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huffyuv.c
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1 /*
2  * huffyuv codec for libavcodec
3  *
4  * Copyright (c) 2002-2014 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * see http://www.pcisys.net/~melanson/codecs/huffyuv.txt for a description of
7  * the algorithm used
8  *
9  * This file is part of FFmpeg.
10  *
11  * FFmpeg is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU Lesser General Public
13  * License as published by the Free Software Foundation; either
14  * version 2.1 of the License, or (at your option) any later version.
15  *
16  * FFmpeg is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19  * Lesser General Public License for more details.
20  *
21  * You should have received a copy of the GNU Lesser General Public
22  * License along with FFmpeg; if not, write to the Free Software
23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24  */
25 
26 /**
27  * @file
28  * huffyuv codec for libavcodec.
29  */
30 
31 #include <stdint.h>
32 
33 #include "libavutil/mem.h"
34 
35 #include "avcodec.h"
36 #include "bswapdsp.h"
37 #include "huffyuv.h"
38 
39 int ff_huffyuv_generate_bits_table(uint32_t *dst, const uint8_t *len_table, int n)
40 {
41  int len, index;
42  uint32_t bits = 0;
43 
44  for (len = 32; len > 0; len--) {
45  for (index = 0; index < n; index++) {
46  if (len_table[index] == len)
47  dst[index] = bits++;
48  }
49  if (bits & 1) {
50  av_log(NULL, AV_LOG_ERROR, "Error generating huffman table\n");
51  return -1;
52  }
53  bits >>= 1;
54  }
55  return 0;
56 }
57 
59 {
60  int i;
61 
62  for (i=0; i<3; i++) {
63  s->temp[i]= av_malloc(4*s->width + 16);
64  if (!s->temp[i])
65  return AVERROR(ENOMEM);
66  s->temp16[i] = (uint16_t*)s->temp[i];
67  }
68  return 0;
69 }
70 
72 {
73  HYuvContext *s = avctx->priv_data;
74 
75  s->avctx = avctx;
76  s->flags = avctx->flags;
77 
79  ff_llviddsp_init(&s->llviddsp, avctx);
80 
81  s->width = avctx->width;
82  s->height = avctx->height;
83 
84  av_assert1(s->width > 0 && s->height > 0);
85 }
86 
88 {
89  int i;
90 
91  for(i = 0; i < 3; i++) {
92  av_freep(&s->temp[i]);
93  s->temp16[i] = NULL;
94  }
95 }