xref: /third_party/ffmpeg/libavcodec/huffyuv.c (revision cabdff1a) 
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
39int 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
58av_cold int ff_huffyuv_alloc_temp(HYuvContext *s)
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
71av_cold void ff_huffyuv_common_init(AVCodecContext *avctx)
72{
73    HYuvContext *s = avctx->priv_data;
74
75    s->avctx = avctx;
76    s->flags = avctx->flags;
77
78    ff_bswapdsp_init(&s->bdsp);
79
80    s->width = avctx->width;
81    s->height = avctx->height;
82
83    av_assert1(s->width > 0 && s->height > 0);
84}
85
86av_cold void ff_huffyuv_common_end(HYuvContext *s)
87{
88    int i;
89
90    for(i = 0; i < 3; i++) {
91        av_freep(&s->temp[i]);
92        s->temp16[i] = NULL;
93    }
94}
95