/*
  * lossless JPEG encoder

  * Copyright (c) 2000, 2001 Fabrice Bellard

  * Copyright (c) 2003 Alex Beregszaszi
  * Copyright (c) 2003-2004 Michael Niedermayer
  *

  * Support for external huffman table, various fixes (AVID workaround),
  * aspecting, new decode_frame mechanism and apple mjpeg-b support
  *                                  by Alex Beregszaszi
  *

  * 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

  * lossless JPEG encoder.
  */
 
 #include "avcodec.h"
 #include "dsputil.h"

 #include "internal.h"

 #include "mpegvideo.h"
 #include "mjpeg.h"
 #include "mjpegenc.h"
 
 

 static int encode_picture_lossless(AVCodecContext *avctx, AVPacket *pkt,
                                    const AVFrame *pict, int *got_packet)
 {

     MpegEncContext * const s = avctx->priv_data;
     MJpegContext * const m = s->mjpeg_ctx;
     const int width= s->width;
     const int height= s->height;

     AVFrame * const p = &s->current_picture.f;

     const int predictor= avctx->prediction_method+1;

     const int mb_width  = (width  + s->mjpeg_hsample[0] - 1) / s->mjpeg_hsample[0];
     const int mb_height = (height + s->mjpeg_vsample[0] - 1) / s->mjpeg_vsample[0];
     int ret, max_pkt_size = FF_MIN_BUFFER_SIZE;
 

     if (avctx->pix_fmt == AV_PIX_FMT_BGRA)

         max_pkt_size += width * height * 3 * 4;
     else {
         max_pkt_size += mb_width * mb_height * 3 * 4
                         * s->mjpeg_hsample[0] * s->mjpeg_vsample[0];
     }

 
     if (!s->edge_emu_buffer &&
         (ret = ff_mpv_frame_size_alloc(s, pict->linesize[0])) < 0) {
         av_log(avctx, AV_LOG_ERROR, "failed to allocate context scratch buffers.\n");
         return ret;
     }
 

     if ((ret = ff_alloc_packet2(avctx, pkt, max_pkt_size)) < 0)

         return ret;

     init_put_bits(&s->pb, pkt->data, pkt->size);

 
     *p = *pict;

     p->pict_type= AV_PICTURE_TYPE_I;

     p->key_frame= 1;
 

     ff_mjpeg_encode_picture_header(s);

 
     s->header_bits= put_bits_count(&s->pb);
 

     if(avctx->pix_fmt == AV_PIX_FMT_BGR0
         || avctx->pix_fmt == AV_PIX_FMT_BGRA
         || avctx->pix_fmt == AV_PIX_FMT_BGR24){

         int x, y, i;
         const int linesize= p->linesize[0];
         uint16_t (*buffer)[4]= (void *) s->rd_scratchpad;
         int left[3], top[3], topleft[3];
 
         for(i=0; i<3; i++){
             buffer[0][i]= 1 << (9 - 1);
         }
 
         for(y = 0; y < height; y++) {
             const int modified_predictor= y ? predictor : 1;
             uint8_t *ptr = p->data[0] + (linesize * y);
 
             if(s->pb.buf_end - s->pb.buf - (put_bits_count(&s->pb)>>3) < width*3*4){
                 av_log(s->avctx, AV_LOG_ERROR, "encoded frame too large\n");
                 return -1;
             }
 
             for(i=0; i<3; i++){
                 top[i]= left[i]= topleft[i]= buffer[0][i];
             }
             for(x = 0; x < width; x++) {

                 if(avctx->pix_fmt == AV_PIX_FMT_BGR24){

                     buffer[x][1] = ptr[3*x+0] - ptr[3*x+1] + 0x100;
                     buffer[x][2] = ptr[3*x+2] - ptr[3*x+1] + 0x100;
                     buffer[x][0] = (ptr[3*x+0] + 2*ptr[3*x+1] + ptr[3*x+2])>>2;
                 }else{

                 buffer[x][1] = ptr[4*x+0] - ptr[4*x+1] + 0x100;
                 buffer[x][2] = ptr[4*x+2] - ptr[4*x+1] + 0x100;
                 buffer[x][0] = (ptr[4*x+0] + 2*ptr[4*x+1] + ptr[4*x+2])>>2;

                 }

 
                 for(i=0;i<3;i++) {
                     int pred, diff;
 
