SVG rendering module. It uses the text rendering API, and converts

plain text to SVG. It can be used to have more control on the subtitle
rendering.

configure.ac

@@ -2635,6 +2635,22 @@ from http://www.freetype.org/, or configure with --disable-freetype. Have a nice
   fi
 fi
 
+dnl
+dnl  SVG module
+dnl
+AC_ARG_ENABLE(svg,
+  [  --enable-svg       SVG support (default disabled)])
+if test "${enable_svg}" == "yes"
+then
+  PKG_CHECK_MODULES(SVG, 
+	librsvg-2.0 >= 2.5.0,
+	[
+ 	  AX_ADD_LDFLAGS([svg],[$SVG_LIBS])
+      	  AX_ADD_CFLAGS([svg],[$SVG_CFLAGS])
+          AX_ADD_PLUGINS([svg]) ],
+        [AC_MSG_WARN(SVG library not found)])
+fi
+
 dnl
 dnl  Qt Embedded module
 dnl  (disabled by default)

modules/misc/Modules.am

@@ -7,3 +7,4 @@ SOURCES_screensaver = screensaver.c
 SOURCES_qte_main = qte_main.cpp
 SOURCES_freetype = freetype.c
 SOURCES_logger = logger.c
+SOURCES_svg = svg.c

modules/misc/svg.c

+/*****************************************************************************
+ * svg.c : Put SVG on the video
+ *****************************************************************************
+ * Copyright (C) 2002, 2003 VideoLAN
+ * $Id: svg.c,v 1.2 2003/07/23 17:26:56 oaubert Exp $
+ *
+ * Authors: Olivier Aubert <oaubert@lisi.univ-lyon1.fr>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option ) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Preamble
+ *****************************************************************************/
+#include <stdlib.h>                                      /* malloc( ), free( ) */
+#include <string.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <vlc/vlc.h>
+#include <vlc/vout.h>
+
+#include <librsvg-2/librsvg/rsvg.h>
+
+/*****************************************************************************
+ * Local prototypes
+ *****************************************************************************/
+static int  Create    ( vlc_object_t * );
+static void Destroy   ( vlc_object_t * );
+static void Render    ( vout_thread_t *, picture_t *,
+                        const subpicture_t * );
+static subpicture_t *AddText ( vout_thread_t *p_vout, int i_channel,
+                               char *psz_string, text_style_t *p_style, int i_flags,
+                               int i_hmargin, int i_vmargin, mtime_t i_start,
+                               mtime_t i_stop );
+static byte_t *svg_GetTemplate ();
+static void svg_SizeCallback  (int *width, int *height, gpointer data );
+static void svg_RenderPicture (vout_thread_t *p_vout,
+                               subpicture_sys_t *p_string );
+static void FreeString( subpicture_t * );
+
+/*****************************************************************************
+ * Module descriptor
+ *****************************************************************************/
+
+#define TEMPLATE_TEXT N_( "SVG template file" )
+#define TEMPLATE_LONGTEXT N_( "Location of a file holding a SVG template for automatic string conversion" )
+
+vlc_module_begin();
+ set_capability( "text renderer", 100 );
+ add_shortcut( "svg" );
+ add_string( "svg-template-file", "", NULL, TEMPLATE_TEXT, TEMPLATE_LONGTEXT, VLC_TRUE );
+ set_callbacks( Create, Destroy );
+vlc_module_end();
+
+/**
+   Describes a SVG string to be displayed on the video
+*/
+struct subpicture_sys_t
+{
+    int            i_width;
+    int            i_height;
+    int            i_chroma;
+    /** The SVG source associated with this subpicture */
+    byte_t        *psz_text;
+    /* The rendered SVG, as a GdkPixbuf */
+    GdkPixbuf      *p_rendition;
+};
+
+/*****************************************************************************
+ * vout_sys_t: svg local data
+ *****************************************************************************
+ * This structure is part of the video output thread descriptor.
+ * It describes the svg specific properties of an output thread.
+ *****************************************************************************/
+struct text_renderer_sys_t
+{
+    /* The SVG template used to convert strings */
