/*
  * 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 "libavutil/frame.h"
 #include "libavutil/mem.h"
 #include "libavutil/pixdesc.h"
 

 #include "avcodec.h"

 #include "idctdsp.h"

 #include "internal.h"

 #include "mjpegenc_common.h"

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

 typedef struct LJpegEncContext {

     IDCTDSPContext idsp;

     ScanTable scantable;
     uint16_t matrix[64];
 
     int vsample[3];
     int hsample[3];
 
     uint16_t huff_code_dc_luminance[12];
     uint16_t huff_code_dc_chrominance[12];
     uint8_t  huff_size_dc_luminance[12];
     uint8_t  huff_size_dc_chrominance[12];
 
     uint16_t (*scratch)[4];
 } LJpegEncContext;

 static int ljpeg_encode_bgr(AVCodecContext *avctx, PutBitContext *pb,
                             const AVFrame *frame)
 {
     LJpegEncContext *s    = avctx->priv_data;
     const int width       = frame->width;
     const int height      = frame->height;
     const int linesize    = frame->linesize[0];
     uint16_t (*buffer)[4] = s->scratch;
     const int predictor   = avctx->prediction_method+1;
     int left[3], top[3], topleft[3];
     int x, y, i;
 
     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 = frame->data[0] + (linesize * y);
 

         if (pb->buf_end - pb->buf - (put_bits_count(pb) >> 3) < width * 3 * 4) {

             av_log(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(pb, diff, s->huff_size_dc_luminance, s->huff_code_dc_luminance); //FIXME ugly
                 else
                     ff_mjpeg_encode_dc(pb, diff, s->huff_size_dc_chrominance, s->huff_code_dc_chrominance);
             }
         }
     }
 
     return 0;
 }
 

 static inline void ljpeg_encode_yuv_mb(LJpegEncContext *s, PutBitContext *pb,
                                        const AVFrame *frame, int predictor,
                                        int mb_x, int mb_y)
 {
     int i;
 
     if (mb_x == 0 || mb_y == 0) {
         for (i = 0; i < 3; i++) {
             uint8_t *ptr;
             int x, y, h, v, linesize;
             h = s->hsample[i];
             v = s->vsample[i];
             linesize = frame->linesize[i];
 
             for (y = 0; y < v; y++) {
                 for (x = 0; x < h; x++) {
                     int pred;
 
                     ptr = frame->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(pb, *ptr - pred, s->huff_size_dc_luminance, s->huff_code_dc_luminance); //FIXME ugly
                     else
                         ff_mjpeg_encode_dc(pb, *ptr - pred, s->huff_size_dc_chrominance, s->huff_code_dc_chrominance);
                 }
             }
         }
     } else {
         for (i = 0; i < 3; i++) {
             uint8_t *ptr;
             int x, y, h, v, linesize;
             h = s->hsample[i];
             v = s->vsample[i];
             linesize = frame->linesize[i];
 
             for (y = 0; y < v; y++) {
                 for (x = 0; x < h; x++) {
                     int pred;
 
                     ptr = frame->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(pb, *ptr - pred, s->huff_size_dc_luminance, s->huff_code_dc_luminance); //FIXME ugly
                     else
                         ff_mjpeg_encode_dc(pb, *ptr - pred, s->huff_size_dc_chrominance, s->huff_code_dc_chrominance);
                 }
             }
         }
     }
 }
 
 static int ljpeg_encode_yuv(AVCodecContext *avctx, PutBitContext *pb,
                             const AVFrame *frame)
 {
     const int predictor = avctx->prediction_method + 1;
     LJpegEncContext *s  = avctx->priv_data;
     const int mb_width  = (avctx->width  + s->hsample[0] - 1) / s->hsample[0];
     const int mb_height = (avctx->height + s->vsample[0] - 1) / s->vsample[0];
     int mb_x, mb_y;
 
     for (mb_y = 0; mb_y < mb_height; mb_y++) {
         if (pb->buf_end - pb->buf - (put_bits_count(pb) >> 3) <
             mb_width * 4 * 3 * s->hsample[0] * s->vsample[0]) {
             av_log(avctx, AV_LOG_ERROR, "encoded frame too large\n");
             return -1;
         }
 
         for (mb_x = 0; mb_x < mb_width; mb_x++)
             ljpeg_encode_yuv_mb(s, pb, frame, predictor, mb_x, mb_y);
     }
 
     return 0;
 }
 

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

 {

     LJpegEncContext *s = avctx->priv_data;
     PutBitContext pb;
     const int width  = avctx->width;
     const int height = avctx->height;
     const int mb_width  = (width  + s->hsample[0] - 1) / s->hsample[0];
     const int mb_height = (height + s->vsample[0] - 1) / s->vsample[0];
     int max_pkt_size = FF_MIN_BUFFER_SIZE;
     int ret, header_bits;

