libavcodec/mjpegdec.h

   1 /*
   2  * MJPEG decoder
   3  * Copyright (c) 2000, 2001 Fabrice Bellard
   4  * Copyright (c) 2003 Alex Beregszaszi
   5  * Copyright (c) 2003-2004 Michael Niedermayer
   6  *
   7  * This file is part of Libav.
   8  *
   9  * Libav is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * Libav is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with Libav; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 /**
  25  * @file
  26  * MJPEG decoder.
  27  */
  28
  29 #ifndef AVCODEC_MJPEGDEC_H
  30 #define AVCODEC_MJPEGDEC_H
  31
  32 #include "libavutil/log.h"
  33
  34 #include "avcodec.h"
  35 #include "get_bits.h"
  36 #include "dsputil.h"
  37
  38 #define MAX_COMPONENTS 4
  39
  40 typedef struct MJpegDecodeContext {
  41     AVClass *class;
  42     AVCodecContext *avctx;
  43     GetBitContext gb;
  44
  45     int start_code; /* current start code */
  46     int buffer_size;
  47     uint8_t *buffer;
  48
  49     int16_t quant_matrixes[4][64];
  50     VLC vlcs[3][4];
  51     int qscale[4];      ///< quantizer scale calculated from quant_matrixes
  52
  53     int org_height;  /* size given at codec init */
  54     int first_picture;    /* true if decoding first picture */
  55     int interlaced;     /* true if interlaced */
  56     int bottom_field;   /* true if bottom field */
  57     int lossless;
  58     int ls;
  59     int progressive;
  60     int rgb;
  61     int rct;            /* standard rct */
  62     int pegasus_rct;    /* pegasus reversible colorspace transform */
  63     int bits;           /* bits per component */
  64
  65     int maxval;
  66     int near;         ///< near lossless bound (si 0 for lossless)
  67     int t1,t2,t3;
  68     int reset;        ///< context halfing intervall ?rename
  69
  70     int width, height;
  71     int mb_width, mb_height;
  72     int nb_components;
  73     int block_stride[MAX_COMPONENTS];
  74     int component_id[MAX_COMPONENTS];
  75     int h_count[MAX_COMPONENTS]; /* horizontal and vertical count for each component */
  76     int v_count[MAX_COMPONENTS];
  77     int comp_index[MAX_COMPONENTS];
  78     int dc_index[MAX_COMPONENTS];
  79     int ac_index[MAX_COMPONENTS];
  80     int nb_blocks[MAX_COMPONENTS];
  81     int h_scount[MAX_COMPONENTS];
  82     int v_scount[MAX_COMPONENTS];
  83     int h_max, v_max; /* maximum h and v counts */
  84     int quant_index[4];   /* quant table index for each component */
  85     int last_dc[MAX_COMPONENTS]; /* last DEQUANTIZED dc (XXX: am I right to do that ?) */
  86     AVFrame picture; /* picture structure */
  87     AVFrame *picture_ptr; /* pointer to picture structure */
  88     int got_picture;                                ///< we found a SOF and picture is valid, too.
  89     int linesize[MAX_COMPONENTS];                   ///< linesize << interlaced
  90     int8_t *qscale_table;
  91     DECLARE_ALIGNED(16, int16_t, block)[64];
  92     int16_t (*blocks[MAX_COMPONENTS])[64]; ///< intermediate sums (progressive mode)
  93     uint8_t *last_nnz[MAX_COMPONENTS];
  94     uint64_t coefs_finished[MAX_COMPONENTS]; ///< bitmask of which coefs have been completely decoded (progressive mode)
  95     ScanTable scantable;
  96     DSPContext dsp;
  97
  98     int restart_interval;
  99     int restart_count;
 100
 101     int buggy_avid;
 102     int cs_itu601;
 103     int interlace_polarity;
 104
 105     int mjpb_skiptosod;
 106
 107     int cur_scan; /* current scan, used by JPEG-LS */
 108     int flipped; /* true if picture is flipped */
 109
 110     uint16_t (*ljpeg_buffer)[4];
 111     unsigned int ljpeg_buffer_size;
 112
 113     int extern_huff;
 114 } MJpegDecodeContext;
 115
 116 int ff_mjpeg_decode_init(AVCodecContext *avctx);
 117 int ff_mjpeg_decode_end(AVCodecContext *avctx);
 118 int ff_mjpeg_decode_frame(AVCodecContext *avctx,
 119                           void *data, int *got_frame,
 120                           AVPacket *avpkt);
 121 int ff_mjpeg_decode_dqt(MJpegDecodeContext *s);
 122 int ff_mjpeg_decode_dht(MJpegDecodeContext *s);
 123 int ff_mjpeg_decode_sof(MJpegDecodeContext *s);
 124 int ff_mjpeg_decode_sos(MJpegDecodeContext *s,
 125                         const uint8_t *mb_bitmask, const AVFrame *reference);
 126 int ff_mjpeg_find_marker(MJpegDecodeContext *s,
 127                          const uint8_t **buf_ptr, const uint8_t *buf_end,
 128                          const uint8_t **unescaped_buf_ptr, int *unescaped_buf_size);
 129
 130 #endif /* AVCODEC_MJPEGDEC_H */