140 lines
		
	
	
		
			4.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			140 lines
		
	
	
		
			4.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * MJPEG decoder
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|  * Copyright (c) 2000, 2001 Fabrice Bellard
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|  * Copyright (c) 2003 Alex Beregszaszi
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|  * Copyright (c) 2003-2004 Michael Niedermayer
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|  *
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|  * This file is part of FFmpeg.
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|  *
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|  * FFmpeg 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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|  * FFmpeg 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 FFmpeg; 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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| 
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| /**
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|  * @file
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|  * MJPEG decoder.
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|  */
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| 
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| #ifndef AVCODEC_MJPEGDEC_H
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| #define AVCODEC_MJPEGDEC_H
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| 
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| #include "libavutil/log.h"
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| 
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| #include "avcodec.h"
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| #include "get_bits.h"
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| #include "dsputil.h"
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| #include "hpeldsp.h"
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| 
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| #define MAX_COMPONENTS 4
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| 
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| typedef struct MJpegDecodeContext {
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|     AVClass *class;
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|     AVCodecContext *avctx;
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|     GetBitContext gb;
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| 
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|     int start_code; /* current start code */
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|     int buffer_size;
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|     uint8_t *buffer;
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| 
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|     int16_t quant_matrixes[4][64];
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|     VLC vlcs[3][4];
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|     int qscale[4];      ///< quantizer scale calculated from quant_matrixes
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| 
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|     int org_height;  /* size given at codec init */
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|     int first_picture;    /* true if decoding first picture */
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|     int interlaced;     /* true if interlaced */
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|     int bottom_field;   /* true if bottom field */
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|     int lossless;
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|     int ls;
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|     int progressive;
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|     int rgb;
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|     int upscale_h;
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|     int chroma_height;
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|     int upscale_v;
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|     int rct;            /* standard rct */
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|     int pegasus_rct;    /* pegasus reversible colorspace transform */
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|     int bits;           /* bits per component */
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|     int colr;
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|     int xfrm;
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| 
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|     int maxval;
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|     int near;         ///< near lossless bound (si 0 for lossless)
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|     int t1,t2,t3;
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|     int reset;        ///< context halfing interval ?rename
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| 
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|     int width, height;
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|     int mb_width, mb_height;
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|     int nb_components;
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|     int block_stride[MAX_COMPONENTS];
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|     int component_id[MAX_COMPONENTS];
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|     int h_count[MAX_COMPONENTS]; /* horizontal and vertical count for each component */
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|     int v_count[MAX_COMPONENTS];
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|     int comp_index[MAX_COMPONENTS];
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|     int dc_index[MAX_COMPONENTS];
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|     int ac_index[MAX_COMPONENTS];
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|     int nb_blocks[MAX_COMPONENTS];
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|     int h_scount[MAX_COMPONENTS];
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|     int v_scount[MAX_COMPONENTS];
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|     int quant_sindex[MAX_COMPONENTS];
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|     int h_max, v_max; /* maximum h and v counts */
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|     int quant_index[4];   /* quant table index for each component */
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|     int last_dc[MAX_COMPONENTS]; /* last DEQUANTIZED dc (XXX: am I right to do that ?) */
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|     AVFrame picture; /* picture structure */
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|     AVFrame *picture_ptr; /* pointer to picture structure */
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|     int got_picture;                                ///< we found a SOF and picture is valid, too.
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|     int linesize[MAX_COMPONENTS];                   ///< linesize << interlaced
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|     int8_t *qscale_table;
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|     DECLARE_ALIGNED(16, int16_t, block)[64];
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|     int16_t (*blocks[MAX_COMPONENTS])[64]; ///< intermediate sums (progressive mode)
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|     uint8_t *last_nnz[MAX_COMPONENTS];
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|     uint64_t coefs_finished[MAX_COMPONENTS]; ///< bitmask of which coefs have been completely decoded (progressive mode)
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|     ScanTable scantable;
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|     DSPContext dsp;
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|     HpelDSPContext hdsp;
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| 
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|     int restart_interval;
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|     int restart_count;
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| 
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|     int buggy_avid;
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|     int cs_itu601;
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|     int interlace_polarity;
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| 
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|     int mjpb_skiptosod;
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| 
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|     int cur_scan; /* current scan, used by JPEG-LS */
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|     int flipped; /* true if picture is flipped */
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| 
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|     uint16_t (*ljpeg_buffer)[4];
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|     unsigned int ljpeg_buffer_size;
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| 
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|     int extern_huff;
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|     AVDictionary *exif_metadata;
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| } MJpegDecodeContext;
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| 
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| int ff_mjpeg_decode_init(AVCodecContext *avctx);
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| int ff_mjpeg_decode_end(AVCodecContext *avctx);
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| int ff_mjpeg_decode_frame(AVCodecContext *avctx,
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|                           void *data, int *got_frame,
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|                           AVPacket *avpkt);
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| int ff_mjpeg_decode_dqt(MJpegDecodeContext *s);
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| int ff_mjpeg_decode_dht(MJpegDecodeContext *s);
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| int ff_mjpeg_decode_sof(MJpegDecodeContext *s);
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| int ff_mjpeg_decode_sos(MJpegDecodeContext *s,
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|                         const uint8_t *mb_bitmask, const AVFrame *reference);
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| int ff_mjpeg_find_marker(MJpegDecodeContext *s,
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|                          const uint8_t **buf_ptr, const uint8_t *buf_end,
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|                          const uint8_t **unescaped_buf_ptr, int *unescaped_buf_size);
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| 
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| #endif /* AVCODEC_MJPEGDEC_H */
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