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/*
* JPEG-LS encoder
* 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 encoder.
*/
#include "avcodec.h"
#include "get_bits.h"
#include "golomb.h"
#include "mathops.h"
#include "dsputil.h"
#include "mjpeg.h"
#include "jpegls.h"
/**
* Encode error from regular symbol
*/
static inline void ls_encode_regular(JLSState *state, PutBitContext *pb, int Q, int err){
int k;
int val;
int map;
for(k = 0; (state->N[Q] << k) < state->A[Q]; k++);
map = !state->near && !k && (2 * state->B[Q] <= -state->N[Q]);
if(err < 0)
err += state->range;
if(err >= ((state->range + 1) >> 1)) {
err -= state->range;
val = 2 * FFABS(err) - 1 - map;
} else
val = 2 * err + map;
set_ur_golomb_jpegls(pb, val, k, state->limit, state->qbpp);
ff_jpegls_update_state_regular(state, Q, err);
}
/**
* Encode error from run termination
*/
static inline void ls_encode_runterm(JLSState *state, PutBitContext *pb, int RItype, int err, int limit_add){
int k;
int val, map;
int Q = 365 + RItype;
int temp;
temp = state->A[Q];
if(RItype)
temp += state->N[Q] >> 1;
for(k = 0; (state->N[Q] << k) < temp; k++);
map = 0;
if(!k && err && (2 * state->B[Q] < state->N[Q]))
map = 1;
if(err < 0)
val = - (2 * err) - 1 - RItype + map;
else
val = 2 * err - RItype - map;
set_ur_golomb_jpegls(pb, val, k, state->limit - limit_add - 1, state->qbpp);
if(err < 0)
state->B[Q]++;
state->A[Q] += (val + 1 - RItype) >> 1;
ff_jpegls_downscale_state(state, Q);
}
/**
* Encode run value as specified by JPEG-LS standard
*/
static inline void ls_encode_run(JLSState *state, PutBitContext *pb, int run, int comp, int trail){
while(run >= (1 << ff_log2_run[state->run_index[comp]])){
put_bits(pb, 1, 1);
run -= 1 << ff_log2_run[state->run_index[comp]];
if(state->run_index[comp] < 31)
state->run_index[comp]++;
}
/* if hit EOL, encode another full run, else encode aborted run */
if(!trail && run) {
put_bits(pb, 1, 1);
}else if(trail){
put_bits(pb, 1, 0);
if(ff_log2_run[state->run_index[comp]])
put_bits(pb, ff_log2_run[state->run_index[comp]], run);
}
}
/**
* Encode one line of image
*/
static inline void ls_encode_line(JLSState *state, PutBitContext *pb, void *last, void *cur, int last2, int w, int stride, int comp, int bits){
int x = 0;
int Ra, Rb, Rc, Rd;
int D0, D1, D2;
while(x < w) {
int err, pred, sign;
/* compute gradients */
Ra = x ? R(cur, 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 RUNval, RItype, run;
run = 0;
RUNval = Ra;
while(x < w && (FFABS(R(cur, x) - RUNval) <= state->near)){
run++;
W(cur, x, Ra);
x += stride;
}
ls_encode_run(state, pb, run, comp, x < w);
if(x >= w)
return;
Rb = R(last, x);
RItype = (FFABS(Ra - Rb) <= state->near);
pred = RItype ? Ra : Rb;
err = R(cur, x) - pred;
if(!RItype && Ra > Rb)
err = -err;
if(state->near){
if(err > 0)
err = (state->near + err) / state->twonear;
else
err = -(state->near - err) / state->twonear;
if(RItype || (Rb >= Ra))
Ra = av_clip(pred + err * state->twonear, 0, state->maxval);
