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