/*
  * RL2 Format Demuxer
  * Copyright (c) 2008 Sascha Sommer (saschasommer@freenet.de)
  *
  * 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
  */
 
 /**
  * RL2 file demuxer

  * @file

  * @author Sascha Sommer (saschasommer@freenet.de)
  * For more information regarding the RL2 file format, visit:
  *   http://wiki.multimedia.cx/index.php?title=RL2
  *
  * extradata:
  * 2 byte le initial drawing offset within 320x200 viewport
  * 4 byte le number of used colors
  * 256 * 3 bytes rgb palette
  * optional background_frame
  */
 

 #include "libavutil/intreadwrite.h"

 #include "avformat.h"
 
 #define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr, palette
 
 #define FORM_TAG MKBETAG('F', 'O', 'R', 'M')
 #define RLV2_TAG MKBETAG('R', 'L', 'V', '2')
 #define RLV3_TAG MKBETAG('R', 'L', 'V', '3')
 
 typedef struct Rl2DemuxContext {

     unsigned int index_pos[2];   ///< indexes in the sample tables

 } Rl2DemuxContext;
 
 
 /**
  * check if the file is in rl2 format
  * @param p probe buffer
  * @return 0 when the probe buffer does not contain rl2 data, > 0 otherwise
  */
 static int rl2_probe(AVProbeData *p)
 {
 
     if(AV_RB32(&p->buf[0]) != FORM_TAG)
         return 0;
 
     if(AV_RB32(&p->buf[8]) != RLV2_TAG &&
         AV_RB32(&p->buf[8]) != RLV3_TAG)
         return 0;
 
     return AVPROBE_SCORE_MAX;
 }
 
 /**
  * read rl2 header data and setup the avstreams
  * @param s demuxer context
  * @param ap format parameters
  * @return 0 on success, AVERROR otherwise
  */
 static av_cold int rl2_read_header(AVFormatContext *s,
                             AVFormatParameters *ap)
 {

     AVIOContext *pb = s->pb;

     AVStream *st;
     unsigned int frame_count;
     unsigned int audio_frame_counter = 0;
     unsigned int video_frame_counter = 0;
     unsigned int back_size;
     unsigned short sound_rate;
     unsigned short rate;
     unsigned short channels;
     unsigned short def_sound_size;
     unsigned int signature;
     unsigned int pts_den = 11025; /* video only case */
     unsigned int pts_num = 1103;
     unsigned int* chunk_offset = NULL;
     int* chunk_size = NULL;
     int* audio_size = NULL;
     int i;
     int ret = 0;
 

     avio_skip(pb,4);          /* skip FORM tag */

     back_size = avio_rl32(pb); /**< get size of the background frame */
     signature = avio_rb32(pb);

     avio_skip(pb, 4);         /* data size */

     frame_count = avio_rl32(pb);

 
     /* disallow back_sizes and frame_counts that may lead to overflows later */
     if(back_size > INT_MAX/2  || frame_count > INT_MAX / sizeof(uint32_t))
         return AVERROR_INVALIDDATA;
 

     avio_skip(pb, 2);         /* encoding mentod */

     sound_rate = avio_rl16(pb);
     rate = avio_rl16(pb);
     channels = avio_rl16(pb);
     def_sound_size = avio_rl16(pb);

 
     /** setup 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_RL2;
     st->codec->codec_tag = 0;  /* no fourcc */
     st->codec->width = 320;
     st->codec->height = 200;
 
     /** allocate and fill extradata */
     st->codec->extradata_size = EXTRADATA1_SIZE;
 
     if(signature == RLV3_TAG && back_size > 0)
         st->codec->extradata_size += back_size;
 
     st->codec->extradata = av_mallocz(st->codec->extradata_size +
                                           FF_INPUT_BUFFER_PADDING_SIZE);
     if(!st->codec->extradata)
         return AVERROR(ENOMEM);
 

     if(avio_read(pb,st->codec->extradata,st->codec->extradata_size) !=

                       st->codec->extradata_size)
         return AVERROR(EIO);
 
     /** setup audio stream if present */
     if(sound_rate){
         pts_num = def_sound_size;
         pts_den = rate;
 
         st = av_new_stream(s, 0);
         if (!st)
             return AVERROR(ENOMEM);

         st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

         st->codec->codec_id = CODEC_ID_PCM_U8;
         st->codec->codec_tag = 1;
         st->codec->channels = channels;

         st->codec->bits_per_coded_sample = 8;

         st->codec->sample_rate = rate;
         st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *

             st->codec->bits_per_coded_sample;

         st->codec->block_align = st->codec->channels *

             st->codec->bits_per_coded_sample / 8;

         av_set_pts_info(st,32,1,rate);
     }
 
     av_set_pts_info(s->streams[0], 32, pts_num, pts_den);
 
     chunk_size =   av_malloc(frame_count * sizeof(uint32_t));
     audio_size =   av_malloc(frame_count * sizeof(uint32_t));
     chunk_offset = av_malloc(frame_count * sizeof(uint32_t));
 
     if(!chunk_size || !audio_size || !chunk_offset){
         av_free(chunk_size);
         av_free(audio_size);
         av_free(chunk_offset);
         return AVERROR(ENOMEM);
     }
 
