/*
  * DXA demuxer

  * Copyright (c) 2007 Konstantin Shishkov

  *
  * 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 <inttypes.h>
 

 #include "libavutil/intreadwrite.h"

 #include "avformat.h"

 #include "internal.h"

 #include "riff.h"
 
 #define DXA_EXTRA_SIZE  9
 

 typedef struct DXAContext {

     int frames;
     int has_sound;
     int bpc;
     uint32_t bytes_left;
     int64_t wavpos, vidpos;
     int readvid;
 }DXAContext;
 
 static int dxa_probe(AVProbeData *p)
 {

     int w, h;
     if (p->buf_size < 15)
         return 0;
     w = AV_RB16(p->buf + 11);
     h = AV_RB16(p->buf + 13);

     /* check file header */
     if (p->buf[0] == 'D' && p->buf[1] == 'E' &&

         p->buf[2] == 'X' && p->buf[3] == 'A' &&
         w && w <= 2048 && h && h <= 2048)

         return AVPROBE_SCORE_MAX;
     else
         return 0;
 }
 

 static int dxa_read_header(AVFormatContext *s)

 {

     AVIOContext *pb = s->pb;

     DXAContext *c = s->priv_data;
     AVStream *st, *ast;
     uint32_t tag;
     int32_t fps;
     int w, h;
     int num, den;
     int flags;

     int ret;

     tag = avio_rl32(pb);

     if (tag != MKTAG('D', 'E', 'X', 'A'))

         return AVERROR_INVALIDDATA;

     flags = avio_r8(pb);
     c->frames = avio_rb16(pb);

     if(!c->frames){
         av_log(s, AV_LOG_ERROR, "File contains no frames ???\n");

         return AVERROR_INVALIDDATA;

     }
 

     fps = avio_rb32(pb);

     if(fps > 0){
         den = 1000;
         num = fps;
     }else if (fps < 0){
         den = 100000;
         num = -fps;
     }else{
         den = 10;
         num = 1;
     }

     w = avio_rb16(pb);
     h = avio_rb16(pb);

     c->has_sound = 0;
 

     st = avformat_new_stream(s, NULL);

     if (!st)

         return AVERROR(ENOMEM);

 
     // Parse WAV data header

     if(avio_rl32(pb) == MKTAG('W', 'A', 'V', 'E')){

         uint32_t size, fsize;
         c->has_sound = 1;

         size = avio_rb32(pb);

         c->vidpos = avio_tell(pb) + size;

         avio_skip(pb, 16);

         fsize = avio_rl32(pb);

         ast = avformat_new_stream(s, NULL);

         if (!ast)

             return AVERROR(ENOMEM);

         ret = ff_get_wav_header(s, pb, ast->codecpar, fsize, 0);

         if (ret < 0)
             return ret;

         if (ast->codecpar->sample_rate > 0)
             avpriv_set_pts_info(ast, 64, 1, ast->codecpar->sample_rate);

         // find 'data' chunk

         while(avio_tell(pb) < c->vidpos && !avio_feof(pb)){

             tag = avio_rl32(pb);
             fsize = avio_rl32(pb);

             if(tag == MKTAG('d', 'a', 't', 'a')) break;

             avio_skip(pb, fsize);

         }
         c->bpc = (fsize + c->frames - 1) / c->frames;

         if(ast->codecpar->block_align)
             c->bpc = ((c->bpc + ast->codecpar->block_align - 1) / ast->codecpar->block_align) * ast->codecpar->block_align;

         c->bytes_left = fsize;

         c->wavpos = avio_tell(pb);

         avio_seek(pb, c->vidpos, SEEK_SET);

     }
 
     /* now we are ready: build format streams */

     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
     st->codecpar->codec_id   = AV_CODEC_ID_DXA;
     st->codecpar->width      = w;
     st->codecpar->height     = h;

     av_reduce(&den, &num, den, num, (1UL<<31)-1);

     avpriv_set_pts_info(st, 33, num, den);

     /* flags & 0x80 means that image is interlaced,
      * flags & 0x40 means that image has double height
      * either way set true height
      */
     if(flags & 0xC0){

         st->codecpar->height >>= 1;

