/*

 * Bethsoft VID format Demuxer

 * Copyright (c) 2007 Nicholas Tung

 *

 * 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 Bethesda Softworks VID (.vid) file demuxer

 * @author Nicholas Tung [ntung (at. ntung com] (2007-03)

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

 * @see http://www.svatopluk.com/andux/docs/dfvid.html

 */

#include "libavutil/attributes.h"

#include "libavutil/channel_layout.h"

#include "libavutil/imgutils.h"

#include "libavutil/intreadwrite.h"

#include "libavutil/mem.h"

#include "avformat.h"

#include "avio_internal.h"

#include "demux.h"

#include "internal.h"

#include "libavcodec/bethsoftvideo.h"

#define BVID_PALETTE_SIZE 3 * 256

#define DEFAULT_SAMPLE_RATE 11111

typedef struct BVID_DemuxContext

{

    int nframes;

    int sample_rate;        /**< audio sample rate */

    int width;              /**< video width       */

    int height;             /**< video height      */

    /** delay value between frames, added to individual frame delay.

     * custom units, which will be added to other custom units (~=16ms according

     * to free, unofficial documentation) */

    int bethsoft_global_delay;

    int video_index;        /**< video stream index */

    int audio_index;        /**< audio stream index */

    int has_palette;

    uint8_t palette[BVID_PALETTE_SIZE];

    int is_finished;

} BVID_DemuxContext;

static int vid_probe(const AVProbeData *p)

{

    // little-endian VID tag, file starts with "VID\0"

    if (AV_RL32(p->buf) != MKTAG('V', 'I', 'D', 0))

        return 0;

    if (p->buf[4] != 2)

        return AVPROBE_SCORE_MAX / 4;

    return AVPROBE_SCORE_MAX;

}

static int vid_read_header(AVFormatContext *s)

{

    BVID_DemuxContext *vid = s->priv_data;

    AVIOContext *pb = s->pb;

    int ret;

    /* load main header. Contents:

    *    bytes: 'V' 'I' 'D'

    *    int16s: always_512, nframes, width, height, delay, always_14

    */

    avio_skip(pb, 5);

    vid->nframes = avio_rl16(pb);

    vid->width   = avio_rl16(pb);

    vid->height  = avio_rl16(pb);

    vid->bethsoft_global_delay = avio_rl16(pb);

    avio_rl16(pb);

    ret = av_image_check_size(vid->width, vid->height, 0, s);

    if (ret < 0)

        return ret;

    // wait until the first packet to create each stream

    vid->video_index = -1;

    vid->audio_index = -1;

    vid->sample_rate = DEFAULT_SAMPLE_RATE;

    s->ctx_flags |= AVFMTCTX_NOHEADER;

    return 0;

}

#define BUFFER_PADDING_SIZE 1000

static int read_frame(BVID_DemuxContext *vid, AVIOContext *pb, AVPacket *pkt,

                      uint8_t block_type, AVFormatContext *s)

{

    uint8_t * vidbuf_start = NULL;

    int vidbuf_nbytes = 0;

    int code;

    int bytes_copied = 0;

    int position, duration, npixels;

    unsigned int vidbuf_capacity;

    int ret = 0;

    AVStream *st;

    if (vid->video_index < 0) {

        st = avformat_new_stream(s, NULL);

        if (!st)

            return AVERROR(ENOMEM);

        vid->video_index = st->index;

        if (vid->audio_index < 0) {

            avpriv_request_sample(s, "Using default video time base since "

                                  "having no audio packet before the first "

                                  "video packet");

        }

        avpriv_set_pts_info(st, 64, 185, vid->sample_rate);

        st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;

        st->codecpar->codec_id   = AV_CODEC_ID_BETHSOFTVID;

        st->codecpar->width      = vid->width;

        st->codecpar->height     = vid->height;

    }

    st      = s->streams[vid->video_index];

    npixels = st->codecpar->width * st->codecpar->height;

    vidbuf_start = av_malloc(vidbuf_capacity = BUFFER_PADDING_SIZE);

    if(!vidbuf_start)

        return AVERROR(ENOMEM);

    // save the file position for the packet, include block type

    position = avio_tell(pb) - 1;

    vidbuf_start[vidbuf_nbytes++] = block_type;

    // get the current packet duration

    duration = vid->bethsoft_global_delay + avio_rl16(pb);

    // set the y offset if it exists (decoder header data should be in data section)

    if(block_type == VIDEO_YOFF_P_FRAME){

        ret = ffio_read_size(pb, &vidbuf_start[vidbuf_nbytes], 2);

        if (ret < 0)

            goto fail;

        vidbuf_nbytes += 2;

    }

    do{

        uint8_t *tmp = av_fast_realloc(vidbuf_start, &vidbuf_capacity,

                                       vidbuf_nbytes + BUFFER_PADDING_SIZE);

        if (!tmp) {

            ret = AVERROR(ENOMEM);

            goto fail;

        }

        vidbuf_start = tmp;

        code = avio_r8(pb);

        vidbuf_start[vidbuf_nbytes++] = code;

        if(code >= 0x80){ // rle sequence

            if(block_type == VIDEO_I_FRAME)

                vidbuf_start[vidbuf_nbytes++] = avio_r8(pb);

