/*

 * Creative Voice File demuxer.

 * Copyright (c) 2006  Aurelien Jacobs <aurel@gnuage.org>

 *

 * 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/intreadwrite.h"

#include "demux.h"

#include "voc.h"

#include "internal.h"

static int voc_probe(const AVProbeData *p)

{

    int version, check;

    if (memcmp(p->buf, ff_voc_magic, sizeof(ff_voc_magic) - 1))

        return 0;

    version = AV_RL16(p->buf + 22);

    check = AV_RL16(p->buf + 24);

    if (~version + 0x1234 != check)

        return 10;

    return AVPROBE_SCORE_MAX;

}

static int voc_read_header(AVFormatContext *s)

{

    VocDecContext *voc = s->priv_data;

    AVIOContext *pb = s->pb;

    int header_size;

    avio_skip(pb, 20);

    header_size = avio_rl16(pb) - 22;

    if (header_size != 4) {

        av_log(s, AV_LOG_ERROR, "unknown header size: %d\n", header_size);

        return AVERROR(ENOSYS);

    }

    avio_skip(pb, header_size);

    s->ctx_flags |= AVFMTCTX_NOHEADER;

    voc->remaining_size = 0;

    return 0;

}

static int voc_read_packet(AVFormatContext *s, AVPacket *pkt)

{

    if (!s->nb_streams) {

        AVStream *st = avformat_new_stream(s, NULL);

        if (!st)

            return AVERROR(ENOMEM);

        st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;

    }

    return ff_voc_get_packet(s, pkt, s->streams[0], 0);

}

static int voc_read_seek(AVFormatContext *s, int stream_index,

                         int64_t timestamp, int flags)

{

    VocDecContext *voc = s->priv_data;

    AVStream *st;

    FFStream *sti;

    int index;

    if (s->nb_streams < 1) {

        av_log(s, AV_LOG_ERROR, "cannot seek while no stream was found yet\n");

        return AVERROR(EINVAL);

    }

    st = s->streams[stream_index];

    sti = ffstream(st);

    index = av_index_search_timestamp(st, timestamp, flags);

    if (index >= 0 && index < sti->nb_index_entries - 1) {

        const AVIndexEntry *const e = &sti->index_entries[index];

        avio_seek(s->pb, e->pos, SEEK_SET);

        voc->pts = e->timestamp;

        voc->remaining_size = e->size;

        return 0;

    } else if (sti->nb_index_entries && sti->index_entries[0].timestamp <= timestamp) {

        const AVIndexEntry *const e = &sti->index_entries[sti->nb_index_entries - 1];

        // prepare context for seek_frame_generic()

        voc->pts = e->timestamp;

        voc->remaining_size = e->size;

    }

    return -1;

}

const FFInputFormat ff_voc_demuxer = {

    .p.name         = "voc",

    .p.long_name    = NULL_IF_CONFIG_SMALL("Creative Voice"),

    .p.codec_tag    = ff_voc_codec_tags_list,

    .priv_data_size = sizeof(VocDecContext),

    .read_probe     = voc_probe,

    .read_header    = voc_read_header,

    .read_packet    = voc_read_packet,

    .read_seek      = voc_read_seek,

};