/*

 * RL2 Format Demuxer

 * Copyright (c) 2008 Sascha Sommer (saschasommer@freenet.de)

 *

 * 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

 */

/**

 * RL2 file demuxer

 * @file

 * @author Sascha Sommer (saschasommer@freenet.de)

 * @see http://wiki.multimedia.cx/index.php?title=RL2

 *

 * extradata:

 * 2 byte le initial drawing offset within 320x200 viewport

 * 4 byte le number of used colors

 * 256 * 3 bytes rgb palette

 * optional background_frame

 */

#include <stdint.h>

#include "libavutil/intreadwrite.h"

#include "libavutil/mathematics.h"

#include "libavutil/mem.h"

#include "avformat.h"

#include "demux.h"

#include "internal.h"

#define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr, palette

#define FORM_TAG MKBETAG('F', 'O', 'R', 'M')

#define RLV2_TAG MKBETAG('R', 'L', 'V', '2')

#define RLV3_TAG MKBETAG('R', 'L', 'V', '3')

typedef struct Rl2DemuxContext {

    unsigned int index_pos[2];   ///< indexes in the sample tables

} Rl2DemuxContext;

/**

 * check if the file is in rl2 format

 * @param p probe buffer

 * @return 0 when the probe buffer does not contain rl2 data, > 0 otherwise

 */

static int rl2_probe(const AVProbeData *p)

{

    if(AV_RB32(&p->buf[0]) != FORM_TAG)

        return 0;

    if(AV_RB32(&p->buf[8]) != RLV2_TAG &&

        AV_RB32(&p->buf[8]) != RLV3_TAG)

        return 0;

    return AVPROBE_SCORE_MAX;

}

/**

 * read rl2 header data and setup the avstreams

 * @param s demuxer context

 * @return 0 on success, AVERROR otherwise

 */

static av_cold int rl2_read_header(AVFormatContext *s)

{

    AVIOContext *pb = s->pb;

    AVStream *st;

    unsigned int frame_count;

    unsigned int audio_frame_counter = 0;

    unsigned int video_frame_counter = 0;

    unsigned int back_size;

    unsigned short sound_rate;

    unsigned short rate;

    unsigned short channels;

    unsigned short def_sound_size;

    unsigned int signature;

    unsigned int pts_den = 11025; /* video only case */

    unsigned int pts_num = 1103;

    unsigned int* chunk_offset = NULL;

    int* chunk_size = NULL;

    int* audio_size = NULL;

    int i;

    int ret = 0;

    avio_skip(pb,4);          /* skip FORM tag */

    back_size = avio_rl32(pb); /**< get size of the background frame */

    signature = avio_rb32(pb);

    avio_skip(pb, 4);         /* data size */

    frame_count = avio_rl32(pb);

    /* disallow back_sizes and frame_counts that may lead to overflows later */

    if(back_size > INT_MAX/2  || frame_count > INT_MAX / sizeof(uint32_t))

        return AVERROR_INVALIDDATA;

    avio_skip(pb, 2);         /* encoding method */

    sound_rate = avio_rl16(pb);

    rate = avio_rl16(pb);

    channels = avio_rl16(pb);

    def_sound_size = avio_rl16(pb);

    /** setup video stream */

    st = avformat_new_stream(s, NULL);

    if(!st)

         return AVERROR(ENOMEM);

    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;

    st->codecpar->codec_id = AV_CODEC_ID_RL2;

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

    st->codecpar->width = 320;

    st->codecpar->height = 200;

    /** allocate and fill extradata */

    st->codecpar->extradata_size = EXTRADATA1_SIZE;

    if(signature == RLV3_TAG && back_size > 0)

        st->codecpar->extradata_size += back_size;

    ret = ff_get_extradata(s, st->codecpar, pb, st->codecpar->extradata_size);

    if (ret < 0)

        return ret;

    /** setup audio stream if present */

    if(sound_rate){

        if (!channels || channels > 42) {

            av_log(s, AV_LOG_ERROR, "Invalid number of channels: %d\n", channels);

            return AVERROR_INVALIDDATA;

        }

        pts_num = def_sound_size;

        pts_den = rate;

        st = avformat_new_stream(s, NULL);

        if (!st)

            return AVERROR(ENOMEM);

        st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;

        st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;

        st->codecpar->codec_tag = 1;

        st->codecpar->ch_layout.nb_channels = channels;

        st->codecpar->bits_per_coded_sample = 8;

        st->codecpar->sample_rate = rate;

        st->codecpar->bit_rate = channels * st->codecpar->sample_rate *

            st->codecpar->bits_per_coded_sample;

        st->codecpar->block_align = channels *

            st->codecpar->bits_per_coded_sample / 8;

        avpriv_set_pts_info(st,32,1,rate);

