/*

 * Apple Intermediate Codec decoder

 *

 * Copyright (c) 2013 Konstantin Shishkov

 *

 * 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/mem.h"

#include "libavutil/mem_internal.h"

#include "avcodec.h"

#include "bytestream.h"

#include "codec_internal.h"

#include "get_bits.h"

#include "golomb.h"

#include "idctdsp.h"

#include "thread.h"

#include "unary.h"

#define AIC_HDR_SIZE    24

#define AIC_BAND_COEFFS (64 + 32 + 192 + 96)

enum AICBands {

    COEFF_LUMA = 0,

    COEFF_CHROMA,

    COEFF_LUMA_EXT,

    COEFF_CHROMA_EXT,

    NUM_BANDS

};

static const uint8_t aic_num_band_coeffs[NUM_BANDS] = { 64, 32, 192, 96 };

static const uint16_t aic_band_off[NUM_BANDS] = { 0, 64, 96, 288 };

static const uint8_t aic_quant_matrix[64] = {

     8, 16, 19, 22, 22, 26, 26, 27,

    16, 16, 22, 22, 26, 27, 27, 29,

    19, 22, 26, 26, 27, 29, 29, 35,

    22, 24, 27, 27, 29, 32, 34, 38,

    26, 27, 29, 29, 32, 35, 38, 46,

    27, 29, 34, 34, 35, 40, 46, 56,

    29, 34, 34, 37, 40, 48, 56, 69,

    34, 37, 38, 40, 48, 58, 69, 83,

};

static const uint8_t aic_y_scan[64] = {

     0,  4,  1,  2,  5,  8, 12,  9,

     6,  3,  7, 10, 13, 14, 11, 15,

    47, 43, 46, 45, 42, 39, 35, 38,

    41, 44, 40, 37, 34, 33, 36, 32,

    16, 20, 17, 18, 21, 24, 28, 25,

    22, 19, 23, 26, 29, 30, 27, 31,

    63, 59, 62, 61, 58, 55, 51, 54,

    57, 60, 56, 53, 50, 49, 52, 48,

};

static const uint8_t aic_y_ext_scan[192] = {

     64,  72,  65,  66,  73,  80,  88,  81,

     74,  67,  75,  82,  89,  90,  83,  91,

      0,   4,   1,   2,   5,   8,  12,   9,

      6,   3,   7,  10,  13,  14,  11,  15,

     16,  20,  17,  18,  21,  24,  28,  25,

     22,  19,  23,  26,  29,  30,  27,  31,

    155, 147, 154, 153, 146, 139, 131, 138,

    145, 152, 144, 137, 130, 129, 136, 128,

     47,  43,  46,  45,  42,  39,  35,  38,

     41,  44,  40,  37,  34,  33,  36,  32,

     63,  59,  62,  61,  58,  55,  51,  54,

     57,  60,  56,  53,  50,  49,  52,  48,

     96, 104,  97,  98, 105, 112, 120, 113,

    106,  99, 107, 114, 121, 122, 115, 123,

     68,  76,  69,  70,  77,  84,  92,  85,

     78,  71,  79,  86,  93,  94,  87,  95,

    100, 108, 101, 102, 109, 116, 124, 117,

    110, 103, 111, 118, 125, 126, 119, 127,

    187, 179, 186, 185, 178, 171, 163, 170,

    177, 184, 176, 169, 162, 161, 168, 160,

    159, 151, 158, 157, 150, 143, 135, 142,

    149, 156, 148, 141, 134, 133, 140, 132,

    191, 183, 190, 189, 182, 175, 167, 174,

    181, 188, 180, 173, 166, 165, 172, 164,

};

static const uint8_t aic_c_scan[64] = {

     0,  4,  1,  2,  5,  8, 12,  9,

     6,  3,  7, 10, 13, 14, 11, 15,

    31, 27, 30, 29, 26, 23, 19, 22,

    25, 28, 24, 21, 18, 17, 20, 16,

    32, 36, 33, 34, 37, 40, 44, 41,

    38, 35, 39, 42, 45, 46, 43, 47,

    63, 59, 62, 61, 58, 55, 51, 54,

    57, 60, 56, 53, 50, 49, 52, 48,

};

