/*
 * Copyright (C) 2006 Michael Niedermayer <michaelni@gmx.at>
 *
 * This file is part of MPlayer.
 *
 * MPlayer is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * MPlayer 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with MPlayer; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */


/*
Known Issues:
* The motion estimation is somewhat at the mercy of the input, if the input
  frames are created purely based on spatial interpolation then for example
  a thin black line or another random and not interpolateable pattern
  will cause problems
  Note: completly ignoring the "unavailable" lines during motion estimation
  didnt look any better, so the most obvious solution would be to improve
  tfields or penalize problematic motion vectors ...

* If non iterative ME is used then snow currently ignores the OBMC window
  and as a result sometimes creates artifacts

* only past frames are used, we should ideally use future frames too, something
  like filtering the whole movie in forward and then backward direction seems
  like a interresting idea but the current filter framework is FAR from
  supporting such things

* combining the motion compensated image with the input image also isnt
  as trivial as it seems, simple blindly taking even lines from one and
  odd ones from the other doesnt work at all as ME/MC sometimes simple
  has nothing in the previous frames which matches the current, the current
  algo has been found by trial and error and almost certainly can be
  improved ...
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
#include <math.h>

#include "mp_msg.h"
#include "cpudetect.h"

#include "libavutil/internal.h"
#include "libavutil/intreadwrite.h"
#include "libavcodec/avcodec.h"
#include "libavcodec/dsputil.h"

#undef fprintf
#undef free
#undef malloc

#include "img_format.h"
#include "mp_image.h"
#include "vf.h"
#include "vd_ffmpeg.h"

#define MIN(a,b) ((a) > (b) ? (b) : (a))
#define MAX(a,b) ((a) < (b) ? (b) : (a))
#define ABS(a) ((a) > 0 ? (a) : (-(a)))

//===========================================================================//

struct vf_priv_s {
    int mode;
    int qp;
    int parity;
#if 0
    int temp_stride[3];
    uint8_t *src[3];
    int16_t *temp[3];
#endif
    int outbuf_size;
    uint8_t *outbuf;
    AVCodecContext *avctx_enc;
    AVFrame *frame;
    AVFrame *frame_dec;
};

static void filter(struct vf_priv_s *p, uint8_t *dst[3], uint8_t *src[3], int dst_stride[3], int src_stride[3], int width, int height){
    int x, y, i;

    for(i=0; i<3; i++){
        p->frame->data[i]= src[i];
        p->frame->linesize[i]= src_stride[i];
    }

    p->avctx_enc->me_cmp=
    p->avctx_enc->me_sub_cmp= FF_CMP_SAD /*| (p->parity ? FF_CMP_ODD : FF_CMP_EVEN)*/;
    p->frame->quality= p->qp*FF_QP2LAMBDA;
    avcodec_encode_video(p->avctx_enc, p->outbuf, p->outbuf_size, p->frame);
    p->frame_dec = p->avctx_enc->coded_frame;

    for(i=0; i<3; i++){
        int is_chroma= !!i;
        int w= width >>is_chroma;
        int h= height>>is_chroma;
        int fils= p->frame_dec->linesize[i];
        int srcs= src_stride[i];

        for(y=0; y<h; y++){
            if((y ^ p->parity) & 1){
                for(x=0; x<w; x++){
                    if((x-2)+(y-1)*w>=0 && (x+2)+(y+1)*w<w*h){ //FIXME either alloc larger images or optimize this
                        uint8_t *filp= &p->frame_dec->data[i][x + y*fils];
                        uint8_t *srcp= &src[i][x + y*srcs];
                        int diff0= filp[-fils] - srcp[-srcs];
                        int diff1= filp[+fils] - srcp[+srcs];
                        int spatial_score= ABS(srcp[-srcs-1] - srcp[+srcs-1])
                                          +ABS(srcp[-srcs  ] - srcp[+srcs  ])
                                          +ABS(srcp[-srcs+1] - srcp[+srcs+1]) - 1;
                        int temp= filp[0];

