/*

 * Canopus HQX decoder

 *

 * 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

 */

#include <inttypes.h>

#include "libavutil/imgutils.h"

#include "libavutil/intreadwrite.h"

#include "avcodec.h"

#include "canopus.h"

#include "codec_internal.h"

#include "get_bits.h"

#include "thread.h"

#include "hqx.h"

#include "hqxdsp.h"

/* HQX has four modes - 422, 444, 422alpha and 444alpha - all 12-bit */

enum HQXFormat {

    HQX_422 = 0,

    HQX_444,

    HQX_422A,

    HQX_444A,

};

#define HQX_HEADER_SIZE 59

/* macroblock selects a group of 4 possible quants and

 * a block can use any of those four quantisers

 * one column is powers of 2, the other one is powers of 2 * 3,

 * then there is the special one, powers of 2 * 5 */

static const int hqx_quants[16][4] = {

    {  0x1,   0x2,   0x4,   0x8 }, {  0x1,  0x3,   0x6,   0xC },

    {  0x2,   0x4,   0x8,  0x10 }, {  0x3,  0x6,   0xC,  0x18 },

    {  0x4,   0x8,  0x10,  0x20 }, {  0x6,  0xC,  0x18,  0x30 },

    {  0x8,  0x10,  0x20,  0x40 },

                      { 0xA, 0x14, 0x28, 0x50 },

                                   {  0xC, 0x18,  0x30,  0x60 },

    { 0x10,  0x20,  0x40,  0x80 }, { 0x18, 0x30,  0x60,  0xC0 },

    { 0x20,  0x40,  0x80, 0x100 }, { 0x30, 0x60,  0xC0, 0x180 },

    { 0x40,  0x80, 0x100, 0x200 }, { 0x60, 0xC0, 0x180, 0x300 },

    { 0x80, 0x100, 0x200, 0x400 }

};

static const uint8_t hqx_quant_luma[64] = {

    16,  16,  16,  19,  19,  19,  42,  44,

    16,  16,  19,  19,  19,  38,  43,  45,

    16,  19,  19,  19,  40,  41,  45,  48,

    19,  19,  19,  40,  41,  42,  46,  49,

    19,  19,  40,  41,  42,  43,  48, 101,

    19,  38,  41,  42,  43,  44,  98, 104,

    42,  43,  45,  46,  48,  98, 109, 116,

    44,  45,  48,  49, 101, 104, 116, 123,

};

static const uint8_t hqx_quant_chroma[64] = {

    16,  16,  19,  25,  26,  26,  42,  44,

    16,  19,  25,  25,  26,  38,  43,  91,

    19,  25,  26,  27,  40,  41,  91,  96,

    25,  25,  27,  40,  41,  84,  93, 197,

    26,  26,  40,  41,  84,  86, 191, 203,

    26,  38,  41,  84,  86, 177, 197, 209,

    42,  43,  91,  93, 191, 197, 219, 232,

    44,  91,  96, 197, 203, 209, 232, 246,

};

static inline void put_blocks(HQXContext *ctx, int plane,

                              int x, int y, int ilace,

                              int16_t *block0, int16_t *block1,

                              const uint8_t *quant)

{

    int fields = ilace ? 2 : 1;

    int lsize = ctx->pic->linesize[plane];

    uint8_t *p = ctx->pic->data[plane] + x * 2;

    ctx->hqxdsp.idct_put((uint16_t *)(p + y * lsize),

                         lsize * fields, block0, quant);

    ctx->hqxdsp.idct_put((uint16_t *)(p + (y + (ilace ? 1 : 8)) * lsize),

                         lsize * fields, block1, quant);

}

static inline void hqx_get_ac(GetBitContext *gb, const HQXAC *ac,

                              int *run, int *lev)

{

    int val;

    val = show_bits(gb, ac->lut_bits);

    if (ac->lut[val].bits == -1) {

        GetBitContext gb2 = *gb;

        skip_bits(&gb2, ac->lut_bits);

        val = ac->lut[val].lev + show_bits(&gb2, ac->extra_bits);

    }

    *run = ac->lut[val].run;

    *lev = ac->lut[val].lev;

    skip_bits(gb, ac->lut[val].bits);

}

static int decode_block(GetBitContext *gb, VLC *vlc,

                        const int *quants, int dcb,

                        int16_t block[64], int *last_dc)

