modules/misc/svg.c

   1 /*****************************************************************************
   2  * svg.c : Put SVG on the video
   3  *****************************************************************************
   4  * Copyright (C) 2002, 2003 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Olivier Aubert <oaubert@lisi.univ-lyon1.fr>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option ) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_fs.h>
  35 #include <vlc_vout.h>
  36 #include <vlc_osd.h>
  37 #include <vlc_block.h>
  38 #include <vlc_filter.h>
  39
  40 #include <sys/types.h>
  41
  42 #ifdef HAVE_UNISTD_H
  43 #    include <unistd.h>
  44 #elif defined( WIN32 ) && !defined( UNDER_CE )
  45 #   include <io.h>
  46 #endif
  47
  48 #include <glib.h>
  49 #include <glib/gstdio.h>
  50 #include <glib-object.h>                                  /* g_object_unref( ) */
  51 #include <librsvg-2/librsvg/rsvg.h>
  52
  53 typedef struct svg_rendition_t svg_rendition_t;
  54
  55 /*****************************************************************************
  56  * Local prototypes
  57  *****************************************************************************/
  58 static int  Create    ( vlc_object_t * );
  59 static void Destroy   ( vlc_object_t * );
  60 static int  RenderText( filter_t *p_filter, subpicture_region_t *p_region_out,
  61                         subpicture_region_t *p_region_in );
  62 static char *svg_GetTemplate( vlc_object_t *p_this );
  63
  64 /*****************************************************************************
  65  * Module descriptor
  66  *****************************************************************************/
  67
  68 #define TEMPLATE_TEXT N_( "SVG template file" )
  69 #define TEMPLATE_LONGTEXT N_( "Location of a file holding a SVG template "\
  70         "for automatic string conversion" )
  71
  72 vlc_module_begin ()
  73     set_category( CAT_INPUT )
  74     set_category( SUBCAT_INPUT_SCODEC )
  75     set_capability( "text renderer", 99 )
  76     add_shortcut( "svg" )
  77     add_string( "svg-template-file", "", NULL, TEMPLATE_TEXT, TEMPLATE_LONGTEXT, true )
  78     set_callbacks( Create, Destroy )
  79 vlc_module_end ()
  80
  81 /**
  82    Describes a SVG string to be displayed on the video
  83 */
  84 struct svg_rendition_t
  85 {
  86     int            i_width;
  87     int            i_height;
  88     int            i_chroma;
  89     /** The SVG source associated with this subpicture */
  90     char           *psz_text;
  91     /* The rendered SVG, as a GdkPixbuf */
  92     GdkPixbuf      *p_rendition;
  93 };
  94
  95 static int Render( filter_t *, subpicture_region_t *, svg_rendition_t *, int, int);
  96 static char *svg_GetTemplate ();
  97 static void svg_set_size( filter_t *p_filter, int width, int height );
  98 static void svg_SizeCallback  ( int *width, int *height, gpointer data );
  99 static void svg_RenderPicture ( filter_t *p_filter,
 100                                 svg_rendition_t *p_svg );
 101 static void FreeString( svg_rendition_t * );
 102
 103 /*****************************************************************************
 104  * filter_sys_t: svg local data
 105  *****************************************************************************
 106  * This structure is part of the filter thread descriptor.
 107  * It describes the svg specific properties of an output thread.
 108  *****************************************************************************/
 109 struct filter_sys_t
 110 {
 111     /* The SVG template used to convert strings */
 112     char          *psz_template;
 113     /* Default size for rendering. Initialized to the output size. */
 114     int            i_width;
 115     int            i_height;
 116 };
 117
 118 /*****************************************************************************
 119  * Create: allocates svg video thread output method
 120  *****************************************************************************
 121  * This function allocates and initializes a  vout method.
