int64_t (*seek)(void *opaque, int64_t offset, int whence));
+/**
+ * Read size bytes from AVIOContext, returning a pointer.
+ * Note that the data pointed at by the returned pointer is only
+ * valid until the next call that references the same IO context.
+ * @param s IO context
+ * @param buf pointer to buffer into which to assemble the requested
+ * data if it is not available in contiguous addresses in the
+ * underlying buffer
+ * @param size number of bytes requested
+ * @param data address at which to store pointer: this will be a
+ * a direct pointer into the underlying buffer if the requested
+ * number of bytes are available at contiguous addresses, otherwise
+ * will be a copy of buf
+ * @return number of bytes read or AVERROR
+ */
+int ffio_read_indirect(AVIOContext *s, unsigned char *buf, int size, const unsigned char **data);
+
/**
* Read size bytes from AVIOContext into buf.
* This reads at most 1 packet. If that is not enough fewer bytes will be