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/*
* huffyuv codec for libavcodec
*
* Copyright (c) 2002-2014 Michael Niedermayer <michaelni@gmx.at>
*
* see https://multimedia.cx/huffyuv.txt for a description of
* the algorithm used
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* huffyuv codec for libavcodec.
*/
#include <stddef.h>
#include <stdint.h>
#include "libavutil/error.h"
#include "libavutil/log.h"
#include "libavutil/macros.h"
#include "huffyuv.h"
int ff_huffyuv_generate_bits_table(uint32_t *dst, const uint8_t *len_table, int n)
{
int lens[33] = { 0 };
uint32_t codes[33];
for (int i = 0; i < n; i++)
lens[len_table[i]]++;
codes[32] = 0;
for (int i = FF_ARRAY_ELEMS(lens) - 1; i > 0; i--) {
if ((lens[i] + codes[i]) & 1) {
av_log(NULL, AV_LOG_ERROR, "Error generating huffman table\n");
return AVERROR_INVALIDDATA;
}
codes[i - 1] = (lens[i] + codes[i]) >> 1;
}
for (int i = 0; i < n; i++) {
if (len_table[i])
dst[i] = codes[len_table[i]]++;
}
return 0;
}
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