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libavcodec
jpegls.h
Go to the documentation of this file.
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/*
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* JPEG-LS common code
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* Copyright (c) 2003 Michael Niedermayer
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* Copyright (c) 2006 Konstantin Shishkov
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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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#ifndef AVCODEC_JPEGLS_H
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#define AVCODEC_JPEGLS_H
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#include "
libavutil/common.h
"
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#include "
avcodec.h
"
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typedef
struct
JpeglsContext
{
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AVCodecContext
*
avctx
;
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}
JpeglsContext
;
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typedef
struct
JLSState
{
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int
T1
,
T2
,
T3
;
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int
A
[367],
B
[367],
C
[365],
N
[367];
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int
limit
,
reset
,
bpp
,
qbpp
,
maxval
,
range
;
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int
near
,
twonear
;
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int
run_index
[3];
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}
JLSState
;
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extern
const
uint8_t
ff_log2_run
[32];
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void
ff_jpegls_init_state
(
JLSState
*
state
);
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static
inline
int
ff_jpegls_quantize
(
JLSState
*s,
int
v)
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{
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if
(v == 0)
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return
0;
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if
(v < 0) {
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if
(v <= -s->T3)
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return
-4;
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if
(v <= -s->T2)
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return
-3;
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if
(v <= -s->T1)
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return
-2;
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if
(v < -s->near)
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return
-1;
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return
0;
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}
else
{
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if
(v <= s->near)
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return
0;
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if
(v < s->T1)
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return
1;
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if
(v < s->T2)
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return
2;
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if
(v < s->T3)
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return
3;
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return
4;
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}
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}
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void
ff_jpegls_reset_coding_parameters
(
JLSState
*s,
int
reset_all);
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static
inline
void
ff_jpegls_downscale_state
(
JLSState
*
state
,
int
Q)
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{
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if
(state->
N
[Q] == state->
reset
) {
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state->
A
[Q] >>= 1;
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state->
B
[Q] >>= 1;
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state->
N
[Q] >>= 1;
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}
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state->
N
[Q]++;
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}
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static
inline
int
ff_jpegls_update_state_regular
(
JLSState
*
state
,
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int
Q,
int
err)
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{
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state->
A
[Q] +=
FFABS
(err);
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err *= state->
twonear
;
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state->
B
[Q] += err;
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ff_jpegls_downscale_state
(state, Q);
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if
(state->
B
[Q] <= -state->
N
[Q]) {
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state->
B
[Q] =
FFMAX
(state->
B
[Q] + state->
N
[Q], 1 - state->
N
[Q]);
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if
(state->
C
[Q] > -128)
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state->
C
[Q]--;
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}
else
if
(state->
B
[Q] > 0) {
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state->
B
[Q] =
FFMIN
(state->
B
[Q] - state->
N
[Q], 0);
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if
(state->
C
[Q] < 127)
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state->
C
[Q]++;
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}
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return
err;
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}
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#define R(a, i) (bits == 8 ? ((uint8_t *)(a))[i] : ((uint16_t *)(a))[i])
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#define W(a, i, v) (bits == 8 ? (((uint8_t *)(a))[i] = v) : (((uint16_t *)(a))[i] = v))
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#endif
/* AVCODEC_JPEGLS_H */
JLSState::reset
int reset
Definition:
jpegls.h:41
JLSState::T2
int T2
Definition:
jpegls.h:39
JpeglsContext
Definition:
jpegls.h:34
JLSState::C
int C[365]
Definition:
jpegls.h:40
JLSState::twonear
int twonear
Definition:
jpegls.h:42
JLSState::limit
int limit
Definition:
jpegls.h:41
ff_jpegls_init_state
void ff_jpegls_init_state(JLSState *state)
Calculate initial JPEG-LS parameters.
Definition:
jpegls.c:30
JLSState::bpp
int bpp
Definition:
jpegls.h:41
JLSState
Definition:
jpegls.h:38
JLSState::maxval
int maxval
Definition:
jpegls.h:41
uint8_t
uint8_t
Definition:
audio_convert.c:194
JLSState::run_index
int run_index[3]
Definition:
jpegls.h:43
ff_jpegls_update_state_regular
static int ff_jpegls_update_state_regular(JLSState *state, int Q, int err)
Definition:
jpegls.h:98
JLSState::B
int B[367]
Definition:
jpegls.h:40
FFMAX
#define FFMAX(a, b)
Definition:
common.h:55
JLSState::near
int near
Definition:
jpegls.h:42
ff_log2_run
const uint8_t ff_log2_run[32]
Definition:
bitstream.c:36
FFMIN
#define FFMIN(a, b)
Definition:
common.h:57
FFABS
#define FFABS(a)
Definition:
common.h:52
JLSState::qbpp
int qbpp
Definition:
jpegls.h:41
avcodec.h
Libavcodec external API header.
JpeglsContext::avctx
AVCodecContext * avctx
Definition:
jpegls.h:35
ff_jpegls_reset_coding_parameters
void ff_jpegls_reset_coding_parameters(JLSState *s, int reset_all)
Calculate JPEG-LS codec values.
Definition:
jpegls.c:63
AVCodecContext
main external API structure.
Definition:
avcodec.h:1050
JLSState::A
int A[367]
Definition:
jpegls.h:40
JLSState::T1
int T1
Definition:
jpegls.h:39
JLSState::range
int range
Definition:
jpegls.h:41
JLSState::N
int N[367]
Definition:
jpegls.h:40
state
static uint32_t state
Definition:
trasher.c:27
common.h
common internal and external API header
ff_jpegls_quantize
static int ff_jpegls_quantize(JLSState *s, int v)
Calculate quantized gradient value, used for context determination.
Definition:
jpegls.h:56
JLSState::T3
int T3
Definition:
jpegls.h:39
ff_jpegls_downscale_state
static void ff_jpegls_downscale_state(JLSState *state, int Q)
Definition:
jpegls.h:88
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