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/*

 * Microsoft Windows ICO demuxer

 * Copyright (c) 2011 Peter Ross (pross@xvid.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

 */

/**

 * @file

 * Microsoft Windows ICO demuxer

 */

#include "libavutil/intreadwrite.h"

#include "libavcodec/bytestream.h"

#include "libavcodec/bmp.h"

#include "avformat.h"

#include "internal.h"

typedef struct {

    int offset;

    int size;

    int nb_pal;

} IcoImage;

typedef struct {

    int current_image;

    int nb_images;

    IcoImage * images;

} IcoDemuxContext;

static int probe(AVProbeData *p)

{

    if (AV_RL16(p->buf) == 0 && AV_RL16(p->buf + 2) == 1 && AV_RL16(p->buf + 4))

        return AVPROBE_SCORE_MAX / 3;

    return 0;

}

static int read_header(AVFormatContext *s)

{

    IcoDemuxContext *ico = s->priv_data;

    AVIOContext *pb = s->pb;

    int i, codec;

    avio_skip(pb, 4);

    ico->nb_images = avio_rl16(pb);

    ico->images = av_malloc(ico->nb_images * sizeof(IcoImage));

    if (!ico->images)

        return AVERROR(ENOMEM);

    for (i = 0; i < ico->nb_images; i++) {

        AVStream *st;

        int tmp;

        if (avio_seek(pb, 6 + i * 16, SEEK_SET) < 0)

            break;

        st = avformat_new_stream(s, NULL);

        if (!st)

            return AVERROR(ENOMEM);

        st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

        st->codec->width      = avio_r8(pb);

        st->codec->height     = avio_r8(pb);

        ico->images[i].nb_pal = avio_r8(pb);

        if (ico->images[i].nb_pal == 255)

            ico->images[i].nb_pal = 0;

        avio_skip(pb, 5);

        ico->images[i].size   = avio_rl32(pb);

        ico->images[i].offset = avio_rl32(pb);

        if (avio_seek(pb, ico->images[i].offset, SEEK_SET) < 0)

            break;

        codec = avio_rl32(pb);

        switch (codec) {

        case MKTAG(0x89, 'P', 'N', 'G'):

            st->codec->codec_id = AV_CODEC_ID_PNG;

            st->codec->width    = 0;

            st->codec->height   = 0;

            break;

        case 40:

            if (ico->images[i].size < 40)

                return AVERROR_INVALIDDATA;

            st->codec->codec_id = AV_CODEC_ID_BMP;

            tmp = avio_rl32(pb);

            if (tmp)

                st->codec->width = tmp;

            tmp = avio_rl32(pb);

            if (tmp)

                st->codec->height = tmp / 2;

            break;

        default:

            avpriv_request_sample(s, "codec %d", codec);

            return AVERROR_INVALIDDATA;

        }

    }

    return 0;

}

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

{

    IcoDemuxContext *ico = s->priv_data;

    IcoImage *image;

    AVIOContext *pb = s->pb;

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

    int ret;

    if (ico->current_image >= ico->nb_images)

        return AVERROR(EIO);

    image = &ico->images[ico->current_image];

    if ((ret = avio_seek(pb, image->offset, SEEK_SET)) < 0)

        return ret;

    if (s->streams[ico->current_image]->codec->codec_id == AV_CODEC_ID_PNG) {

        if ((ret = av_get_packet(pb, pkt, image->size)) < 0)

            return ret;

    } else {

        uint8_t *buf;

        if ((ret = av_new_packet(pkt, 14 + image->size)) < 0)

            return ret;

        buf = pkt->data;

        /* add BMP header */

        bytestream_put_byte(&buf, 'B');

        bytestream_put_byte(&buf, 'M');

        bytestream_put_le32(&buf, pkt->size);

        bytestream_put_le16(&buf, 0);

        bytestream_put_le16(&buf, 0);

        bytestream_put_le32(&buf, 0);

        if ((ret = avio_read(pb, buf, image->size)) < 0)

            return ret;

        st->codec->bits_per_coded_sample = AV_RL16(buf + 14);

        if (AV_RL32(buf + 32))

            image->nb_pal = AV_RL32(buf + 32);

        if (st->codec->bits_per_coded_sample <= 8 && !image->nb_pal) {

            image->nb_pal = 1 << st->codec->bits_per_coded_sample;

            AV_WL32(buf + 32, image->nb_pal);

        }

        AV_WL32(buf - 4, 14 + 40 + image->nb_pal * 4);

        AV_WL32(buf + 8, AV_RL32(buf + 8) / 2);

    }

    pkt->stream_index = ico->current_image++;

    pkt->flags |= AV_PKT_FLAG_KEY;

    return 0;

}

AVInputFormat ff_ico_demuxer = {

    .name           = "ico",

    .long_name      = NULL_IF_CONFIG_SMALL("Microsoft Windows ICO"),

    .priv_data_size = sizeof(IcoDemuxContext),

    .read_probe     = probe,

    .read_header    = read_header,

    .read_packet    = read_packet,

    .flags          = AVFMT_NOTIMESTAMPS,

};