/*
  * VQF demuxer
  * Copyright (c) 2009 Vitor Sessak
  *
  * 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 "avformat.h"
 #include "libavutil/intreadwrite.h"

 #include "libavutil/dict.h"

 
 typedef struct VqfContext {
     int frame_bit_len;
     uint8_t last_frame_bits;
     int remaining_bits;
 } VqfContext;
 
 static int vqf_probe(AVProbeData *probe_packet)
 {
     if (AV_RL32(probe_packet->buf) != MKTAG('T','W','I','N'))
         return 0;
 
     if (!memcmp(probe_packet->buf + 4, "97012000", 8))
         return AVPROBE_SCORE_MAX;
 
     if (!memcmp(probe_packet->buf + 4, "00052200", 8))
         return AVPROBE_SCORE_MAX;
 
     return AVPROBE_SCORE_MAX/2;
 }
 
 static void add_metadata(AVFormatContext *s, const char *tag,
                          unsigned int tag_len, unsigned int remaining)
 {

     int len = FFMIN(tag_len, remaining);
     char *buf;

     if (len == UINT_MAX)
         return;

     buf = av_malloc(len+1);
     if (!buf)
         return;

     avio_read(s->pb, buf, len);

     buf[len] = 0;

     av_dict_set(&s->metadata, tag, buf, AV_DICT_DONT_STRDUP_VAL);

 }
 
 static int vqf_read_header(AVFormatContext *s, AVFormatParameters *ap)
 {
     VqfContext *c = s->priv_data;
     AVStream *st  = av_new_stream(s, 0);
     int chunk_tag;
     int rate_flag = -1;
     int header_size;
     int read_bitrate = 0;
     int size;
 
     if (!st)
         return AVERROR(ENOMEM);
 

     avio_skip(s->pb, 12);

     header_size = avio_rb32(s->pb);

     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

     st->codec->codec_id   = CODEC_ID_TWINVQ;
     st->start_time = 0;
 
     do {
         int len;

         chunk_tag = avio_rl32(s->pb);

 
         if (chunk_tag == MKTAG('D','A','T','A'))
             break;
 

         len = avio_rb32(s->pb);

 
         if ((unsigned) len > INT_MAX/2) {
             av_log(s, AV_LOG_ERROR, "Malformed header\n");
             return -1;
         }
 
         header_size -= 8;
 
         switch(chunk_tag){
         case MKTAG('C','O','M','M'):

             st->codec->channels = avio_rb32(s->pb) + 1;
             read_bitrate        = avio_rb32(s->pb);
             rate_flag           = avio_rb32(s->pb);

             avio_skip(s->pb, len-12);

 
             st->codec->bit_rate              = read_bitrate*1000;
             st->codec->bits_per_coded_sample = 16;
             break;
         case MKTAG('N','A','M','E'):
             add_metadata(s, "title"    , len, header_size);
             break;
         case MKTAG('(','c',')',' '):
             add_metadata(s, "copyright", len, header_size);
             break;
         case MKTAG('A','U','T','H'):
             add_metadata(s, "author"   , len, header_size);
             break;
         case MKTAG('A','L','B','M'):
             add_metadata(s, "album"    , len, header_size);
             break;
         case MKTAG('T','R','C','K'):
             add_metadata(s, "track"    , len, header_size);
             break;
         case MKTAG('C','O','M','T'):
             add_metadata(s, "comment"  , len, header_size);
             break;
         case MKTAG('F','I','L','E'):
             add_metadata(s, "filename" , len, header_size);
             break;
         case MKTAG('D','S','I','Z'):
             add_metadata(s, "size"     , len, header_size);
             break;
         case MKTAG('D','A','T','E'):
             add_metadata(s, "date"     , len, header_size);
             break;
         case MKTAG('G','E','N','R'):
             add_metadata(s, "genre"    , len, header_size);
             break;
         default:
             av_log(s, AV_LOG_ERROR, "Unknown chunk: %c%c%c%c\n",
                    ((char*)&chunk_tag)[0], ((char*)&chunk_tag)[1],
                    ((char*)&chunk_tag)[2], ((char*)&chunk_tag)[3]);

             avio_skip(s->pb, FFMIN(len, header_size));

             break;
         }
 
         header_size -= len;
 
