/*
 * XVideo Motion Compensation
 * Copyright (c) 2003 Ivan Kalvachev
 *
 * 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 <limits.h>

//avcodec include
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"

#undef NDEBUG
#include <assert.h>

//X11 includes are in libavcodec/xvmc.h
//by replacing it with non-X one
//XvMC emulation could be performed

#include "xvmc.h"

//set s->block
void XVMC_init_block(MpegEncContext *s)
{
    struct xvmc_render_state * render;
    render = (struct xvmc_render_state*)s->current_picture.data[2];
    assert(render);
    if (!render || (render->magic != AV_XVMC_RENDER_MAGIC)) {
        assert(0);
        return;//make sure that this is a render packet
    }
    s->block = (DCTELEM *)(render->data_blocks+(render->next_free_data_block_num)*64);
}

void XVMC_pack_pblocks(MpegEncContext *s, int cbp)
{
    int i,j;
    const int mb_block_count = 4 + (1 << s->chroma_format);

    j = 0;
    cbp <<= 12-mb_block_count;
    for (i = 0; i < mb_block_count; i++) {
        if (cbp & (1<<11)) {
            s->pblocks[i] = (short *)(&s->block[(j++)]);
        }else{
            s->pblocks[i] = NULL;
        }
        cbp+=cbp;
    }
}

//These functions should be called on every new field and/or frame.
//They should be safe if they are called a few times for the same field!
int XVMC_field_start(MpegEncContext*s, AVCodecContext *avctx)
{
    struct xvmc_render_state * render, * last, * next;

    assert(avctx);

    render = (struct xvmc_render_state*)s->current_picture.data[2];
    assert(render);
    if (!render || (render->magic != AV_XVMC_RENDER_MAGIC))
        return -1;//make sure that this is render packet

    render->picture_structure = s->picture_structure;
    render->flags             = (s->first_field) ? 0 : XVMC_SECOND_FIELD;

//make sure that all data is drawn by XVMC_end_frame
    assert(render->filled_mv_blocks_num == 0);

    render->p_future_surface = NULL;
    render->p_past_surface   = NULL;

    switch(s->pict_type){
        case  FF_I_TYPE:
            return 0;// no prediction from other frames
        case  FF_B_TYPE:
            next = (struct xvmc_render_state*)s->next_picture.data[2];
            assert(next);
            if (!next)
                return -1;
            if (next->magic != AV_XVMC_RENDER_MAGIC)
                return -1;
            render->p_future_surface = next->p_surface;
            //no return here, going to set forward prediction
        case  FF_P_TYPE:
            last = (struct xvmc_render_state*)s->last_picture.data[2];
            if (!last)// && !s->first_field)
                last = render;//predict second field from the first
            if (last->magic != AV_XVMC_RENDER_MAGIC)
                return -1;
            render->p_past_surface = last->p_surface;
            return 0;
    }

return -1;
}

void XVMC_field_end(MpegEncContext *s)
{
    struct xvmc_render_state * render;
    render = (struct xvmc_render_state*)s->current_picture.data[2];
    assert(render);

    if (render->filled_mv_blocks_num > 0)
        ff_draw_horiz_band(s,0,0);
}

void XVMC_decode_mb(MpegEncContext *s)
{
    XvMCMacroBlock * mv_block;
    struct xvmc_render_state * render;
    int i,cbp,blocks_per_mb;

    const int mb_xy = s->mb_y * s->mb_stride + s->mb_x;


    if (s->encoding) {
        av_log(s->avctx, AV_LOG_ERROR, "XVMC doesn't support encoding!!!\n");
        return;
    }

   //from MPV_decode_mb(),
    /* update DC predictors for P macroblocks */
    if (!s->mb_intra) {
        s->last_dc[0] =
        s->last_dc[1] =
        s->last_dc[2] =  128 << s->intra_dc_precision;
    }

   //MC doesn't skip blocks
    s->mb_skipped = 0;


   // Do I need to export quant when I could not perform postprocessing?
   // Anyway, it doesn't hurt.
    s->current_picture.qscale_table[mb_xy] = s->qscale;

//START OF XVMC specific code
    render = (struct xvmc_render_state*)s->current_picture.data[2];
    assert(render);
    assert(render->magic==AV_XVMC_RENDER_MAGIC);
    assert(render->mv_blocks);

    //take the next free macroblock
    mv_block = &render->mv_blocks[render->start_mv_blocks_num +
                                  render->filled_mv_blocks_num ];

    mv_block->x        = s->mb_x;
    mv_block->y        = s->mb_y;
    mv_block->dct_type = s->interlaced_dct;//XVMC_DCT_TYPE_FRAME/FIELD;
    if (s->mb_intra){
        mv_block->macroblock_type = XVMC_MB_TYPE_INTRA;//no MC, all done
    }else{
        mv_block->macroblock_type = XVMC_MB_TYPE_PATTERN;

