x = 0;
 309       for(n = bitmap_width; n>0; --n){
 310         v = *bitp;
 311         if (v) {
 312           *p = v;
 313           if (!skip_y) {
 314             u_p[0] = u_p[u_plane_size] = 0x80;
 315           }
 316         }
 317         if (!skip_y) {
 318           skip_x = !skip_x;
 319           if (!skip_x) u_p++;
 320         }
 321         p++;
 322         bitp++;
 323       }
 324       /*if (!skip_x && !skip_y) u_p--; */
 325       p += rowinc;
 326       bitp += bit_rowinc;
 327       skip_y = !skip_y;
 328       u_p += skip_y? uv_rowinc : 0;
 329     }
 330 }
 331
 332
 333 static void
 334 gst_textoverlay_video_chain(GstPad *pad, GstData *_data)
 335 {
 336     GstBuffer *buf = GST_BUFFER (_data);
 337     GstTextOverlay *overlay;
 338     guchar         *pixbuf;
 339     gint            x0, y0;
 340
 341     g_return_if_fail(pad != NULL);
 342     g_return_if_fail(GST_IS_PAD(pad));
 343     g_return_if_fail(buf != NULL);
 344     overlay = GST_TEXTOVERLAY(gst_pad_get_parent(pad));
 345     g_return_if_fail(overlay != NULL);
 346     g_return_if_fail(GST_IS_TEXTOVERLAY(overlay));
 347
 348     pixbuf = GST_BUFFER_DATA(buf);
 349
 350     x0 = overlay->x0;
 351     y0 = overlay->y0;
 352     switch (overlay->valign)
 353     {
 354     case GST_TEXT_OVERLAY_VALIGN_BOTTOM:
 355         y0 += overlay->bitmap.rows;
 356         break;
 357     case GST_TEXT_OVERLAY_VALIGN_BASELINE:
 358         y0 -= (overlay->bitmap.rows - overlay->baseline_y);
 359         break;
 360     case GST_TEXT_OVERLAY_VALIGN_TOP:
 361         break;
 362     }
 363
 364     switch (overlay->halign)
 365     {
 366     case GST_TEXT_OVERLAY_HALIGN_LEFT:
 367         break;
 368     case GST_TEXT_OVERLAY_HALIGN_RIGHT:
 369         x0 -= overlay->bitmap.width;
 370         break;
 371     case GST_TEXT_OVERLAY_HALIGN_CENTER:
 372         x0 -= overlay->bitmap.width / 2;
 373         break;
 374     }
 375
 376     if (overlay->bitmap.buffer)
 377         gst_text_overlay_blit_yuv420(overlay, &overlay->bitmap, pixbuf, x0, y0);
 378
 379     gst_pad_push(overlay->srcpad, GST_DATA (buf));
 380 }
 381
 382 #define PAST_END(buffer, time) \
 383   (GST_BUFFER_TIMESTAMP (buffer) != GST_CLOCK_TIME_NONE && \
 384    GST_BUFFER_DURATION (buffer) != GST_CLOCK_TIME_NONE && \
 385    GST_BUFFER_TIMESTAMP (buffer) + GST_BUFFER_DURATION (buffer) \
 386      < (time))
 387
 388 static void
 389 gst_textoverlay_loop(GstElement *element)
 390 {
 391     GstTextOverlay *overlay;
 392     GstBuffer      *video_frame;
 393     guint64         now;
 394
 395     g_return_if_fail(element != NULL);
 396     g_return_if_fail(GST_IS_TEXTOVERLAY(element));
 397     overlay = GST_TEXTOVERLAY(element);
 398
 399     video_frame = GST_BUFFER (gst_pad_pull(overlay->video_sinkpad));
 400     now = GST_BUFFER_TIMESTAMP(video_frame);
 401
 402     /*
 403      * This state machine has a bug that can't be resolved easily.
 404      * (Needs a more complicated state machine.)  Basically, if the
 405      * text that came from a buffer from the sink pad is being
 406      * displayed, and the default text is changed by set_parameter,
 407      * we'll incorrectly display the default text.