     }
     c->readvid = !c->has_sound;

     c->vidpos  = avio_tell(pb);

     s->start_time = 0;
     s->duration = (int64_t)c->frames * AV_TIME_BASE * num / den;
     av_log(s, AV_LOG_DEBUG, "%d frame(s)\n",c->frames);
 
     return 0;
 }
 
 static int dxa_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     DXAContext *c = s->priv_data;
     int ret;
     uint32_t size;
     uint8_t buf[DXA_EXTRA_SIZE], pal[768+4];
     int pal_size = 0;
 
     if(!c->readvid && c->has_sound && c->bytes_left){
         c->readvid = 1;

         avio_seek(s->pb, c->wavpos, SEEK_SET);

         size = FFMIN(c->bytes_left, c->bpc);

         ret = av_get_packet(s->pb, pkt, size);

         pkt->stream_index = 1;
         if(ret != size)

             return AVERROR(EIO);

         c->bytes_left -= size;

         c->wavpos = avio_tell(s->pb);

         return 0;
     }

     avio_seek(s->pb, c->vidpos, SEEK_SET);

     while(!avio_feof(s->pb) && c->frames){

         uint32_t tag;

         if ((ret = avio_read(s->pb, buf, 4)) != 4) {
             av_log(s, AV_LOG_ERROR, "failed reading chunk type\n");
             return ret < 0 ? ret : AVERROR_INVALIDDATA;
         }

         tag = AV_RL32(buf);
         switch (tag) {

         case MKTAG('N', 'U', 'L', 'L'):
             if(av_new_packet(pkt, 4 + pal_size) < 0)

                 return AVERROR(ENOMEM);

             pkt->stream_index = 0;
             if(pal_size) memcpy(pkt->data, pal, pal_size);
             memcpy(pkt->data + pal_size, buf, 4);
             c->frames--;

             c->vidpos = avio_tell(s->pb);

             c->readvid = 0;
             return 0;
         case MKTAG('C', 'M', 'A', 'P'):
             pal_size = 768+4;
             memcpy(pal, buf, 4);

             avio_read(s->pb, pal + 4, 768);

             break;
         case MKTAG('F', 'R', 'A', 'M'):

             if ((ret = avio_read(s->pb, buf + 4, DXA_EXTRA_SIZE - 4)) != DXA_EXTRA_SIZE - 4) {
                 av_log(s, AV_LOG_ERROR, "failed reading dxa_extra\n");
                 return ret < 0 ? ret : AVERROR_INVALIDDATA;
             }

             size = AV_RB32(buf + 5);
             if(size > 0xFFFFFF){

                 av_log(s, AV_LOG_ERROR, "Frame size is too big: %"PRIu32"\n",
                        size);

                 return AVERROR_INVALIDDATA;

             }
             if(av_new_packet(pkt, size + DXA_EXTRA_SIZE + pal_size) < 0)

                 return AVERROR(ENOMEM);

             memcpy(pkt->data + pal_size, buf, DXA_EXTRA_SIZE);

             ret = avio_read(s->pb, pkt->data + DXA_EXTRA_SIZE + pal_size, size);

             if(ret != size){

                 av_packet_unref(pkt);

                 return AVERROR(EIO);

             }
             if(pal_size) memcpy(pkt->data, pal, pal_size);
             pkt->stream_index = 0;
             c->frames--;

             c->vidpos = avio_tell(s->pb);

             c->readvid = 0;
             return 0;
         default:

             av_log(s, AV_LOG_ERROR, "Unknown tag %s\n", av_fourcc2str(tag));

             return AVERROR_INVALIDDATA;

         }
     }

     return AVERROR_EOF;

 }
 

 AVInputFormat ff_dxa_demuxer = {

     .name           = "dxa",
     .long_name      = NULL_IF_CONFIG_SMALL("DXA"),
     .priv_data_size = sizeof(DXAContext),
     .read_probe     = dxa_probe,
     .read_header    = dxa_read_header,
     .read_packet    = dxa_read_packet,

 };