/*

 * Adobe Filmstrip demuxer

 * Copyright (c) 2010 Peter Ross

 *

 * 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

 */

/**

 * @file

 * Adobe Filmstrip demuxer

 */

#include "libavutil/intreadwrite.h"

#include "libavutil/imgutils.h"

#include "avformat.h"

#include "demux.h"

#include "internal.h"

#define RAND_TAG MKBETAG('R','a','n','d')

typedef struct FilmstripDemuxContext {

    int leading;

} FilmstripDemuxContext;

static int read_header(AVFormatContext *s)

{

    FilmstripDemuxContext *film = s->priv_data;

    AVIOContext *pb = s->pb;

    AVStream *st;

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

        return AVERROR(ENOSYS);

    avio_seek(pb, avio_size(pb) - 36, SEEK_SET);

    if (avio_rb32(pb) != RAND_TAG) {

        av_log(s, AV_LOG_ERROR, "magic number not found\n");

        return AVERROR_INVALIDDATA;

    }

    st = avformat_new_stream(s, NULL);

    if (!st)

        return AVERROR(ENOMEM);

    st->nb_frames = avio_rb32(pb);

    if (avio_rb16(pb) != 0) {

        avpriv_request_sample(s, "Unsupported packing method");

        return AVERROR_PATCHWELCOME;

    }

    avio_skip(pb, 2);

    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;

    st->codecpar->codec_id   = AV_CODEC_ID_RAWVIDEO;

    st->codecpar->format     = AV_PIX_FMT_RGBA;

    st->codecpar->codec_tag  = 0; /* no fourcc */

    st->codecpar->width      = avio_rb16(pb);

    st->codecpar->height     = avio_rb16(pb);

    film->leading         = avio_rb16(pb);

    if (av_image_check_size(st->codecpar->width, st->codecpar->height, 0, s) < 0)

        return AVERROR_INVALIDDATA;

    avpriv_set_pts_info(st, 64, 1, avio_rb16(pb));

    avio_seek(pb, 0, SEEK_SET);

    return 0;

}

static int read_packet(AVFormatContext *s,

                       AVPacket *pkt)

{

    FilmstripDemuxContext *film = s->priv_data;

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

    if (avio_feof(s->pb))

        return AVERROR_EOF;

    pkt->dts = avio_tell(s->pb) / (st->codecpar->width * (int64_t)(st->codecpar->height + film->leading) * 4);

    pkt->size = av_get_packet(s->pb, pkt, st->codecpar->width * st->codecpar->height * 4);

    avio_skip(s->pb, st->codecpar->width * (int64_t) film->leading * 4);

    if (pkt->size < 0)

        return pkt->size;

    pkt->flags |= AV_PKT_FLAG_KEY;

    return 0;

}

static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)

{

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

    if (avio_seek(s->pb, FFMAX(timestamp, 0) * st->codecpar->width * st->codecpar->height * 4, SEEK_SET) < 0)

        return -1;

    return 0;

}

const FFInputFormat ff_filmstrip_demuxer = {

    .p.name         = "filmstrip",

    .p.long_name    = NULL_IF_CONFIG_SMALL("Adobe Filmstrip"),

    .p.extensions   = "flm",

    .priv_data_size = sizeof(FilmstripDemuxContext),

    .read_header    = read_header,

    .read_packet    = read_packet,

    .read_seek      = read_seek,

};