+void ff_mpeg12_init_vlcs(void);
+
+static inline int decode_dc(GetBitContext *gb, int component)
+{
+ int code, diff;
+
+ if (component == 0) {
+ code = get_vlc2(gb, ff_dc_lum_vlc.table, DC_VLC_BITS, 2);
+ } else {
+ code = get_vlc2(gb, ff_dc_chroma_vlc.table, DC_VLC_BITS, 2);
+ }
+ if (code < 0){
+ av_log(NULL, AV_LOG_ERROR, "invalid dc code at\n");
+ return 0xffff;
+ }
+ if (code == 0) {
+ diff = 0;
+ } else {
+ diff = get_xbits(gb, code);
+ }
+ return diff;
+}
+
+int ff_mpeg1_decode_block_intra(MpegEncContext *s, int16_t *block, int n);
+void ff_mpeg1_clean_buffers(MpegEncContext *s);
+int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size, AVCodecParserContext *s);