else
Ra = av_clip(pred - err * state->twonear, 0, state->maxval);
W(cur, x, Ra);
}
if(err < 0)
err += state->range;
if(err >= ((state->range + 1) >> 1))
err -= state->range;
ls_encode_runterm(state, pb, RItype, err, ff_log2_run[state->run_index[comp]]);
if(state->run_index[comp] > 0)
state->run_index[comp]--;
} else { /* regular mode */
int context;
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;
pred = av_clip(pred - state->C[context], 0, state->maxval);
err = pred - R(cur, x);
}else{
sign = 0;
pred = av_clip(pred + state->C[context], 0, state->maxval);
err = R(cur, x) - pred;
}
if(state->near){
if(err > 0)
err = (state->near + err) / state->twonear;
else
err = -(state->near - err) / state->twonear;
if(!sign)
Ra = av_clip(pred + err * state->twonear, 0, state->maxval);
else
Ra = av_clip(pred - err * state->twonear, 0, state->maxval);
W(cur, x, Ra);
}
ls_encode_regular(state, pb, context, err);
}
x += stride;
}
}
static void ls_store_lse(JLSState *state, PutBitContext *pb){
/* Test if we have default params and don't need to store LSE */
JLSState state2;
memset(&state2, 0, sizeof(JLSState));
state2.bpp = state->bpp;
state2.near = state->near;
ff_jpegls_reset_coding_parameters(&state2, 1);
if(state->T1 == state2.T1 && state->T2 == state2.T2 && state->T3 == state2.T3 && state->reset == state2.reset)
return;
/* store LSE type 1 */
put_marker(pb, LSE);
put_bits(pb, 16, 13);
put_bits(pb, 8, 1);
put_bits(pb, 16, state->maxval);
put_bits(pb, 16, state->T1);
put_bits(pb, 16, state->T2);
put_bits(pb, 16, state->T3);
put_bits(pb, 16, state->reset);
}
static int encode_picture_ls(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
JpeglsContext * const s = avctx->priv_data;
AVFrame *pict = data;
AVFrame * const p= (AVFrame*)&s->picture;
const int near = avctx->prediction_method;
PutBitContext pb, pb2;
GetBitContext gb;
uint8_t *buf2, *zero, *cur, *last;
JLSState *state;
int i, size;
int comps;
buf2 = av_malloc(buf_size);
init_put_bits(&pb, buf, buf_size);
init_put_bits(&pb2, buf2, buf_size);
*p = *pict;
p->pict_type= FF_I_TYPE;
p->key_frame= 1;
if(avctx->pix_fmt == PIX_FMT_GRAY8 || avctx->pix_fmt == PIX_FMT_GRAY16)
comps = 1;
else
comps = 3;
/* write our own JPEG header, can't use mjpeg_picture_header */
put_marker(&pb, SOI);
put_marker(&pb, SOF48);
put_bits(&pb, 16, 8 + comps * 3); // header size depends on components
put_bits(&pb, 8, (avctx->pix_fmt == PIX_FMT_GRAY16) ? 16 : 8); // bpp
put_bits(&pb, 16, avctx->height);
put_bits(&pb, 16, avctx->width);
put_bits(&pb, 8, comps); // components
for(i = 1; i <= comps; i++) {
put_bits(&pb, 8, i); // component ID
put_bits(&pb, 8, 0x11); // subsampling: none
put_bits(&pb, 8, 0); // Tiq, used by JPEG-LS ext
}
put_marker(&pb, SOS);
put_bits(&pb, 16, 6 + comps * 2);
put_bits(&pb, 8, comps);
for(i = 1; i <= comps; i++) {
put_bits(&pb, 8, i); // component ID
put_bits(&pb, 8, 0); // mapping index: none
}
put_bits(&pb, 8, near);
