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/*
* JPEG-LS decoder
* Copyright (c) 2003 Michael Niedermayer
* Copyright (c) 2006 Konstantin Shishkov
*
* 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
* JPEG-LS decoder.
*/
#include "avcodec.h"
#include "get_bits.h"
#include "golomb.h"
#include "mathops.h"
#include "mjpeg.h"
#include "mjpegdec.h"
#include "jpegls.h"
#include "jpeglsdec.h"
/*
* Uncomment this to significantly speed up decoding of broken JPEG-LS
* (or test broken JPEG-LS decoder) and slow down ordinary decoding a bit.
*
* There is no Golomb code with length >= 32 bits possible, so check and
* avoid situation of 32 zeros, FFmpeg Golomb decoder is painfully slow
* on this errors.
*/
//#define JLS_BROKEN
/**
* Decode LSE block with initialization parameters
*/
int ff_jpegls_decode_lse(MJpegDecodeContext *s)
{
int id;
skip_bits(&s->gb, 16); /* length: FIXME: verify field validity */
id = get_bits(&s->gb, 8);
switch(id){
case 1:
s->maxval= get_bits(&s->gb, 16);
s->t1= get_bits(&s->gb, 16);
s->t2= get_bits(&s->gb, 16);
s->t3= get_bits(&s->gb, 16);
s->reset= get_bits(&s->gb, 16);
// ff_jpegls_reset_coding_parameters(s, 0);
//FIXME quant table?
break;
case 2:
case 3:
av_log(s->avctx, AV_LOG_ERROR, "palette not supported\n");
return -1;
case 4:
av_log(s->avctx, AV_LOG_ERROR, "oversize image not supported\n");
return -1;
default:
av_log(s->avctx, AV_LOG_ERROR, "invalid id %d\n", id);
return -1;
}
av_dlog(s->avctx, "ID=%i, T=%i,%i,%i\n", id, s->t1, s->t2, s->t3);
return 0;
}
/**
* Get context-dependent Golomb code, decode it and update context
*/
static inline int ls_get_code_regular(GetBitContext *gb, JLSState *state, int Q){
int k, ret;
for(k = 0; (state->N[Q] << k) < state->A[Q]; k++);
#ifdef JLS_BROKEN
if(!show_bits_long(gb, 32))return -1;
#endif
ret = get_ur_golomb_jpegls(gb, k, state->limit, state->qbpp);
/* decode mapped error */
if(ret & 1)
ret = -((ret + 1) >> 1);
else
ret >>= 1;
/* for NEAR=0, k=0 and 2*B[Q] <= - N[Q] mapping is reversed */
if(!state->near && !k && (2 * state->B[Q] <= -state->N[Q]))
ret = -(ret + 1);
ret= ff_jpegls_update_state_regular(state, Q, ret);
return ret;
}
/**
* Get Golomb code, decode it and update state for run termination
*/
static inline int ls_get_code_runterm(GetBitContext *gb, JLSState *state, int RItype, int limit_add){
int k, ret, temp, map;
int Q = 365 + RItype;
temp= state->A[Q];
if(RItype)
temp += state->N[Q] >> 1;
for(k = 0; (state->N[Q] << k) < temp; k++);
#ifdef JLS_BROKEN
if(!show_bits_long(gb, 32))return -1;
#endif
ret = get_ur_golomb_jpegls(gb, k, state->limit - limit_add - 1, state->qbpp);
/* decode mapped error */
map = 0;
if(!k && (RItype || ret) && (2 * state->B[Q] < state->N[Q]))
map = 1;
ret += RItype + map;
if(ret & 1){
ret = map - ((ret + 1) >> 1);
state->B[Q]++;
} else {
ret = ret >> 1;
}
/* update state */
state->A[Q] += FFABS(ret) - RItype;
ret *= state->twonear;
ff_jpegls_downscale_state(state, Q);
return ret;
}
/**
* Decode one line of image
*/
static inline void ls_decode_line(JLSState *state, MJpegDecodeContext *s, void *last, void *dst, int last2, int w, int stride, int comp, int bits){
int i, x = 0;
int Ra, Rb, Rc, Rd;
int D0, D1, D2;
while(x < w) {
int err, pred;
/* compute gradients */
Ra = x ? R(dst, x - stride) : R(last, x);
Rb = R(last, x);
Rc = x ? R(last, x - stride) : last2;
Rd = (x >= w - stride) ? R(last, x) : R(last, x + stride);
D0 = Rd - Rb;
D1 = Rb - Rc;
D2 = Rc - Ra;
/* run mode */
if((FFABS(D0) <= state->near) && (FFABS(D1) <= state->near) && (FFABS(D2) <= state->near)) {
int r;
int RItype;
/* decode full runs while available */
while(get_bits1(&s->gb)) {
int r;
r = 1 << ff_log2_run[state->run_index[comp]];
if(x + r * stride > w) {
r = (w - x) / stride;
}
for(i = 0; i < r; i++) {
W(dst, x, Ra);
x += stride;
}
/* if EOL reached, we stop decoding */
if(r != (1 << ff_log2_run[state->run_index[comp]]))
return;
if(state->run_index[comp] < 31)
state->run_index[comp]++;
if(x + stride > w)
return;
}
/* decode aborted run */
r = ff_log2_run[state->run_index[comp]];
if(r)
r = get_bits_long(&s->gb, r);
if(x + r * stride > w) {
r = (w - x) / stride;
}
for(i = 0; i < r; i++) {
W(dst, x, Ra);
x += stride;
}
/* decode run termination value */
Rb = R(last, x);
RItype = (FFABS(Ra - Rb) <= state->near) ? 1 : 0;
