/*
  * JPEG 2000 decoding support via OpenJPEG
  * Copyright (c) 2009 Jaikrishnan Menon <realityman@gmx.net>
  *
  * 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 2000 decoder using libopenjpeg
 */
 

 #include "libavutil/imgutils.h"

 #include "avcodec.h"
 #include "libavutil/intreadwrite.h"
 #define  OPJ_STATIC

 #include <openjpeg.h>

 
 #define JP2_SIG_TYPE    0x6A502020
 #define JP2_SIG_VALUE   0x0D0A870A
 
 typedef struct {
     opj_dparameters_t dec_params;
     AVFrame image;
 } LibOpenJPEGContext;
 
 static int check_image_attributes(opj_image_t *image)
 {

     return image->comps[0].dx == image->comps[1].dx &&

            image->comps[1].dx == image->comps[2].dx &&
            image->comps[0].dy == image->comps[1].dy &&
            image->comps[1].dy == image->comps[2].dy &&
            image->comps[0].prec == image->comps[1].prec &&

            image->comps[1].prec == image->comps[2].prec;

 }
 
 static av_cold int libopenjpeg_decode_init(AVCodecContext *avctx)
 {
     LibOpenJPEGContext *ctx = avctx->priv_data;
 
     opj_set_default_decoder_parameters(&ctx->dec_params);

     avcodec_get_frame_defaults(&ctx->image);

     avctx->coded_frame = &ctx->image;
     return 0;
 }
 
 static int libopenjpeg_decode_frame(AVCodecContext *avctx,
                                     void *data, int *data_size,

                                     AVPacket *avpkt)

 {

     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;

     LibOpenJPEGContext *ctx = avctx->priv_data;
     AVFrame *picture = &ctx->image, *output = data;
     opj_dinfo_t *dec;
     opj_cio_t *stream;
     opj_image_t *image;
     int width, height, has_alpha = 0, ret = -1;
     int x, y, index;
     uint8_t *img_ptr;
     int adjust[4];
 
     *data_size = 0;
 
     // Check if input is a raw jpeg2k codestream or in jp2 wrapping
     if((AV_RB32(buf) == 12) &&
        (AV_RB32(buf + 4) == JP2_SIG_TYPE) &&
        (AV_RB32(buf + 8) == JP2_SIG_VALUE)) {

         dec = opj_create_decompress(CODEC_JP2);

     } else {

         // If the AVPacket contains a jp2c box, then skip to
         // the starting byte of the codestream.
         if (AV_RB32(buf + 4) == AV_RB32("jp2c"))
             buf += 8;

         dec = opj_create_decompress(CODEC_J2K);

     }
 
     if(!dec) {
         av_log(avctx, AV_LOG_ERROR, "Error initializing decoder.\n");
         return -1;
     }
     opj_set_event_mgr((opj_common_ptr)dec, NULL, NULL);
 

     ctx->dec_params.cp_reduce = avctx->lowres;

     // Tie decoder with decoding parameters
     opj_setup_decoder(dec, &ctx->dec_params);
     stream = opj_cio_open((opj_common_ptr)dec, buf, buf_size);
     if(!stream) {
         av_log(avctx, AV_LOG_ERROR, "Codestream could not be opened for reading.\n");
         opj_destroy_decompress(dec);
         return -1;
     }
 
     // Decode the codestream
     image = opj_decode_with_info(dec, stream, NULL);
     opj_cio_close(stream);
     if(!image) {
         av_log(avctx, AV_LOG_ERROR, "Error decoding codestream.\n");
         opj_destroy_decompress(dec);
         return -1;
     }

     width  = image->comps[0].w << avctx->lowres;
     height = image->comps[0].h << avctx->lowres;

     if(av_image_check_size(width, height, 0, avctx) < 0) {

         av_log(avctx, AV_LOG_ERROR, "%dx%d dimension invalid.\n", width, height);
         goto done;
     }
     avcodec_set_dimensions(avctx, width, height);
 
     switch(image->numcomps)
     {
         case 1:  avctx->pix_fmt = PIX_FMT_GRAY8;
                  break;
         case 3:  if(check_image_attributes(image)) {
                      avctx->pix_fmt = PIX_FMT_RGB24;
                  } else {
                      avctx->pix_fmt = PIX_FMT_GRAY8;
                      av_log(avctx, AV_LOG_ERROR, "Only first component will be used.\n");
                  }
                  break;
         case 4:  has_alpha = 1;

                  avctx->pix_fmt = PIX_FMT_RGBA;

                  break;
         default: av_log(avctx, AV_LOG_ERROR, "%d components unsupported.\n", image->numcomps);
                  goto done;
     }
 
     if(picture->data[0])
         avctx->release_buffer(avctx, picture);
 
     if(avctx->get_buffer(avctx, picture) < 0) {
         av_log(avctx, AV_LOG_ERROR, "Couldn't allocate image buffer.\n");
         return -1;
     }
 
     for(x = 0; x < image->numcomps; x++) {
         adjust[x] = FFMAX(image->comps[x].prec - 8, 0);
     }
 

     for(y = 0; y < avctx->height; y++) {
         index = y*avctx->width;

         img_ptr = picture->data[0] + y*picture->linesize[0];

         for(x = 0; x < avctx->width; x++, index++) {

             *img_ptr++ = image->comps[0].data[index] >> adjust[0];
             if(image->numcomps > 2 && check_image_attributes(image)) {
                 *img_ptr++ = image->comps[1].data[index] >> adjust[1];
                 *img_ptr++ = image->comps[2].data[index] >> adjust[2];
                 if(has_alpha)
                     *img_ptr++ = image->comps[3].data[index] >> adjust[3];
             }
         }
     }
 
     *output    = ctx->image;
     *data_size = sizeof(AVPicture);
     ret = buf_size;
 
 done:
     opj_image_destroy(image);
     opj_destroy_decompress(dec);
     return ret;
 }
 
 static av_cold int libopenjpeg_decode_close(AVCodecContext *avctx)
 {
     LibOpenJPEGContext *ctx = avctx->priv_data;
 
     if(ctx->image.data[0])
         avctx->release_buffer(avctx, &ctx->image);
     return 0 ;
 }
 
 

 AVCodec ff_libopenjpeg_decoder = {

     "libopenjpeg",

     AVMEDIA_TYPE_VIDEO,

     CODEC_ID_JPEG2000,
     sizeof(LibOpenJPEGContext),
     libopenjpeg_decode_init,
     NULL,
     libopenjpeg_decode_close,
     libopenjpeg_decode_frame,

     CODEC_CAP_DR1,

     .max_lowres = 5,

     .long_name = NULL_IF_CONFIG_SMALL("OpenJPEG based JPEG 2000 decoder"),
 } ;