/*

 * Brute Force & Ignorance (BFI) demuxer

 * Copyright (c) 2008 Sisir Koppaka

 *

 * 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

 * @brief Brute Force & Ignorance (.bfi) file demuxer

 * @author Sisir Koppaka ( sisir.koppaka at gmail dot com )

 * @see http://wiki.multimedia.cx/index.php?title=BFI

 */

#include "libavutil/channel_layout.h"

#include "libavutil/intreadwrite.h"

#include "avformat.h"

#include "demux.h"

#include "internal.h"

typedef struct BFIContext {

    int nframes;

    int audio_frame;

    int video_frame;

    int video_size;

    int avflag;

} BFIContext;

static int bfi_probe(const AVProbeData * p)

{

    /* Check file header */

    if (AV_RL32(p->buf) == MKTAG('B', 'F', '&', 'I'))

        return AVPROBE_SCORE_MAX;

    else

        return 0;

}

static int bfi_read_header(AVFormatContext * s)

{

    BFIContext *bfi = s->priv_data;

    AVIOContext *pb = s->pb;

    AVStream *vstream;

    AVStream *astream;

    int ret, fps, chunk_header;

    /* Initialize the video codec... */

    vstream = avformat_new_stream(s, NULL);

    if (!vstream)

        return AVERROR(ENOMEM);

    /* Initialize the audio codec... */

    astream = avformat_new_stream(s, NULL);

    if (!astream)

        return AVERROR(ENOMEM);

    /* Set the total number of frames. */

    avio_skip(pb, 8);

    chunk_header           = avio_rl32(pb);

    if (chunk_header < 3)

        return AVERROR_INVALIDDATA;

    bfi->nframes           = avio_rl32(pb);

    if (bfi->nframes < 0)

        return AVERROR_INVALIDDATA;

    avio_rl32(pb);

    avio_rl32(pb);

    avio_rl32(pb);

    fps                    = avio_rl32(pb);

    avio_skip(pb, 12);

    vstream->codecpar->width  = avio_rl32(pb);

    vstream->codecpar->height = avio_rl32(pb);

    /*Load the palette to extradata */

    avio_skip(pb, 8);

    ret = ff_get_extradata(s, vstream->codecpar, pb, 768);

    if (ret < 0)

        return ret;

    astream->codecpar->sample_rate = avio_rl32(pb);

    if (astream->codecpar->sample_rate <= 0) {

        av_log(s, AV_LOG_ERROR, "Invalid sample rate %d\n", astream->codecpar->sample_rate);

        return AVERROR_INVALIDDATA;

    }

    /* Set up the video codec... */

    avpriv_set_pts_info(vstream, 32, 1, fps);

    vstream->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;

    vstream->codecpar->codec_id   = AV_CODEC_ID_BFI;

    vstream->codecpar->format     = AV_PIX_FMT_PAL8;

    vstream->nb_frames            =

    vstream->duration             = bfi->nframes;

    /* Set up the audio codec now... */

    astream->codecpar->codec_type      = AVMEDIA_TYPE_AUDIO;

    astream->codecpar->codec_id        = AV_CODEC_ID_PCM_U8;

    astream->codecpar->ch_layout       = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;

    astream->codecpar->bits_per_coded_sample = 8;

    astream->codecpar->bit_rate        =

        (int64_t)astream->codecpar->sample_rate * astream->codecpar->bits_per_coded_sample;

    avio_seek(pb, chunk_header - 3, SEEK_SET);

    avpriv_set_pts_info(astream, 64, 1, astream->codecpar->sample_rate);

    return 0;

}

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

{

    BFIContext *bfi = s->priv_data;

    AVIOContext *pb = s->pb;

    int ret, audio_offset, video_offset, chunk_size, audio_size = 0;

    if (bfi->nframes == 0 || avio_feof(pb)) {

        return AVERROR_EOF;

    }

    /* If all previous chunks were completely read, then find a new one... */

    if (!bfi->avflag) {

        uint32_t state = 0;

        while(state != MKTAG('S','A','V','I')){

            if (avio_feof(pb))

                return AVERROR_INVALIDDATA;

            state = 256*state + avio_r8(pb);

        }

        /* Now that the chunk's location is confirmed, we proceed... */

        chunk_size      = avio_rl32(pb);

        avio_rl32(pb);

        audio_offset    = avio_rl32(pb);

        avio_rl32(pb);

        video_offset    = avio_rl32(pb);

        if (audio_offset < 0 || video_offset < audio_offset || chunk_size < video_offset) {

            av_log(s, AV_LOG_ERROR, "Invalid audio/video offsets or chunk size\n");

            return AVERROR_INVALIDDATA;

        }

        audio_size      = video_offset - audio_offset;

        bfi->video_size = chunk_size - video_offset;

        //Tossing an audio packet at the audio decoder.

        ret = av_get_packet(pb, pkt, audio_size);

        if (ret < 0)

            return ret;

        pkt->pts          = bfi->audio_frame;

        bfi->audio_frame += ret;

    } else if (bfi->video_size > 0) {

        //Tossing a video packet at the video decoder.

        ret = av_get_packet(pb, pkt, bfi->video_size);

        if (ret < 0)

            return ret;

        pkt->pts          = bfi->video_frame;

        bfi->video_frame += ret / bfi->video_size;

        /* One less frame to read. A cursory decrement. */

        bfi->nframes--;

    } else {

        /* Empty video packet */

        ret = AVERROR(EAGAIN);

    }

    bfi->avflag       = !bfi->avflag;

    pkt->stream_index = bfi->avflag;

    return ret;

}

const FFInputFormat ff_bfi_demuxer = {

    .p.name         = "bfi",

    .p.long_name    = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),

    .priv_data_size = sizeof(BFIContext),

    .read_probe     = bfi_probe,

    .read_header    = bfi_read_header,

    .read_packet    = bfi_read_packet,

};