err = ls_get_code_runterm(&s->gb, state, RItype, ff_log2_run[state->run_index[comp]]);
if(state->run_index[comp])
state->run_index[comp]--;
if(state->near && RItype){
pred = Ra + err;
} else {
if(Rb < Ra)
pred = Rb - err;
else
pred = Rb + err;
}
} else { /* regular mode */
int context, sign;
context = ff_jpegls_quantize(state, D0) * 81 + ff_jpegls_quantize(state, D1) * 9 + ff_jpegls_quantize(state, D2);
pred = mid_pred(Ra, Ra + Rb - Rc, Rb);
if(context < 0){
context = -context;
sign = 1;
}else{
sign = 0;
}
if(sign){
pred = av_clip(pred - state->C[context], 0, state->maxval);
err = -ls_get_code_regular(&s->gb, state, context);
} else {
pred = av_clip(pred + state->C[context], 0, state->maxval);
err = ls_get_code_regular(&s->gb, state, context);
}
/* we have to do something more for near-lossless coding */
pred += err;
}
if(state->near){
if(pred < -state->near)
pred += state->range * state->twonear;
else if(pred > state->maxval + state->near)
pred -= state->range * state->twonear;
pred = av_clip(pred, 0, state->maxval);
}
pred &= state->maxval;
W(dst, x, pred);
x += stride;
}
}
int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near, int point_transform, int ilv){
int i, t = 0;
uint8_t *zero, *last, *cur;
JLSState *state;
int off = 0, stride = 1, width, shift;
zero = av_mallocz(s->picture.linesize[0]);
last = zero;
cur = s->picture.data[0];
state = av_mallocz(sizeof(JLSState));
/* initialize JPEG-LS state from JPEG parameters */
state->near = near;
state->bpp = (s->bits < 2) ? 2 : s->bits;
state->maxval = s->maxval;
state->T1 = s->t1;
state->T2 = s->t2;
state->T3 = s->t3;
state->reset = s->reset;
ff_jpegls_reset_coding_parameters(state, 0);
ff_jpegls_init_state(state);
if(s->bits <= 8)
shift = point_transform + (8 - s->bits);
else
shift = point_transform + (16 - s->bits);
if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
av_log(s->avctx, AV_LOG_DEBUG, "JPEG-LS params: %ix%i NEAR=%i MV=%i T(%i,%i,%i) RESET=%i, LIMIT=%i, qbpp=%i, RANGE=%i\n",
s->width, s->height, state->near, state->maxval,
state->T1, state->T2, state->T3,
state->reset, state->limit, state->qbpp, state->range);
av_log(s->avctx, AV_LOG_DEBUG, "JPEG params: ILV=%i Pt=%i BPP=%i, scan = %i\n",
ilv, point_transform, s->bits, s->cur_scan);
}
if(ilv == 0) { /* separate planes */
stride = (s->nb_components > 1) ? 3 : 1;
off = av_clip(s->cur_scan - 1, 0, stride);
width = s->width * stride;
cur += off;
for(i = 0; i < s->height; i++) {
if(s->bits <= 8){
ls_decode_line(state, s, last, cur, t, width, stride, off, 8);
t = last[0];
}else{
ls_decode_line(state, s, last, cur, t, width, stride, off, 16);
t = *((uint16_t*)last);
}
last = cur;
cur += s->picture.linesize[0];
if (s->restart_interval && !--s->restart_count) {
align_get_bits(&s->gb);
skip_bits(&s->gb, 16); /* skip RSTn */
}
}
} else if(ilv == 1) { /* line interleaving */
int j;
int Rc[3] = {0, 0, 0};
stride = (s->nb_components > 1) ? 3 : 1;
memset(cur, 0, s->picture.linesize[0]);
width = s->width * stride;
for(i = 0; i < s->height; i++) {
for(j = 0; j < stride; j++) {
ls_decode_line(state, s, last + j, cur + j, Rc[j], width, stride, j, 8);
Rc[j] = last[j];
if (s->restart_interval && !--s->restart_count) {
align_get_bits(&s->gb);
skip_bits(&s->gb, 16); /* skip RSTn */
}
}
last = cur;
cur += s->picture.linesize[0];
}
} else if(ilv == 2) { /* sample interleaving */
av_log(s->avctx, AV_LOG_ERROR, "Sample interleaved images are not supported.\n");
av_free(state);
av_free(zero);
return -1;
}
if(shift){ /* we need to do point transform or normalize samples */
int x, w;
w = s->width * s->nb_components;
if(s->bits <= 8){
uint8_t *src = s->picture.data[0];
for(i = 0; i < s->height; i++){
for(x = off; x < w; x+= stride){
src[x] <<= shift;
}
src += s->picture.linesize[0];
}
}else{
uint16_t *src = (uint16_t*) s->picture.data[0];
for(i = 0; i < s->height; i++){
for(x = 0; x < w; x++){
src[x] <<= shift;
}
src += s->picture.linesize[0]/2;
}
}
}
av_free(state);
av_free(zero);
return 0;
}
AVCodec ff_jpegls_decoder = {
.name = "jpegls",
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_JPEGLS,
.priv_data_size = sizeof(MJpegDecodeContext),
.init = ff_mjpeg_decode_init,
.close = ff_mjpeg_decode_end,
.decode = ff_mjpeg_decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("JPEG-LS"),
};
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