| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * MJPEG encoder | ||
| 3 | * Copyright (c) 2016 William Ma, Ted Ying, Jerry Jiang | ||
| 4 | * | ||
| 5 | * This file is part of FFmpeg. | ||
| 6 | * | ||
| 7 | * FFmpeg is free software; you can redistribute it and/or | ||
| 8 | * modify it under the terms of the GNU Lesser General Public | ||
| 9 | * License as published by the Free Software Foundation; either | ||
| 10 | * version 2.1 of the License, or (at your option) any later version. | ||
| 11 | * | ||
| 12 | * FFmpeg is distributed in the hope that it will be useful, | ||
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
| 15 | * Lesser General Public License for more details. | ||
| 16 | * | ||
| 17 | * You should have received a copy of the GNU Lesser General Public | ||
| 18 | * License along with FFmpeg; if not, write to the Free Software | ||
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
| 20 | */ | ||
| 21 | |||
| 22 | /** | ||
| 23 | * @file | ||
| 24 | * Huffman table generation for MJPEG encoder. | ||
| 25 | */ | ||
| 26 | |||
| 27 | #ifndef AVCODEC_MJPEGENC_HUFFMAN_H | ||
| 28 | #define AVCODEC_MJPEGENC_HUFFMAN_H | ||
| 29 | |||
| 30 | #include <stdint.h> | ||
| 31 | |||
| 32 | typedef struct MJpegEncHuffmanContext { | ||
| 33 | int val_count[256]; | ||
| 34 | } MJpegEncHuffmanContext; | ||
| 35 | |||
| 36 | // Uses the package merge algorithm to compute the Huffman table. | ||
| 37 | void ff_mjpeg_encode_huffman_init(MJpegEncHuffmanContext *s); | ||
| 38 | 28822754 | static inline void ff_mjpeg_encode_huffman_increment(MJpegEncHuffmanContext *s, | |
| 39 | uint8_t val) | ||
| 40 | { | ||
| 41 | 28822754 | s->val_count[val]++; | |
| 42 | 28822754 | } | |
| 43 | void ff_mjpeg_encode_huffman_close(MJpegEncHuffmanContext *s, | ||
| 44 | uint8_t bits[17], uint8_t val[], | ||
| 45 | int max_nval); | ||
| 46 | |||
| 47 | |||
| 48 | /** | ||
| 49 | * Used to assign a occurrence count or "probability" to an input value | ||
| 50 | */ | ||
| 51 | typedef struct PTable { | ||
| 52 | int value; ///< input value | ||
| 53 | int prob; ///< number of occurences of this value in input | ||
| 54 | } PTable; | ||
| 55 | |||
| 56 | /** | ||
| 57 | * Used to store intermediate lists in the package merge algorithm | ||
| 58 | */ | ||
| 59 | typedef struct PackageMergerList { | ||
| 60 | int nitems; ///< number of items in the list and probability ex. 4 | ||
| 61 | int item_idx[515]; ///< index range for each item in items 0, 2, 5, 9, 13 | ||
| 62 | int probability[514]; ///< probability of each item 3, 8, 18, 46 | ||
| 63 | int items[257 * 16]; ///< chain of all individual values that make up items A, B, A, B, C, A, B, C, D, C, D, D, E | ||
| 64 | } PackageMergerList; | ||
| 65 | |||
| 66 | /** | ||
| 67 | * Used to store optimal huffman encoding results | ||
| 68 | */ | ||
| 69 | typedef struct HuffTable { | ||
| 70 | int code; ///< code is the input value | ||
| 71 | int length; ///< length of the encoding | ||
| 72 | } HuffTable; | ||
| 73 | |||
| 74 | void ff_mjpegenc_huffman_compute_bits(PTable *prob_table, HuffTable *distincts, | ||
| 75 | int size, int max_length); | ||
| 76 | #endif /* AVCODEC_MJPEGENC_HUFFMAN_H */ | ||
| 77 |