/*
  * 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
  */
 
 #include "bytestream.h"
 #include "h2645_parse.h"

 #include "hevc.h"

 #include "hevc_parse.h"
 
 static int hevc_decode_nal_units(const uint8_t *buf, int buf_size, HEVCParamSets *ps,

                                  HEVCSEIContext *sei, int is_nalff, int nal_length_size,
                                  int err_recognition, int apply_defdispwin, void *logctx)

 {
     int i;
     int ret = 0;
     H2645Packet pkt = { 0 };
 
     ret = ff_h2645_packet_split(&pkt, buf, buf_size, logctx, is_nalff, nal_length_size, AV_CODEC_ID_HEVC, 1);
     if (ret < 0) {
         goto done;
     }
 
     for (i = 0; i < pkt.nb_nals; i++) {
         H2645NAL *nal = &pkt.nals[i];
 
         /* ignore everything except parameter sets and VCL NALUs */
         switch (nal->type) {

         case HEVC_NAL_VPS:
             ret = ff_hevc_decode_nal_vps(&nal->gb, logctx, ps);
             if (ret < 0)
                 goto done;
             break;
         case HEVC_NAL_SPS:

             ret = ff_hevc_decode_nal_sps(&nal->gb, logctx, ps, apply_defdispwin);

             if (ret < 0)
                 goto done;
             break;
         case HEVC_NAL_PPS:
             ret = ff_hevc_decode_nal_pps(&nal->gb, logctx, ps);
             if (ret < 0)
                 goto done;
             break;

         case HEVC_NAL_SEI_PREFIX:
         case HEVC_NAL_SEI_SUFFIX:
             ret = ff_hevc_decode_nal_sei(&nal->gb, logctx, sei, ps, nal->type);
             if (ret < 0)
                 goto done;
             break;

         default:
             av_log(logctx, AV_LOG_VERBOSE, "Ignoring NAL type %d in extradata\n", nal->type);

             break;
         }
     }
 
 done:
     ff_h2645_packet_uninit(&pkt);

     if (err_recognition & AV_EF_EXPLODE)
         return ret;
 
     return 0;

 }
 
 int ff_hevc_decode_extradata(const uint8_t *data, int size, HEVCParamSets *ps,

                              HEVCSEIContext *sei, int *is_nalff, int *nal_length_size,
                              int err_recognition, int apply_defdispwin, void *logctx)

 {
     int ret = 0;
     GetByteContext gb;
 
     bytestream2_init(&gb, data, size);
 
     if (size > 3 && (data[0] || data[1] || data[2] > 1)) {
         /* It seems the extradata is encoded as hvcC format.
          * Temporarily, we support configurationVersion==0 until 14496-15 3rd
          * is finalized. When finalized, configurationVersion will be 1 and we
          * can recognize hvcC by checking if avctx->extradata[0]==1 or not. */
         int i, j, num_arrays, nal_len_size;
 
         *is_nalff = 1;
 
         bytestream2_skip(&gb, 21);
         nal_len_size = (bytestream2_get_byte(&gb) & 3) + 1;
         num_arrays   = bytestream2_get_byte(&gb);
 
         /* nal units in the hvcC always have length coded with 2 bytes,
          * so put a fake nal_length_size = 2 while parsing them */
         *nal_length_size = 2;
 
         /* Decode nal units from hvcC. */
         for (i = 0; i < num_arrays; i++) {
             int type = bytestream2_get_byte(&gb) & 0x3f;
             int cnt  = bytestream2_get_be16(&gb);
 
             for (j = 0; j < cnt; j++) {
                 // +2 for the nal size field
                 int nalsize = bytestream2_peek_be16(&gb) + 2;
                 if (bytestream2_get_bytes_left(&gb) < nalsize) {
                     av_log(logctx, AV_LOG_ERROR,
                            "Invalid NAL unit size in extradata.\n");
                     return AVERROR_INVALIDDATA;
                 }
 

                 ret = hevc_decode_nal_units(gb.buffer, nalsize, ps, sei, *is_nalff,
                                             *nal_length_size, err_recognition, apply_defdispwin,
                                             logctx);

                 if (ret < 0) {
                     av_log(logctx, AV_LOG_ERROR,
                            "Decoding nal unit %d %d from hvcC failed\n",
                            type, i);
                     return ret;
                 }
                 bytestream2_skip(&gb, nalsize);
             }
         }
 
         /* Now store right nal length size, that will be used to parse
          * all other nals */
         *nal_length_size = nal_len_size;
     } else {
         *is_nalff = 0;

         ret = hevc_decode_nal_units(data, size, ps, sei, *is_nalff, *nal_length_size,

                                     err_recognition, apply_defdispwin, logctx);

         if (ret < 0)
             return ret;
     }
 
     return ret;
 }