/*

 * Sony PlayStation MDEC (Motion DECoder)

 * Copyright (c) 2003 Michael Niedermayer

 *

 * based upon code from Sebastian Jedruszkiewicz <elf@frogger.rules.pl>

 *

 * 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

 * Sony PlayStation MDEC (Motion DECoder)

 * This is very similar to intra-only MPEG-1.

 */

#include "libavutil/mem.h"

#include "libavutil/mem_internal.h"

#include "avcodec.h"

#include "blockdsp.h"

#include "bswapdsp.h"

#include "codec_internal.h"

#include "idctdsp.h"

#include "mpeg12data.h"

#include "mpeg12dec.h"

#include "thread.h"

typedef struct MDECContext {

    AVCodecContext *avctx;

    BlockDSPContext bdsp;

    BswapDSPContext bbdsp;

    IDCTDSPContext idsp;

    GetBitContext gb;

    uint8_t permutated_scantable[64];

    int version;

    int qscale;

    int last_dc[3];

    int mb_width;

    int mb_height;

    int mb_x, mb_y;

    DECLARE_ALIGNED(32, int16_t, block)[6][64];

    DECLARE_ALIGNED(16, uint16_t, quant_matrix)[64];

    uint8_t *bitstream_buffer;

    unsigned int bitstream_buffer_size;

} MDECContext;

//very similar to MPEG-1

static inline int mdec_decode_block_intra(MDECContext *a, int16_t *block, int n)

{

    int level, diff, i, j, run;

    int component;

    const uint8_t *const scantable = a->permutated_scantable;

    const uint16_t *quant_matrix = a->quant_matrix;

    const int qscale = a->qscale;

    /* DC coefficient */

    if (a->version <= 2) {

        block[0] = 2 * get_sbits(&a->gb, 10) + 1024;

    } else {

        component = (n <= 3 ? 0 : n - 4 + 1);

        diff = decode_dc(&a->gb, component);

        a->last_dc[component] += diff;

        block[0] = a->last_dc[component] * (1 << 3);

    }

    i = 0;

    {

        OPEN_READER(re, &a->gb);

        /* now quantify & encode AC coefficients */

        for (;;) {

            UPDATE_CACHE(re, &a->gb);

            GET_RL_VLC(level, run, re, &a->gb, ff_mpeg1_rl_vlc, TEX_VLC_BITS, 2, 0);

            if (level == 127) {

                break;

            } else if (level != 0) {

                i += run;

                if (i > 63) {

                    av_log(a->avctx, AV_LOG_ERROR,

                           "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);

                    return AVERROR_INVALIDDATA;

                }

                j     = scantable[i];

                level = (level * qscale * quant_matrix[j]) >> 3;

                level = (level ^ SHOW_SBITS(re, &a->gb, 1)) - SHOW_SBITS(re, &a->gb, 1);

                LAST_SKIP_BITS(re, &a->gb, 1);

            } else {

                /* escape */

                run = SHOW_UBITS(re, &a->gb, 6) + 1;

                SKIP_BITS(re, &a->gb, 6);

                level = SHOW_SBITS(re, &a->gb, 10);

                LAST_SKIP_BITS(re, &a->gb, 10);

                i += run;

                if (i > 63) {

                    av_log(a->avctx, AV_LOG_ERROR,

                           "ac-tex damaged at %d %d\n", a->mb_x, a->mb_y);

                    return AVERROR_INVALIDDATA;

                }

                j = scantable[i];

                if (level < 0) {

                    level = -level;

                    level = (level * (unsigned)qscale * quant_matrix[j]) >> 3;

                    level = (level - 1) | 1;

                    level = -level;

                } else {

                    level = (level * (unsigned)qscale * quant_matrix[j]) >> 3;

                    level = (level - 1) | 1;

                }

            }

            block[j] = level;

        }

        CLOSE_READER(re, &a->gb);

    }

    return 0;

}

static inline int decode_mb(MDECContext *a, int16_t block[6][64])

{

    int i, ret;

    static const int block_index[6] = { 5, 4, 0, 1, 2, 3 };

    a->bdsp.clear_blocks(block[0]);

    for (i = 0; i < 6; i++) {

        if ((ret = mdec_decode_block_intra(a, block[block_index[i]],

                                           block_index[i])) < 0)

            return ret;

        if (get_bits_left(&a->gb) < 0)

            return AVERROR_INVALIDDATA;

