/*

 * Cinepak Video Decoder

 * Copyright (C) 2003 The FFmpeg project

 *

 * 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

 * Cinepak video decoder

 * @author Ewald Snel <ewald@rambo.its.tudelft.nl>

 *

 * @see For more information on the Cinepak algorithm, visit:

 *   http://www.csse.monash.edu.au/~timf/

 * @see For more information on the quirky data inside Sega FILM/CPK files, visit:

 *   http://wiki.multimedia.cx/index.php?title=Sega_FILM

 *

 * Cinepak colorspace support (c) 2013 Rl, Aetey Global Technologies AB

 * @author Cinepak colorspace, Rl, Aetey Global Technologies AB

 */

#include <stdio.h>

#include <string.h>

#include "libavutil/common.h"

#include "libavutil/intreadwrite.h"

#include "avcodec.h"

#include "codec_internal.h"

#include "decode.h"

typedef uint8_t cvid_codebook[12];

#define MAX_STRIPS      32

typedef struct cvid_strip {

    uint16_t          id;

    uint16_t          x1, y1;

    uint16_t          x2, y2;

    cvid_codebook     v4_codebook[256];

    cvid_codebook     v1_codebook[256];

} cvid_strip;

typedef struct CinepakContext {

    AVCodecContext *avctx;

    AVFrame *frame;

    const unsigned char *data;

    int size;

    int width, height;

    int palette_video;

    cvid_strip strips[MAX_STRIPS];

    int sega_film_skip_bytes;

    uint32_t pal[256];

} CinepakContext;

static void cinepak_decode_codebook (cvid_codebook *codebook,

                                     int chunk_id, int size, const uint8_t *data)

{

    const uint8_t *eod = (data + size);

    uint32_t flag, mask;

    int      i, n;

    uint8_t *p;

    /* check if this chunk contains 4- or 6-element vectors */

    n    = (chunk_id & 0x04) ? 4 : 6;

    flag = 0;

    mask = 0;

    p = codebook[0];

    for (i=0; i < 256; i++) {

        if ((chunk_id & 0x01) && !(mask >>= 1)) {

            if ((data + 4) > eod)

                break;

            flag  = AV_RB32 (data);

            data += 4;

            mask  = 0x80000000;

        }

        if (!(chunk_id & 0x01) || (flag & mask)) {

            int k, kk;

            if ((data + n) > eod)

                break;

            for (k = 0; k < 4; ++k) {

                int r = *data++;

                for (kk = 0; kk < 3; ++kk)

                    *p++ = r;

            }

            if (n == 6) {

                int r, g, b, u, v;

                u = *(int8_t *)data++;

                v = *(int8_t *)data++;

                p -= 12;

                for(k=0; k<4; ++k) {

                    r = *p++ + v*2;

                    g = *p++ - (u/2) - v;

                    b = *p   + u*2;

                    p -= 2;

                    *p++ = av_clip_uint8(r);

                    *p++ = av_clip_uint8(g);

                    *p++ = av_clip_uint8(b);

                }

            }

        } else {

            p += 12;

        }

    }

}

static int cinepak_decode_vectors (CinepakContext *s, cvid_strip *strip,

                                   int chunk_id, int size, const uint8_t *data)

{

    const uint8_t   *eod = (data + size);

    uint32_t         flag, mask;

    uint8_t         *cb0, *cb1, *cb2, *cb3;

    int             x, y;

    char            *ip0, *ip1, *ip2, *ip3;

    flag = 0;

    mask = 0;

    for (y=strip->y1; y < strip->y2; y+=4) {

/* take care of y dimension not being multiple of 4, such streams exist */

        ip0 = ip1 = ip2 = ip3 = s->frame->data[0] +

          (s->palette_video?strip->x1:strip->x1*3) + (y * s->frame->linesize[0]);

        if(s->avctx->height - y > 1) {

            ip1 = ip0 + s->frame->linesize[0];

            if(s->avctx->height - y > 2) {

                ip2 = ip1 + s->frame->linesize[0];

                if(s->avctx->height - y > 3) {

                    ip3 = ip2 + s->frame->linesize[0];