     /** read offset and size tables */
     for(i=0; i < frame_count;i++)

         chunk_size[i] = avio_rl32(pb);

     for(i=0; i < frame_count;i++)

         chunk_offset[i] = avio_rl32(pb);

     for(i=0; i < frame_count;i++)

         audio_size[i] = avio_rl32(pb) & 0xFFFF;

 
     /** build the sample index */
     for(i=0;i<frame_count;i++){
         if(chunk_size[i] < 0 || audio_size[i] > chunk_size[i]){
             ret = AVERROR_INVALIDDATA;
             break;
         }
 
         if(sound_rate && audio_size[i]){
             av_add_index_entry(s->streams[1], chunk_offset[i],
                 audio_frame_counter,audio_size[i], 0, AVINDEX_KEYFRAME);
             audio_frame_counter += audio_size[i] / channels;
         }
         av_add_index_entry(s->streams[0], chunk_offset[i] + audio_size[i],
             video_frame_counter,chunk_size[i]-audio_size[i],0,AVINDEX_KEYFRAME);
         ++video_frame_counter;
     }
 
 
     av_free(chunk_size);
     av_free(audio_size);
     av_free(chunk_offset);
 
     return ret;
 }
 
 /**
  * read a single audio or video packet
  * @param s demuxer context
  * @param pkt the packet to be filled
  * @return 0 on success, AVERROR otherwise
  */
 static int rl2_read_packet(AVFormatContext *s,
                             AVPacket *pkt)
 {
     Rl2DemuxContext *rl2 = s->priv_data;

     AVIOContext *pb = s->pb;

     AVIndexEntry *sample = NULL;
     int i;
     int ret = 0;
     int stream_id = -1;
     int64_t pos = INT64_MAX;
 
     /** check if there is a valid video or audio entry that can be used */
     for(i=0; i<s->nb_streams; i++){
         if(rl2->index_pos[i] < s->streams[i]->nb_index_entries
               && s->streams[i]->index_entries[ rl2->index_pos[i] ].pos < pos){
             sample = &s->streams[i]->index_entries[ rl2->index_pos[i] ];
             pos= sample->pos;
             stream_id= i;
         }
     }
 
     if(stream_id == -1)
         return AVERROR(EIO);
 
     ++rl2->index_pos[stream_id];
 
     /** position the stream (will probably be there anyway) */

     avio_seek(pb, sample->pos, SEEK_SET);

 
     /** fill the packet */
     ret = av_get_packet(pb, pkt, sample->size);
     if(ret != sample->size){
         av_free_packet(pkt);
         return AVERROR(EIO);
     }
 
     pkt->stream_index = stream_id;
     pkt->pts = sample->timestamp;
 
     return ret;
 }
 
 /**
  * seek to a new timestamp
  * @param s demuxer context
  * @param stream_index index of the stream that should be seeked
  * @param timestamp wanted timestamp
  * @param flags direction and seeking mode
  * @return 0 on success, -1 otherwise
  */
 static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
 {
     AVStream *st = s->streams[stream_index];
     Rl2DemuxContext *rl2 = s->priv_data;
     int i;
     int index = av_index_search_timestamp(st, timestamp, flags);
     if(index < 0)
         return -1;
 
     rl2->index_pos[stream_index] = index;
     timestamp = st->index_entries[index].timestamp;
 
     for(i=0; i < s->nb_streams; i++){
         AVStream *st2 = s->streams[i];
         index = av_index_search_timestamp(st2,
                     av_rescale_q(timestamp, st->time_base, st2->time_base),
                     flags | AVSEEK_FLAG_BACKWARD);
 
         if(index < 0)
             index = 0;
 
         rl2->index_pos[i] = index;
     }
 
     return 0;
 }
 

 AVInputFormat ff_rl2_demuxer = {

     "rl2",

     NULL_IF_CONFIG_SMALL("RL2 format"),

     sizeof(Rl2DemuxContext),
     rl2_probe,
     rl2_read_header,
     rl2_read_packet,
     NULL,
     rl2_read_seek,
 };