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