avformat/rmdec: Better duplicate tags check

Fixes: memleaks
Fixes: 44810/clusterfuzz-testcase-minimized-ffmpeg_dem_IVR_fuzzer-5619494647627776

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/rmdec.c

@@ -127,10 +127,6 @@ static int rm_read_audio_stream_info(AVFormatContext *s, AVIOContext *pb,
     uint32_t version;
     int ret;
 
-    // Duplicate tags
-    if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO)
-        return AVERROR_INVALIDDATA;
-
     /* ra type header */
     version = avio_rb16(pb); /* version */
     if (version == 3) {
@@ -330,6 +326,11 @@ int ff_rm_read_mdpr_codecdata(AVFormatContext *s, AVIOContext *pb,
     if (codec_data_size == 0)
         return 0;
 
+    // Duplicate tags
+    if (   st->codecpar->codec_type != AVMEDIA_TYPE_UNKNOWN
+        && st->codecpar->codec_type != AVMEDIA_TYPE_DATA)
+        return AVERROR_INVALIDDATA;
+
     avpriv_set_pts_info(st, 64, 1, 1000);
     codec_pos = avio_tell(pb);
     v = avio_rb32(pb);