 122  *****************************************************************************/
 123 static int Create( vlc_object_t *p_this )
 124 {
 125     filter_t *p_filter = ( filter_t * )p_this;
 126     filter_sys_t *p_sys;
 127
 128     /* Allocate structure */
 129     p_sys = malloc( sizeof( filter_sys_t ) );
 130     if( !p_sys )
 131         return VLC_ENOMEM;
 132
 133     /* Initialize psz_template */
 134     p_sys->psz_template = svg_GetTemplate( p_this );
 135     if( !p_sys->psz_template )
 136     {
 137         free( p_sys );
 138         return VLC_ENOMEM;
 139     }
 140
 141     p_sys->i_width = p_filter->fmt_out.video.i_width;
 142     p_sys->i_height = p_filter->fmt_out.video.i_height;
 143
 144     p_filter->pf_render_text = RenderText;
 145     p_filter->pf_render_html = NULL;
 146     p_filter->p_sys = p_sys;
 147
 148     /* MUST call this before any RSVG funcs */
 149     rsvg_init( );
 150
 151     return VLC_SUCCESS;
 152 }
 153
 154 static char *svg_GetTemplate( vlc_object_t *p_this )
 155 {
 156     filter_t *p_filter = ( filter_t * )p_this;
 157     char *psz_filename;
 158     char *psz_template;
 159     FILE *file;
 160
 161     psz_filename = var_InheritString( p_filter, "svg-template-file" );
 162     if( !psz_filename || (psz_filename[0] == 0) )
 163     {
 164         /* No filename. Use a default value. */
 165         psz_template = NULL;
 166     }
 167     else
 168     {
 169         /* Read the template */
 170         file = vlc_fopen( psz_filename, "rt" );
 171         if( !file )
 172         {
 173             msg_Warn( p_this, "SVG template file %s does not exist.",
 174                                          psz_filename );
 175             psz_template = NULL;
 176         }
 177         else
 178         {
 179             struct stat s;
 180
 181             if( fstat( fileno( file ), &s ) )
 182             {
 183                 /* Problem accessing file information. Should not
 184                    happen as we could open it. */
 185                 psz_template = NULL;
 186             }
 187             else
 188             if( ((signed)s.st_size) < 0 )
 189             {
 190                 msg_Err( p_this, "SVG template too big" );
 191                 psz_template = NULL;
 192             }
 193             else
 194             {
 195                 msg_Dbg( p_this, "reading %ld bytes from template %s",
 196                          (unsigned long)s.st_size, psz_filename );
 197
 198                 psz_template = malloc( s.st_size + 42 );
 199                 if( !psz_template )
 200                 {
 201                     fclose( file );
 202                     free( psz_filename );
 203                     return NULL;
 204                 }
 205                 memset( psz_template, 0, s.st_size + 1 );
 206                 if(! fread( psz_template, s.st_size, 1, file ) )
 207                 {
 208                     msg_Dbg( p_this, "No data read from template." );
 209                 }
 210             }
 211             fclose( file );
 212         }
 213     }
 214     free( psz_filename );
 215     if( !psz_template )
 216     {
 217         /* Either there was no file, or there was an error.
 218            Use the default value */
 219         psz_template = strdup( "<?xml version='1.0' encoding='UTF-8' standalone='no'?> \
 220 <svg version='1' preserveAspectRatio='xMinYMin meet' viewBox='0 0 800 600'> \
 221   <text x='10' y='560' fill='white' font-size='32'  \
 222         font-family='sans-serif'>%s</text></svg>" );
 223     }
 224
 225     return psz_template;
 226 }
 227
 228 /*****************************************************************************
 229  * Destroy: destroy Clone video thread output method
 230  *****************************************************************************
 231  * Clean up all data and library connections
 232  *****************************************************************************/
 233 static void Destroy( vlc_object_t *p_this )
 234 {
 235     filter_t *p_filter = ( filter_t * )p_this;
 236     filter_sys_t *p_sys = p_filter->p_sys;
 237
 238     free( p_sys->psz_template );
 239     free( p_sys );
 240     rsvg_term( );
 241 }
 242
 243 /*****************************************************************************
 244  * Render: render SVG in picture
 245  *****************************************************************************/
 246 static int Render( filter_t *p_filter, subpicture_region_t *p_region,
 247                    svg_rendition_t *p_svg, int i_width, int i_height )
 248 {
 249     video_format_t fmt;
 250     uint8_t *p_y, *p_u, *p_v, *p_a;
 251     int x, y, i_pitch, i_u_pitch;
 252     guchar *pixels_in = NULL;
 253     int rowstride_in;
 254     int channels_in;
 255     int alpha;
 256     picture_t *p_pic;
 257
 258     if ( p_filter->p_sys->i_width != i_width ||
 259          p_filter->p_sys->i_height != i_height )
 260     {
 261         svg_set_size( p_filter, i_width, i_height );
 262         p_svg->p_rendition = NULL;
 263     }
 264
 265     if( p_svg->p_rendition == NULL ) {
 266         svg_RenderPicture( p_filter, p_svg );
 267         if( ! p_svg->p_rendition )
 268         {
 269             msg_Err( p_filter, "Cannot render SVG" );
 270             return VLC_EGENERIC;
 271         }
 272     }
 273     i_width = gdk_pixbuf_get_width( p_svg->p_rendition );
 274     i_height = gdk_pixbuf_get_height( p_svg->p_rendition );
 275
 276     /* Create a new subpicture region */
 277     memset( &fmt, 0, sizeof( video_format_t ) );
 278     fmt.i_chroma = VLC_CODEC_YUVA;
 279     fmt.i_width = fmt.i_visible_width = i_width;
 280     fmt.i_height = fmt.i_visible_height = i_height;
 281     fmt.i_x_offset = fmt.i_y_offset = 0;
 282     fmt.i_sar_num = 1;
 283     fmt.i_sar_den = 1;
 284
 285     p_region->p_picture = picture_NewFromFormat( &fmt );
 286     if( !p_region->p_picture )
 287         return VLC_EGENERIC;
 288     p_region->fmt = fmt;
 289
 290     p_region->i_x = p_region->i_y = 0;
 291     p_y = p_region->p_picture->Y_PIXELS;
 292     p_u = p_region->p_picture->U_PIXELS;
 293     p_v = p_region->p_picture->V_PIXELS;
 294     p_a = p_region->p_picture->A_PIXELS;
 295
 296     i_pitch = p_region->p_picture->Y_PITCH;
 297     i_u_pitch = p_region->p_picture->U_PITCH;
 298
 299     /* Initialize the region pixels (only the alpha will be changed later) */
 300     memset( p_y, 0x00, i_pitch * p_region->fmt.i_height );
 301     memset( p_u, 0x80, i_u_pitch * p_region->fmt.i_height );
 302     memset( p_v, 0x80, i_u_pitch * p_region->fmt.i_height );
 303
 304     p_pic = p_region->p_picture;
 305
 306     /* Copy the data */
 307
 308     /* This rendering code is in no way optimized. If someone has some time to
 309        make it work faster or better, please do.