{

    int q, dc;

    int ac_idx;

    int run, lev, pos = 1;

    memset(block, 0, 64 * sizeof(*block));

    dc = get_vlc2(gb, vlc->table, HQX_DC_VLC_BITS, 2);

    *last_dc += dc;

    block[0] = sign_extend(*last_dc << (12 - dcb), 12);

    q = quants[get_bits(gb, 2)];

    if (q >= 128)

        ac_idx = HQX_AC_Q128;

    else if (q >= 64)

        ac_idx = HQX_AC_Q64;

    else if (q >= 32)

        ac_idx = HQX_AC_Q32;

    else if (q >= 16)

        ac_idx = HQX_AC_Q16;

    else if (q >= 8)

        ac_idx = HQX_AC_Q8;

    else

        ac_idx = HQX_AC_Q0;

    do {

        hqx_get_ac(gb, &ff_hqx_ac[ac_idx], &run, &lev);

        pos += run;

        if (pos >= 64)

            break;

        block[ff_zigzag_direct[pos++]] = lev * q;

    } while (pos < 64);

    return 0;

}

static int hqx_decode_422(HQXContext *ctx, int slice_no, int x, int y)

{

    HQXSlice *slice = &ctx->slice[slice_no];

    GetBitContext *gb = &slice->gb;

    const int *quants;

    int flag;

    int last_dc;

    int i, ret;

    if (ctx->interlaced)

        flag = get_bits1(gb);

    else

        flag = 0;

    quants = hqx_quants[get_bits(gb, 4)];

    for (i = 0; i < 8; i++) {

        int vlc_index = ctx->dcb - 9;

        if (i == 0 || i == 4 || i == 6)

            last_dc = 0;

        ret = decode_block(gb, &ctx->dc_vlc[vlc_index], quants,

                           ctx->dcb, slice->block[i], &last_dc);

        if (ret < 0)

            return ret;

    }

    put_blocks(ctx, 0, x,      y, flag, slice->block[0], slice->block[2], hqx_quant_luma);

    put_blocks(ctx, 0, x + 8,  y, flag, slice->block[1], slice->block[3], hqx_quant_luma);

    put_blocks(ctx, 2, x >> 1, y, flag, slice->block[4], slice->block[5], hqx_quant_chroma);

    put_blocks(ctx, 1, x >> 1, y, flag, slice->block[6], slice->block[7], hqx_quant_chroma);

    return 0;

}

static int hqx_decode_422a(HQXContext *ctx, int slice_no, int x, int y)

{

    HQXSlice *slice = &ctx->slice[slice_no];

    GetBitContext *gb = &slice->gb;

    const int *quants;

    int flag = 0;

    int last_dc;

    int i, ret;

    int cbp;

    cbp = get_vlc2(gb, ctx->cbp_vlc.table, HQX_CBP_VLC_BITS, 1);

    for (i = 0; i < 12; i++)

        memset(slice->block[i], 0, sizeof(**slice->block) * 64);

    for (i = 0; i < 12; i++)

        slice->block[i][0] = -0x800;

    if (cbp) {

        if (ctx->interlaced)

            flag = get_bits1(gb);

        quants = hqx_quants[get_bits(gb, 4)];

        cbp |= cbp << 4; // alpha CBP

        if (cbp & 0x3)   // chroma CBP - top

            cbp |= 0x500;

        if (cbp & 0xC)   // chroma CBP - bottom

            cbp |= 0xA00;

        for (i = 0; i < 12; i++) {

            if (i == 0 || i == 4 || i == 8 || i == 10)

                last_dc = 0;

            if (cbp & (1 << i)) {

                int vlc_index = ctx->dcb - 9;

                ret = decode_block(gb, &ctx->dc_vlc[vlc_index], quants,

                                   ctx->dcb, slice->block[i], &last_dc);

                if (ret < 0)

                    return ret;

            }

        }

    }

    put_blocks(ctx, 3, x,      y, flag, slice->block[ 0], slice->block[ 2], hqx_quant_luma);

    put_blocks(ctx, 3, x + 8,  y, flag, slice->block[ 1], slice->block[ 3], hqx_quant_luma);

    put_blocks(ctx, 0, x,      y, flag, slice->block[ 4], slice->block[ 6], hqx_quant_luma);

    put_blocks(ctx, 0, x + 8,  y, flag, slice->block[ 5], slice->block[ 7], hqx_quant_luma);

    put_blocks(ctx, 2, x >> 1, y, flag, slice->block[ 8], slice->block[ 9], hqx_quant_chroma);

    put_blocks(ctx, 1, x >> 1, y, flag, slice->block[10], slice->block[11], hqx_quant_chroma);

    return 0;

