erase.c

VLC Player Source Code

}

/*****************************************************************************
 * FilterErase
 *****************************************************************************/
static void FilterErase( filter_t *p_filter, picture_t *p_inpic,
                                             picture_t *p_outpic )
{
    filter_sys_t *p_sys = p_filter->p_sys;

    int i_plane;

    const int i_mask_pitch = p_sys->p_mask->A_PITCH;
    const int i_mask_visible_pitch = p_sys->p_mask->p[A_PLANE].i_visible_pitch;
    const int i_mask_visible_lines = p_sys->p_mask->p[A_PLANE].i_visible_lines;

    for( i_plane = 0; i_plane < p_inpic->i_planes; i_plane++ )
    {
        const int i_pitch = p_inpic->p[i_plane].i_pitch;
        const int i_2pitch = i_pitch<<1;
        const int i_visible_pitch = p_inpic->p[i_plane].i_visible_pitch;
        const int i_lines = p_inpic->p[i_plane].i_lines;
        const int i_visible_lines = p_inpic->p[i_plane].i_visible_lines;

        uint8_t *p_inpix = p_inpic->p[i_plane].p_pixels;
        uint8_t *p_outpix = p_outpic->p[i_plane].p_pixels;
        uint8_t *p_mask = p_sys->p_mask->A_PIXELS;

        int i_x = p_sys->i_x,
            i_y = p_sys->i_y;
        int x, y;
        int i_height = i_mask_visible_lines;
        int i_width  = i_mask_visible_pitch;

        const bool b_line_factor = ( i_plane /* U_PLANE or V_PLANE */ &&
            !( p_inpic->format.i_chroma == VLC_FOURCC('I','4','2','2')
            || p_inpic->format.i_chroma == VLC_FOURCC('J','4','2','2') ) );

        if( i_plane ) /* U_PLANE or V_PLANE */
        {
            i_width  >>= 1;
            i_x      >>= 1;
        }
        if( b_line_factor )
        {
            i_height >>= 1;
            i_y      >>= 1;
        }
        i_height = __MIN( i_visible_lines - i_y, i_height );
        i_width  = __MIN( i_visible_pitch - i_x, i_width  );

        /* Copy original pixel buffer */
        vlc_memcpy( p_outpix, p_inpix, i_pitch * i_lines );

        /* Horizontal linear interpolation of masked areas */
        p_outpix = p_outpic->p[i_plane].p_pixels + i_y*i_pitch + i_x;
        for( y = 0; y < i_height;
             y++, p_mask += i_mask_pitch, p_outpix += i_pitch )
        {
            uint8_t prev, next = 0;
            int prev_x = -1, next_x = -2;
            int quot = 0;

            /* Find a suitable value for the previous color to use when
             * interpoling a masked pixel's value */
            if( i_x )
            {
                /* There are pixels before current position on the same line.
                 * Use those */
                prev = *(p_outpix-1);
            }
            else if( y || i_y )
            {
                /* This is the first pixel on a line but there other lines
                 * above us. Use the pixel right above */
                prev = *(p_outpix-i_pitch);
            }
            else
            {
                /* We're in the upper left corner. This sucks. We can't use
                 * any previous value, so we'll use a dummy one. In most
                 * cases this dummy value will be fixed later on in the
                 * algorithm */
                prev = 0xff;
            }