+    byte_t        *psz_template;
+    vlc_mutex_t   *lock;
+};
+
+/*****************************************************************************
+ * Create: allocates svg video thread output method
+ *****************************************************************************
+ * This function allocates and initializes a  vout method.
+ *****************************************************************************/
+static int Create( vlc_object_t *p_this )
+{
+    vout_thread_t *p_vout = ( vout_thread_t * )p_this;
+
+    /* Allocate structure */
+    p_vout->p_text_renderer_data = malloc( sizeof( text_renderer_sys_t ) );
+    if( p_vout->p_text_renderer_data == NULL )
+    {
+        msg_Err( p_vout, "Out of memory" );
+        return VLC_ENOMEM;
+    }
+    p_vout->pf_add_string = AddText;
+
+    /* Initialize psz_template */
+    p_vout->p_text_renderer_data->psz_template = svg_GetTemplate( p_this );
+    if( !p_vout->p_text_renderer_data->psz_template )
+    {
+        msg_Err( p_vout, "Out of memory" );
+        return VLC_ENOMEM;
+    }
+
+    return VLC_SUCCESS;
+}
+
+static byte_t *svg_GetTemplate( vlc_object_t *p_this )
+{
+    vout_thread_t *p_vout = ( vout_thread_t * )p_this;
+    char *psz_filename;
+    char *psz_template;
+    FILE *file;
+
+    psz_filename = config_GetPsz( p_vout, "svg-template-file" );
+    if( !psz_filename || psz_filename[0] == 0 )
+    {
+        /* No filename. Use a default value. */
+        psz_template = NULL;
+    }
+    else
+    {
+        /* Read the template */
+        file = fopen( psz_filename, "rt" );
+        if( !file )
+        {
+            msg_Warn( p_this, "SVG template file %s does not exist.", psz_filename );
+            psz_template = NULL;
+        }
+        else
+        {
+            struct stat s;
+            int i_ret;
+
+            i_ret = lstat( psz_filename, &s );
+            if( i_ret )
+            {
+                /* Problem accessing file information. Should not
+                   happen as we could open it. */
+                psz_template = NULL;
+            }
+            else
+            {
+                fprintf( stderr, "Reading %ld bytes from %s\n", (long)s.st_size, psz_filename );
+
+                psz_template = malloc( s.st_size + 42 );
+                if( !psz_template )
+                {
+                    msg_Err( p_vout, "Out of memory" );
+                    return NULL;
+                }
+                fread( psz_template, s.st_size, 1, file );
+                fclose( file );
+            }
+        }
+    }
+    if( !psz_template )
+    {
+        /* Either there was no file, or there was an error.
+           Use the default value */
+        psz_template = strdup( "<?xml version='1.0' encoding='UTF-8' standalone='no'?> \
+<svg version='1' preserveAspectRatio='xMinYMin meet' viewBox='0 0 800 600'> \
+  <text x='10' y='560' fill='white' font-size='32'  \
+        font-family='sans-serif'>%s</text></svg>" );
+    }
+
+    return psz_template;
+}
+
+/*****************************************************************************
+ * Destroy: destroy Clone video thread output method
+ *****************************************************************************
+ * Clean up all data and library connections
+ *****************************************************************************/
+static void Destroy( vlc_object_t *p_this )
+{
+    vout_thread_t *p_vout = ( vout_thread_t * )p_this;
+    free( p_vout->p_text_renderer_data->psz_template );
+    free( p_vout->p_text_renderer_data );
+}
+
+/*****************************************************************************
+ * Render: render SVG in picture
+ *****************************************************************************
+ * This function merges the previously rendered SVG subpicture into a picture
+ *****************************************************************************/
+static void Render( vout_thread_t *p_vout, picture_t *p_pic,
+                    const subpicture_t *p_subpic )
