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