+/**
+ * Get the length in bytes which is needed to store val as v.
+ */
+int ff_get_v_length(uint64_t val);
+
+/**
+ * Put val using a variable number of bytes.
+ */
+void ff_put_v(AVIOContext *bc, uint64_t val);
+
+/**
+ * Read a whole line of text from AVIOContext. Stop reading after reaching
+ * either a \\n, a \\0 or EOF. The returned string is always \\0-terminated,
+ * and may be truncated if the buffer is too small.
+ *
+ * @param s the read-only AVIOContext
+ * @param buf buffer to store the read line
+ * @param maxlen size of the buffer
+ * @return the length of the string written in the buffer, not including the
+ * final \\0
+ */
+int ff_get_line(AVIOContext *s, char *buf, int maxlen);
+
+#define SPACE_CHARS " \t\r\n"
+
+/**
+ * Callback function type for ff_parse_key_value.
+ *
+ * @param key a pointer to the key
+ * @param key_len the number of bytes that belong to the key, including the '='
+ * char
+ * @param dest return the destination pointer for the value in *dest, may
+ * be null to ignore the value
+ * @param dest_len the length of the *dest buffer
+ */
+typedef void (*ff_parse_key_val_cb)(void *context, const char *key,
+ int key_len, char **dest, int *dest_len);
+/**
+ * Parse a string with comma-separated key=value pairs. The value strings
+ * may be quoted and may contain escaped characters within quoted strings.
+ *
+ * @param str the string to parse
+ * @param callback_get_buf function that returns where to store the
+ * unescaped value string.
+ * @param context the opaque context pointer to pass to callback_get_buf
+ */
+void ff_parse_key_value(const char *str, ff_parse_key_val_cb callback_get_buf,
+ void *context);
+
+/**
+ * Find stream index based on format-specific stream ID
+ * @return stream index, or < 0 on error
+ */
+int ff_find_stream_index(AVFormatContext *s, int id);
+
+/**
+ * Internal version of av_index_search_timestamp
+ */
+int ff_index_search_timestamp(const AVIndexEntry *entries, int nb_entries,
+ int64_t wanted_timestamp, int flags);
+
+/**
+ * Internal version of av_add_index_entry
+ */
+int ff_add_index_entry(AVIndexEntry **index_entries,
+ int *nb_index_entries,
+ unsigned int *index_entries_allocated_size,
+ int64_t pos, int64_t timestamp, int size, int distance, int flags);
+
+/**
+ * Add a new chapter.
+ *
+ * @param s media file handle
+ * @param id unique ID for this chapter
+ * @param start chapter start time in time_base units
+ * @param end chapter end time in time_base units
+ * @param title chapter title
+ *
+ * @return AVChapter or NULL on error
+ */
+AVChapter *avpriv_new_chapter(AVFormatContext *s, int id, AVRational time_base,
+ int64_t start, int64_t end, const char *title);
+
+/**
+ * Ensure the index uses less memory than the maximum specified in
+ * AVFormatContext.max_index_size by discarding entries if it grows
+ * too large.
+ */
+void ff_reduce_index(AVFormatContext *s, int stream_index);
+
+enum AVCodecID ff_guess_image2_codec(const char *filename);
+
+/**
+ * Convert a date string in ISO8601 format to Unix timestamp.
+ */
+int64_t ff_iso8601_to_unix_time(const char *datestr);
+
+/**
+ * Perform a binary search using av_index_search_timestamp() and
+ * AVInputFormat.read_timestamp().
+ *
+ * @param target_ts target timestamp in the time base of the given stream
+ * @param stream_index stream number
+ */
+int ff_seek_frame_binary(AVFormatContext *s, int stream_index,
+ int64_t target_ts, int flags);
+
+/**
+ * Update cur_dts of all streams based on the given timestamp and AVStream.
+ *
+ * Stream ref_st unchanged, others set cur_dts in their native time base.