 408      *
 409      * Otherwise, this is a pretty decent state machine that handles
 410      * buffer timestamps and durations correctly.  (I think)
 411      */
 412
 413     while (overlay->next_buffer == NULL){
 414       GST_DEBUG("attempting to pull a buffer");
 415
 416       /* read all text buffers until we get one "in the future" */
 417       if(!GST_PAD_IS_USABLE(overlay->text_sinkpad)){
 418         break;
 419       }
 420       overlay->next_buffer = GST_BUFFER (gst_pad_pull(overlay->text_sinkpad));
 421       if (!overlay->next_buffer)
 422         break;
 423
 424       if (PAST_END(overlay->next_buffer, now)){
 425         gst_buffer_unref(overlay->next_buffer);
 426         overlay->next_buffer = NULL;
 427       }
 428     }
 429
 430     if (overlay->next_buffer &&
 431         (GST_BUFFER_TIMESTAMP(overlay->next_buffer) <= now ||
 432         GST_BUFFER_TIMESTAMP(overlay->next_buffer) == GST_CLOCK_TIME_NONE)){
 433       GST_DEBUG("using new buffer");
 434
 435       if (overlay->current_buffer){
 436         gst_buffer_unref (overlay->current_buffer);
 437       }
 438       overlay->current_buffer = overlay->next_buffer;
 439       overlay->next_buffer = NULL;
 440
 441       GST_DEBUG ( "rendering '%*s'",
 442           GST_BUFFER_SIZE(overlay->current_buffer),
 443           GST_BUFFER_DATA(overlay->current_buffer));
 444       pango_layout_set_markup(overlay->layout,
 445           GST_BUFFER_DATA(overlay->current_buffer),
 446           GST_BUFFER_SIZE(overlay->current_buffer));
 447       render_text(overlay);
 448       overlay->need_render = FALSE;
 449     }
 450
 451     if (overlay->current_buffer && PAST_END(overlay->current_buffer, now)){
 452       GST_DEBUG("dropping old buffer");
 453
 454       gst_buffer_unref(overlay->current_buffer);
 455       overlay->current_buffer = NULL;
 456
 457       overlay->need_render = TRUE;
 458     }
 459
 460     if(overlay->need_render){
 461       GST_DEBUG ( "rendering '%s'", overlay->default_text);
 462       pango_layout_set_markup(overlay->layout,
 463           overlay->default_text, strlen(overlay->default_text));
 464       render_text(overlay);
 465
 466       overlay->need_render = FALSE;
 467     }
 468
 469     gst_textoverlay_video_chain(overlay->srcpad, GST_DATA (video_frame));
 470 }
 471
 472
 473 static GstElementStateReturn
 474 gst_textoverlay_change_state(GstElement *element)
 475 {
 476     GstTextOverlay *overlay;
 477
 478     overlay = GST_TEXTOVERLAY(element);
 479
 480     switch (GST_STATE_TRANSITION(element))
 481     {
 482     case GST_STATE_PAUSED_TO_PLAYING:
 483         break;
 484     case GST_STATE_PLAYING_TO_PAUSED:
 485         break;
 486     case GST_STATE_PAUSED_TO_READY:
 487         break;
 488     }
 489
 490     parent_class->change_state(element);
 491
 492     return GST_STATE_SUCCESS;
 493 }
 494
 495 static void
 496 gst_textoverlay_finalize(GObject *object)
 497 {
 498     GstTextOverlay *overlay = GST_TEXTOVERLAY(object);
 499
 500     if (overlay->layout) {
 501         g_object_unref(overlay->layout);
 502         overlay->layout = NULL;
 503     }
 504     if (overlay->bitmap.buffer) {
 505         g_free(overlay->bitmap.buffer);
 506         overlay->bitmap.buffer = NULL;
 507     }
 508
 509     G_OBJECT_CLASS(parent_class)->finalize(object);
 510 }
 511
 512 static void
 513 gst_textoverlay_init(GstTextOverlay *overlay)
 514 {
 515     /* video sink */
 516     overlay->video_sinkpad = gst_pad_new_from_template(
 517         GST_PAD_TEMPLATE_GET(video_sink_template_factory), "video_sink");
 518 /*     gst_pad_set_chain_function(overlay->video_sinkpad, gst_textoverlay_video_chain); */
 519     gst_pad_set_link_function(overlay->video_sinkpad, gst_textoverlay_video_sinkconnect);
 520     gst_element_add_pad(GST_ELEMENT(overlay), overlay->video_sinkpad);
 521
 522     /* text sink */
 523     overlay->text_sinkpad = gst_pad_new_from_template(
 524         GST_PAD_TEMPLATE_GET(text_sink_template_factory), "text_sink");
 525 /*     gst_pad_set_link_function(overlay->text_sinkpad, gst_textoverlay_text_sinkconnect); */
 526     gst_element_add_pad(GST_ELEMENT(overlay), overlay->text_sinkpad);
 527
 528     /* (video) source */
 529     overlay->srcpad = gst_pad_new_from_template(
 530         GST_PAD_TEMPLATE_GET(textoverlay_src_template_factory), "src");