                     PREDICT(pred, topleft[i], top[i], left[i], modified_predictor);
 
                     topleft[i]= top[i];
                     top[i]= buffer[x+1][i];
 
                     left[i]= buffer[x][i];
 
                     diff= ((left[i] - pred + 0x100)&0x1FF) - 0x100;
 
                     if(i==0)

                         ff_mjpeg_encode_dc(s, diff, m->huff_size_dc_luminance, m->huff_code_dc_luminance); //FIXME ugly

                     else

                         ff_mjpeg_encode_dc(s, diff, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);

                 }
             }
         }
     }else{
         int mb_x, mb_y, i;
 
         for(mb_y = 0; mb_y < mb_height; mb_y++) {
             if(s->pb.buf_end - s->pb.buf - (put_bits_count(&s->pb)>>3) < mb_width * 4 * 3 * s->mjpeg_hsample[0] * s->mjpeg_vsample[0]){
                 av_log(s->avctx, AV_LOG_ERROR, "encoded frame too large\n");
                 return -1;
             }
             for(mb_x = 0; mb_x < mb_width; mb_x++) {
                 if(mb_x==0 || mb_y==0){
                     for(i=0;i<3;i++) {
                         uint8_t *ptr;
                         int x, y, h, v, linesize;
                         h = s->mjpeg_hsample[i];
                         v = s->mjpeg_vsample[i];
                         linesize= p->linesize[i];
 
                         for(y=0; y<v; y++){
                             for(x=0; x<h; x++){
                                 int pred;
 
                                 ptr = p->data[i] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap
                                 if(y==0 && mb_y==0){
                                     if(x==0 && mb_x==0){
                                         pred= 128;
                                     }else{
                                         pred= ptr[-1];
                                     }
                                 }else{
                                     if(x==0 && mb_x==0){
                                         pred= ptr[-linesize];
                                     }else{
                                         PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);
                                     }
                                 }
 
                                 if(i==0)

                                     ff_mjpeg_encode_dc(s, *ptr - pred, m->huff_size_dc_luminance, m->huff_code_dc_luminance); //FIXME ugly

                                 else

                                     ff_mjpeg_encode_dc(s, *ptr - pred, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);

                             }
                         }
                     }
                 }else{
                     for(i=0;i<3;i++) {
                         uint8_t *ptr;
                         int x, y, h, v, linesize;
                         h = s->mjpeg_hsample[i];
                         v = s->mjpeg_vsample[i];
                         linesize= p->linesize[i];
 
                         for(y=0; y<v; y++){
                             for(x=0; x<h; x++){
                                 int pred;
 
                                 ptr = p->data[i] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap
                                 PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);
 
                                 if(i==0)

                                     ff_mjpeg_encode_dc(s, *ptr - pred, m->huff_size_dc_luminance, m->huff_code_dc_luminance); //FIXME ugly

                                 else

                                     ff_mjpeg_encode_dc(s, *ptr - pred, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);

                             }
                         }
                     }
                 }
             }
         }
     }
 
     emms_c();

     av_assert0(s->esc_pos == s->header_bits >> 3);
     ff_mjpeg_encode_stuffing(s);

     ff_mjpeg_encode_picture_trailer(s);

     s->picture_number++;
 
     flush_put_bits(&s->pb);

     pkt->size   = put_bits_ptr(&s->pb) - s->pb.buf;
     pkt->flags |= AV_PKT_FLAG_KEY;
     *got_packet = 1;
 
     return 0;

 //    return (put_bits_count(&f->pb)+7)/8;
 }
 
 

 AVCodec ff_ljpeg_encoder = { //FIXME avoid MPV_* lossless JPEG should not need them

     .name           = "ljpeg",
     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_LJPEG,

     .priv_data_size = sizeof(MpegEncContext),

     .init           = ff_MPV_encode_init,

     .encode2        = encode_picture_lossless,

     .close          = ff_MPV_encode_end,

     .pix_fmts       = (const enum AVPixelFormat[]){
         AV_PIX_FMT_BGR24, AV_PIX_FMT_BGRA, AV_PIX_FMT_BGR0,
         AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ422P,
         AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P,
         AV_PIX_FMT_NONE},

     .long_name      = NULL_IF_CONFIG_SMALL("Lossless JPEG"),

 };