 310     */
 311
 312     /*
 313       p_pixbuf->get_rowstride() is the number of bytes in a line.
 314       p_pixbuf->get_height() is the number of lines.
 315
 316       The number of bytes of p_pixbuf->p_pixels is get_rowstride * get_height
 317
 318       if( has_alpha() ) {
 319       alpha = pixels [ n_channels * ( y*rowstride + x ) + 3 ];
 320       }
 321       red   = pixels [ n_channels * ( y*rowstride ) + x ) ];
 322       green = pixels [ n_channels * ( y*rowstride ) + x ) + 1 ];
 323       blue  = pixels [ n_channels * ( y*rowstride ) + x ) + 2 ];
 324     */
 325
 326     pixels_in = gdk_pixbuf_get_pixels( p_svg->p_rendition );
 327     rowstride_in = gdk_pixbuf_get_rowstride( p_svg->p_rendition );
 328     channels_in = gdk_pixbuf_get_n_channels( p_svg->p_rendition );
 329     alpha = gdk_pixbuf_get_has_alpha( p_svg->p_rendition );
 330
 331     /*
 332       This crashes the plugin (if !alpha). As there is always an alpha value,
 333       it does not matter for the moment :
 334
 335     if( !alpha )
 336       memset( p_a, 0xFF, i_pitch * p_region->fmt.i_height );
 337     */
 338
 339 #define INDEX_IN( x, y ) ( y * rowstride_in + x * channels_in )
 340 #define INDEX_OUT( x, y ) ( y * i_pitch + x * p_pic->p[Y_PLANE].i_pixel_pitch )
 341
 342     for( y = 0; y < i_height; y++ )
 343     {
 344         for( x = 0; x < i_width; x++ )
 345         {
 346             guchar *p_in;
 347             int i_out;
 348
 349             p_in = &pixels_in[INDEX_IN( x, y )];
 350
 351 #define R( pixel ) *pixel
 352 #define G( pixel ) *( pixel+1 )
 353 #define B( pixel ) *( pixel+2 )
 354 #define ALPHA( pixel ) *( pixel+3 )
 355
 356             /* From http://www.geocrawler.com/archives/3/8263/2001/6/0/6020594/ :
 357                Y = 0.29900 * R + 0.58700 * G + 0.11400 * B
 358                U = -0.1687 * r  - 0.3313 * g + 0.5 * b + 128
 359                V = 0.5   * r - 0.4187 * g - 0.0813 * b + 128
 360             */
 361             if ( alpha ) {
 362                 i_out = INDEX_OUT( x, y );
 363
 364                 p_pic->Y_PIXELS[i_out] = .299 * R( p_in ) + .587 * G( p_in ) + .114 * B( p_in );
 365
 366                 p_pic->U_PIXELS[i_out] = -.1687 * R( p_in ) - .3313 * G( p_in ) + .5 * B( p_in ) + 128;
 367                 p_pic->V_PIXELS[i_out] = .5 * R( p_in ) - .4187 * G( p_in ) - .0813 * B( p_in ) + 128;
 368
 369                 p_pic->A_PIXELS[i_out] = ALPHA( p_in );
 370             }
 371         }
 372     }
 373
 374     return VLC_SUCCESS;
 375 }
 376
 377 static void svg_set_size( filter_t *p_filter, int width, int height )
 378 {
 379   p_filter->p_sys->i_width = width;
 380   p_filter->p_sys->i_height = height;
 381 }
 382
 383 static void svg_SizeCallback( int *width, int *height, gpointer data )
 384 {
 385     filter_t *p_filter = data;
 386
 387     *width = p_filter->p_sys->i_width;
 388     *height = p_filter->p_sys->i_height;
 389     return;
 390 }
 391
 392 static void svg_RenderPicture( filter_t *p_filter,
 393                                svg_rendition_t *p_svg )
 394 {
 395     /* Render the SVG string p_string->psz_text into a new picture_t
 396        p_string->p_rendition with dimensions ( ->i_width, ->i_height ) */
 397     RsvgHandle *p_handle;
 398     GError *error = NULL;
 399
 400     p_svg->p_rendition = NULL;
 401
 402     p_handle = rsvg_handle_new();
 403
 404     if( !p_handle )
 405     {
