avio: move ff_rewind_with_probe_data from avio.h to avio_internal.h

also change its prefix to ffio

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

libavformat/avio_internal.h

@@ -47,4 +47,18 @@ static av_always_inline void ffio_wfourcc(AVIOContext *pb, const uint8_t *s)
     avio_wl32(pb, MKTAG(s[0], s[1], s[2], s[3]));
 }
 
+/**
+ * Rewind the AVIOContext using the specified buffer containing the first buf_size bytes of the file.
+ * Used after probing to avoid seeking.
+ * Joins buf and s->buffer, taking any overlap into consideration.
+ * @note s->buffer must overlap with buf or they can't be joined and the function fails
+ *
+ * @param s The read-only AVIOContext to rewind
+ * @param buf The probe buffer containing the first buf_size bytes of the file
+ * @param buf_size The size of buf
+ * @return 0 in case of success, a negative value corresponding to an
+ * AVERROR code in case of failure
+ */
+int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char *buf, int buf_size);
+
 #endif // AVFORMAT_AVIO_INTERNAL_H