avcodec/jpeg2000dec: account two last bytes from end of bytestream as EOC marker

This silences missing EOC marker when decoding j2k files with Psot set to 0.

Signed-off-by: Paul B Mahol <onemda@gmail.com>

diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index c13670e6d6708d2e9fc830b150fc501d30175f8f..962b7bc79c9f3690c488dbc4dd24f908cb821ded 100644 (file)
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -737,9 +737,9 @@ static int get_sot(Jpeg2000DecoderContext *s, int n)
     bytestream2_get_byteu(&s->g);               // TNsot
 
     if (!Psot)
-        Psot = bytestream2_get_bytes_left(&s->g) + n + 2;
+        Psot = bytestream2_get_bytes_left(&s->g) - 2 + n + 2;
 
-    if (Psot > bytestream2_get_bytes_left(&s->g) + n + 2) {
+    if (Psot > bytestream2_get_bytes_left(&s->g) - 2 + n + 2) {
         av_log(s->avctx, AV_LOG_ERROR, "Psot %"PRIu32" too big\n", Psot);
         return AVERROR_INVALIDDATA;
     }