}

static int hqx_decode_444(HQXContext *ctx, int slice_no, int x, int y)

{

    HQXSlice *slice = &ctx->slice[slice_no];

    GetBitContext *gb = &slice->gb;

    const int *quants;

    int flag;

    int last_dc;

    int i, ret;

    if (ctx->interlaced)

        flag = get_bits1(gb);

    else

        flag = 0;

    quants = hqx_quants[get_bits(gb, 4)];

    for (i = 0; i < 12; i++) {

        int vlc_index = ctx->dcb - 9;

        if (i == 0 || i == 4 || i == 8)

            last_dc = 0;

        ret = decode_block(gb, &ctx->dc_vlc[vlc_index], quants,

                           ctx->dcb, slice->block[i], &last_dc);

        if (ret < 0)

            return ret;

    }

    put_blocks(ctx, 0, x,     y, flag, slice->block[0], slice->block[ 2], hqx_quant_luma);

    put_blocks(ctx, 0, x + 8, y, flag, slice->block[1], slice->block[ 3], hqx_quant_luma);

    put_blocks(ctx, 2, x,     y, flag, slice->block[4], slice->block[ 6], hqx_quant_chroma);

    put_blocks(ctx, 2, x + 8, y, flag, slice->block[5], slice->block[ 7], hqx_quant_chroma);

    put_blocks(ctx, 1, x,     y, flag, slice->block[8], slice->block[10], hqx_quant_chroma);

    put_blocks(ctx, 1, x + 8, y, flag, slice->block[9], slice->block[11], hqx_quant_chroma);

    return 0;

}

static int hqx_decode_444a(HQXContext *ctx, int slice_no, int x, int y)

{

    HQXSlice *slice = &ctx->slice[slice_no];

    GetBitContext *gb = &slice->gb;

    const int *quants;

    int flag = 0;

    int last_dc;

    int i, ret;

    int cbp;

    cbp = get_vlc2(gb, ctx->cbp_vlc.table, HQX_CBP_VLC_BITS, 1);

    for (i = 0; i < 16; i++)

        memset(slice->block[i], 0, sizeof(**slice->block) * 64);

    for (i = 0; i < 16; i++)

        slice->block[i][0] = -0x800;

    if (cbp) {

        if (ctx->interlaced)

            flag = get_bits1(gb);

        quants = hqx_quants[get_bits(gb, 4)];

        cbp |= cbp << 4; // alpha CBP

        cbp |= cbp << 8; // chroma CBP

        for (i = 0; i < 16; i++) {

            if (i == 0 || i == 4 || i == 8 || i == 12)

                last_dc = 0;

            if (cbp & (1 << i)) {

                int vlc_index = ctx->dcb - 9;

                ret = decode_block(gb, &ctx->dc_vlc[vlc_index], quants,

                                   ctx->dcb, slice->block[i], &last_dc);

                if (ret < 0)

                    return ret;

            }

        }

    }

    put_blocks(ctx, 3, x,     y, flag, slice->block[ 0], slice->block[ 2], hqx_quant_luma);

    put_blocks(ctx, 3, x + 8, y, flag, slice->block[ 1], slice->block[ 3], hqx_quant_luma);

    put_blocks(ctx, 0, x,     y, flag, slice->block[ 4], slice->block[ 6], hqx_quant_luma);

    put_blocks(ctx, 0, x + 8, y, flag, slice->block[ 5], slice->block[ 7], hqx_quant_luma);

    put_blocks(ctx, 2, x,     y, flag, slice->block[ 8], slice->block[10], hqx_quant_chroma);

    put_blocks(ctx, 2, x + 8, y, flag, slice->block[ 9], slice->block[11], hqx_quant_chroma);

    put_blocks(ctx, 1, x,     y, flag, slice->block[12], slice->block[14], hqx_quant_chroma);

    put_blocks(ctx, 1, x + 8, y, flag, slice->block[13], slice->block[15], hqx_quant_chroma);

    return 0;

}

static const int shuffle_16[16] = {

    0, 5, 11, 14, 2, 7, 9, 13, 1, 4, 10, 15, 3, 6, 8, 12

};

static int decode_slice(HQXContext *ctx, int slice_no)

