<fo:instream-foreign-object width="2cm" height="1.2cm">                       
    <svg xmlns="http://www.w3.org/2000/svg" width="2cm" height="1.2cm">
      <polygon fill="#C8837D" points="29.89,3.184 29.936,3.141 30.02,3.098 30.064,3.051 30.105"/>
       ...........
    </svg>
</fo:instream-foreign-object>

<fo:instream-foreign-object content-width="100%" content-height="100%">                     
     <xsl:call-template name="barcode-code128">
                     <xsl:with-param name="value" select="$value"/>
                     <xsl:with-param name="subset" select="$subset"/>
                     <xsl:with-param name="string" select="$value"/>
                     <xsl:with-param name="module" select="'0.01in'"/>
                     <xsl:with-param name="height" select="'1cm'"/>
                     <xsl:with-param name="font-height" select="'8pt'"/>
                     <xsl:with-param name="quiet-horizontal" select="'0.8in'"/>
                     </xsl:call-template>
</fo:instream-foreign-object>

xml error: cvc-complex-type.2.1: Element 'fo:instream-foreign-object' must have no character or element information item [children], because the type's content type is empty., line: -1, column: -1
xml error: cvc-complex-type.2.1: Element 'fo:instream-foreign-object' must have no character or element information item [children], because the type's content type is empty., line: -1, column: -1

xml error: cvc-complex-type.2.1: Element 'fo:instream-foreign-object' must have no character or element information item [children], because the type's content type is empty., line: -1, column: -1