It's never called in any code compiled without CONFIG_ENCODERS.
Originally committed as revision 10655 to svn://svn.ffmpeg.org/ffmpeg/trunk
int dir);
void ff_set_mpeg4_time(MpegEncContext * s);
void mpeg4_encode_picture_header(MpegEncContext *s, int picture_number);
-#ifdef CONFIG_ENCODERS
void h263_encode_init(MpegEncContext *s);
-#else
-static void h263_encode_init(MpegEncContext *s) {assert(0);}
-#endif
void h263_decode_init_vlc(MpegEncContext *s);
int h263_decode_picture_header(MpegEncContext *s);
int ff_h263_decode_gob_header(MpegEncContext *s);