avcodec/rangecoder: Add and test ff_rac_check_termination()

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

1 files changed, 9 insertions, 0 deletions

diff --git a/libavcodec/rangecoder.h b/libavcodec/rangecoder.h
index 4495f6df1a..4d4ca4d526 100644
--- a/libavcodec/rangecoder.h
+++ b/libavcodec/rangecoder.h
@@ -57,6 +57,15 @@ void ff_init_range_decoder(RangeCoder *c, const uint8_t *buf, int buf_size);
  */
 int ff_rac_terminate(RangeCoder *c, int version);
 
+/**
+ * Check if at the current position there is a valid looking termination
+ * @param version version 0 requires the decoder to know the data size in bytes
+ *                version 1 needs about 1 bit more space but does not need to
+ *                          carry the size from encoder to decoder
+ * @returns negative AVERROR code on error or non negative.
+ */
+int ff_rac_check_termination(RangeCoder *c, int version);
+
 void ff_build_rac_states(RangeCoder *c, int factor, int max_p);
 
 static inline void renorm_encoder(RangeCoder *c)