        } else if(code){ // plain sequence

            ret = ffio_read_size(pb, &vidbuf_start[vidbuf_nbytes], code);

            if (ret < 0)

                goto fail;

            vidbuf_nbytes += code;

        }

        bytes_copied += code & 0x7F;

        if(bytes_copied == npixels){ // sometimes no stop character is given, need to keep track of bytes copied

            // may contain a 0 byte even if read all pixels

            if(avio_r8(pb))

                avio_seek(pb, -1, SEEK_CUR);

            break;

        }

        if (bytes_copied > npixels) {

            ret = AVERROR_INVALIDDATA;

            goto fail;

        }

    } while(code);

    // copy data into packet

    if ((ret = av_new_packet(pkt, vidbuf_nbytes)) < 0)

        goto fail;

    memcpy(pkt->data, vidbuf_start, vidbuf_nbytes);

    pkt->pos = position;

    pkt->stream_index = vid->video_index;

    pkt->duration = duration;

    if (block_type == VIDEO_I_FRAME)

        pkt->flags |= AV_PKT_FLAG_KEY;

    /* if there is a new palette available, add it to packet side data */

    if (vid->has_palette) {

        uint8_t *pdata = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE,

                                                 BVID_PALETTE_SIZE);

        if (!pdata) {

            ret = AVERROR(ENOMEM);

            av_log(s, AV_LOG_ERROR, "Failed to allocate palette side data\n");

            goto fail;

        }

        memcpy(pdata, vid->palette, BVID_PALETTE_SIZE);

        vid->has_palette = 0;

    }

    vid->nframes--;  // used to check if all the frames were read

fail:

    av_free(vidbuf_start);

    return ret;

}

static int vid_read_packet(AVFormatContext *s,

                           AVPacket *pkt)

{

    BVID_DemuxContext *vid = s->priv_data;

    AVIOContext *pb = s->pb;

    unsigned char block_type;

    int audio_length;

    int ret_value;

    if(vid->is_finished || avio_feof(pb))

        return AVERROR_EOF;

    block_type = avio_r8(pb);

    switch(block_type){

        case PALETTE_BLOCK:

            if (vid->has_palette) {

                av_log(s, AV_LOG_WARNING, "discarding unused palette\n");

                vid->has_palette = 0;

            }

            ret_value = ffio_read_size(pb, vid->palette, BVID_PALETTE_SIZE);

            if (ret_value < 0)

                return ret_value;

            vid->has_palette = 1;

            return vid_read_packet(s, pkt);

        case FIRST_AUDIO_BLOCK:

            avio_rl16(pb);

            // soundblaster DAC used for sample rate, as on specification page (link above)

            vid->sample_rate = 1000000 / (256 - avio_r8(pb));

            av_fallthrough;

        case AUDIO_BLOCK:

            if (vid->audio_index < 0) {

                AVStream *st = avformat_new_stream(s, NULL);

                if (!st)

                    return AVERROR(ENOMEM);

                vid->audio_index                 = st->index;

                st->codecpar->codec_type            = AVMEDIA_TYPE_AUDIO;

                st->codecpar->codec_id              = AV_CODEC_ID_PCM_U8;

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

                st->codecpar->bits_per_coded_sample = 8;

                st->codecpar->sample_rate           = vid->sample_rate;

                st->codecpar->bit_rate              = 8 * st->codecpar->sample_rate;

                st->start_time                   = 0;

                avpriv_set_pts_info(st, 64, 1, vid->sample_rate);

            }

            audio_length = avio_rl16(pb);

            if ((ret_value = av_get_packet(pb, pkt, audio_length)) != audio_length) {

                if (ret_value < 0)

                    return ret_value;

                av_log(s, AV_LOG_ERROR, "incomplete audio block\n");

                return AVERROR_INVALIDDATA;

            }

            pkt->stream_index = vid->audio_index;

            pkt->duration     = audio_length;

            pkt->flags |= AV_PKT_FLAG_KEY;

            return 0;

        case VIDEO_P_FRAME:

        case VIDEO_YOFF_P_FRAME:

        case VIDEO_I_FRAME:

            return read_frame(vid, pb, pkt, block_type, s);

        case EOF_BLOCK:

            if(vid->nframes != 0)

                av_log(s, AV_LOG_VERBOSE, "reached terminating character but not all frames read.\n");

            vid->is_finished = 1;

            return AVERROR_INVALIDDATA;

        default:

            av_log(s, AV_LOG_ERROR, "unknown block (character = %c, decimal = %d, hex = %x)!!!\n",

                   block_type, block_type, block_type);

            return AVERROR_INVALIDDATA;

    }

}

const FFInputFormat ff_bethsoftvid_demuxer = {

    .p.name         = "bethsoftvid",

    .p.long_name    = NULL_IF_CONFIG_SMALL("Bethesda Softworks VID"),

    .priv_data_size = sizeof(BVID_DemuxContext),

    .read_probe     = vid_probe,

    .read_header    = vid_read_header,

    .read_packet    = vid_read_packet,

};