    }

    avpriv_set_pts_info(s->streams[0], 32, pts_num, pts_den);

    chunk_size =   av_malloc(frame_count * sizeof(uint32_t));

    audio_size =   av_malloc(frame_count * sizeof(uint32_t));

    chunk_offset = av_malloc(frame_count * sizeof(uint32_t));

    if(!chunk_size || !audio_size || !chunk_offset){

        av_free(chunk_size);

        av_free(audio_size);

        av_free(chunk_offset);

        return AVERROR(ENOMEM);

    }

    /** read offset and size tables */

    for(i=0; i < frame_count;i++) {

        if (avio_feof(pb)) {

            ret = AVERROR_INVALIDDATA;

            goto end;

        }

        chunk_size[i] = avio_rl32(pb);

    }

    for(i=0; i < frame_count;i++) {

        if (avio_feof(pb)) {

            ret = AVERROR_INVALIDDATA;

            goto end;

        }

        chunk_offset[i] = avio_rl32(pb);

    }

    for(i=0; i < frame_count;i++) {

        if (avio_feof(pb)) {

            ret = AVERROR_INVALIDDATA;

            goto end;

        }

        audio_size[i] = avio_rl32(pb) & 0xFFFF;

    }

    /** build the sample index */

    for(i=0;i<frame_count;i++){

        if(chunk_size[i] < 0 || audio_size[i] > chunk_size[i]){

            ret = AVERROR_INVALIDDATA;

            break;

        }

        if(sound_rate && audio_size[i]){

            av_add_index_entry(s->streams[1], chunk_offset[i],

                audio_frame_counter,audio_size[i], 0, AVINDEX_KEYFRAME);

            audio_frame_counter += audio_size[i] / channels;

        }

        av_add_index_entry(s->streams[0], chunk_offset[i] + audio_size[i],

            video_frame_counter,chunk_size[i]-audio_size[i],0,AVINDEX_KEYFRAME);

        ++video_frame_counter;

    }

end:

    av_free(chunk_size);

    av_free(audio_size);

    av_free(chunk_offset);

    return ret;

}

/**

 * read a single audio or video packet

 * @param s demuxer context

 * @param pkt the packet to be filled

 * @return 0 on success, AVERROR otherwise

 */

static int rl2_read_packet(AVFormatContext *s,

                            AVPacket *pkt)

{

    Rl2DemuxContext *rl2 = s->priv_data;

    AVIOContext *pb = s->pb;

    AVIndexEntry *sample = NULL;

    int i;

    int ret = 0;

    int stream_id = -1;

    int64_t pos = INT64_MAX;

    /** check if there is a valid video or audio entry that can be used */

    for(i=0; i<s->nb_streams; i++){

        const FFStream *const sti = ffstream(s->streams[i]);

        if (rl2->index_pos[i] < sti->nb_index_entries

              && sti->index_entries[ rl2->index_pos[i] ].pos < pos) {

            sample = &sti->index_entries[ rl2->index_pos[i] ];

            pos= sample->pos;

            stream_id= i;

        }

    }

    if(stream_id == -1)

        return AVERROR_EOF;

    ++rl2->index_pos[stream_id];

    /** position the stream (will probably be there anyway) */

    avio_seek(pb, sample->pos, SEEK_SET);

    /** fill the packet */

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

    if(ret != sample->size){

        return AVERROR_INVALIDDATA;

    }

    pkt->stream_index = stream_id;

    pkt->pts = sample->timestamp;

    return ret;

}

/**

 * seek to a new timestamp

 * @param s demuxer context

 * @param stream_index index of the stream that should be seeked

 * @param timestamp wanted timestamp

 * @param flags direction and seeking mode

 * @return 0 on success, -1 otherwise

 */

static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)

{

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

    Rl2DemuxContext *rl2 = s->priv_data;

    int i;

    int index = av_index_search_timestamp(st, timestamp, flags);

    if(index < 0)

        return -1;

    rl2->index_pos[stream_index] = index;

    timestamp = ffstream(st)->index_entries[index].timestamp;

    for(i=0; i < s->nb_streams; i++){

        AVStream *st2 = s->streams[i];

        index = av_index_search_timestamp(st2,

                    av_rescale_q(timestamp, st->time_base, st2->time_base),

                    flags | AVSEEK_FLAG_BACKWARD);

        if(index < 0)

            index = 0;

        rl2->index_pos[i] = index;

    }

    return 0;

}

const FFInputFormat ff_rl2_demuxer = {

    .p.name         = "rl2",

    .p.long_name    = NULL_IF_CONFIG_SMALL("RL2"),

    .priv_data_size = sizeof(Rl2DemuxContext),

    .read_probe     = rl2_probe,

    .read_header    = rl2_read_header,

    .read_packet    = rl2_read_packet,

    .read_seek      = rl2_read_seek,

};