/*
  * TTA demuxer
  * Copyright (c) 2006 Alex Beregszaszi
  *

  * 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 "libavcodec/get_bits.h"

 #include "apetag.h"

 #include "avformat.h"

 #include "avio_internal.h"

 #include "internal.h"

 #include "id3v1.h"

 #include "libavutil/crc.h"

 #include "libavutil/dict.h"

 
 typedef struct {
     int totalframes, currentframe;

     int frame_size;
     int last_frame_size;

 } TTAContext;
 

 static unsigned long tta_check_crc(unsigned long checksum, const uint8_t *buf,
                                    unsigned int len)
 {
     return av_crc(av_crc_get_table(AV_CRC_32_IEEE_LE), checksum, buf, len);
 }
 

 static int tta_probe(AVProbeData *p)
 {

     if (AV_RL32(&p->buf[0]) == MKTAG('T', 'T', 'A', '1') &&
         (AV_RL16(&p->buf[4]) == 1 || AV_RL16(&p->buf[4]) == 2) &&
         AV_RL16(&p->buf[6]) > 0 &&
         AV_RL16(&p->buf[8]) > 0 &&
         AV_RL32(&p->buf[10]) > 0)

         return AVPROBE_SCORE_EXTENSION + 30;

     return 0;
 }
 

 static int tta_read_header(AVFormatContext *s)

 {
     TTAContext *c = s->priv_data;
     AVStream *st;

     int i, channels, bps, samplerate;

     uint64_t framepos, start_offset;

     uint32_t nb_samples, crc;

     ff_id3v1_read(s);

     start_offset = avio_tell(s->pb);

     ffio_init_checksum(s->pb, tta_check_crc, UINT32_MAX);

     if (avio_rl32(s->pb) != AV_RL32("TTA1"))

         return AVERROR_INVALIDDATA;

     avio_skip(s->pb, 2); // FIXME: flags

     channels = avio_rl16(s->pb);
     bps = avio_rl16(s->pb);
     samplerate = avio_rl32(s->pb);

     if(samplerate <= 0 || samplerate > 1000000){
         av_log(s, AV_LOG_ERROR, "nonsense samplerate\n");

         return AVERROR_INVALIDDATA;

     }
 

     nb_samples = avio_rl32(s->pb);
     if (!nb_samples) {
         av_log(s, AV_LOG_ERROR, "invalid number of samples\n");

         return AVERROR_INVALIDDATA;

     }
 

     crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;
     if (crc != avio_rl32(s->pb)) {
         av_log(s, AV_LOG_ERROR, "Header CRC error\n");
         return AVERROR_INVALIDDATA;
     }

     c->frame_size      = samplerate * 256 / 245;

     c->last_frame_size = nb_samples % c->frame_size;

     if (!c->last_frame_size)
         c->last_frame_size = c->frame_size;

     c->totalframes = nb_samples / c->frame_size + (c->last_frame_size < c->frame_size);

     c->currentframe = 0;
 

     if(c->totalframes >= UINT_MAX/sizeof(uint32_t) || c->totalframes <= 0){
         av_log(s, AV_LOG_ERROR, "totalframes %d invalid\n", c->totalframes);

         return AVERROR_INVALIDDATA;

     }

     st = avformat_new_stream(s, NULL);

     if (!st)

         return AVERROR(ENOMEM);

     avpriv_set_pts_info(st, 64, 1, samplerate);

     st->start_time = 0;

     st->duration = nb_samples;

     framepos = avio_tell(s->pb) + 4*c->totalframes + 4;

     if (ff_alloc_extradata(st->codec, avio_tell(s->pb) - start_offset))

         return AVERROR(ENOMEM);
 
     avio_seek(s->pb, start_offset, SEEK_SET);
     avio_read(s->pb, st->codec->extradata, st->codec->extradata_size);
 

     ffio_init_checksum(s->pb, tta_check_crc, UINT32_MAX);

     for (i = 0; i < c->totalframes; i++) {

         uint32_t size = avio_rl32(s->pb);

         av_add_index_entry(st, framepos, i * c->frame_size, size, 0,
                            AVINDEX_KEYFRAME);

         framepos += size;
     }

     crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;
     if (crc != avio_rl32(s->pb)) {
         av_log(s, AV_LOG_ERROR, "Seek table CRC error\n");
         return AVERROR_INVALIDDATA;
     }

     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

     st->codec->codec_id = AV_CODEC_ID_TTA;

     st->codec->channels = channels;
     st->codec->sample_rate = samplerate;

     st->codec->bits_per_coded_sample = bps;

     if (s->pb->seekable) {
         int64_t pos = avio_tell(s->pb);
         ff_ape_parse_tag(s);
         avio_seek(s->pb, pos, SEEK_SET);
     }
 

     return 0;
 }
 
 static int tta_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     TTAContext *c = s->priv_data;

     AVStream *st = s->streams[0];

     int size, ret;

 
     // FIXME!

     if (c->currentframe >= c->totalframes)

         return AVERROR_EOF;

     size = st->index_entries[c->currentframe].size;

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

     pkt->dts = st->index_entries[c->currentframe++].timestamp;

     pkt->duration = c->currentframe == c->totalframes ? c->last_frame_size :
                                                         c->frame_size;

     return ret;

 }
 

 static int tta_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
 {
     TTAContext *c = s->priv_data;
     AVStream *st = s->streams[stream_index];
     int index = av_index_search_timestamp(st, timestamp, flags);
     if (index < 0)
         return -1;

     if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
         return -1;

 
     c->currentframe = index;
 
     return 0;
 }
 

 AVInputFormat ff_tta_demuxer = {

     .name           = "tta",

     .long_name      = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),

     .priv_data_size = sizeof(TTAContext),
     .read_probe     = tta_probe,
     .read_header    = tta_read_header,
     .read_packet    = tta_read_packet,
     .read_seek      = tta_read_seek,

     .extensions     = "tta",

 };