avdevice/decklink_dec: make some function static

Reviewed-by: Aaron Levinson <alevinsn_dev@levland.net>
Signed-off-by: James Almer <jamrial@gmail.com>

libavdevice/decklink_dec.cpp

@@ -262,7 +262,7 @@ static uint8_t* teletext_data_unit_from_ancillary_packet(uint16_t *py, uint16_t
     return tgt;
 }
 
-uint8_t *vanc_to_cc(AVFormatContext *avctx, uint16_t *buf, size_t words,
+static uint8_t *vanc_to_cc(AVFormatContext *avctx, uint16_t *buf, size_t words,
                            unsigned &cc_count)
 {
     size_t i, len = (buf[5] & 0xff) + 6 + 1;
@@ -352,7 +352,7 @@ uint8_t *vanc_to_cc(AVFormatContext *avctx, uint16_t *buf, size_t words,
     return cc;
 }
 
-uint8_t *get_metadata(AVFormatContext *avctx, uint16_t *buf, size_t width,
+static uint8_t *get_metadata(AVFormatContext *avctx, uint16_t *buf, size_t width,
                              uint8_t *tgt, size_t tgt_size, AVPacket *pkt)
 {
     decklink_cctx *cctx = (struct decklink_cctx *) avctx->priv_data;