lavc: use avpriv_ prefix for ff_dirac_parse_sequence_header.

It's used in lavf.

libavcodec/dirac.c

@@ -242,7 +242,7 @@ static int parse_source_parameters(AVCodecContext *avctx, GetBitContext *gb,
     return 0;
 }
 
-int ff_dirac_parse_sequence_header(AVCodecContext *avctx, GetBitContext *gb,
+int avpriv_dirac_parse_sequence_header(AVCodecContext *avctx, GetBitContext *gb,
                                    dirac_source_params *source)
 {
     unsigned version_major;

libavcodec/dirac.h

@@ -51,7 +51,7 @@ typedef struct {
     uint8_t color_spec_index;       ///< index into dirac_color_spec_presets[]
 } dirac_source_params;
 
-int ff_dirac_parse_sequence_header(AVCodecContext *avctx, GetBitContext *gb,
-                                   dirac_source_params *source);
+int avpriv_dirac_parse_sequence_header(AVCodecContext *avctx, GetBitContext *gb,
+                                       dirac_source_params *source);
 
 #endif /* AVCODEC_DIRAC_H */

libavformat/oggparsedirac.c

@@ -36,7 +36,7 @@ static int dirac_header(AVFormatContext *s, int idx)
         return 0;
 
     init_get_bits(&gb, os->buf + os->pstart + 13, (os->psize - 13) * 8);
-    if (ff_dirac_parse_sequence_header(st->codec, &gb, &source) < 0)
+    if (avpriv_dirac_parse_sequence_header(st->codec, &gb, &source) < 0)
         return -1;
 
     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;