avcodec/av1_parse: Fix bistream typo

Reviewed-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/av1_parse.h

@@ -61,7 +61,7 @@ typedef struct AV1Packet {
 /**
  * Extract an OBU from a raw bitstream.
  *
- * @note This function does not copy or store any bistream data. All
+ * @note This function does not copy or store any bitstream data. All
  *       the pointers in the AV1OBU structure will be valid as long
  *       as the input buffer also is.
  */
@@ -71,7 +71,7 @@ int ff_av1_extract_obu(AV1OBU *obu, const uint8_t *buf, int length,
 /**
  * Split an input packet into OBUs.
  *
- * @note This function does not copy or store any bistream data. All
+ * @note This function does not copy or store any bitstream data. All
  *       the pointers in the AV1Packet structure will be valid as
  *       long as the input buffer also is.
  */