/*

 * Megalux Frame demuxer

 * Copyright (c) 2010 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

 * Megalux Frame demuxer

 */

#include "libavutil/imgutils.h"

#include "libavutil/intreadwrite.h"

#include "avformat.h"

#include "demux.h"

static const enum AVPixelFormat frm_pix_fmt_tags[] = {

    AV_PIX_FMT_RGB555,

    AV_PIX_FMT_RGB0,

    AV_PIX_FMT_RGB24,

    AV_PIX_FMT_BGR0,

    AV_PIX_FMT_BGRA,

};

typedef struct {

    int count;

} FrmContext;

static int frm_read_probe(const AVProbeData *p)

{

    if (p->buf_size > 8 &&

        p->buf[0] == 'F' && p->buf[1] == 'R' && p->buf[2] == 'M' &&

        AV_RL16(&p->buf[4]) && AV_RL16(&p->buf[6]))

        return AVPROBE_SCORE_MAX / 4;

    return 0;

}

static int frm_read_header(AVFormatContext *avctx)

{

    AVIOContext *pb = avctx->pb;

    AVStream *st = avformat_new_stream(avctx, 0);

    unsigned idx;

    if (!st)

        return AVERROR(ENOMEM);

    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;

    st->codecpar->codec_id   = AV_CODEC_ID_RAWVIDEO;

    avio_skip(pb, 3);

    idx = avio_r8(pb) - 1;

    if (idx >= FF_ARRAY_ELEMS(frm_pix_fmt_tags))

        return AVERROR_INVALIDDATA;

    st->codecpar->format = frm_pix_fmt_tags[idx];

    st->codecpar->codec_tag  = 0;

    st->codecpar->width      = avio_rl16(pb);

    st->codecpar->height     = avio_rl16(pb);

    return 0;

}

static int frm_read_packet(AVFormatContext *avctx, AVPacket *pkt)

{

    FrmContext *s = avctx->priv_data;

    AVCodecParameters *par = avctx->streams[0]->codecpar;

    int packet_size, ret;

    if (s->count)

        return AVERROR_EOF;

    packet_size = av_image_get_buffer_size(par->format, par->width, par->height, 1);

    if (packet_size < 0)

        return AVERROR_INVALIDDATA;

    ret = av_get_packet(avctx->pb, pkt, packet_size);

    if (ret < 0)

        return ret;

    if (par->format == AV_PIX_FMT_BGRA) {

        int i;

        for (i = 3; i + 1 <= pkt->size; i += 4)

            pkt->data[i] = 0xFF - pkt->data[i];

    }

    pkt->stream_index = 0;

    s->count++;

    return 0;

}

const FFInputFormat ff_frm_demuxer = {

    .p.name         = "frm",

    .p.long_name    = NULL_IF_CONFIG_SMALL("Megalux Frame"),

    .priv_data_size = sizeof(FrmContext),

    .read_probe     = frm_read_probe,

    .read_header    = frm_read_header,

    .read_packet    = frm_read_packet,

};