put_bits(&pb, 8, (comps > 1) ? 1 : 0); // interleaving: 0 - plane, 1 - line
put_bits(&pb, 8, 0); // point transform: none
state = av_mallocz(sizeof(JLSState));
/* initialize JPEG-LS state from JPEG parameters */
state->near = near;
state->bpp = (avctx->pix_fmt == PIX_FMT_GRAY16) ? 16 : 8;
ff_jpegls_reset_coding_parameters(state, 0);
ff_jpegls_init_state(state);
ls_store_lse(state, &pb);
zero = av_mallocz(p->linesize[0]);
last = zero;
cur = p->data[0];
if(avctx->pix_fmt == PIX_FMT_GRAY8){
int t = 0;
for(i = 0; i < avctx->height; i++) {
ls_encode_line(state, &pb2, last, cur, t, avctx->width, 1, 0, 8);
t = last[0];
last = cur;
cur += p->linesize[0];
}
}else if(avctx->pix_fmt == PIX_FMT_GRAY16){
int t = 0;
for(i = 0; i < avctx->height; i++) {
ls_encode_line(state, &pb2, last, cur, t, avctx->width, 1, 0, 16);
t = *((uint16_t*)last);
last = cur;
cur += p->linesize[0];
}
}else if(avctx->pix_fmt == PIX_FMT_RGB24){
int j, width;
int Rc[3] = {0, 0, 0};
width = avctx->width * 3;
for(i = 0; i < avctx->height; i++) {
for(j = 0; j < 3; j++) {
ls_encode_line(state, &pb2, last + j, cur + j, Rc[j], width, 3, j, 8);
Rc[j] = last[j];
}
last = cur;
cur += s->picture.linesize[0];
}
}else if(avctx->pix_fmt == PIX_FMT_BGR24){
int j, width;
int Rc[3] = {0, 0, 0};
width = avctx->width * 3;
for(i = 0; i < avctx->height; i++) {
for(j = 2; j >= 0; j--) {
ls_encode_line(state, &pb2, last + j, cur + j, Rc[j], width, 3, j, 8);
Rc[j] = last[j];
}
last = cur;
cur += s->picture.linesize[0];
}
}
av_free(zero);
av_free(state);
// the specification says that after doing 0xff escaping unused bits in the
// last byte must be set to 0, so just append 7 "optional" zero-bits to
// avoid special-casing.
put_bits(&pb2, 7, 0);
size = put_bits_count(&pb2);
flush_put_bits(&pb2);
/* do escape coding */
init_get_bits(&gb, buf2, size);
size -= 7;
while(get_bits_count(&gb) < size){
int v;
v = get_bits(&gb, 8);
put_bits(&pb, 8, v);
if(v == 0xFF){
v = get_bits(&gb, 7);
put_bits(&pb, 8, v);
}
}
align_put_bits(&pb);
av_free(buf2);
/* End of image */
put_marker(&pb, EOI);
flush_put_bits(&pb);
emms_c();
return put_bits_count(&pb) >> 3;
}
static av_cold int encode_init_ls(AVCodecContext *ctx) {
JpeglsContext *c = (JpeglsContext*)ctx->priv_data;
c->avctx = ctx;
ctx->coded_frame = &c->picture;
if(ctx->pix_fmt != PIX_FMT_GRAY8 && ctx->pix_fmt != PIX_FMT_GRAY16 && ctx->pix_fmt != PIX_FMT_RGB24 && ctx->pix_fmt != PIX_FMT_BGR24){
av_log(ctx, AV_LOG_ERROR, "Only grayscale and RGB24/BGR24 images are supported\n");
return -1;
}
return 0;
}
AVCodec jpegls_encoder = { //FIXME avoid MPV_* lossless JPEG should not need them
"jpegls",
AVMEDIA_TYPE_VIDEO,
CODEC_ID_JPEGLS,
sizeof(JpeglsContext),
encode_init_ls,
encode_picture_ls,
NULL,
.pix_fmts= (const enum PixelFormat[]){PIX_FMT_BGR24, PIX_FMT_RGB24, PIX_FMT_GRAY8, PIX_FMT_GRAY16, PIX_FMT_NONE},
.long_name= NULL_IF_CONFIG_SMALL("JPEG-LS"),
};
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