    }

    return 0;

}

static inline void idct_put(MDECContext *a, AVFrame *frame, int mb_x, int mb_y)

{

    int16_t (*block)[64] = a->block;

    int linesize = frame->linesize[0];

    uint8_t *dest_y  = frame->data[0] + (mb_y * 16* linesize              ) + mb_x * 16;

    uint8_t *dest_cb = frame->data[1] + (mb_y * 8 * frame->linesize[1]) + mb_x * 8;

    uint8_t *dest_cr = frame->data[2] + (mb_y * 8 * frame->linesize[2]) + mb_x * 8;

    a->idsp.idct_put(dest_y,                    linesize, block[0]);

    a->idsp.idct_put(dest_y + 8,                linesize, block[1]);

    a->idsp.idct_put(dest_y + 8 * linesize,     linesize, block[2]);

    a->idsp.idct_put(dest_y + 8 * linesize + 8, linesize, block[3]);

    if (!(a->avctx->flags & AV_CODEC_FLAG_GRAY)) {

        a->idsp.idct_put(dest_cb, frame->linesize[1], block[4]);

        a->idsp.idct_put(dest_cr, frame->linesize[2], block[5]);

    }

}

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

                        int *got_frame, AVPacket *avpkt)

{

    MDECContext * const a = avctx->priv_data;

    const uint8_t *buf    = avpkt->data;

    int buf_size          = avpkt->size;

    int ret;

    if ((ret = ff_thread_get_buffer(avctx, frame, 0)) < 0)

        return ret;

    av_fast_padded_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size, buf_size);

    if (!a->bitstream_buffer)

        return AVERROR(ENOMEM);

    a->bbdsp.bswap16_buf((uint16_t *)a->bitstream_buffer, (uint16_t *)buf, (buf_size + 1) / 2);

    if ((ret = init_get_bits8(&a->gb, a->bitstream_buffer, buf_size)) < 0)

        return ret;

    /* skip over 4 preamble bytes in stream (typically 0xXX 0xXX 0x00 0x38) */

    skip_bits(&a->gb, 32);

    a->qscale  = get_bits(&a->gb, 16);

    a->version = get_bits(&a->gb, 16);

    a->last_dc[0] = a->last_dc[1] = a->last_dc[2] = 128;

    for (a->mb_x = 0; a->mb_x < a->mb_width; a->mb_x++) {

        for (a->mb_y = 0; a->mb_y < a->mb_height; a->mb_y++) {

            if ((ret = decode_mb(a, a->block)) < 0)

                return ret;

            idct_put(a, frame, a->mb_x, a->mb_y);

        }

    }

    *got_frame = 1;

    return (get_bits_count(&a->gb) + 31) / 32 * 4;

}

static av_cold int decode_init(AVCodecContext *avctx)

{

    MDECContext * const a = avctx->priv_data;

    int i;

    a->mb_width  = (avctx->coded_width  + 15) / 16;

    a->mb_height = (avctx->coded_height + 15) / 16;

    a->avctx           = avctx;

    ff_blockdsp_init(&a->bdsp);

    ff_bswapdsp_init(&a->bbdsp);

    ff_idctdsp_init(&a->idsp, avctx);

    ff_mpeg12_init_vlcs();

    ff_permute_scantable(a->permutated_scantable, ff_zigzag_direct,

                         a->idsp.idct_permutation);

    avctx->pix_fmt  = AV_PIX_FMT_YUVJ420P;

    avctx->color_range = AVCOL_RANGE_JPEG;

    /* init q matrix */

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

        int j = a->idsp.idct_permutation[i];

        a->quant_matrix[j] = ff_mpeg1_default_intra_matrix[i];

    }

    return 0;

}

static av_cold int decode_end(AVCodecContext *avctx)

{

    MDECContext * const a = avctx->priv_data;

    av_freep(&a->bitstream_buffer);

    a->bitstream_buffer_size = 0;

    return 0;

}

const FFCodec ff_mdec_decoder = {

    .p.name           = "mdec",

    CODEC_LONG_NAME("Sony PlayStation MDEC (Motion DECoder)"),

    .p.type           = AVMEDIA_TYPE_VIDEO,

    .p.id             = AV_CODEC_ID_MDEC,

    .priv_data_size   = sizeof(MDECContext),

    .init             = decode_init,

    .close            = decode_end,

    FF_CODEC_DECODE_CB(decode_frame),

    .p.capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,

};