ffmpeg/libavcodec/huffyuv.c

98 lines
2.4 KiB
C

/*
* huffyuv codec for libavcodec
*
* Copyright (c) 2002-2003 Michael Niedermayer <michaelni@gmx.at>
*
* see http://www.pcisys.net/~melanson/codecs/huffyuv.txt for a description of
* the algorithm used
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; 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/mem.h"
#include "avcodec.h"
#include "dsputil.h"
#include "huffyuv.h"
int ff_huffyuv_generate_bits_table(uint32_t *dst, const uint8_t *len_table)
{
int len, index;
uint32_t bits = 0;
for (len = 32; len > 0; len--) {
for (index = 0; index < 256; index++) {
if (len_table[index] == len)
dst[index] = bits++;
}
if (bits & 1) {
av_log(NULL, AV_LOG_ERROR, "Error generating huffman table\n");
return -1;
}
bits >>= 1;
}
return 0;
}
av_cold int ff_huffyuv_alloc_temp(HYuvContext *s)
{
int i;
if (s->bitstream_bpp<24) {
for (i=0; i<3; i++) {
s->temp[i]= av_malloc(s->width + 16);
if (!s->temp[i])
return AVERROR(ENOMEM);
}
} else {
s->temp[0]= av_mallocz(4*s->width + 16);
if (!s->temp[0])
return AVERROR(ENOMEM);
}
return 0;
}
av_cold void ff_huffyuv_common_init(AVCodecContext *avctx)
{
HYuvContext *s = avctx->priv_data;
s->avctx = avctx;
s->flags = avctx->flags;
ff_dsputil_init(&s->dsp, avctx);
s->width = avctx->width;
s->height = avctx->height;
assert(s->width>0 && s->height>0);
}
void ff_huffyuv_common_end(HYuvContext *s)
{
int i;
for(i = 0; i < 3; i++) {
av_freep(&s->temp[i]);
}
}