                }

            }

        }

/* to get the correct picture for not-multiple-of-4 cases let us fill each

 * block from the bottom up, thus possibly overwriting the bottommost line

 * more than once but ending with the correct data in place

 * (instead of in-loop checking) */

        for (x=strip->x1; x < strip->x2; x+=4) {

            if ((chunk_id & 0x01) && !(mask >>= 1)) {

                if ((data + 4) > eod)

                    return AVERROR_INVALIDDATA;

                flag  = AV_RB32 (data);

                data += 4;

                mask  = 0x80000000;

            }

            if (!(chunk_id & 0x01) || (flag & mask)) {

                if (!(chunk_id & 0x02) && !(mask >>= 1)) {

                    if ((data + 4) > eod)

                        return AVERROR_INVALIDDATA;

                    flag  = AV_RB32 (data);

                    data += 4;

                    mask  = 0x80000000;

                }

                if ((chunk_id & 0x02) || (~flag & mask)) {

                    uint8_t *p;

                    if (data >= eod)

                        return AVERROR_INVALIDDATA;

                    p = strip->v1_codebook[*data++];

                    if (s->palette_video) {

                        ip3[0] = ip3[1] = ip2[0] = ip2[1] = p[6];

                        ip3[2] = ip3[3] = ip2[2] = ip2[3] = p[9];

                        ip1[0] = ip1[1] = ip0[0] = ip0[1] = p[0];

                        ip1[2] = ip1[3] = ip0[2] = ip0[3] = p[3];

                    } else {

                        p += 6;

                        memcpy(ip3 + 0, p, 3); memcpy(ip3 + 3, p, 3);

                        memcpy(ip2 + 0, p, 3); memcpy(ip2 + 3, p, 3);

                        p += 3; /* ... + 9 */

                        memcpy(ip3 + 6, p, 3); memcpy(ip3 + 9, p, 3);

                        memcpy(ip2 + 6, p, 3); memcpy(ip2 + 9, p, 3);

                        p -= 9; /* ... + 0 */

                        memcpy(ip1 + 0, p, 3); memcpy(ip1 + 3, p, 3);

                        memcpy(ip0 + 0, p, 3); memcpy(ip0 + 3, p, 3);

                        p += 3; /* ... + 3 */

                        memcpy(ip1 + 6, p, 3); memcpy(ip1 + 9, p, 3);

                        memcpy(ip0 + 6, p, 3); memcpy(ip0 + 9, p, 3);

                    }

                } else if (flag & mask) {

                    if ((data + 4) > eod)

                        return AVERROR_INVALIDDATA;

                    cb0 = strip->v4_codebook[*data++];

                    cb1 = strip->v4_codebook[*data++];

                    cb2 = strip->v4_codebook[*data++];

                    cb3 = strip->v4_codebook[*data++];

                    if (s->palette_video) {

                        uint8_t *p;

                        p = ip3;

                        *p++ = cb2[6];

                        *p++ = cb2[9];

                        *p++ = cb3[6];

                        *p   = cb3[9];

                        p = ip2;

                        *p++ = cb2[0];

                        *p++ = cb2[3];

                        *p++ = cb3[0];

                        *p   = cb3[3];

                        p = ip1;

                        *p++ = cb0[6];

                        *p++ = cb0[9];

                        *p++ = cb1[6];

                        *p   = cb1[9];

                        p = ip0;

                        *p++ = cb0[0];

                        *p++ = cb0[3];

                        *p++ = cb1[0];

                        *p   = cb1[3];

                    } else {

                        memcpy(ip3 + 0, cb2 + 6, 6);

                        memcpy(ip3 + 6, cb3 + 6, 6);

                        memcpy(ip2 + 0, cb2 + 0, 6);

                        memcpy(ip2 + 6, cb3 + 0, 6);

                        memcpy(ip1 + 0, cb0 + 6, 6);

                        memcpy(ip1 + 6, cb1 + 6, 6);

                        memcpy(ip0 + 0, cb0 + 0, 6);

                        memcpy(ip0 + 6, cb1 + 0, 6);

                    }

                }

            }

            if (s->palette_video) {

                ip0 += 4;  ip1 += 4;

                ip2 += 4;  ip3 += 4;

            } else {

                ip0 += 12;  ip1 += 12;

                ip2 += 12;  ip3 += 12;

            }

        }

    }

    return 0;