            for( x = 0; x < i_width; x++ )
            {
                if( p_mask[i_plane?x<<1:x] > 127 )
                {
                    /* This is a masked pixel */
                    if( next_x <= prev_x )
                    {
                        int x0;
                        /* Look for the next non masked pixel on the same
                         * line (inside the mask's bounding box) */
                        for( x0 = x; x0 < i_width; x0++ )
                        {
                            if( p_mask[i_plane?x0<<1:x0] <= 127 )
                            {
                                /* We found an unmasked pixel. Victory! */
                                next_x = x0;
                                next = p_outpix[x0];
                                break;
                            }
                        }
                        if( next_x <= prev_x )
                        {
                            /* We didn't find an unmasked pixel yet. Try
                             * harder */
                            if( x0 == x ) x0++;
                            if( x0 < i_visible_pitch )
                            {
                                /* If we didn't find a non masked pixel on the
                                 * same line inside the mask's bounding box,
                                 * use the next pixel on the line (except if
                                 * it doesn't exist) */
                                next_x = x0;
                                next = p_outpix[x0];
                            }
                            else
                            {
                                /* The last pixel on the line is masked,
                                 * so we'll use the "prev" value. A better
                                 * approach would be to use unmasked pixels
                                 * at the end of adjacent lines */
                                next_x = x0;
                                next = prev;
                            }
                        }
                        if( !( i_x || y || i_y ) )
                            /* We were unable to find a suitable value for
                             * the previous color (which means that we are
                             * on the first line in the upper left corner)
                             */
                            prev = next;

                        /* Divide only once instead of next_x-prev_x-1 times */
                        quot = ((next-prev)<<16)/(next_x-prev_x);
                    }
                    /* Interpolate new value, and round correctly */
                    p_outpix[x] = prev + (((x-prev_x)*quot+(1<<16))>>16);
                }
                else
                {
                    /* This pixel isn't masked. It's thus suitable as a
                     * previous color for the next interpolation */
                    prev = p_outpix[x];
                    prev_x = x;
                }
            }
        }

        /* Vertical bluring */
        p_mask = p_sys->p_mask->A_PIXELS;
        i_height = b_line_factor ? i_mask_visible_lines>>1
                                 : i_mask_visible_lines;
        /* Make sure that we stop at least 2 lines before the picture's end
         * (since our bluring algorithm uses the 2 next lines) */
        i_height = __MIN( i_visible_lines - i_y - 2, i_height );
        /* Make sure that we start at least 2 lines from the top (since our
         * bluring algorithm uses the 2 previous lines) */
        y = __MAX(i_y,2);
        p_outpix = p_outpic->p[i_plane].p_pixels + (i_y+y)*i_pitch + i_x;
        for( ; y < i_height; y++, p_mask += i_mask_pitch, p_outpix += i_pitch )
        {
            for( x = 0; x < i_width; x++ )
            {
                if( p_mask[i_plane?x<<1:x] > 127 )
                {
                    /* Ugly bluring function */
                    p_outpix[x] =
                        ( (p_outpix[x-i_2pitch]<<1)       /* 2 */
                        + (p_outpix[x-i_pitch ]<<2)       /* 4 */
                        + (p_outpix[x         ]<<2)       /* 4 */
                        + (p_outpix[x+i_pitch ]<<2)       /* 4 */
                        + (p_outpix[x+i_2pitch]<<1) )>>4; /* 2 */
                }
            }
        }
    }
}

static int EraseCallback( vlc_object_t *p_this, char const *psz_var,
                          vlc_value_t oldval, vlc_value_t newval, void *p_data )
{
    VLC_UNUSED(oldval);
    filter_sys_t *p_sys = (filter_sys_t *)p_data;

    if( !strcmp( psz_var, CFG_PREFIX "x" ) )
    {
        vlc_mutex_lock( &p_sys->lock );
        p_sys->i_x = newval.i_int;
        vlc_mutex_unlock( &p_sys->lock );
    }
    else if( !strcmp( psz_var, CFG_PREFIX "y" ) )
    {
        vlc_mutex_lock( &p_sys->lock );
        p_sys->i_y = newval.i_int;
        vlc_mutex_unlock( &p_sys->lock );
    }
    else if( !strcmp( psz_var, CFG_PREFIX "mask" ) )
    {
        vlc_mutex_lock( &p_sys->lock );
        LoadMask( (filter_t*)p_this, newval.psz_string );
        vlc_mutex_unlock( &p_sys->lock );
    }
    else
    {
        msg_Warn( p_this, "Unknown callback command." );
    }
    return VLC_SUCCESS;
}