+ * Only needed for timestamp wrapping or if (dts not set and pts!=dts).
+ * @param timestamp new dts expressed in time_base of param ref_st
+ * @param ref_st reference stream giving time_base of param timestamp
+ */
+void ff_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp);
+
+/**
+ * Perform a binary search using read_timestamp().
+ *
+ * @param target_ts target timestamp in the time base of the given stream
+ * @param stream_index stream number
+ */
+int64_t ff_gen_search(AVFormatContext *s, int stream_index,
+ int64_t target_ts, int64_t pos_min,
+ int64_t pos_max, int64_t pos_limit,
+ int64_t ts_min, int64_t ts_max,
+ int flags, int64_t *ts_ret,
+ int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));
+
+/**
+ * Set the time base and wrapping info for a given stream. This will be used
+ * to interpret the stream's timestamps. If the new time base is invalid
+ * (numerator or denominator are non-positive), it leaves the stream
+ * unchanged.
+ *
+ * @param s stream
+ * @param pts_wrap_bits number of bits effectively used by the pts
+ * (used for wrap control)
+ * @param pts_num time base numerator
+ * @param pts_den time base denominator
+ */
+void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits,
+ unsigned int pts_num, unsigned int pts_den);
+
+/**
+ * Add side data to a packet for changing parameters to the given values.
+ * Parameters set to 0 aren't included in the change.
+ */
+int ff_add_param_change(AVPacket *pkt, int32_t channels,
+ uint64_t channel_layout, int32_t sample_rate,
+ int32_t width, int32_t height);
+
+/**
+ * Set the timebase for each stream from the corresponding codec timebase and
+ * print it.
+ */
+int ff_framehash_write_header(AVFormatContext *s);
+
+/**
+ * Read a transport packet from a media file.
+ *
+ * @param s media file handle
+ * @param pkt is filled
+ * @return 0 if OK, AVERROR_xxx on error
+ */
+int ff_read_packet(AVFormatContext *s, AVPacket *pkt);
+
+/**
+ * Interleave a packet per dts in an output media file.
+ *
+ * Packets with pkt->destruct == av_destruct_packet will be freed inside this
+ * function, so they cannot be used after it. Note that calling av_free_packet()
+ * on them is still safe.
+ *
+ * @param s media file handle
+ * @param out the interleaved packet will be output here
+ * @param pkt the input packet
+ * @param flush 1 if no further packets are available as input and all
+ * remaining packets should be output
+ * @return 1 if a packet was output, 0 if no packet could be output,
+ * < 0 if an error occurred
+ */
+int ff_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
+ AVPacket *pkt, int flush);
+
+/**
+ * Return the frame duration in seconds. Return 0 if not available.
+ */
+void ff_compute_frame_duration(int *pnum, int *pden, AVStream *st,
+ AVCodecParserContext *pc, AVPacket *pkt);
+
+int ff_get_audio_frame_size(AVCodecContext *enc, int size, int mux);
+
+unsigned int ff_codec_get_tag(const AVCodecTag *tags, enum AVCodecID id);
+
+enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag);
+
+/**
+ * Select a PCM codec based on the given parameters.
+ *
+ * @param bps bits-per-sample
+ * @param flt floating-point
+ * @param be big-endian
+ * @param sflags signed flags. each bit corresponds to one byte of bit depth.
+ * e.g. the 1st bit indicates if 8-bit should be signed or
+ * unsigned, the 2nd bit indicates if 16-bit should be signed or
+ * unsigned, etc... This is useful for formats such as WAVE where
+ * only 8-bit is unsigned and all other bit depths are signed.
+ * @return a PCM codec id or AV_CODEC_ID_NONE
+ */
+enum AVCodecID ff_get_pcm_codec_id(int bps, int flt, int be, int sflags);
+
+/**
+ * Generate standard extradata for AVC-Intra based on width/height and field
+ * order.
+ */
+int ff_generate_avci_extradata(AVStream *st);
+