/*
 * Copyright (c) 2003 Michael Niedermayer
 *
 * 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
 * ASUS V1/V2 decoder.
 */

#include "libavutil/attributes.h"
#include "libavutil/mem.h"

#include "asv.h"
#include "avcodec.h"
#include "put_bits.h"
#include "dsputil.h"
#include "mathops.h"
#include "mpeg12data.h"

#define VLC_BITS 6
#define ASV2_LEVEL_VLC_BITS 10

static VLC ccp_vlc;
static VLC level_vlc;
static VLC dc_ccp_vlc;
static VLC ac_ccp_vlc;
static VLC asv2_level_vlc;

static av_cold void init_vlcs(ASV1Context *a){
    static int done = 0;

    if (!done) {
        done = 1;

        INIT_VLC_STATIC(&ccp_vlc, VLC_BITS, 17,
                 &ff_asv_ccp_tab[0][1], 2, 1,
                 &ff_asv_ccp_tab[0][0], 2, 1, 64);
        INIT_VLC_STATIC(&dc_ccp_vlc, VLC_BITS, 8,
                 &ff_asv_dc_ccp_tab[0][1], 2, 1,
                 &ff_asv_dc_ccp_tab[0][0], 2, 1, 64);
        INIT_VLC_STATIC(&ac_ccp_vlc, VLC_BITS, 16,
                 &ff_asv_ac_ccp_tab[0][1], 2, 1,
                 &ff_asv_ac_ccp_tab[0][0], 2, 1, 64);
        INIT_VLC_STATIC(&level_vlc,  VLC_BITS, 7,
                 &ff_asv_level_tab[0][1], 2, 1,
                 &ff_asv_level_tab[0][0], 2, 1, 64);
        INIT_VLC_STATIC(&asv2_level_vlc, ASV2_LEVEL_VLC_BITS, 63,
                 &ff_asv2_level_tab[0][1], 2, 1,
                 &ff_asv2_level_tab[0][0], 2, 1, 1024);
    }
}

//FIXME write a reversed bitstream reader to avoid the double reverse
static inline int asv2_get_bits(GetBitContext *gb, int n){
    return ff_reverse[ get_bits(gb, n) << (8-n) ];
}

static inline int asv1_get_level(GetBitContext *gb){
    int code= get_vlc2(gb, level_vlc.table, VLC_BITS, 1);

    if(code==3) return get_sbits(gb, 8);
    else        return code - 3;
}

static inline int asv2_get_level(GetBitContext *gb){
    int code= get_vlc2(gb, asv2_level_vlc.table, ASV2_LEVEL_VLC_BITS, 1);

    if(code==31) return (int8_t)asv2_get_bits(gb, 8);
    else         return code - 31;
}

static inline int asv1_decode_block(ASV1Context *a, DCTELEM block[64]){
    int i;

    block[0]= 8*get_bits(&a->gb, 8);

    for(i=0; i<11; i++){
        const int ccp= get_vlc2(&a->gb, ccp_vlc.table, VLC_BITS, 1);

        if(ccp){
            if(ccp == 16) break;
            if(ccp < 0 || i>=10){
                av_log(a->avctx, AV_LOG_ERROR, "coded coeff pattern damaged\n");
                return -1;
            }

            if(ccp&8) block[a->scantable.permutated[4*i+0]]= (asv1_get_level(&a->gb) * a->intra_matrix[4*i+0])>>4;
            if(ccp&4) block[a->scantable.permutated[4*i+1]]= (asv1_get_level(&a->gb) * a->intra_matrix[4*i+1])>>4;
            if(ccp&2) block[a->scantable.permutated[4*i+2]]= (asv1_get_level(&a->gb) * a->intra_matrix[4*i+2])>>4;
            if(ccp&1) block[a->scantable.permutated[4*i+3]]= (asv1_get_level(&a->gb) * a->intra_matrix[4*i+3])>>4;
        }
    }

    return 0;
}

static inline int asv2_decode_block(ASV1Context *a, DCTELEM block[64]){
    int i, count, ccp;

