mpeg/psi/descriptors: Add length and show desc id as hex in XML printer.

mpeg/psi/descriptors.h

@@ -79,8 +79,8 @@ static inline void desc_print_begin(const uint8_t *p_desc, f_print pf_print,
             sprintf(psz_value + 2 * i, "%2.2hhx", p_desc[2 + i]);
         psz_value[2 * i] = '\0';
 
-        pf_print(opaque, "<DESC id=\"%hhu\" value=\"%s\">",
-                 desc_get_tag(p_desc), psz_value);
+        pf_print(opaque, "<DESC id=\"0x%02x\" length=\"%u\" value=\"%s\">",
+                 desc_get_tag(p_desc), i_length, psz_value);
         break;
     }
     default: