/*

 * 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 "libavutil/crc.h"

#include "libavutil/dict.h"

#include "libavutil/intreadwrite.h"

#include "apetag.h"

#include "avformat.h"

#include "avio_internal.h"

#include "demux.h"

#include "internal.h"

#include "id3v1.h"

typedef struct TTAContext {

    int totalframes, currentframe;

    int frame_size;

    int last_frame_size;

} TTAContext;

static int tta_probe(const 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;

    int64_t framepos;

    uint8_t header[22];

    ff_id3v1_read(s);

    int ret = ffio_read_size(s->pb, header, sizeof(header));

    if (ret < 0)

        return ret;

    if (AV_RL32(header) != MKTAG('T', 'T', 'A', '1'))

        return AVERROR_INVALIDDATA;

    int channels   = AV_RL16(header +  6);

    int bps        = AV_RL16(header +  8);

    int samplerate = AV_RL32(header + 10);

    if(samplerate <= 0 || samplerate > 1000000){

        av_log(s, AV_LOG_ERROR, "nonsense samplerate\n");

        return AVERROR_INVALIDDATA;

    }

    uint32_t nb_samples = AV_RL32(header + 14);

    if (!nb_samples) {

        av_log(s, AV_LOG_ERROR, "invalid number of samples\n");

        return AVERROR_INVALIDDATA;

    }

    uint32_t crc = av_crc(av_crc_get_table(AV_CRC_32_IEEE_LE), UINT32_MAX, header, 18) ^ UINT32_MAX;

    if (crc != AV_RL32(header + 18) && s->error_recognition & AV_EF_CRCCHECK) {

        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 >= (INT_MAX - 4)/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;

    ret = ff_alloc_extradata(st->codecpar, sizeof(header));

    if (ret < 0)

        return ret;

    memcpy(st->codecpar->extradata, header, sizeof(header));

    framepos = avio_tell(s->pb);

    if (framepos < 0)

        return framepos;

    framepos += 4 * c->totalframes + 4;

    ffio_init_checksum(s->pb, ff_crcEDB88320_update, UINT32_MAX);

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

        uint32_t size = avio_rl32(s->pb);

        int r;

        if (avio_feof(s->pb))

            return AVERROR_INVALIDDATA;

        if ((r = av_add_index_entry(st, framepos, i * (int64_t)c->frame_size, size, 0,

                                    AVINDEX_KEYFRAME)) < 0)

            return r;

        framepos += size;

    }

    crc = ffio_get_checksum(s->pb) ^ UINT32_MAX;

    if (crc != avio_rl32(s->pb) && s->error_recognition & AV_EF_CRCCHECK) {

        av_log(s, AV_LOG_ERROR, "Seek table CRC error\n");

        return AVERROR_INVALIDDATA;

    }

    st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;

    st->codecpar->codec_id = AV_CODEC_ID_TTA;

    st->codecpar->ch_layout.nb_channels = channels;

    st->codecpar->sample_rate = samplerate;

    st->codecpar->bits_per_coded_sample = bps;

    if (s->pb->seekable & AVIO_SEEKABLE_NORMAL) {

        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];

    FFStream *const sti = ffstream(st);

    int size, ret;

    // FIXME!

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

        return AVERROR_EOF;

    if (sti->nb_index_entries < c->totalframes) {

        av_log(s, AV_LOG_ERROR, "Index entry disappeared\n");

        return AVERROR_INVALIDDATA;

    }

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

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

    pkt->dts = sti->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, ffstream(st)->index_entries[index].pos, SEEK_SET) < 0)

        return -1;

    c->currentframe = index;

    return 0;

}

const FFInputFormat ff_tta_demuxer = {

    .p.name         = "tta",

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

    .p.extensions   = "tta",

    .priv_data_size = sizeof(TTAContext),

    .flags_internal = FF_INFMT_FLAG_ID3V2_AUTO,

    .read_probe     = tta_probe,

    .read_header    = tta_read_header,

    .read_packet    = tta_read_packet,

    .read_seek      = tta_read_seek,

};