    count= asv2_get_bits(&a->gb, 4);

    block[0]= 8*asv2_get_bits(&a->gb, 8);

    ccp= get_vlc2(&a->gb, dc_ccp_vlc.table, VLC_BITS, 1);
    if(ccp){
        if(ccp&4) block[a->scantable.permutated[1]]= (asv2_get_level(&a->gb) * a->intra_matrix[1])>>4;
        if(ccp&2) block[a->scantable.permutated[2]]= (asv2_get_level(&a->gb) * a->intra_matrix[2])>>4;
        if(ccp&1) block[a->scantable.permutated[3]]= (asv2_get_level(&a->gb) * a->intra_matrix[3])>>4;
    }

    for(i=1; i<count+1; i++){
        const int ccp= get_vlc2(&a->gb, ac_ccp_vlc.table, VLC_BITS, 1);

        if(ccp){
            if(ccp&8) block[a->scantable.permutated[4*i+0]]= (asv2_get_level(&a->gb) * a->intra_matrix[4*i+0])>>4;
            if(ccp&4) block[a->scantable.permutated[4*i+1]]= (asv2_get_level(&a->gb) * a->intra_matrix[4*i+1])>>4;
            if(ccp&2) block[a->scantable.permutated[4*i+2]]= (asv2_get_level(&a->gb) * a->intra_matrix[4*i+2])>>4;
            if(ccp&1) block[a->scantable.permutated[4*i+3]]= (asv2_get_level(&a->gb) * a->intra_matrix[4*i+3])>>4;
        }
    }

    return 0;
}

static inline int decode_mb(ASV1Context *a, DCTELEM block[6][64]){
    int i;

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

    if(a->avctx->codec_id == AV_CODEC_ID_ASV1){
        for(i=0; i<6; i++){
            if( asv1_decode_block(a, block[i]) < 0)
                return -1;
        }
    }else{
        for(i=0; i<6; i++){
            if( asv2_decode_block(a, block[i]) < 0)
                return -1;
        }
    }
    return 0;
}

static inline void idct_put(ASV1Context *a, int mb_x, int mb_y){
    DCTELEM (*block)[64]= a->block;
    int linesize= a->picture.linesize[0];

    uint8_t *dest_y  = a->picture.data[0] + (mb_y * 16* linesize              ) + mb_x * 16;
    uint8_t *dest_cb = a->picture.data[1] + (mb_y * 8 * a->picture.linesize[1]) + mb_x * 8;
    uint8_t *dest_cr = a->picture.data[2] + (mb_y * 8 * a->picture.linesize[2]) + mb_x * 8;

    a->dsp.idct_put(dest_y                 , linesize, block[0]);
    a->dsp.idct_put(dest_y              + 8, linesize, block[1]);
    a->dsp.idct_put(dest_y + 8*linesize    , linesize, block[2]);
    a->dsp.idct_put(dest_y + 8*linesize + 8, linesize, block[3]);

    if(!(a->avctx->flags&CODEC_FLAG_GRAY)){
        a->dsp.idct_put(dest_cb, a->picture.linesize[1], block[4]);
        a->dsp.idct_put(dest_cr, a->picture.linesize[2], block[5]);
    }
}

static int decode_frame(AVCodecContext *avctx,
                        void *data, int *data_size,
                        AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    ASV1Context * const a = avctx->priv_data;
    AVFrame *picture = data;
    AVFrame * const p= &a->picture;
    int mb_x, mb_y;

    if(p->data[0])
        avctx->release_buffer(avctx, p);

    p->reference= 0;
    if(avctx->get_buffer(avctx, p) < 0){
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return -1;
    }
    p->pict_type= AV_PICTURE_TYPE_I;
    p->key_frame= 1;

    av_fast_padded_malloc(&a->bitstream_buffer, &a->bitstream_buffer_size,
                          buf_size);
    if (!a->bitstream_buffer)
        return AVERROR(ENOMEM);

