/*

 * SMJPEG demuxer

 * Copyright (c) 2011 Paul B Mahol

 *

 * 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

 * This is a demuxer for Loki SDL Motion JPEG files

 */

#include <inttypes.h>

#include "libavutil/mem.h"

#include "avformat.h"

#include "demux.h"

#include "internal.h"

#include "smjpeg.h"

typedef struct SMJPEGContext {

    int audio_stream_index;

    int video_stream_index;

} SMJPEGContext;

static int smjpeg_probe(const AVProbeData *p)

{

    if (!memcmp(p->buf, SMJPEG_MAGIC, 8))

        return AVPROBE_SCORE_MAX;

    return 0;

}

static int smjpeg_read_header(AVFormatContext *s)

{

    SMJPEGContext *sc = s->priv_data;

    AVStream *ast = NULL, *vst = NULL;

    AVIOContext *pb = s->pb;

    uint32_t version, htype, hlength, duration;

    char *comment;

    sc->audio_stream_index =

    sc->video_stream_index = -1;

    avio_skip(pb, 8); // magic

    version = avio_rb32(pb);

    if (version)

        avpriv_request_sample(s, "Unknown version %"PRIu32, version);

    duration = avio_rb32(pb); // in msec

    while (!avio_feof(pb)) {

        htype = avio_rl32(pb);

        switch (htype) {

        case SMJPEG_TXT:

            hlength = avio_rb32(pb);

            if (!hlength || hlength > 512)

                return AVERROR_INVALIDDATA;

            comment = av_malloc(hlength + 1);

            if (!comment)

                return AVERROR(ENOMEM);

            if (avio_read(pb, comment, hlength) != hlength) {

                av_freep(&comment);

                av_log(s, AV_LOG_ERROR, "error when reading comment\n");

                return AVERROR_INVALIDDATA;

            }

            comment[hlength] = 0;

            av_dict_set(&s->metadata, "comment", comment,

                        AV_DICT_DONT_STRDUP_VAL);

            break;

        case SMJPEG_SND:

            if (ast) {

                avpriv_request_sample(s, "Multiple audio streams");

                return AVERROR_PATCHWELCOME;

            }

            hlength = avio_rb32(pb);

            if (hlength < 8)

                return AVERROR_INVALIDDATA;

            ast = avformat_new_stream(s, 0);

            if (!ast)

                return AVERROR(ENOMEM);

            ast->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;

            ast->codecpar->sample_rate = avio_rb16(pb);

            ast->codecpar->bits_per_coded_sample = avio_r8(pb);

            ast->codecpar->ch_layout.nb_channels = avio_r8(pb);

            ast->codecpar->codec_tag   = avio_rl32(pb);

            ast->codecpar->codec_id    = ff_codec_get_id(ff_codec_smjpeg_audio_tags,

                                                         ast->codecpar->codec_tag);

            ast->duration           = duration;

            sc->audio_stream_index  = ast->index;

            avpriv_set_pts_info(ast, 32, 1, 1000);

            avio_skip(pb, hlength - 8);

            break;

        case SMJPEG_VID:

            if (vst) {

                avpriv_request_sample(s, "Multiple video streams");

                return AVERROR_INVALIDDATA;

            }

            hlength = avio_rb32(pb);

            if (hlength < 12)

                return AVERROR_INVALIDDATA;

            vst = avformat_new_stream(s, 0);

            if (!vst)

                return AVERROR(ENOMEM);

            vst->nb_frames            = avio_rb32(pb);

            vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;

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

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

            vst->codecpar->codec_tag  = avio_rl32(pb);

            vst->codecpar->codec_id   = ff_codec_get_id(ff_codec_smjpeg_video_tags,

                                                        vst->codecpar->codec_tag);

            vst->duration          = duration;

            sc->video_stream_index = vst->index;

            avpriv_set_pts_info(vst, 32, 1, 1000);

            avio_skip(pb, hlength - 12);

            break;

        case SMJPEG_HEND:

            return 0;

        default:

            av_log(s, AV_LOG_ERROR, "unknown header %"PRIx32"\n", htype);

            return AVERROR_INVALIDDATA;

        }

    }

    return AVERROR_EOF;

}

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

{

    SMJPEGContext *sc = s->priv_data;

    uint32_t dtype, size, timestamp;

    int64_t pos;

    int ret;

    if (avio_feof(s->pb))

        return AVERROR_EOF;

    pos   = avio_tell(s->pb);

    dtype = avio_rl32(s->pb);

    switch (dtype) {

    case SMJPEG_SNDD:

        if (sc->audio_stream_index < 0)

            return AVERROR_INVALIDDATA;

        timestamp = avio_rb32(s->pb);

        size = avio_rb32(s->pb);

        ret = av_get_packet(s->pb, pkt, size);

        pkt->stream_index = sc->audio_stream_index;

        pkt->pts = timestamp;

        pkt->pos = pos;

        break;

    case SMJPEG_VIDD:

        if (sc->video_stream_index < 0)

            return AVERROR_INVALIDDATA;

        timestamp = avio_rb32(s->pb);

        size = avio_rb32(s->pb);

        ret = av_get_packet(s->pb, pkt, size);

        pkt->stream_index = sc->video_stream_index;

        pkt->pts = timestamp;

        pkt->pos = pos;

        break;

    case SMJPEG_DONE:

        ret = AVERROR_EOF;

        break;

    default:

        av_log(s, AV_LOG_ERROR, "unknown chunk %"PRIx32"\n", dtype);

        ret = AVERROR_INVALIDDATA;

        break;

    }

    return ret;

}

const FFInputFormat ff_smjpeg_demuxer = {

    .p.name         = "smjpeg",

    .p.long_name    = NULL_IF_CONFIG_SMALL("Loki SDL MJPEG"),

    .p.extensions   = "mjpg",

    .p.flags        = AVFMT_GENERIC_INDEX,

    .priv_data_size = sizeof(SMJPEGContext),

    .read_probe     = smjpeg_probe,

    .read_header    = smjpeg_read_header,

    .read_packet    = smjpeg_read_packet,

};