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