#define CHECK(j)\
    {   int score= ABS(srcp[-srcs-1+(j)] - srcp[+srcs-1-(j)])\
                 + ABS(srcp[-srcs  +(j)] - srcp[+srcs  -(j)])\
                 + ABS(srcp[-srcs+1+(j)] - srcp[+srcs+1-(j)]);\
        if(score < spatial_score){\
            spatial_score= score;\
            diff0= filp[-fils+(j)] - srcp[-srcs+(j)];\
            diff1= filp[+fils-(j)] - srcp[+srcs-(j)];

                        CHECK(-1) CHECK(-2) }} }}
                        CHECK( 1) CHECK( 2) }} }}
#if 0
                        if((diff0 ^ diff1) > 0){
                            int mindiff= ABS(diff0) > ABS(diff1) ? diff1 : diff0;
                            temp-= mindiff;
                        }
#elif 1
                        if(diff0 + diff1 > 0)
                            temp-= (diff0 + diff1 - ABS( ABS(diff0) - ABS(diff1) )/2)/2;
                        else
                            temp-= (diff0 + diff1 + ABS( ABS(diff0) - ABS(diff1) )/2)/2;
#else
                        temp-= (diff0 + diff1)/2;
#endif
#if 1
                        filp[0]=
                        dst[i][x + y*dst_stride[i]]= temp > 255U ? ~(temp>>31) : temp;
#else
                        dst[i][x + y*dst_stride[i]]= filp[0];
                        filp[0]= temp > 255U ? ~(temp>>31) : temp;
#endif
                    }else
                        dst[i][x + y*dst_stride[i]]= p->frame_dec->data[i][x + y*fils];
                }
            }
        }
        for(y=0; y<h; y++){
            if(!((y ^ p->parity) & 1)){
                for(x=0; x<w; x++){
#if 1
                    p->frame_dec->data[i][x + y*fils]=
                    dst[i][x + y*dst_stride[i]]= src[i][x + y*srcs];
#else
                    dst[i][x + y*dst_stride[i]]= p->frame_dec->data[i][x + y*fils];
                    p->frame_dec->data[i][x + y*fils]= src[i][x + y*srcs];
#endif
                }
            }
        }
    }
    p->parity ^= 1;

}

static int config(struct vf_instance *vf,
        int width, int height, int d_width, int d_height,
        unsigned int flags, unsigned int outfmt){
        int i;
        AVCodec *enc= avcodec_find_encoder(AV_CODEC_ID_SNOW);

        for(i=0; i<3; i++){
            AVCodecContext *avctx_enc;
#if 0
            int is_chroma= !!i;
            int w= ((width  + 31) & (~31))>>is_chroma;
            int h= ((height + 31) & (~31))>>is_chroma;

            vf->priv->temp_stride[i]= w;
            vf->priv->temp[i]= malloc(vf->priv->temp_stride[i]*h*sizeof(int16_t));
            vf->priv->src [i]= malloc(vf->priv->temp_stride[i]*h*sizeof(uint8_t));
#endif
            avctx_enc=
            vf->priv->avctx_enc= avcodec_alloc_context();
            avctx_enc->width = width;
            avctx_enc->height = height;
            avctx_enc->time_base= (AVRational){1,25};  // meaningless
            avctx_enc->gop_size = 300;
            avctx_enc->max_b_frames= 0;
            avctx_enc->pix_fmt = AV_PIX_FMT_YUV420P;
            avctx_enc->flags = CODEC_FLAG_QSCALE | CODEC_FLAG_LOW_DELAY;
            avctx_enc->strict_std_compliance = FF_COMPLIANCE_EXPERIMENTAL;
            avctx_enc->global_quality= 1;
            avctx_enc->flags2= CODEC_FLAG2_MEMC_ONLY;
            avctx_enc->me_cmp=
            avctx_enc->me_sub_cmp= FF_CMP_SAD; //SSE;
            avctx_enc->mb_cmp= FF_CMP_SSE;

            switch(vf->priv->mode){
            case 3:
                avctx_enc->refs= 3;
            case 2:
                avctx_enc->me_method= ME_ITER;
            case 1:
                avctx_enc->flags |= CODEC_FLAG_4MV;
                avctx_enc->dia_size=2;
//                avctx_enc->mb_decision = MB_DECISION_RD;
            case 0:
                avctx_enc->flags |= CODEC_FLAG_QPEL;
            }

            avcodec_open(avctx_enc, enc);