}

static int cinepak_decode_strip (CinepakContext *s,

                                 cvid_strip *strip, const uint8_t *data, int size)

{

    const uint8_t *eod = (data + size);

    int      chunk_id, chunk_size;

    /* coordinate sanity checks */

    if (strip->x2 > s->width   ||

        strip->y2 > s->height  ||

        strip->x1 >= strip->x2 || strip->y1 >= strip->y2)

        return AVERROR_INVALIDDATA;

    while ((data + 4) <= eod) {

        chunk_id   = data[0];

        chunk_size = AV_RB24 (&data[1]) - 4;

        if(chunk_size < 0)

            return AVERROR_INVALIDDATA;

        data      += 4;

        chunk_size = ((data + chunk_size) > eod) ? (eod - data) : chunk_size;

        switch (chunk_id) {

        case 0x20:

        case 0x21:

        case 0x24:

        case 0x25:

            cinepak_decode_codebook (strip->v4_codebook, chunk_id,

                chunk_size, data);

            break;

        case 0x22:

        case 0x23:

        case 0x26:

        case 0x27:

            cinepak_decode_codebook (strip->v1_codebook, chunk_id,

                chunk_size, data);

            break;

        case 0x30:

        case 0x31:

        case 0x32:

            return cinepak_decode_vectors (s, strip, chunk_id,

                chunk_size, data);

        }

        data += chunk_size;

    }

    return AVERROR_INVALIDDATA;

}

static int cinepak_predecode_check (CinepakContext *s)

{

    int           num_strips;

    int           encoded_buf_size;

    num_strips  = AV_RB16 (&s->data[8]);

    encoded_buf_size = AV_RB24(&s->data[1]);

    if (s->size < encoded_buf_size * (int64_t)(100 - s->avctx->discard_damaged_percentage) / 100)

        return AVERROR_INVALIDDATA;

    /* if this is the first frame, check for deviant Sega FILM data */

    if (s->sega_film_skip_bytes == -1) {

        if (!encoded_buf_size) {

            avpriv_request_sample(s->avctx, "encoded_buf_size 0");

            return AVERROR_PATCHWELCOME;

        }

        if (encoded_buf_size != s->size && (s->size % encoded_buf_size) != 0) {

            /* If the encoded frame size differs from the frame size as indicated

             * by the container file, this data likely comes from a Sega FILM/CPK file.

             * If the frame header is followed by the bytes FE 00 00 06 00 00 then

             * this is probably one of the two known files that have 6 extra bytes

             * after the frame header. Else, assume 2 extra bytes. The container

             * size also cannot be a multiple of the encoded size. */

            if (s->size >= 16 &&

                (s->data[10] == 0xFE) &&

                (s->data[11] == 0x00) &&

                (s->data[12] == 0x00) &&

                (s->data[13] == 0x06) &&

                (s->data[14] == 0x00) &&

                (s->data[15] == 0x00))

                s->sega_film_skip_bytes = 6;

            else

                s->sega_film_skip_bytes = 2;

        } else

            s->sega_film_skip_bytes = 0;

    }

    if (s->size < 10 + s->sega_film_skip_bytes + num_strips * 12)

        return AVERROR_INVALIDDATA;

    if (num_strips) {

        const uint8_t *data = s->data + 10 + s->sega_film_skip_bytes;

        int strip_size = AV_RB24 (data + 1);

        if (strip_size < 12 || strip_size > encoded_buf_size)

            return AVERROR_INVALIDDATA;

    }

    return 0;

}

static int cinepak_decode (CinepakContext *s)

{

    const uint8_t  *eod = (s->data + s->size);

    int           i, result, strip_size, frame_flags, num_strips;

    int           y0 = 0;

    frame_flags = s->data[0];

    num_strips  = AV_RB16 (&s->data[8]);

    s->data += 10 + s->sega_film_skip_bytes;

    num_strips = FFMIN(num_strips, MAX_STRIPS);

    s->frame->flags &= ~AV_FRAME_FLAG_KEY;

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

        if ((s->data + 12) > eod)

            return AVERROR_INVALIDDATA;

        s->strips[i].id = s->data[0];

