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 40typedef 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, DCTELEM, block)[64]; 92 DCTELEM (*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 116int ff_mjpeg_decode_init(AVCodecContext *avctx); 117int ff_mjpeg_decode_end(AVCodecContext *avctx); 118int ff_mjpeg_decode_frame(AVCodecContext *avctx, 119 void *data, int *data_size, 120 AVPacket *avpkt); 121int ff_mjpeg_decode_dqt(MJpegDecodeContext *s); 122int ff_mjpeg_decode_dht(MJpegDecodeContext *s); 123int ff_mjpeg_decode_sof(MJpegDecodeContext *s); 124int ff_mjpeg_decode_sos(MJpegDecodeContext *s, 125 const uint8_t *mb_bitmask, const AVFrame *reference); 126int 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 */ 131