ffmpeg/libavcodec/huffyuv.c

85 lines
2.2 KiB
C

/*
* 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 <stdint.h>
#include "libavutil/attributes.h"
#include "libavutil/error.h"
#include "libavutil/log.h"
#include "libavutil/mem.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 -1;
}
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;
}
av_cold int ff_huffyuv_alloc_temp(uint8_t *temp[3], uint16_t *temp16[3], int width)
{
int i;
for (i=0; i<3; i++) {
temp[i] = av_malloc(4 * width + 16);
if (!temp[i])
return AVERROR(ENOMEM);
temp16[i] = (uint16_t*)temp[i];
}
return 0;
}
av_cold void ff_huffyuv_common_end(uint8_t *temp[3], uint16_t *temp16[3])
{
int i;
for(i = 0; i < 3; i++) {
av_freep(&temp[i]);
temp16[i] = NULL;
}
}