/*
  * 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 "internal.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 = { 0 };

     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, AVPacket *pkt,
                              const AVFrame *pict, int *got_packet)
 {

     JpeglsContext * const s = avctx->priv_data;

     AVFrame * const p = &s->picture;

     const int near = avctx->prediction_method;
     PutBitContext pb, pb2;
     GetBitContext gb;
     uint8_t *buf2, *zero, *cur, *last;
     JLSState *state;

     int i, size, ret;

     int comps;
 
     *p = *pict;

     p->pict_type= AV_PICTURE_TYPE_I;

     p->key_frame= 1;
 

     if(avctx->pix_fmt == AV_PIX_FMT_GRAY8 || avctx->pix_fmt == AV_PIX_FMT_GRAY16)

         comps = 1;
     else
         comps = 3;
 

     if ((ret = ff_alloc_packet2(avctx, pkt, avctx->width*avctx->height*comps*4 +

                                     FF_MIN_BUFFER_SIZE)) < 0)

         return ret;
 
     buf2 = av_malloc(pkt->size);
 
     init_put_bits(&pb, pkt->data, pkt->size);
     init_put_bits(&pb2, buf2, pkt->size);
 

     /* 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 == AV_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 == AV_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(FFABS(p->linesize[0]));

     if (!zero) {
         av_free(state);

         return AVERROR(ENOMEM);

     }

     last = zero;
     cur = p->data[0];

     if(avctx->pix_fmt == AV_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 == AV_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 == AV_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 == AV_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_freep(&zero);
     av_freep(&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);
         }
     }

     avpriv_align_put_bits(&pb);

     av_free(buf2);
 
     /* End of image */
     put_marker(&pb, EOI);
     flush_put_bits(&pb);
 
     emms_c();
 

     pkt->size   = put_bits_count(&pb) >> 3;
     pkt->flags |= AV_PKT_FLAG_KEY;
     *got_packet = 1;
     return 0;

 }
 

 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 != AV_PIX_FMT_GRAY8 && ctx->pix_fmt != AV_PIX_FMT_GRAY16 && ctx->pix_fmt != AV_PIX_FMT_RGB24 && ctx->pix_fmt != AV_PIX_FMT_BGR24){

         av_log(ctx, AV_LOG_ERROR, "Only grayscale and RGB24/BGR24 images are supported\n");
         return -1;
     }
     return 0;
 }
 

 AVCodec ff_jpegls_encoder = {

     .name           = "jpegls",
     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_JPEGLS,

     .priv_data_size = sizeof(JpeglsContext),
     .init           = encode_init_ls,

     .encode2        = encode_picture_ls,

     .pix_fmts       = (const enum AVPixelFormat[]){
         AV_PIX_FMT_BGR24, AV_PIX_FMT_RGB24, AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY16,
         AV_PIX_FMT_NONE

     },

     .long_name      = NULL_IF_CONFIG_SMALL("JPEG-LS"),

 };