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huffyuv.c
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1 /*
2  * huffyuv codec for libavcodec
3  *
4  * Copyright (c) 2002-2003 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 "huffyuv.h"
37 
38 int ff_huffyuv_generate_bits_table(uint32_t *dst, const uint8_t *len_table)
39 {
40  int len, index;
41  uint32_t bits = 0;
42 
43  for (len = 32; len > 0; len--) {
44  for (index = 0; index < 256; index++) {
45  if (len_table[index] == len)
46  dst[index] = bits++;
47  }
48  if (bits & 1) {
49  av_log(NULL, AV_LOG_ERROR, "Error generating huffman table\n");
50  return -1;
51  }
52  bits >>= 1;
53  }
54  return 0;
55 }
56 
58 {
59  int i;
60 
61  if (s->bitstream_bpp<24) {
62  for (i=0; i<3; i++) {
63  s->temp[i]= av_malloc(s->width + 16);
64  if (!s->temp[i])
65  return AVERROR(ENOMEM);
66  }
67  } else {
68  s->temp[0]= av_mallocz(4*s->width + 16);
69  if (!s->temp[0])
70  return AVERROR(ENOMEM);
71  }
72  return 0;
73 }
74 
76 {
77  HYuvContext *s = avctx->priv_data;
78 
79  s->avctx = avctx;
80  s->flags = avctx->flags;
81 
82  ff_dsputil_init(&s->dsp, avctx);
83 
84  s->width = avctx->width;
85  s->height = avctx->height;
86 
87  av_assert1(s->width > 0 && s->height > 0);
88 }
89 
91 {
92  int i;
93 
94  for(i = 0; i < 3; i++) {
95  av_freep(&s->temp[i]);
96  }
97 }