1/* 2 * MJPEG encoder 3 * Copyright (c) 2000, 2001 Fabrice Bellard 4 * Copyright (c) 2003 Alex Beregszaszi 5 * Copyright (c) 2003-2004 Michael Niedermayer 6 * 7 * Support for external huffman table, various fixes (AVID workaround), 8 * aspecting, new decode_frame mechanism and apple mjpeg-b support 9 * by Alex Beregszaszi 10 * 11 * This file is part of FFmpeg. 12 * 13 * FFmpeg is free software; you can redistribute it and/or 14 * modify it under the terms of the GNU Lesser General Public 15 * License as published by the Free Software Foundation; either 16 * version 2.1 of the License, or (at your option) any later version. 17 * 18 * FFmpeg is distributed in the hope that it will be useful, 19 * but WITHOUT ANY WARRANTY; without even the implied warranty of 20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 21 * Lesser General Public License for more details. 22 * 23 * You should have received a copy of the GNU Lesser General Public 24 * License along with FFmpeg; if not, write to the Free Software 25 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 26 */ 27 28/** 29 * @file 30 * MJPEG encoder. 31 */ 32 33#ifndef AVCODEC_MJPEGENC_H 34#define AVCODEC_MJPEGENC_H 35 36#include <stdint.h> 37 38#include "mjpeg.h" 39#include "mpegvideo.h" 40#include "put_bits.h" 41 42/** 43 * Buffer of JPEG frame data. 44 * 45 * Optimal Huffman table generation requires the frame data to be loaded into 46 * a buffer so that the tables can be computed. 47 * There are at most mb_width*mb_height*12*64 of these per frame. 48 */ 49typedef struct MJpegHuffmanCode { 50 // 0=DC lum, 1=DC chrom, 2=AC lum, 3=AC chrom 51 uint8_t table_id; ///< The Huffman table id associated with the data. 52 uint8_t code; ///< The exponent. 53 uint16_t mant; ///< The mantissa. 54} MJpegHuffmanCode; 55 56/** 57 * Holds JPEG frame data and Huffman table data. 58 */ 59typedef struct MJpegContext { 60 int huffman; 61 /* Force duplication of mjpeg matrices, useful for rtp streaming */ 62 int force_duplicated_matrix; 63 //FIXME use array [3] instead of lumi / chroma, for easier addressing 64 uint8_t huff_size_dc_luminance[12]; ///< DC luminance Huffman table size. 65 uint16_t huff_code_dc_luminance[12]; ///< DC luminance Huffman table codes. 66 uint8_t huff_size_dc_chrominance[12]; ///< DC chrominance Huffman table size. 67 uint16_t huff_code_dc_chrominance[12]; ///< DC chrominance Huffman table codes. 68 69 uint8_t huff_size_ac_luminance[256]; ///< AC luminance Huffman table size. 70 uint16_t huff_code_ac_luminance[256]; ///< AC luminance Huffman table codes. 71 uint8_t huff_size_ac_chrominance[256]; ///< AC chrominance Huffman table size. 72 uint16_t huff_code_ac_chrominance[256]; ///< AC chrominance Huffman table codes. 73 74 /** Storage for AC luminance VLC (in MpegEncContext) */ 75 uint8_t uni_ac_vlc_len[64 * 64 * 2]; 76 /** Storage for AC chrominance VLC (in MpegEncContext) */ 77 uint8_t uni_chroma_ac_vlc_len[64 * 64 * 2]; 78 79 // Default DC tables have exactly 12 values 80 uint8_t bits_dc_luminance[17]; ///< DC luminance Huffman bits. 81 uint8_t val_dc_luminance[12]; ///< DC luminance Huffman values. 82 uint8_t bits_dc_chrominance[17]; ///< DC chrominance Huffman bits. 83 uint8_t val_dc_chrominance[12]; ///< DC chrominance Huffman values. 84 85 // 8-bit JPEG has max 256 values 86 uint8_t bits_ac_luminance[17]; ///< AC luminance Huffman bits. 87 uint8_t val_ac_luminance[256]; ///< AC luminance Huffman values. 88 uint8_t bits_ac_chrominance[17]; ///< AC chrominance Huffman bits. 89 uint8_t val_ac_chrominance[256]; ///< AC chrominance Huffman values. 90 91 size_t huff_ncode; ///< Number of current entries in the buffer. 92 MJpegHuffmanCode *huff_buffer; ///< Buffer for Huffman code values. 93} MJpegContext; 94 95/** 96 * Enum for the Huffman encoding strategy. 97 */ 98enum HuffmanTableOption { 99 HUFFMAN_TABLE_DEFAULT = 0, ///< Use the default Huffman tables. 100 HUFFMAN_TABLE_OPTIMAL = 1, ///< Compute and use optimal Huffman tables. 101 NB_HUFFMAN_TABLE_OPTION = 2 102}; 103 104static inline void put_marker(PutBitContext *p, enum JpegMarker code) 105{ 106 put_bits(p, 8, 0xff); 107 put_bits(p, 8, code); 108} 109 110int ff_mjpeg_encode_init(MpegEncContext *s); 111void ff_mjpeg_amv_encode_picture_header(MpegEncContext *s); 112void ff_mjpeg_encode_mb(MpegEncContext *s, int16_t block[12][64]); 113int ff_mjpeg_encode_stuffing(MpegEncContext *s); 114 115#endif /* AVCODEC_MJPEGENC_H */ 116