     } while (header_size >= 0);
 
     switch (rate_flag) {
     case -1:
         av_log(s, AV_LOG_ERROR, "COMM tag not found!\n");
         return -1;
     case 44:
         st->codec->sample_rate = 44100;
         break;
     case 22:
         st->codec->sample_rate = 22050;
         break;
     case 11:
         st->codec->sample_rate = 11025;
         break;
     default:
         st->codec->sample_rate = rate_flag*1000;
         break;
     }
 
     switch (((st->codec->sample_rate/1000) << 8) +
             read_bitrate/st->codec->channels) {
     case (11<<8) + 8 :
     case (8 <<8) + 8 :
     case (11<<8) + 10:
     case (22<<8) + 32:
         size = 512;
         break;
     case (16<<8) + 16:
     case (22<<8) + 20:
     case (22<<8) + 24:
         size = 1024;
         break;
     case (44<<8) + 40:
     case (44<<8) + 48:
         size = 2048;
         break;
     default:
         av_log(s, AV_LOG_ERROR, "Mode not suported: %d Hz, %d kb/s.\n",
                st->codec->sample_rate, st->codec->bit_rate);
         return -1;
     }
     c->frame_bit_len = st->codec->bit_rate*size/st->codec->sample_rate;

     av_set_pts_info(st, 64, 1, st->codec->sample_rate);

 
     return 0;
 }
 
 static int vqf_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     VqfContext *c = s->priv_data;
     int ret;
     int size = (c->frame_bit_len - c->remaining_bits + 7)>>3;
 

     pkt->pos          = avio_tell(s->pb);

     pkt->stream_index = 0;
 
     if (av_new_packet(pkt, size+2) < 0)
         return AVERROR(EIO);
 
     pkt->data[0] = 8 - c->remaining_bits; // Number of bits to skip
     pkt->data[1] = c->last_frame_bits;

     ret = avio_read(s->pb, pkt->data+2, size);

 
     if (ret<=0) {
         av_free_packet(pkt);
         return AVERROR(EIO);
     }
 
     c->last_frame_bits = pkt->data[size+1];
     c->remaining_bits  = (size << 3) - c->frame_bit_len + c->remaining_bits;
 
     return size+2;
 }
 
 static int vqf_read_seek(AVFormatContext *s,
                          int stream_index, int64_t timestamp, int flags)
 {
     VqfContext *c = s->priv_data;
     AVStream *st;
     int ret;
     int64_t pos;
 
     st = s->streams[stream_index];
     pos = av_rescale_rnd(timestamp * st->codec->bit_rate,
                          st->time_base.num,
                          st->time_base.den * (int64_t)c->frame_bit_len,
                          (flags & AVSEEK_FLAG_BACKWARD) ?
                                                    AV_ROUND_DOWN : AV_ROUND_UP);
     pos *= c->frame_bit_len;
 
     st->cur_dts = av_rescale(pos, st->time_base.den,
                              st->codec->bit_rate * (int64_t)st->time_base.num);
 

     if ((ret = avio_seek(s->pb, ((pos-7) >> 3) + s->data_offset, SEEK_SET)) < 0)

         return ret;
 
     c->remaining_bits = -7 - ((pos-7)&7);
     return 0;
 }
 

 AVInputFormat ff_vqf_demuxer = {

     "vqf",
     NULL_IF_CONFIG_SMALL("Nippon Telegraph and Telephone Corporation (NTT) TwinVQ"),
     sizeof(VqfContext),
     vqf_probe,
     vqf_read_header,
     vqf_read_packet,
     NULL,
     vqf_read_seek,
     .extensions = "vqf",
 };