 406         msg_Err( p_filter, "Error creating SVG reader" );
 407         return;
 408     }
 409
 410     rsvg_handle_set_size_callback( p_handle, svg_SizeCallback, p_filter, NULL );
 411
 412     if( ! rsvg_handle_write( p_handle,
 413                  ( guchar* )p_svg->psz_text, strlen( p_svg->psz_text ),
 414                  &error ) )
 415     {
 416         msg_Err( p_filter, "error while rendering SVG: %s", error->message );
 417         g_object_unref( G_OBJECT( p_handle ) );
 418         return;
 419     }
 420
 421     if( ! rsvg_handle_close( p_handle, &error ) )
 422     {
 423         msg_Err( p_filter, "error while rendering SVG (close): %s", error->message );
 424         g_object_unref( G_OBJECT( p_handle ) );
 425         return;
 426     }
 427
 428     p_svg->p_rendition = rsvg_handle_get_pixbuf( p_handle );
 429
 430     g_object_unref( G_OBJECT( p_handle ) );
 431 }
 432
 433
 434 static int RenderText( filter_t *p_filter, subpicture_region_t *p_region_out,
 435                        subpicture_region_t *p_region_in )
 436 {
 437     filter_sys_t *p_sys = p_filter->p_sys;
 438     svg_rendition_t *p_svg = NULL;
 439     char *psz_string;
 440
 441     /* Sanity check */
 442     if( !p_region_in || !p_region_out ) return VLC_EGENERIC;
 443     psz_string = p_region_in->psz_text;
 444     if( !psz_string || !*psz_string ) return VLC_EGENERIC;
 445
 446     p_svg = malloc( sizeof( svg_rendition_t ) );
 447     if( !p_svg )
 448         return VLC_ENOMEM;
 449
 450     p_region_out->i_x = p_region_in->i_x;
 451     p_region_out->i_y = p_region_in->i_y;
 452
 453     /* Check if the data is SVG or pure text. In the latter case,
 454        convert the text to SVG. FIXME: find a better test */
 455     if( strstr( psz_string, "<svg" ))
 456     {
 457         /* Data is SVG: duplicate */
 458         p_svg->psz_text = strdup( psz_string );
 459         if( !p_svg->psz_text )
 460         {
 461             free( p_svg );
 462             return VLC_ENOMEM;
 463         }
 464     }
 465     else
 466     {
 467         /* Data is text. Convert to SVG */
 468         /* FIXME: handle p_style attributes */
 469         int length;
 470         char* psz_template = p_sys->psz_template;
 471         length = strlen( psz_string ) + strlen( psz_template ) + 42;
 472         p_svg->psz_text = malloc( length + 1 );
 473         if( !p_svg->psz_text )
 474         {
 475             free( p_svg );
 476             return VLC_ENOMEM;
 477         }
 478         memset( p_svg->psz_text, 0, length + 1 );
 479         snprintf( p_svg->psz_text, length, psz_template, psz_string );
 480     }
 481     p_svg->i_width = p_sys->i_width;
 482     p_svg->i_height = p_sys->i_height;
 483     p_svg->i_chroma = VLC_CODEC_YUVA;
 484
 485     /* Render the SVG.
 486        The input data is stored in the p_string structure,
 487        and the function updates the p_rendition attribute. */
 488     svg_RenderPicture( p_filter, p_svg );
 489
 490     Render( p_filter, p_region_out, p_svg, p_svg->i_width, p_svg->i_height );
 491     FreeString( p_svg );
 492
 493     return VLC_SUCCESS;
 494 }
 495
 496 static void FreeString( svg_rendition_t *p_svg )
 497 {
 498     free( p_svg->psz_text );
 499     /* p_svg->p_rendition is a GdkPixbuf, and its allocation is
 500        managed through ref. counting */
 501     if( p_svg->p_rendition )
 502         g_object_unref( p_svg->p_rendition );
 503     free( p_svg );
 504 }