{

    int mb_w = (ctx->width  + 15) >> 4;

    int mb_h = (ctx->height + 15) >> 4;

    int grp_w = (mb_w + 4) / 5;

    int grp_h = (mb_h + 4) / 5;

    int grp_h_edge = grp_w * (mb_w / grp_w);

    int grp_v_edge = grp_h * (mb_h / grp_h);

    int grp_v_rest = mb_w - grp_h_edge;

    int grp_h_rest = mb_h - grp_v_edge;

    int num_mbs = mb_w * mb_h;

    int num_tiles = (num_mbs + 479) / 480;

    int std_tile_blocks = num_mbs / (16 * num_tiles);

    int g_tile = slice_no * num_tiles;

    int blk_addr, loc_addr, mb_x, mb_y, pos, loc_row, i;

    int tile_blocks, tile_limit, tile_no;

    for (tile_no = 0; tile_no < num_tiles; tile_no++, g_tile++) {

        tile_blocks = std_tile_blocks;

        tile_limit = -1;

        if (g_tile < num_mbs - std_tile_blocks * 16 * num_tiles) {

            tile_limit = num_mbs / (16 * num_tiles);

            tile_blocks++;

        }

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

            if (i == tile_limit)

                blk_addr = g_tile + 16 * num_tiles * i;

            else

                blk_addr = tile_no + 16 * num_tiles * i +

                           num_tiles * shuffle_16[(i + slice_no) & 0xF];

            loc_row  = grp_h * (blk_addr / (grp_h * mb_w));

            loc_addr =          blk_addr % (grp_h * mb_w);

            if (loc_row >= grp_v_edge) {

                mb_x = grp_w * (loc_addr / (grp_h_rest * grp_w));

                pos  =          loc_addr % (grp_h_rest * grp_w);

            } else {

                mb_x = grp_w * (loc_addr / (grp_h * grp_w));

                pos  =          loc_addr % (grp_h * grp_w);

            }

            if (mb_x >= grp_h_edge) {

                mb_x +=            pos % grp_v_rest;

                mb_y  = loc_row + (pos / grp_v_rest);

            } else {

                mb_x +=            pos % grp_w;

                mb_y  = loc_row + (pos / grp_w);

            }

            ctx->decode_func(ctx, slice_no, mb_x * 16, mb_y * 16);

        }

    }

    return 0;

}

static int decode_slice_thread(AVCodecContext *avctx, void *arg,

                               int slice_no, int threadnr)

{

    HQXContext *ctx = avctx->priv_data;

    uint32_t *slice_off = ctx->slice_off;

    int ret;

    if (slice_off[slice_no] < HQX_HEADER_SIZE ||

        slice_off[slice_no] >= slice_off[slice_no + 1] ||

        slice_off[slice_no + 1] > ctx->data_size) {

        av_log(avctx, AV_LOG_ERROR, "Invalid slice size %d.\n", ctx->data_size);

        return AVERROR_INVALIDDATA;

    }

    ret = init_get_bits8(&ctx->slice[slice_no].gb,

                         ctx->src + slice_off[slice_no],

                         slice_off[slice_no + 1] - slice_off[slice_no]);

    if (ret < 0)

        return ret;

    return decode_slice(ctx, slice_no);

}

static int hqx_decode_frame(AVCodecContext *avctx, AVFrame *frame,

                            int *got_picture_ptr, AVPacket *avpkt)

{

    HQXContext *ctx = avctx->priv_data;

    const uint8_t *src = avpkt->data;

    uint32_t info_tag;

    int data_start;

    int i, ret;

    if (avpkt->size < 4 + 4) {

        av_log(avctx, AV_LOG_ERROR, "Frame is too small %d.\n", avpkt->size);

        return AVERROR_INVALIDDATA;

    }

    info_tag    = AV_RL32(src);

    if (info_tag == MKTAG('I', 'N', 'F', 'O')) {

        uint32_t info_offset = AV_RL32(src + 4);

        if (info_offset > INT_MAX || info_offset + 8 > avpkt->size) {

            av_log(avctx, AV_LOG_ERROR,

                   "Invalid INFO header offset: 0x%08"PRIX32" is too large.\n",

                   info_offset);

            return AVERROR_INVALIDDATA;

        }

        ff_canopus_parse_info_tag(avctx, src + 8, info_offset);

        info_offset += 8;

        src         += info_offset;

