1/* 2 * MPEG1/2 common code 3 * Copyright (c) 2007 Aurelien Jacobs <aurel@gnuage.org> 4 * 5 * This file is part of Libav. 6 * 7 * Libav is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * Libav is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with Libav; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#ifndef AVCODEC_MPEG12_H 23#define AVCODEC_MPEG12_H 24 25#include "mpegvideo.h" 26 27#define DC_VLC_BITS 9 28#define TEX_VLC_BITS 9 29 30extern VLC ff_dc_lum_vlc; 31extern VLC ff_dc_chroma_vlc; 32 33typedef struct Mpeg1Context { 34 MpegEncContext mpeg_enc_ctx; 35 int mpeg_enc_ctx_allocated; /* true if decoding context allocated */ 36 int repeat_field; /* true if we must repeat the field */ 37 AVPanScan pan_scan; /**< some temporary storage for the panscan */ 38 int slice_count; 39 int swap_uv;//indicate VCR2 40 int save_aspect_info; 41 int save_width, save_height, save_progressive_seq; 42 AVRational frame_rate_ext; ///< MPEG-2 specific framerate modificator 43 int sync; ///< Did we reach a sync point like a GOP/SEQ/KEYFrame? 44 int closed_gop; ///< GOP is closed 45 int extradata_decoded; 46} Mpeg1Context; 47 48extern uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3]; 49 50void ff_mpeg12_common_init(MpegEncContext *s); 51void ff_mpeg12_init_vlcs(void); 52 53static inline int decode_dc(GetBitContext *gb, int component) 54{ 55 int code, diff; 56 57 if (component == 0) { 58 code = get_vlc2(gb, ff_dc_lum_vlc.table, DC_VLC_BITS, 2); 59 } else { 60 code = get_vlc2(gb, ff_dc_chroma_vlc.table, DC_VLC_BITS, 2); 61 } 62 if (code < 0){ 63 av_log(NULL, AV_LOG_ERROR, "invalid dc code at\n"); 64 return 0xffff; 65 } 66 if (code == 0) { 67 diff = 0; 68 } else { 69 diff = get_xbits(gb, code); 70 } 71 return diff; 72} 73 74extern int ff_mpeg1_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n); 75 76#endif /* AVCODEC_MPEG12_H */ 77