static const uint8_t aic_c_ext_scan[192] = {

     16,  24,  17,  18,  25,  32,  40,  33,

     26,  19,  27,  34,  41,  42,  35,  43,

      0,   4,   1,   2,   5,   8,  12,   9,

      6,   3,   7,  10,  13,  14,  11,  15,

     20,  28,  21,  22,  29,  36,  44,  37,

     30,  23,  31,  38,  45,  46,  39,  47,

     95,  87,  94,  93,  86,  79,  71,  78,

     85,  92,  84,  77,  70,  69,  76,  68,

     63,  59,  62,  61,  58,  55,  51,  54,

     57,  60,  56,  53,  50,  49,  52,  48,

     91,  83,  90,  89,  82,  75,  67,  74,

     81,  88,  80,  73,  66,  65,  72,  64,

    112, 120, 113, 114, 121, 128, 136, 129,

    122, 115, 123, 130, 137, 138, 131, 139,

     96, 100,  97,  98, 101, 104, 108, 105,

    102,  99, 103, 106, 109, 110, 107, 111,

    116, 124, 117, 118, 125, 132, 140, 133,

    126, 119, 127, 134, 141, 142, 135, 143,

    191, 183, 190, 189, 182, 175, 167, 174,

    181, 188, 180, 173, 166, 165, 172, 164,

    159, 155, 158, 157, 154, 151, 147, 150,

    153, 156, 152, 149, 146, 145, 148, 144,

    187, 179, 186, 185, 178, 171, 163, 170,

    177, 184, 176, 169, 162, 161, 168, 160,

};

static const uint8_t * const aic_scan[NUM_BANDS] = {

    aic_y_scan, aic_c_scan, aic_y_ext_scan, aic_c_ext_scan

};

typedef struct AICContext {

    AVCodecContext *avctx;

    AVFrame        *frame;

    IDCTDSPContext idsp;

    int            num_x_slices;

    int            slice_width;

    int            mb_width, mb_height;

    int            quant;

    int            interlaced;

    int16_t        *slice_data;

    int16_t        *data_ptr[NUM_BANDS];

    DECLARE_ALIGNED(16, int16_t, block)[64];

    DECLARE_ALIGNED(16, uint8_t, quant_matrix)[64];

} AICContext;

static int aic_decode_header(AICContext *ctx, const uint8_t *src, int size)

{

    uint32_t frame_size;

    int width, height;

    if (src[0] != 1) {

        av_log(ctx->avctx, AV_LOG_ERROR, "Invalid version %d\n", src[0]);

        return AVERROR_INVALIDDATA;

    }

    if (src[1] != AIC_HDR_SIZE - 2) {

        av_log(ctx->avctx, AV_LOG_ERROR, "Invalid header size %d\n", src[1]);

        return AVERROR_INVALIDDATA;

    }

    frame_size = AV_RB32(src + 2);

    width      = AV_RB16(src + 6);

    height     = AV_RB16(src + 8);

    if (frame_size > size) {

        av_log(ctx->avctx, AV_LOG_ERROR, "Frame size should be %"PRIu32" got %d\n",

               frame_size, size);

        return AVERROR_INVALIDDATA;

    }

    if (width != ctx->avctx->width || height != ctx->avctx->height) {

        av_log(ctx->avctx, AV_LOG_ERROR,

               "Picture dimension changed: old: %d x %d, new: %d x %d\n",

               ctx->avctx->width, ctx->avctx->height, width, height);

        return AVERROR_INVALIDDATA;

    }

    ctx->quant      = src[15];

    ctx->interlaced = ((src[16] >> 4) == 3);

    return 0;

}

#define GET_CODE(val, type, add_bits)                         \

    do {                                                      \

        if (type)                                             \

            val = get_ue_golomb(gb);                          \

        else                                                  \

            val = get_unary(gb, 1, 31);                       \

        if (add_bits)                                         \

            val = (val << add_bits) + get_bits(gb, add_bits); \

    } while (0)

static int aic_decode_coeffs(GetBitContext *gb, int16_t *dst,

                             int band, int slice_width, int force_chroma)

{

    int has_skips, coeff_type, coeff_bits, skip_type, skip_bits;

    const int num_coeffs = aic_num_band_coeffs[band];

    const uint8_t *scan = aic_scan[band | force_chroma];

    int mb, idx;

    unsigned val;

    if (get_bits_left(gb) < 5)

        return AVERROR_INVALIDDATA;

    has_skips  = get_bits1(gb);

    coeff_type = get_bits1(gb);

    coeff_bits = get_bits(gb, 3);

    if (has_skips) {

        skip_type = get_bits1(gb);

        skip_bits = get_bits(gb, 3);

        for (mb = 0; mb < slice_width; mb++) {

            idx = -1;

            do {

                GET_CODE(val, skip_type, skip_bits);

                if (val >= 0x10000)

                    return AVERROR_INVALIDDATA;

                idx += val + 1;

                if (idx >= num_coeffs)

                    break;