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

         max_pkt_size += width * height * 3 * 4;
     else {
         max_pkt_size += mb_width * mb_height * 3 * 4

                         * s->hsample[0] * s->vsample[0];

     }
 

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

         return ret;

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

     ff_mjpeg_encode_picture_header(avctx, &pb, &s->scantable,

                                    s->matrix, s->matrix);

     header_bits = put_bits_count(&pb);

     if(    avctx->pix_fmt == AV_PIX_FMT_BGR0

         || avctx->pix_fmt == AV_PIX_FMT_BGRA

         || avctx->pix_fmt == AV_PIX_FMT_BGR24)

         ret = ljpeg_encode_bgr(avctx, &pb, pict);

     else
         ret = ljpeg_encode_yuv(avctx, &pb, pict);
     if (ret < 0)
         return ret;

 
     emms_c();
 

     ff_mjpeg_escape_FF(&pb, header_bits >> 3);

     ff_mjpeg_encode_picture_trailer(&pb, header_bits);

     flush_put_bits(&pb);
     pkt->size   = put_bits_ptr(&pb) - pb.buf;

     pkt->flags |= AV_PKT_FLAG_KEY;
     *got_packet = 1;
 
     return 0;

 }
 

 static av_cold int ljpeg_encode_close(AVCodecContext *avctx)
 {
     LJpegEncContext *s = avctx->priv_data;
 
     av_frame_free(&avctx->coded_frame);
     av_freep(&s->scratch);
 
     return 0;
 }
 
 static av_cold int ljpeg_encode_init(AVCodecContext *avctx)
 {
     LJpegEncContext *s = avctx->priv_data;
 
     if ((avctx->pix_fmt == AV_PIX_FMT_YUV420P ||
          avctx->pix_fmt == AV_PIX_FMT_YUV422P ||

          avctx->pix_fmt == AV_PIX_FMT_YUV444P ||
          avctx->color_range == AVCOL_RANGE_MPEG) &&

         avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) {
         av_log(avctx, AV_LOG_ERROR,
                "Limited range YUV is non-standard, set strict_std_compliance to "
                "at least unofficial to use it.\n");
         return AVERROR(EINVAL);
     }
 
     avctx->coded_frame = av_frame_alloc();
     if (!avctx->coded_frame)
         return AVERROR(ENOMEM);
 
     avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
     avctx->coded_frame->key_frame = 1;
 
     s->scratch = av_malloc_array(avctx->width + 1, sizeof(*s->scratch));
 

     ff_idctdsp_init(&s->idsp, avctx);
     ff_init_scantable(s->idsp.idct_permutation, &s->scantable,
                       ff_zigzag_direct);

     ff_mjpeg_init_hvsample(avctx, s->hsample, s->vsample);

 
     ff_mjpeg_build_huffman_codes(s->huff_size_dc_luminance,
                                  s->huff_code_dc_luminance,
                                  avpriv_mjpeg_bits_dc_luminance,
                                  avpriv_mjpeg_val_dc);
     ff_mjpeg_build_huffman_codes(s->huff_size_dc_chrominance,
                                  s->huff_code_dc_chrominance,
                                  avpriv_mjpeg_bits_dc_chrominance,
                                  avpriv_mjpeg_val_dc);
 
     return 0;
 }

 AVCodec ff_ljpeg_encoder = {

     .name           = "ljpeg",

     .long_name      = NULL_IF_CONFIG_SMALL("Lossless JPEG"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_LJPEG,

     .priv_data_size = sizeof(LJpegEncContext),
     .init           = ljpeg_encode_init,

     .encode2        = ljpeg_encode_frame,

     .close          = ljpeg_encode_close,

     .capabilities   = CODEC_CAP_FRAME_THREADS | CODEC_CAP_INTRA_ONLY,

     .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},

 };