void ff_mpeg4_pred_ac(MpegEncContext *s, int16_t *block, int n,
int dir);
void ff_set_mpeg4_time(MpegEncContext *s);
-void ff_mpeg4_encode_picture_header(MpegEncContext *s, int picture_number);
+int ff_mpeg4_encode_picture_header(MpegEncContext *s, int picture_number);
int ff_mpeg4_decode_picture_header(Mpeg4DecContext *ctx, GetBitContext *gb);
void ff_mpeg4_encode_video_packet_header(MpegEncContext *s);