avformat/pjsdec: Check duration for overflow

Fixes: signed integer overflow: -3 - 9223372036854775807 cannot be represented in type 'long'
Fixes: 17828/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5645915116797952

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

libavformat/pjsdec.c

@@ -55,6 +55,8 @@ static int64_t read_ts(char **line, int *duration)
     if (sscanf(*line, "%"SCNd64",%"SCNd64, &start, &end) == 2) {
         *line += strcspn(*line, "\"");
         *line += !!**line;
+        if (end < start || end - (uint64_t)start > INT_MAX)
+            return AV_NOPTS_VALUE;
         *duration = end - start;
         return start;
     }