svg.c

video linux conference

/*****************************************************************************
 * 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 <[e-mail]>
 *
 * 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 "osd.h"
#include "vlc_block.h"
#include "vlc_filter.h"

#include <librsvg-2/librsvg/rsvg.h>

typedef struct svg_rendition_t svg_rendition_t;

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static int  Create    ( vlc_object_t * );
static void Destroy   ( vlc_object_t * );
static int RenderText( filter_t *p_filter, subpicture_region_t *p_region_out,
                       subpicture_region_t *p_region_in );


/*****************************************************************************
 * 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_category( CAT_INPUT);
 set_category( SUBCAT_INPUT_SCODEC );
 set_capability( "text renderer", 101 );
 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 svg_rendition_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;
};

static int Render( filter_t *, subpicture_region_t *, svg_rendition_t *, int, int);
static byte_t *svg_GetTemplate ();
static void svg_set_size( filter_t *p_filter, int width, int height );
static void svg_SizeCallback  ( int *width, int *height, gpointer data );
static void svg_RenderPicture ( filter_t *p_filter,
                                svg_rendition_t *p_svg );
static void FreeString( svg_rendition_t * );

/*****************************************************************************
 * filter_sys_t: svg local data
 *****************************************************************************
 * This structure is part of the filter thread descriptor.
 * It describes the svg specific properties of an output thread.
 *****************************************************************************/
struct filter_sys_t
{
    /* The SVG template used to convert strings */
    byte_t        *psz_template;
    /* Default size for rendering. Initialized to the output size. */
    int            i_width;
    int            i_height;
    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 )
{
    filter_t *p_filter = (filter_t *)p_this;
    filter_sys_t *p_sys;

    /* Allocate structure */
    p_sys = malloc( sizeof( filter_sys_t ) );
    if( !p_sys )
    {
        msg_Err( p_filter, "Out of memory" );
        return VLC_ENOMEM;
    }

    /* Initialize psz_template */
    p_sys->psz_template = svg_GetTemplate( p_this );
    if( !p_sys->psz_template )
    {
        msg_Err( p_filter, "Out of memory" );
        return VLC_ENOMEM;
    }

    p_sys->i_width = p_filter->fmt_out.video.i_width;
    p_sys->i_height = p_filter->fmt_out.video.i_height;

    p_filter->pf_render_text = RenderText;
    p_filter->p_sys = p_sys;

    /* MUST call this before any RSVG funcs */
    g_type_init ();

    return VLC_SUCCESS;
}

static byte_t *svg_GetTemplate( vlc_object_t *p_this )
{
    filter_t *p_filter = (filter_t *)p_this;
    char *psz_filename;
    char *psz_template;
    FILE *file;

    psz_filename = config_GetPsz( p_filter, "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
            {
                msg_Dbg( p_this, "Reading %ld bytes from template %s\n", (long)s.st_size, psz_filename );

                psz_template = malloc( s.st_size + 42 );
                if( !psz_template )
                {
                    msg_Err( p_filter, "Out of memory" );
                    return NULL;
                }
                memset( psz_template, 0, s.st_size + 1 );
                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 )
{
    filter_t *p_filter = (filter_t *)p_this;
    filter_sys_t *p_sys = p_filter->p_sys;

    free( p_sys->psz_template );
    free( p_sys );
}

/*****************************************************************************
 * Render: render SVG in picture
 *****************************************************************************/
static int Render( filter_t *p_filter, subpicture_region_t *p_region,
                   svg_rendition_t *p_svg, int i_width, int i_height )
{
    video_format_t fmt;
    uint8_t *p_y, *p_u, *p_v, *p_a;
    int x, y, i_pitch, i_u_pitch;
    guchar *pixels_in = NULL;
    int rowstride_in;
    int channels_in;
    int alpha;
    picture_t *p_pic;
    subpicture_region_t *p_region_tmp;