+/**
+ * Validate the FLAC extradata.
+ * @param[in] avctx codec context containing the extradata.
+ * @param[out] format extradata format.
+ * @param[out] streaminfo_start pointer to start of 34-byte STREAMINFO data.
+ * @return 1 if valid, 0 if not valid.
+ */
+int ff_flac_is_extradata_valid(AVCodecContext *avctx,
+ enum FLACExtradataFormat *format,
+ uint8_t **streaminfo_start);
+
+/**
+ * Parse the metadata block parameters from the header.
+ * @param[in] block_header header data, at least 4 bytes
+ * @param[out] last indicator for last metadata block
+ * @param[out] type metadata block type
+ * @param[out] size metadata block size
+ */
+void ff_flac_parse_block_header(const uint8_t *block_header,
+ int *last, int *type, int *size);
+
+/**
+ * Calculate an estimate for the maximum frame size based on verbatim mode.
+ * @param blocksize block size, in samples
+ * @param ch number of channels
+ * @param bps bits-per-sample
+ */
+int ff_flac_get_max_frame_size(int blocksize, int ch, int bps);
+
+/**
+ * Validate and decode a frame header.
+ * @param avctx AVCodecContext to use as av_log() context
+ * @param gb GetBitContext from which to read frame header
+ * @param[out] fi frame information
+ * @param log_level_offset log level offset. can be used to silence error messages.
+ * @return non-zero on error, 0 if ok
+ */
+int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
+ FLACFrameInfo *fi, int log_level_offset);