LCOV - code coverage report
Current view: top level - libavcodec - mjpegenc_huffman.h (source / functions) Hit Total Coverage
Test: coverage.info Lines: 3 3 100.0 %
Date: 2017-12-13 10:57:33 Functions: 1 1 100.0 %

          Line data    Source code
       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    28811107 : static inline void ff_mjpeg_encode_huffman_increment(MJpegEncHuffmanContext *s,
      39             :                                                      uint8_t val)
      40             : {
      41    28811107 :     s->val_count[val]++;
      42    28811107 : }
      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 */

Generated by: LCOV version 1.13