Fixes CVE-2012-2803.
CC: libav-stable@libav.org
(cherry picked from commit 5823686261)
Conflicts:
	libavcodec/mpeg12.c
		
	
		
			
				
	
	
		
			77 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			77 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * MPEG1/2 common code
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 * Copyright (c) 2007 Aurelien Jacobs <aurel@gnuage.org>
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 *
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 * This file is part of Libav.
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 *
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 * Libav is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * Libav is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with Libav; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#ifndef AVCODEC_MPEG12_H
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#define AVCODEC_MPEG12_H
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#include "mpegvideo.h"
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#define DC_VLC_BITS 9
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#define TEX_VLC_BITS 9
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extern VLC ff_dc_lum_vlc;
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extern VLC ff_dc_chroma_vlc;
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typedef struct Mpeg1Context {
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    MpegEncContext mpeg_enc_ctx;
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    int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
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    int repeat_field; /* true if we must repeat the field */
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    AVPanScan pan_scan;              /**< some temporary storage for the panscan */
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    int slice_count;
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    int swap_uv;//indicate VCR2
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    int save_aspect_info;
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    int save_width, save_height, save_progressive_seq;
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    AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
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    int sync;                        ///< Did we reach a sync point like a GOP/SEQ/KEYFrame?
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    int closed_gop;                  ///< GOP is closed
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    int extradata_decoded;
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} Mpeg1Context;
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extern uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
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void ff_mpeg12_common_init(MpegEncContext *s);
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void ff_mpeg12_init_vlcs(void);
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static inline int decode_dc(GetBitContext *gb, int component)
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{
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    int code, diff;
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    if (component == 0) {
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        code = get_vlc2(gb, ff_dc_lum_vlc.table, DC_VLC_BITS, 2);
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    } else {
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        code = get_vlc2(gb, ff_dc_chroma_vlc.table, DC_VLC_BITS, 2);
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    }
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    if (code < 0){
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        av_log(NULL, AV_LOG_ERROR, "invalid dc code at\n");
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        return 0xffff;
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    }
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    if (code == 0) {
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        diff = 0;
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    } else {
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        diff = get_xbits(gb, code);
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    }
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    return diff;
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}
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extern int ff_mpeg1_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n);
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#endif /* AVCODEC_MPEG12_H */
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