/* zero y1 means "relative to the previous stripe" */

        if (!(s->strips[i].y1 = AV_RB16 (&s->data[4])))

            s->strips[i].y2 = (s->strips[i].y1 = y0) + AV_RB16 (&s->data[8]);

        else

            s->strips[i].y2 = AV_RB16 (&s->data[8]);

        s->strips[i].x1 = AV_RB16 (&s->data[6]);

        s->strips[i].x2 = AV_RB16 (&s->data[10]);

        if (s->strips[i].id == 0x10)

            s->frame->flags |= AV_FRAME_FLAG_KEY;

        strip_size = AV_RB24 (&s->data[1]) - 12;

        if (strip_size < 0)

            return AVERROR_INVALIDDATA;

        s->data   += 12;

        strip_size = ((s->data + strip_size) > eod) ? (eod - s->data) : strip_size;

        if ((i > 0) && !(frame_flags & 0x01)) {

            memcpy (s->strips[i].v4_codebook, s->strips[i-1].v4_codebook,

                sizeof(s->strips[i].v4_codebook));

            memcpy (s->strips[i].v1_codebook, s->strips[i-1].v1_codebook,

                sizeof(s->strips[i].v1_codebook));

        }

        result = cinepak_decode_strip (s, &s->strips[i], s->data, strip_size);

        if (result != 0)

            return result;

        s->data += strip_size;

        y0    = s->strips[i].y2;

    }

    return 0;

}

static av_cold int cinepak_decode_init(AVCodecContext *avctx)

{

    CinepakContext *s = avctx->priv_data;

    s->avctx = avctx;

    s->width = (avctx->width + 3) & ~3;

    s->height = (avctx->height + 3) & ~3;

    s->sega_film_skip_bytes = -1;  /* uninitialized state */

    // check for paletted data

    if (avctx->bits_per_coded_sample != 8) {

        s->palette_video = 0;

        avctx->pix_fmt = AV_PIX_FMT_RGB24;

    } else {

        s->palette_video = 1;

        avctx->pix_fmt = AV_PIX_FMT_PAL8;

    }

    s->frame = av_frame_alloc();

    if (!s->frame)

        return AVERROR(ENOMEM);

    return 0;

}

static int cinepak_decode_frame(AVCodecContext *avctx, AVFrame *rframe,

                                int *got_frame, AVPacket *avpkt)

{

    const uint8_t *buf = avpkt->data;

    int ret = 0, buf_size = avpkt->size;

    CinepakContext *s = avctx->priv_data;

    int num_strips;

    s->data = buf;

    s->size = buf_size;

    if (s->size < 10)

        return AVERROR_INVALIDDATA;

    num_strips = AV_RB16 (&s->data[8]);

    //Empty frame, do not waste time

    if (!num_strips && (!s->palette_video || !av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL)))

        return buf_size;

    if ((ret = cinepak_predecode_check(s)) < 0) {

        av_log(avctx, AV_LOG_ERROR, "cinepak_predecode_check failed\n");

        return ret;

    }

    if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)

        return ret;

    if (s->palette_video) {

        ff_copy_palette(s->pal, avpkt, avctx);

    }

    if ((ret = cinepak_decode(s)) < 0) {

        av_log(avctx, AV_LOG_ERROR, "cinepak_decode failed\n");

    }

    if (s->palette_video)

        memcpy (s->frame->data[1], s->pal, AVPALETTE_SIZE);

    if ((ret = av_frame_ref(rframe, s->frame)) < 0)

        return ret;

    *got_frame = 1;

    /* report that the buffer was completely consumed */

    return buf_size;

}

static av_cold int cinepak_decode_end(AVCodecContext *avctx)

{

    CinepakContext *s = avctx->priv_data;

    av_frame_free(&s->frame);

    return 0;

}

const FFCodec ff_cinepak_decoder = {

    .p.name         = "cinepak",

    CODEC_LONG_NAME("Cinepak"),

    .p.type         = AVMEDIA_TYPE_VIDEO,

    .p.id           = AV_CODEC_ID_CINEPAK,

    .priv_data_size = sizeof(CinepakContext),

    .init           = cinepak_decode_init,

    .close          = cinepak_decode_end,

    FF_CODEC_DECODE_CB(cinepak_decode_frame),

    .p.capabilities = AV_CODEC_CAP_DR1,

};