                GET_CODE(val, coeff_type, coeff_bits);

                val++;

                if (val >= 0x10000)

                    return AVERROR_INVALIDDATA;

                dst[scan[idx]] = val;

            } while (idx < num_coeffs - 1);

            dst += num_coeffs;

        }

    } else {

        for (mb = 0; mb < slice_width; mb++) {

            for (idx = 0; idx < num_coeffs; idx++) {

                GET_CODE(val, coeff_type, coeff_bits);

                if (val >= 0x10000)

                    return AVERROR_INVALIDDATA;

                dst[scan[idx]] = val;

            }

            dst += num_coeffs;

        }

    }

    return 0;

}

static void recombine_block(int16_t *dst, const uint8_t *scan,

                            int16_t **base, int16_t **ext)

{

    int i, j;

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

        for (j = 0; j < 4; j++)

            dst[scan[i * 8 + j]]     = (*base)[j];

        for (j = 0; j < 4; j++)

            dst[scan[i * 8 + j + 4]] = (*ext)[j];

        *base += 4;

        *ext  += 4;

    }

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

        for (j = 0; j < 8; j++)

            dst[scan[i * 8 + j]] = (*ext)[j];

        *ext  += 8;

    }

}

static void recombine_block_il(int16_t *dst, const uint8_t *scan,

                               int16_t **base, int16_t **ext,

                               int block_no)

{

    int i, j;

    if (block_no < 2) {

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

            for (j = 0; j < 4; j++)

                dst[scan[i * 8 + j]]     = (*base)[j];

            for (j = 0; j < 4; j++)

                dst[scan[i * 8 + j + 4]] = (*ext)[j];

            *base += 4;

            *ext  += 4;

        }

    } else {

        for (i = 0; i < 64; i++)

            dst[scan[i]] = (*ext)[i];

        *ext += 64;

    }

}

static void unquant_block(int16_t *block, int q, uint8_t *quant_matrix)

{

    int i;

    for (i = 0; i < 64; i++) {

        int val  = (uint16_t)block[i];

        int sign = val & 1;

        block[i] = (((val >> 1) ^ -sign) * q * quant_matrix[i] >> 4)

                   + sign;

    }

}

static int aic_decode_slice(AICContext *ctx, int mb_x, int mb_y,

                            const uint8_t *src, int src_size)

{

    GetBitContext gb;

    int ret, i, mb, blk;

    int slice_width = FFMIN(ctx->slice_width, ctx->mb_width - mb_x);

    int last_row = mb_y && mb_y == ctx->mb_height - 1;

    int y_pos, c_pos;

    uint8_t *Y, *C[2];

    uint8_t *dst;

    int16_t *base_y = ctx->data_ptr[COEFF_LUMA];

    int16_t *base_c = ctx->data_ptr[COEFF_CHROMA];

    int16_t *ext_y  = ctx->data_ptr[COEFF_LUMA_EXT];

    int16_t *ext_c  = ctx->data_ptr[COEFF_CHROMA_EXT];

    const int ystride = ctx->frame->linesize[0];

    if (last_row) {

        y_pos = (ctx->avctx->height - 16);

        c_pos = ((ctx->avctx->height+1)/2 - 8);

    } else {

        y_pos = mb_y * 16;

        c_pos = mb_y * 8;

    }

    Y = ctx->frame->data[0] + mb_x * 16 + y_pos * ystride;

    for (i = 0; i < 2; i++)

        C[i] = ctx->frame->data[i + 1] + mb_x * 8

               + c_pos * ctx->frame->linesize[i + 1];

    init_get_bits(&gb, src, src_size * 8);

    memset(ctx->slice_data, 0,

           sizeof(*ctx->slice_data) * slice_width * AIC_BAND_COEFFS);

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

        if ((ret = aic_decode_coeffs(&gb, ctx->data_ptr[i],

                                     i, slice_width,

                                     !ctx->interlaced)) < 0)

            return ret;

    for (mb = 0; mb < slice_width; mb++) {

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

            if (!ctx->interlaced)

                recombine_block(ctx->block, ctx->idsp.idct_permutation,

                                &base_y, &ext_y);

            else

                recombine_block_il(ctx->block, ctx->idsp.idct_permutation,

                                   &base_y, &ext_y, blk);

            unquant_block(ctx->block, ctx->quant, ctx->quant_matrix);

            ctx->idsp.idct(ctx->block);

            if (!ctx->interlaced) {

                dst = Y + (blk >> 1) * 8 * ystride + (blk & 1) * 8;

                ctx->idsp.put_signed_pixels_clamped(ctx->block, dst, ystride);

