avformat/psxstr: fix unknown sector type 00/80

This third patch fixes warnings that are false positives (still on STRv1).

That's because these sectors are simply empty ones as can be read in "System Description CD-ROM XA, May 1991,
4.3.2.3".

Haven't attempted significant refactoring as it just works, left a comment instead about the situation.

The result is that there are no more false warnings when converting.

Signed-off-by: aybe <aybe@users.noreply.github.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/psxstr.c

@@ -48,6 +48,7 @@
 #define CDXA_TYPE_DATA     0x08
 #define CDXA_TYPE_AUDIO    0x04
 #define CDXA_TYPE_VIDEO    0x02
+#define CDXA_TYPE_EMPTY    0x00
 
 #define STR_MAGIC (0x80010160)
 
@@ -270,6 +271,10 @@ static int str_read_packet(AVFormatContext *s,
                 str->channels[channel].audio_stream_index;
             pkt->duration = 1;
             return 0;
+        case CDXA_TYPE_EMPTY: /* CD-ROM XA, May 1991, 4.3.2.3 */
+            /* NOTE this also catches 0x80 (EOF bit) because of CDXA_TYPE_MASK */
+            /* TODO consider refactoring so as to explicitly handle each case? */
+            break;
         default:
             av_log(s, AV_LOG_WARNING, "Unknown sector type %02X\n", sector[0x12]);
             /* drop the sector and move on */