+{
+    subpicture_sys_t *p_string = p_subpic->p_sys;
+    guchar *pixels_in = NULL;
+    guchar *pixels_out = NULL;
+    int rowstride_in, rowstride_out;
+    int channels_in, channels_out;
+    int x, y;
+    int i_width, i_height;
+    int alpha;
+
+    if( p_string->p_rendition == NULL ) {
+        /* Something changed ( presumably the dimensions ). Get the new
+           dimensions and update the pixbuf */
+        p_string->i_width = p_vout->output.i_width;
+        p_string->i_height = p_vout->output.i_height;
+        svg_RenderPicture( p_vout, p_string );
+    }
+
+    /* This rendering code is in no way optimized. If someone has some
+       time to lose to make it work faster, please do.
+    */
+
+    /* FIXME: The alpha value is not taken into account. */
+
+    /*
+      p_pixbuf->get_rowstride() is the number of bytes in a line.
+      p_pixbuf->get_height() is the number of lines.
+
+      The number of bytes of p_pixbuf->p_pixels is get_rowstride * get_height
+
+      if( has_alpha() ) {
+      alpha = pixels [ n_channels * ( y*rowstride + x ) + 3 ];
+      }
+      red   = pixels [ n_channels * ( y*rowstride ) + x ) ];
+      green = pixels [ n_channels * ( y*rowstride ) + x ) + 1 ];
+      blue  = pixels [ n_channels * ( y*rowstride ) + x ) + 2 ];
+    */
+
+    pixels_in = gdk_pixbuf_get_pixels( p_string->p_rendition );
+    pixels_out = p_pic->p->p_pixels;
+
+    rowstride_in = gdk_pixbuf_get_rowstride( p_string->p_rendition );
+    rowstride_out = p_pic->p->i_pitch;
+
+    channels_in = gdk_pixbuf_get_n_channels( p_string->p_rendition );
+    channels_out = p_pic->p->i_pixel_pitch;
+
+    alpha = gdk_pixbuf_get_has_alpha( p_string->p_rendition );
+
+#define INDEX_IN( x, y ) ( y * rowstride_in + x * channels_in )
+#define INDEX_OUT( x, y ) ( y * rowstride_out + x * channels_out )
+#define UV_INDEX_OUT( x, y ) ( y * p_pic->p[U_PLANE].i_pitch / 2 + x * p_pic->p[U_PLANE].i_pixel_pitch / 2 )
+
+    i_width = gdk_pixbuf_get_width( p_string->p_rendition );
+    i_height = gdk_pixbuf_get_height( p_string->p_rendition );
+
+    switch( p_vout->output.i_chroma )
+    {
+        /* I420 target, no scaling */
+    case VLC_FOURCC( 'I','4','2','0' ):
+    case VLC_FOURCC( 'I','Y','U','V' ):
+    case VLC_FOURCC( 'Y','V','1','2' ):
+        for( y = 0; y < i_height; y++ )
+        {
+            for( x = 0; x < i_width; x++ )
+            {
+                guchar *p_in;
+                int i_out;
+                int i_uv_out;
+
+                p_in = &pixels_in[INDEX_IN( x, y )];
+
+#define R( pixel ) *pixel
+#define G( pixel ) *( pixel+1 )
+#define B( pixel ) *( pixel+2 )
+#define ALPHA( pixel ) *( pixel+3 )
+
+                /* From http://www.geocrawler.com/archives/3/8263/2001/6/0/6020594/ :
+                   Y = 0.29900 * R + 0.58700 * G + 0.11400 * B
+                   U = -0.1687 * r  - 0.3313 * g + 0.5 * b + 128
+                   V = 0.5   * r - 0.4187 * g - 0.0813 * b + 128
+                */
+                if( (alpha && ALPHA( p_in ) > 10 ) || ( ! alpha )) {
+                    i_out = INDEX_OUT( x, y );
+
+                    p_pic->p[Y_PLANE].p_pixels[i_out] = .299 * R( p_in ) + .587 * G( p_in ) + .114 * B( p_in );
+
+                    if( ( x % 2 == 0 ) && ( y % 2 == 0 ) ) {
+                        i_uv_out = UV_INDEX_OUT( x, y );
+
+                        p_pic->p[U_PLANE].p_pixels[i_uv_out] = -.1687 * R( p_in ) - .3313 * G( p_in ) + .5 * B( p_in ) + 128;
+                        p_pic->p[V_PLANE].p_pixels[i_uv_out] = .5 * R( p_in ) - .4187 * G( p_in ) - .0813 * B( p_in ) + 128;
+                    }
+                }
+            }
+        }
+        break;
+
+        /* RV32 target, scaling */
+    case VLC_FOURCC( 'R','V','2','4' ):
+    case VLC_FOURCC( 'R','V','3','2' ):
+        for( y = 0; y < i_height; y++ )
+        {
+            for( x = 0; x < i_width; x++ )
+            {
+                guchar *p_in;
+                guchar *p_out;
+
+                p_in = &pixels_in[INDEX_IN( x, y )];