            } else {

                dst = Y + (blk & 1) * 8 + (blk >> 1) * ystride;

                ctx->idsp.put_signed_pixels_clamped(ctx->block, dst,

                                                    ystride * 2);

            }

        }

        Y += 16;

        for (blk = 0; blk < 2; blk++) {

            recombine_block(ctx->block, ctx->idsp.idct_permutation,

                            &base_c, &ext_c);

            unquant_block(ctx->block, ctx->quant, ctx->quant_matrix);

            ctx->idsp.idct(ctx->block);

            ctx->idsp.put_signed_pixels_clamped(ctx->block, C[blk],

                                                ctx->frame->linesize[blk + 1]);

            C[blk] += 8;

        }

    }

    return 0;

}

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

                            int *got_frame, AVPacket *avpkt)

{

    AICContext *ctx    = avctx->priv_data;

    const uint8_t *buf = avpkt->data;

    int buf_size       = avpkt->size;

    GetByteContext gb;

    uint32_t off;

    int x, y, ret;

    int slice_size;

    ctx->frame            = frame;

    off = FFALIGN(AIC_HDR_SIZE + ctx->num_x_slices * ctx->mb_height * 2, 4);

    if (buf_size < off) {

        av_log(avctx, AV_LOG_ERROR, "Too small frame\n");

        return AVERROR_INVALIDDATA;

    }

    ret = aic_decode_header(ctx, buf, buf_size);

    if (ret < 0) {

        av_log(avctx, AV_LOG_ERROR, "Invalid header\n");

        return ret;

    }

    if ((ret = ff_thread_get_buffer(avctx, ctx->frame, 0)) < 0)

        return ret;

    bytestream2_init(&gb, buf + AIC_HDR_SIZE,

                     ctx->num_x_slices * ctx->mb_height * 2);

    for (y = 0; y < ctx->mb_height; y++) {

        for (x = 0; x < ctx->mb_width; x += ctx->slice_width) {

            slice_size = bytestream2_get_le16(&gb) * 4;

            if (slice_size + off > buf_size || !slice_size) {

                av_log(avctx, AV_LOG_ERROR,

                       "Incorrect slice size %d at %d.%d\n", slice_size, x, y);

                return AVERROR_INVALIDDATA;

            }

            ret = aic_decode_slice(ctx, x, y, buf + off, slice_size);

            if (ret < 0) {

                av_log(avctx, AV_LOG_ERROR,

                       "Error decoding slice at %d.%d\n", x, y);

                return ret;

            }

            off += slice_size;

        }

    }

    *got_frame = 1;

    return avpkt->size;

}

static av_cold int aic_decode_init(AVCodecContext *avctx)

{

    AICContext *ctx = avctx->priv_data;

    int i;

    ctx->avctx = avctx;

    avctx->pix_fmt = AV_PIX_FMT_YUV420P;

    ff_idctdsp_init(&ctx->idsp, avctx);

    for (i = 0; i < 64; i++)

        ctx->quant_matrix[ctx->idsp.idct_permutation[i]] = aic_quant_matrix[i];

    ctx->mb_width  = FFALIGN(avctx->width,  16) >> 4;

    ctx->mb_height = FFALIGN(avctx->height, 16) >> 4;

    ctx->num_x_slices = (ctx->mb_width + 15) >> 4;

    ctx->slice_width  = 16;

    for (i = 1; i < ctx->mb_width; i++) {

        if (!(ctx->mb_width % i) && (ctx->mb_width / i <= 32)) {

            ctx->slice_width  = ctx->mb_width / i;

            ctx->num_x_slices = i;

            break;

        }

    }

    ctx->slice_data = av_calloc(ctx->slice_width, AIC_BAND_COEFFS * sizeof(*ctx->slice_data));

    if (!ctx->slice_data) {

        av_log(avctx, AV_LOG_ERROR, "Error allocating slice buffer\n");

        return AVERROR(ENOMEM);

    }

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

        ctx->data_ptr[i] = ctx->slice_data + ctx->slice_width

                                             * aic_band_off[i];

    return 0;

}

static av_cold int aic_decode_close(AVCodecContext *avctx)

{

    AICContext *ctx = avctx->priv_data;

    av_freep(&ctx->slice_data);

    return 0;

}

const FFCodec ff_aic_decoder = {

    .p.name         = "aic",

    CODEC_LONG_NAME("Apple Intermediate Codec"),

    .p.type         = AVMEDIA_TYPE_VIDEO,

    .p.id           = AV_CODEC_ID_AIC,

    .priv_data_size = sizeof(AICContext),

    .init           = aic_decode_init,

    .close          = aic_decode_close,

    FF_CODEC_DECODE_CB(aic_decode_frame),

    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,

};