matroskadec: directly use ebml_parse() or ebml_parse_id() where it's enough

Originally committed as revision 14598 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/matroskadec.c

@@ -846,6 +846,8 @@ static int matroska_probe(AVProbeData *p)
     return 0;
 }
 
+static int ebml_parse_id(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
+                         uint32_t id, void *data);
 static int ebml_parse_nest(MatroskaDemuxContext *matroska, EbmlSyntax *syntax,
                       void *data, int once);
 
@@ -881,7 +883,7 @@ static int ebml_parse_elem(MatroskaDemuxContext *matroska,
                      if (id == MATROSKA_ID_SEGMENT)
                          matroska->segment_start = url_ftell(matroska->ctx->pb);
                      return ebml_parse_nest(matroska, syntax->def.n, data, 0);
-    case EBML_PASS:  return ebml_parse_nest(matroska, syntax->def.n, data, 1);
+    case EBML_PASS:  return ebml_parse_id(matroska, syntax->def.n, id, data);
     case EBML_STOP:  *(int *)data = 1;      return 1;
     default:         url_fskip(pb, length); return 0;
     }
@@ -1129,7 +1131,7 @@ static int matroska_read_header(AVFormatContext *s, AVFormatParameters *ap)
     matroska->ctx = s;
 
     /* First read the EBML header. */
-    if (ebml_parse_nest(matroska, ebml_syntax, &ebml, 1)
+    if (ebml_parse(matroska, ebml_syntax, &ebml)
         || ebml.version > EBML_VERSION       || ebml.max_size > sizeof(uint64_t)
         || ebml.id_length > sizeof(uint32_t) || strcmp(ebml.doctype, "matroska")
         || ebml.doctype_version > 2) {
@@ -1142,7 +1144,7 @@ static int matroska_read_header(AVFormatContext *s, AVFormatParameters *ap)
     ebml_free(ebml_syntax, &ebml);
 
     /* The next thing is a segment. */
-    if (ebml_parse_nest(matroska, matroska_segments, matroska, 1) < 0)
+    if (ebml_parse(matroska, matroska_segments, matroska) < 0)
         return -1;
     matroska_execute_seekhead(matroska);
 
@@ -1632,7 +1634,7 @@ static int matroska_parse_cluster(MatroskaDemuxContext *matroska)
     MatroskaCluster cluster = { 0 };
     EbmlList *blocks_list;
     MatroskaBlock *blocks;
-    int i, res = ebml_parse_nest(matroska, matroska_clusters, &cluster, 1);
+    int i, res = ebml_parse(matroska, matroska_clusters, &cluster);
     blocks_list = &cluster.blocks;
     blocks = blocks_list->elem;
     for (i=0; !res && i<blocks_list->nb_elem; i++)