/*
  * Deluxe Paint Animation demuxer
  * Copyright (c) 2009 Peter Ross
  *
  * 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

  * Deluxe Paint Animation demuxer
  */
 
 #include "libavutil/intreadwrite.h"
 #include "avformat.h"
 
 typedef struct {
     int base_record;
     unsigned int nb_records;
     int size;
 } Page;
 
 typedef struct {

     unsigned int nb_pages;    /**< total pages in file */
     unsigned int nb_records;  /**< total records in file */

     int page_table_offset;

 #define MAX_PAGES  256        /**< Deluxe Paint hardcoded value */
     Page pt[MAX_PAGES];       /**< page table */
     int page;                 /**< current page (or AVERROR_xxx code) */
     int record;               /**< current record (with in page) */

 } AnmDemuxContext;
 
 #define LPF_TAG  MKTAG('L','P','F',' ')
 #define ANIM_TAG MKTAG('A','N','I','M')
 
 static int probe(AVProbeData *p)
 {
     /* verify tags and video dimensions */
     if (AV_RL32(&p->buf[0])  == LPF_TAG &&
         AV_RL32(&p->buf[16]) == ANIM_TAG &&
         AV_RL16(&p->buf[20]) && AV_RL16(&p->buf[22]))
         return AVPROBE_SCORE_MAX;
     return 0;
 }
 
 /**
  * @return page containing the requested record or AVERROR_XXX
  */
 static int find_record(const AnmDemuxContext *anm, int record)
 {
     int i;
 
     if (record >= anm->nb_records)
         return AVERROR_EOF;
 
     for (i = 0; i < MAX_PAGES; i++) {
         const Page *p = &anm->pt[i];
         if (p->nb_records > 0 && record >= p->base_record && record < p->base_record + p->nb_records)
             return i;
     }
 
     return AVERROR_INVALIDDATA;
 }
 
 static int read_header(AVFormatContext *s,
                        AVFormatParameters *ap)
 {
     AnmDemuxContext *anm = s->priv_data;

     AVIOContext *pb = s->pb;

     AVStream *st;
     int i, ret;
 

     avio_skip(pb, 4); /* magic number */

     if (avio_rl16(pb) != MAX_PAGES) {

         av_log_ask_for_sample(s, "max_pages != " AV_STRINGIFY(MAX_PAGES) "\n");
         return AVERROR_INVALIDDATA;
     }
 

     anm->nb_pages   = avio_rl16(pb);
     anm->nb_records = avio_rl32(pb);

     avio_skip(pb, 2); /* max records per page */

     anm->page_table_offset = avio_rl16(pb);
     if (avio_rl32(pb) != ANIM_TAG)

         return AVERROR_INVALIDDATA;
 
     /* video stream */
     st = av_new_stream(s, 0);
     if (!st)
         return AVERROR(ENOMEM);

     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

     st->codec->codec_id   = CODEC_ID_ANM;
     st->codec->codec_tag  = 0; /* no fourcc */

     st->codec->width      = avio_rl16(pb);
     st->codec->height     = avio_rl16(pb);
     if (avio_r8(pb) != 0)

         goto invalid;

     avio_skip(pb, 1); /* frame rate multiplier info */

 
     /* ignore last delta record (used for looping) */

     if (avio_r8(pb))  /* has_last_delta */

         anm->nb_records = FFMAX(anm->nb_records - 1, 0);
 

     avio_skip(pb, 1); /* last_delta_valid */

     if (avio_r8(pb) != 0)

         goto invalid;
 

     if (avio_r8(pb) != 1)

         goto invalid;
 

     avio_skip(pb, 1); /* other recs per frame */

     if (avio_r8(pb) != 1)

         goto invalid;
 

     avio_skip(pb, 32); /* record_types */

     st->nb_frames = avio_rl32(pb);
     av_set_pts_info(st, 64, 1, avio_rl16(pb));

     avio_skip(pb, 58);

 
     /* color cycling and palette data */
     st->codec->extradata_size = 16*8 + 4*256;
     st->codec->extradata      = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);

     if (!st->codec->extradata)
         return AVERROR(ENOMEM);
 

     ret = avio_read(pb, st->codec->extradata, st->codec->extradata_size);

     if (ret < 0)

         return ret;

 
     /* read page table */

     ret = avio_seek(pb, anm->page_table_offset, SEEK_SET);

     if (ret < 0)

         return ret;

 
     for (i = 0; i < MAX_PAGES; i++) {
         Page *p = &anm->pt[i];

         p->base_record = avio_rl16(pb);
         p->nb_records  = avio_rl16(pb);
         p->size        = avio_rl16(pb);

     }
 
     /* find page of first frame */
     anm->page = find_record(anm, 0);

     if (anm->page < 0)
         return anm->page;

 
     anm->record = -1;
     return 0;
 
 invalid:
     av_log_ask_for_sample(s, NULL);

     return AVERROR_INVALIDDATA;

 }
 
 static int read_packet(AVFormatContext *s,
                        AVPacket *pkt)
 {
     AnmDemuxContext *anm = s->priv_data;

     AVIOContext *pb = s->pb;

     Page *p;
     int tmp, record_size;
 
     if (url_feof(s->pb))
         return AVERROR(EIO);
 
     if (anm->page < 0)

         return anm->page;

 
 repeat:
     p = &anm->pt[anm->page];
 
     /* parse page header */
     if (anm->record < 0) {

         avio_seek(pb, anm->page_table_offset + MAX_PAGES*6 + (anm->page<<16), SEEK_SET);

         avio_skip(pb, 8 + 2*p->nb_records);

         anm->record = 0;
     }
 
     /* if we have fetched all records in this page, then find the
        next page and repeat */
     if (anm->record >= p->nb_records) {
         anm->page = find_record(anm, p->base_record + p->nb_records);
         if (anm->page < 0)
             return anm->page;
         anm->record = -1;
         goto repeat;
     }
 
     /* fetch record size */

     tmp = avio_tell(pb);

     avio_seek(pb, anm->page_table_offset + MAX_PAGES*6 + (anm->page<<16) +

               8 + anm->record * 2, SEEK_SET);

     record_size = avio_rl16(pb);

     avio_seek(pb, tmp, SEEK_SET);

 
     /* fetch record */
     pkt->size = av_get_packet(s->pb, pkt, record_size);
     if (pkt->size < 0)
         return pkt->size;
     if (p->base_record + anm->record == 0)

         pkt->flags |= AV_PKT_FLAG_KEY;

 
     anm->record++;
     return 0;
 }
 

 AVInputFormat ff_anm_demuxer = {

     "anm",
     NULL_IF_CONFIG_SMALL("Deluxe Paint Animation"),
     sizeof(AnmDemuxContext),
     probe,
     read_header,
     read_packet,
 };