avcodec/h264_direct: Fix overflow in POC comparission

[ffmpeg] / libavcodec / dirac_arith.h

diff --git a/libavcodec/dirac_arith.h b/libavcodec/dirac_arith.h
index efe30b79debb76adf41636c0bc67eac9187c3c4f..79526a7ca3c1928cdc0a167632060b6389204d85 100644 (file)
--- a/libavcodec/dirac_arith.h
+++ b/libavcodec/dirac_arith.h
@@ -82,6 +82,7 @@ typedef struct {
 
     uint16_t contexts[DIRAC_CTX_COUNT];
     int error;
+    int overread;
 } DiracArith;
 
 extern const uint8_t ff_dirac_next_ctx[DIRAC_CTX_COUNT];
@@ -119,6 +120,9 @@ static inline void refill(DiracArith *c)
                 new |= 0xff00;
 
             c->bytestream = c->bytestream_end;
+            c->overread ++;
+            if (c->overread > 4)
+                c->error = AVERROR_INVALIDDATA;
         }
 
         c->low += new << counter;