    }

    data_start     = src - avpkt->data;

    ctx->data_size = avpkt->size - data_start;

    ctx->src       = src;

    ctx->pic       = frame;

    if (ctx->data_size < HQX_HEADER_SIZE) {

        av_log(avctx, AV_LOG_ERROR, "Frame too small.\n");

        return AVERROR_INVALIDDATA;

    }

    if (src[0] != 'H' || src[1] != 'Q') {

        av_log(avctx, AV_LOG_ERROR, "Not an HQX frame.\n");

        return AVERROR_INVALIDDATA;

    }

    ctx->interlaced = !(src[2] & 0x80);

    ctx->format     = src[2] & 7;

    ctx->dcb        = (src[3] & 3) + 8;

    ctx->width      = AV_RB16(src + 4);

    ctx->height     = AV_RB16(src + 6);

    for (i = 0; i < 17; i++)

        ctx->slice_off[i] = AV_RB24(src + 8 + i * 3);

    if (ctx->dcb == 8) {

        av_log(avctx, AV_LOG_ERROR, "Invalid DC precision %d.\n", ctx->dcb);

        return AVERROR_INVALIDDATA;

    }

    ret = av_image_check_size(ctx->width, ctx->height, 0, avctx);

    if (ret < 0) {

        av_log(avctx, AV_LOG_ERROR, "Invalid stored dimensions %dx%d.\n",

               ctx->width, ctx->height);

        return AVERROR_INVALIDDATA;

    }

    avctx->coded_width         = FFALIGN(ctx->width,  16);

    avctx->coded_height        = FFALIGN(ctx->height, 16);

    avctx->width               = ctx->width;

    avctx->height              = ctx->height;

    avctx->bits_per_raw_sample = 10;

    //The minimum size is 2bit per macroblock

    // hqx_decode_422 & hqx_decode_444 have a unconditionally stored 4bits hqx_quants index

    // hqx_decode_422a & hqx_decode_444a use cbp_vlc which has a minimum length of 2 bits for its VLCs

    // The code rejects slices overlapping in their input data

    if (avctx->coded_width / 16 * (avctx->coded_height / 16) *

        (100 - avctx->discard_damaged_percentage) / 100 > 4LL * avpkt->size)

        return AVERROR_INVALIDDATA;

    switch (ctx->format) {

    case HQX_422:

        avctx->pix_fmt = AV_PIX_FMT_YUV422P16;

        ctx->decode_func = hqx_decode_422;

        break;

    case HQX_444:

        avctx->pix_fmt = AV_PIX_FMT_YUV444P16;

        ctx->decode_func = hqx_decode_444;

        break;

    case HQX_422A:

        avctx->pix_fmt = AV_PIX_FMT_YUVA422P16;

        ctx->decode_func = hqx_decode_422a;

        break;

    case HQX_444A:

        avctx->pix_fmt = AV_PIX_FMT_YUVA444P16;

        ctx->decode_func = hqx_decode_444a;

        break;

    default:

        av_log(avctx, AV_LOG_ERROR, "Invalid format: %d.\n", ctx->format);

        return AVERROR_INVALIDDATA;

    }

    ret = ff_thread_get_buffer(avctx, frame, 0);

    if (ret < 0)

        return ret;

    avctx->execute2(avctx, decode_slice_thread, NULL, NULL, 16);

    *got_picture_ptr = 1;

    return avpkt->size;

}

static av_cold int hqx_decode_close(AVCodecContext *avctx)

{

    int i;

    HQXContext *ctx = avctx->priv_data;

    ff_vlc_free(&ctx->cbp_vlc);

    for (i = 0; i < 3; i++) {

        ff_vlc_free(&ctx->dc_vlc[i]);

    }

    return 0;

}

static av_cold int hqx_decode_init(AVCodecContext *avctx)

{

    HQXContext *ctx = avctx->priv_data;

    ff_hqxdsp_init(&ctx->hqxdsp);

    return ff_hqx_init_vlcs(ctx);

}

const FFCodec ff_hqx_decoder = {

    .p.name         = "hqx",

    CODEC_LONG_NAME("Canopus HQX"),

    .p.type         = AVMEDIA_TYPE_VIDEO,

    .p.id           = AV_CODEC_ID_HQX,

    .priv_data_size = sizeof(HQXContext),

    .init           = hqx_decode_init,

    FF_CODEC_DECODE_CB(hqx_decode_frame),

    .close          = hqx_decode_close,

    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_SLICE_THREADS |

                      AV_CODEC_CAP_FRAME_THREADS,

    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,

};