        }
        vf->priv->frame= avcodec_alloc_frame();

        vf->priv->outbuf_size= width*height*10;
        vf->priv->outbuf= malloc(vf->priv->outbuf_size);

        return ff_vf_next_config(vf,width,height,d_width,d_height,flags,outfmt);
}

static void get_image(struct vf_instance *vf, mp_image_t *mpi){
    if(mpi->flags&MP_IMGFLAG_PRESERVE) return; // don't change
return; //caused problems, dunno why
    // ok, we can do pp in-place (or pp disabled):
    vf->dmpi=ff_vf_get_image(vf->next,mpi->imgfmt,
        mpi->type, mpi->flags | MP_IMGFLAG_READABLE, mpi->width, mpi->height);
    mpi->planes[0]=vf->dmpi->planes[0];
    mpi->stride[0]=vf->dmpi->stride[0];
    mpi->width=vf->dmpi->width;
    if(mpi->flags&MP_IMGFLAG_PLANAR){
        mpi->planes[1]=vf->dmpi->planes[1];
        mpi->planes[2]=vf->dmpi->planes[2];
        mpi->stride[1]=vf->dmpi->stride[1];
        mpi->stride[2]=vf->dmpi->stride[2];
    }
    mpi->flags|=MP_IMGFLAG_DIRECT;
}

static int put_image(struct vf_instance *vf, mp_image_t *mpi, double pts){
    mp_image_t *dmpi;

    if(!(mpi->flags&MP_IMGFLAG_DIRECT)){
        // no DR, so get a new image! hope we'll get DR buffer:
        dmpi=ff_vf_get_image(vf->next,mpi->imgfmt,
            MP_IMGTYPE_TEMP,
            MP_IMGFLAG_ACCEPT_STRIDE|MP_IMGFLAG_PREFER_ALIGNED_STRIDE,
            mpi->width,mpi->height);
        ff_vf_clone_mpi_attributes(dmpi, mpi);
    }else{
        dmpi=vf->dmpi;
    }

    filter(vf->priv, dmpi->planes, mpi->planes, dmpi->stride, mpi->stride, mpi->w, mpi->h);

    return ff_vf_next_put_image(vf,dmpi, pts);
}

static void uninit(struct vf_instance *vf){
    if(!vf->priv) return;

#if 0
    for(i=0; i<3; i++){
        free(vf->priv->temp[i]);
        vf->priv->temp[i]= NULL;
        free(vf->priv->src[i]);
        vf->priv->src[i]= NULL;
    }
#endif
    if (vf->priv->avctx_enc) {
    avcodec_close(vf->priv->avctx_enc);
    av_freep(&vf->priv->avctx_enc);
    }

    free(vf->priv->outbuf);
    free(vf->priv);
    vf->priv=NULL;
}

//===========================================================================//
static int query_format(struct vf_instance *vf, unsigned int fmt){
    switch(fmt){
        case IMGFMT_YV12:
        case IMGFMT_I420:
        case IMGFMT_IYUV:
        case IMGFMT_Y800:
        case IMGFMT_Y8:
            return ff_vf_next_query_format(vf,fmt);
    }
    return 0;
}

static int vf_open(vf_instance_t *vf, char *args){

    vf->config=config;
    vf->put_image=put_image;
    vf->get_image=get_image;
    vf->query_format=query_format;
    vf->uninit=uninit;
    vf->priv=malloc(sizeof(struct vf_priv_s));
    memset(vf->priv, 0, sizeof(struct vf_priv_s));

    ff_init_avcodec();

    vf->priv->mode=0;
    vf->priv->parity= -1;
    vf->priv->qp=1;

    if (args) sscanf(args, "%d:%d:%d", &vf->priv->mode, &vf->priv->parity, &vf->priv->qp);

    return 1;
}

const vf_info_t ff_vf_info_mcdeint = {
    "motion compensating deinterlacer",
    "mcdeint",
    "Michael Niedermayer",
    "",
    vf_open,
    NULL
};