Fixed es_format_t::i_codec/i_original_fourcc values after the decoder.

es_format_t::i_codec will be the codec from vlc_fourcc.h
es_format_t::i_original_fourcc will contains the original fourcc
value.

This allows to simplify the decoder/packetizer and every sout modules.

src/input/es_out.c

@@ -1387,6 +1387,10 @@ static es_out_id_t *EsOutAdd( es_out_t *out, const es_format_t *fmt )
     es_format_Copy( &es->fmt, fmt );
     if( es->fmt.i_id < 0 )
         es->fmt.i_id = out->p_sys->i_id;
+    if( !es->fmt.i_original_fourcc )
+        es->fmt.i_original_fourcc = es->fmt.i_codec;
+    es->fmt.i_codec = es_fourcc_GetCodec( es->fmt.i_cat, es->fmt.i_codec );
+
     es->i_id = es->fmt.i_id;
     es->i_meta_id = out->p_sys->i_id;
     es->b_scrambled = false;