 531     gst_element_add_pad(GST_ELEMENT(overlay), overlay->srcpad);
 532
 533     overlay->layout = pango_layout_new(GST_TEXTOVERLAY_GET_CLASS(overlay)->pango_context);
 534     memset(&overlay->bitmap, 0, sizeof(overlay->bitmap));
 535
 536     overlay->halign = GST_TEXT_OVERLAY_HALIGN_CENTER;
 537     overlay->valign = GST_TEXT_OVERLAY_VALIGN_BASELINE;
 538     overlay->x0 = overlay->y0 = 0;
 539
 540     overlay->default_text = g_strdup("");
 541     overlay->need_render = TRUE;
 542
 543     gst_element_set_loop_function(GST_ELEMENT(overlay), gst_textoverlay_loop);
 544 }
 545
 546
 547 static void
 548 gst_textoverlay_set_property(GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
 549 {
 550     GstTextOverlay *overlay;
 551
 552     /* it's not null if we got it, but it might not be ours */
 553     g_return_if_fail(GST_IS_TEXTOVERLAY(object));
 554     overlay = GST_TEXTOVERLAY(object);
 555
 556     switch (prop_id)
 557     {
 558
 559     case ARG_TEXT:
 560         if(overlay->default_text){
 561           g_free(overlay->default_text);
 562         }
 563         overlay->default_text = g_strdup(g_value_get_string(value));
 564         overlay->need_render = TRUE;
 565         break;
 566
 567     case ARG_VALIGN:
 568         if (strcasecmp(g_value_get_string(value), "baseline") == 0)
 569             overlay->valign = GST_TEXT_OVERLAY_VALIGN_BASELINE;
 570         else if (strcasecmp(g_value_get_string(value), "bottom") == 0)
 571             overlay->valign = GST_TEXT_OVERLAY_VALIGN_BOTTOM;
 572         else if (strcasecmp(g_value_get_string(value), "top") == 0)
 573             overlay->valign = GST_TEXT_OVERLAY_VALIGN_TOP;
 574         else
 575             g_warning("Invalid 'valign' property value: %s",
 576                       g_value_get_string(value));
 577         break;
 578
 579     case ARG_HALIGN:
 580         if (strcasecmp(g_value_get_string(value), "left") == 0)
 581             overlay->halign = GST_TEXT_OVERLAY_HALIGN_LEFT;
 582         else if (strcasecmp(g_value_get_string(value), "right") == 0)
 583             overlay->halign = GST_TEXT_OVERLAY_HALIGN_RIGHT;
 584         else if (strcasecmp(g_value_get_string(value), "center") == 0)
 585             overlay->halign = GST_TEXT_OVERLAY_HALIGN_CENTER;
 586         else
 587             g_warning("Invalid 'halign' property value: %s",
 588                       g_value_get_string(value));
 589         break;
 590
 591     case ARG_X0:
 592         overlay->x0 = g_value_get_int(value);
 593         break;
 594
 595     case ARG_Y0:
 596         overlay->y0 = g_value_get_int(value);
 597         break;
 598
 599     case ARG_FONT_DESC:
 600     {
 601         PangoFontDescription *desc;
 602         desc = pango_font_description_from_string(g_value_get_string(value));
 603         if (desc) {
 604             g_message("font description set: %s", g_value_get_string(value));
 605             pango_layout_set_font_description(overlay->layout, desc);
 606             pango_font_description_free(desc);
 607             render_text(overlay);
 608         } else
 609             g_warning("font description parse failed: %s", g_value_get_string(value));
 610         break;
 611     }
 612
 613     default:
 614         break;
 615     }
 616 }
 617
 618 static void
 619 gst_textoverlay_get_property(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
 620 {
 621     GstTextOverlay *overlay;
 622
 623     /* it's not null if we got it, but it might not be ours */
 624     g_return_if_fail(GST_IS_TEXTOVERLAY(object));
 625     overlay = GST_TEXTOVERLAY(object);
 626
 627     switch (prop_id) {
 628     default:
 629         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 630         break;
 631     }
 632 }
 633
 634 static gboolean
 635 plugin_init(GstPlugin *plugin)
 636 {
 637     if (!gst_element_register (plugin, "textoverlay", GST_RANK_PRIMARY, GST_TYPE_TEXTOVERLAY))
 638         return FALSE;
 639
 640     /*texttestsrc_plugin_init(module, plugin);*/
 641     /*subparse_plugin_init(module, plugin);*/
 642     return TRUE;
 643 }
 644
 645 GST_PLUGIN_DEFINE (
 646     GST_VERSION_MAJOR,
 647     GST_VERSION_MINOR,
 648     "textoverlay",
 649     "Text overlay",
 650     plugin_init,
 651     VERSION,
 652     "GPL",
 653     GST_COPYRIGHT,
 654     GST_PACKAGE,
 655     GST_ORIGIN)
 656