    if(avctx->codec_id == AV_CODEC_ID_ASV1)
        a->dsp.bswap_buf((uint32_t*)a->bitstream_buffer, (const uint32_t*)buf, buf_size/4);
    else{
        int i;
        for(i=0; i<buf_size; i++)
            a->bitstream_buffer[i]= ff_reverse[ buf[i] ];
    }

    init_get_bits(&a->gb, a->bitstream_buffer, buf_size*8);

    for(mb_y=0; mb_y<a->mb_height2; mb_y++){
        for(mb_x=0; mb_x<a->mb_width2; mb_x++){
            if( decode_mb(a, a->block) <0)
                return -1;

            idct_put(a, mb_x, mb_y);
        }
    }

    if(a->mb_width2 != a->mb_width){
        mb_x= a->mb_width2;
        for(mb_y=0; mb_y<a->mb_height2; mb_y++){
            if( decode_mb(a, a->block) <0)
                return -1;

            idct_put(a, mb_x, mb_y);
        }
    }

    if(a->mb_height2 != a->mb_height){
        mb_y= a->mb_height2;
        for(mb_x=0; mb_x<a->mb_width; mb_x++){
            if( decode_mb(a, a->block) <0)
                return -1;

            idct_put(a, mb_x, mb_y);
        }
    }

    *picture   = a->picture;
    *data_size = sizeof(AVPicture);

    emms_c();

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

static av_cold int decode_init(AVCodecContext *avctx){
    ASV1Context * const a = avctx->priv_data;
    AVFrame *p= &a->picture;
    int i;
    const int scale= avctx->codec_id == AV_CODEC_ID_ASV1 ? 1 : 2;

    ff_asv_common_init(avctx);
    init_vlcs(a);
    ff_init_scantable(a->dsp.idct_permutation, &a->scantable, ff_asv_scantab);
    avctx->pix_fmt= AV_PIX_FMT_YUV420P;

    if(avctx->extradata_size < 1 || (a->inv_qscale= avctx->extradata[0]) == 0){
        av_log(avctx, AV_LOG_ERROR, "illegal qscale 0\n");
        if(avctx->codec_id == AV_CODEC_ID_ASV1)
            a->inv_qscale= 6;
        else
            a->inv_qscale= 10;
    }

    for(i=0; i<64; i++){
        int index = ff_asv_scantab[i];

        a->intra_matrix[i]= 64*scale*ff_mpeg1_default_intra_matrix[index] / a->inv_qscale;
    }

    p->qstride= a->mb_width;
    p->qscale_table= av_malloc( p->qstride * a->mb_height);
    p->quality= (32*scale + a->inv_qscale/2)/a->inv_qscale;
    memset(p->qscale_table, p->quality, p->qstride*a->mb_height);

    return 0;
}

static av_cold int decode_end(AVCodecContext *avctx){
    ASV1Context * const a = avctx->priv_data;

    av_freep(&a->bitstream_buffer);
    av_freep(&a->picture.qscale_table);
    a->bitstream_buffer_size=0;

    if(a->picture.data[0])
        avctx->release_buffer(avctx, &a->picture);

    return 0;
}

#if CONFIG_ASV1_DECODER
AVCodec ff_asv1_decoder = {
    .name           = "asv1",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_ASV1,
    .priv_data_size = sizeof(ASV1Context),
    .init           = decode_init,
    .close          = decode_end,
    .decode         = decode_frame,
    .capabilities   = CODEC_CAP_DR1,
    .long_name      = NULL_IF_CONFIG_SMALL("ASUS V1"),
};
#endif

#if CONFIG_ASV2_DECODER
AVCodec ff_asv2_decoder = {
    .name           = "asv2",
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_ASV2,
    .priv_data_size = sizeof(ASV1Context),
    .init           = decode_init,
    .close          = decode_end,
    .decode         = decode_frame,
    .capabilities   = CODEC_CAP_DR1,
    .long_name      = NULL_IF_CONFIG_SMALL("ASUS V2"),
};
#endif