        if (s->mv_dir & MV_DIR_FORWARD) {
            mv_block->macroblock_type |= XVMC_MB_TYPE_MOTION_FORWARD;
            //pmv[n][dir][xy]=mv[dir][n][xy]
            mv_block->PMV[0][0][0] = s->mv[0][0][0];
            mv_block->PMV[0][0][1] = s->mv[0][0][1];
            mv_block->PMV[1][0][0] = s->mv[0][1][0];
            mv_block->PMV[1][0][1] = s->mv[0][1][1];
        }
        if (s->mv_dir & MV_DIR_BACKWARD) {
            mv_block->macroblock_type |= XVMC_MB_TYPE_MOTION_BACKWARD;
            mv_block->PMV[0][1][0] = s->mv[1][0][0];
            mv_block->PMV[0][1][1] = s->mv[1][0][1];
            mv_block->PMV[1][1][0] = s->mv[1][1][0];
            mv_block->PMV[1][1][1] = s->mv[1][1][1];
        }

        switch(s->mv_type){
            case  MV_TYPE_16X16:
                mv_block->motion_type = XVMC_PREDICTION_FRAME;
                break;
            case  MV_TYPE_16X8:
                mv_block->motion_type = XVMC_PREDICTION_16x8;
                break;
            case  MV_TYPE_FIELD:
                mv_block->motion_type = XVMC_PREDICTION_FIELD;
                if (s->picture_structure == PICT_FRAME) {
                    mv_block->PMV[0][0][1] <<= 1;
                    mv_block->PMV[1][0][1] <<= 1;
                    mv_block->PMV[0][1][1] <<= 1;
                    mv_block->PMV[1][1][1] <<= 1;
                }
                break;
            case  MV_TYPE_DMV:
                mv_block->motion_type = XVMC_PREDICTION_DUAL_PRIME;
                if (s->picture_structure == PICT_FRAME) {

                    mv_block->PMV[0][0][0] = s->mv[0][0][0];//top from top
                    mv_block->PMV[0][0][1] = s->mv[0][0][1]<<1;

                    mv_block->PMV[0][1][0] = s->mv[0][0][0];//bottom from bottom
                    mv_block->PMV[0][1][1] = s->mv[0][0][1]<<1;

                    mv_block->PMV[1][0][0] = s->mv[0][2][0];//dmv00, top from bottom
                    mv_block->PMV[1][0][1] = s->mv[0][2][1]<<1;//dmv01

                    mv_block->PMV[1][1][0] = s->mv[0][3][0];//dmv10, bottom from top
                    mv_block->PMV[1][1][1] = s->mv[0][3][1]<<1;//dmv11

                }else{
                    mv_block->PMV[0][1][0] = s->mv[0][2][0];//dmv00
                    mv_block->PMV[0][1][1] = s->mv[0][2][1];//dmv01
                }
                break;
            default:
                assert(0);
        }

        mv_block->motion_vertical_field_select = 0;

//set correct field references
        if (s->mv_type == MV_TYPE_FIELD || s->mv_type == MV_TYPE_16X8) {
            if (s->field_select[0][0])
                mv_block->motion_vertical_field_select |= 1;
            if (s->field_select[1][0])
                mv_block->motion_vertical_field_select |= 2;
            if (s->field_select[0][1])
                mv_block->motion_vertical_field_select |= 4;
            if (s->field_select[1][1])
                mv_block->motion_vertical_field_select |= 8;
        }
    }//!intra
//time to handle data blocks;
    mv_block->index = render->next_free_data_block_num;

    blocks_per_mb = 6;
    if (s->chroma_format >= 2) {
        blocks_per_mb = 4 + (1 << (s->chroma_format));
    }

//  calculate cbp
    cbp = 0;
    for (i = 0; i < blocks_per_mb; i++) {
        cbp += cbp;
        if (s->block_last_index[i] >= 0)
            cbp++;
    }

    if (s->flags & CODEC_FLAG_GRAY) {
        if (s->mb_intra){//intra frames are always full chroma block
            for (i = 4; i < blocks_per_mb; i++) {
                memset(s->pblocks[i],0,sizeof(short)*8*8);//so we need to clear them
                if (!render->unsigned_intra)
                    s->pblocks[i][0] = 1 << 10;
            }
        }else{
            cbp &= 0xf << (blocks_per_mb - 4);
            blocks_per_mb = 4;//luminance blocks only
        }
    }
    mv_block->coded_block_pattern = cbp;
    if (cbp == 0)
        mv_block->macroblock_type &= ~XVMC_MB_TYPE_PATTERN;

    for (i = 0; i < blocks_per_mb; i++) {
        if (s->block_last_index[i] >= 0) {
            // I do not have unsigned_intra MOCO to test, hope it is OK.
            if ((s->mb_intra) && (render->idct || (!render->idct && !render->unsigned_intra)))
                s->pblocks[i][0] -= 1 << 10;
            if (!render->idct) {
                s->dsp.idct(s->pblocks[i]);
                //!!TODO!clip!!!
            }
//copy blocks only if the codec doesn't support pblocks reordering
            if (s->avctx->xvmc_acceleration == 1) {
                memcpy(&render->data_blocks[(render->next_free_data_block_num)*64],
                       s->pblocks[i],sizeof(short)*8*8);
            }
            render->next_free_data_block_num++;
        }
    }
    render->filled_mv_blocks_num++;

    assert(render->filled_mv_blocks_num     <= render->total_number_of_mv_blocks);
    assert(render->next_free_data_block_num <= render->total_number_of_data_blocks);


    if (render->filled_mv_blocks_num >= render->total_number_of_mv_blocks)
        ff_draw_horiz_band(s,0,0);
}