+                p_out = &pixels_out[INDEX_OUT( x, y )];
+
+                *p_out = *p_in;
+                *( p_out+1 ) = *( p_in+1 );
+                *( p_out+2 ) = *( p_in+2 );
+            }
+        }
+        break;
+
+    default:
+        msg_Err( p_vout, "unknown chroma, can't render SVG" );
+        break;
+    }
+}
+
+static void svg_SizeCallback( int *width, int *height, gpointer data )
+{
+    subpicture_sys_t *p_string = data;
+
+    *width = p_string->i_width;
+    *height = p_string->i_height;
+    return;
+}
+
+static void svg_RenderPicture( vout_thread_t *p_vout,
+                               subpicture_sys_t *p_string )
+{
+    /* Render the SVG string p_string->psz_text into a new picture_t
+       p_string->p_rendition with dimensions ( ->i_width, ->i_height ) */
+    RsvgHandle *p_handle;
+    GError *error;
+
+    p_handle = rsvg_handle_new();
+
+    rsvg_handle_set_size_callback( p_handle, svg_SizeCallback, p_string, NULL );
+
+    rsvg_handle_write( p_handle,
+                       p_string->psz_text, strlen( p_string->psz_text ) + 1,
+                       &error );
+    rsvg_handle_close( p_handle, &error );
+
+    p_string->p_rendition = rsvg_handle_get_pixbuf( p_handle );
+    rsvg_handle_free( p_handle );
+}
+
+
+/**
+ * This function receives a SVG string and creates a subpicture for it.
+ * It is used as pf_add_string callback in the vout method by this module.
+ */
+static subpicture_t *AddText ( vout_thread_t *p_vout, int i_channel,
+                               char *psz_string, text_style_t *p_style, int i_flags,
+                               int i_hmargin, int i_vmargin, mtime_t i_start,
+                               mtime_t i_stop )
+{
+    subpicture_sys_t *p_string;
+    subpicture_t *p_subpic;
+
+    msg_Dbg( p_vout, "adding string \"%s\" start_date "I64Fd
+             " end_date" I64Fd, psz_string, i_start, i_stop );
+
+    /* Create and initialize a subpicture */
+    p_subpic = vout_CreateSubPicture( p_vout, i_channel, GRAPH_CONTENT,
+                                      MEMORY_SUBPICTURE );
+    if( p_subpic == NULL )
+    {
+        return NULL;
+    }
+
+    p_subpic->pf_render = Render;
+    p_subpic->pf_destroy = FreeString;
+    p_subpic->i_start = i_start;
+    p_subpic->i_stop = i_stop;
+    if( i_stop == 0 )
+    {
+        p_subpic->b_ephemer = VLC_TRUE;
+    }
+    else
+    {
+        p_subpic->b_ephemer = VLC_FALSE;
+    }
+
+    /* Create and initialize private data for the subpicture */
+    p_string = malloc( sizeof( subpicture_sys_t ) );
+    if( p_string == NULL )
+    {
+        vout_DestroySubPicture( p_vout, p_subpic );
+        return NULL;
+    }
+    p_subpic->p_sys = p_string;
+
+    /* Check if the data is SVG or pure text. In the latter case,
+       convert the text to SVG. FIXME: find a better test */
+    if( strstr( psz_string, "<svg" ))
+    {
+        /* Data is SVG: duplicate */
+        p_string->psz_text = strdup( psz_string );
+    }
+    else
+    {
+        /* Data is text. Convert to SVG */
+        int length;
+        byte_t* psz_template = p_vout->p_text_renderer_data->psz_template;
+        length = strlen( psz_string ) + strlen( psz_template ) + 42;
+        p_string->psz_text = malloc( length + 1 );
+        if( p_string->psz_text == NULL )
+        {
+            return NULL;
+        }
+        snprintf( p_string->psz_text, length, psz_template, psz_string );
+    }
+
+    p_string->i_width = p_vout->output.i_width;
+    p_string->i_height = p_vout->output.i_height;
+    p_string->i_chroma = p_vout->output.i_chroma;
+
+    /* Render the SVG.
+       The input data is stored in the p_string structure,
+       and the function updates the p_rendition attribute. */
+    svg_RenderPicture( p_vout, p_string );
+
+    vout_DisplaySubPicture( p_vout, p_subpic );
+    return p_subpic;
+}
+
+static void FreeString( subpicture_t *p_subpic )
+{
+    subpicture_sys_t *p_string = p_subpic->p_sys;
+
+    free( p_string->psz_text );
+    free( p_string->p_rendition );
+    free( p_string );
+}