libavcodec/huffyuv.c

   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 Libav.
  10  *
  11  * Libav 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  * Libav 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 Libav; 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)
  40 {
  41     int len, index;
  42     uint32_t bits = 0;
  43
  44     for (len = 32; len > 0; len--) {
  45         for (index = 0; index < 256; 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
  58 av_cold int ff_huffyuv_alloc_temp(HYuvContext *s)
  59 {
  60     int i;
  61
  62     if (s->bitstream_bpp<24) {
  63         for (i=0; i<3; i++) {
  64             s->temp[i]= av_malloc(s->width + 16);
  65             if (!s->temp[i])
  66                 return AVERROR(ENOMEM);
  67         }
  68     } else {
  69         s->temp[0]= av_mallocz(4*s->width + 16);
  70         if (!s->temp[0])
  71             return AVERROR(ENOMEM);
  72     }
  73     return 0;
  74 }
  75
  76 av_cold void ff_huffyuv_common_init(AVCodecContext *avctx)
  77 {
  78     HYuvContext *s = avctx->priv_data;
  79
  80     s->avctx = avctx;
  81     s->flags = avctx->flags;
  82
  83     ff_bswapdsp_init(&s->bdsp);
  84
  85     s->width = avctx->width;
  86     s->height = avctx->height;
  87     assert(s->width>0 && s->height>0);
  88 }
  89
  90 void ff_huffyuv_common_end(HYuvContext *s)
  91 {
  92     int i;
  93
  94     for(i = 0; i < 3; i++) {
  95         av_freep(&s->temp[i]);
  96     }
  97 }