/*
  * DVD navigation block parser for FFmpeg
  * Copyright (c) 2013 The FFmpeg Project
  *
  * 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 "avcodec.h"
 #include "get_bits.h"
 #include "parser.h"
 
 #define PCI_SIZE  980
 #define DSI_SIZE 1018
 
 /* parser definition */
 typedef struct DVDNavParseContext {
     uint32_t     lba;
     uint8_t      buffer[PCI_SIZE+DSI_SIZE];
     int          copied;
 } DVDNavParseContext;
 
 static av_cold int dvd_nav_parse_init(AVCodecParserContext *s)
 {
     DVDNavParseContext *pc = s->priv_data;
 
     pc->lba    = 0xFFFFFFFF;
     pc->copied = 0;
     return 0;
 }
 
 static int dvd_nav_parse(AVCodecParserContext *s,
                          AVCodecContext *avctx,
                          const uint8_t **poutbuf, int *poutbuf_size,
                          const uint8_t *buf, int buf_size)
 {
     DVDNavParseContext *pc1 = s->priv_data;
     int lastPacket          = 0;
     int valid               = 0;
 
     s->pict_type = AV_PICTURE_TYPE_NONE;
 
     avctx->time_base.num = 1;
     avctx->time_base.den = 90000;
 
     if (buf && buf_size) {
         switch(buf[0]) {
             case 0x00:
                 if (buf_size == PCI_SIZE) {
                     /* PCI */
                     uint32_t lba      = AV_RB32(&buf[0x01]);
                     uint32_t startpts = AV_RB32(&buf[0x0D]);
                     uint32_t endpts   = AV_RB32(&buf[0x11]);
 
                     if (endpts > startpts) {
                         pc1->lba    = lba;
                         s->pts      = (int64_t)startpts;
                         s->duration = endpts - startpts;
 
                         memcpy(pc1->buffer, buf, PCI_SIZE);
                         pc1->copied = PCI_SIZE;
                         valid       = 1;
                     }
                 }
                 break;
 
             case 0x01:
                 if ((buf_size == DSI_SIZE) && (pc1->copied == PCI_SIZE)) {
                     /* DSI */
                     uint32_t lba = AV_RB32(&buf[0x05]);
 
                     if (lba == pc1->lba) {
                         memcpy(pc1->buffer + pc1->copied, buf, DSI_SIZE);
                         lastPacket  = 1;
                         valid       = 1;
                     }
                 }
                 break;
         }
     }
 
     if (!valid || lastPacket) {
         pc1->copied = 0;
         pc1->lba    = 0xFFFFFFFF;
     }
 
     if (lastPacket) {
         *poutbuf      = pc1->buffer;
         *poutbuf_size = sizeof(pc1->buffer);
     } else {
         *poutbuf      = NULL;
         *poutbuf_size = 0;
     }
 
     return buf_size;
 }
 
 AVCodecParser ff_dvd_nav_parser = {
     .codec_ids      = { AV_CODEC_ID_DVD_NAV },
     .priv_data_size = sizeof(DVDNavParseContext),
     .parser_init    = dvd_nav_parse_init,
     .parser_parse   = dvd_nav_parse,
 };