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

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

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

#include "libvo/fastmemcpy.h"


struct vf_priv_s {
	int hi, lo;
	float frac;
	int max, last, cnt;
};

#ifdef HAVE_MMX
static int diff_MMX(unsigned char *old, unsigned char *new, int os, int ns)
{
	volatile short out[4];
	asm (
		"movl $8, %%ecx \n\t"
		"pxor %%mm4, %%mm4 \n\t"
		"pxor %%mm7, %%mm7 \n\t"
		
		ASMALIGN(4)
		"1: \n\t"
		
		"movq (%%"REG_S"), %%mm0 \n\t"
		"movq (%%"REG_S"), %%mm2 \n\t"
		"add %%"REG_a", %%"REG_S" \n\t"
		"movq (%%"REG_D"), %%mm1 \n\t"
		"add %%"REG_b", %%"REG_D" \n\t"
		"psubusb %%mm1, %%mm2 \n\t"
		"psubusb %%mm0, %%mm1 \n\t"
		"movq %%mm2, %%mm0 \n\t"
		"movq %%mm1, %%mm3 \n\t"
		"punpcklbw %%mm7, %%mm0 \n\t"
		"punpcklbw %%mm7, %%mm1 \n\t"
		"punpckhbw %%mm7, %%mm2 \n\t"
		"punpckhbw %%mm7, %%mm3 \n\t"
		"paddw %%mm0, %%mm4 \n\t"
		"paddw %%mm1, %%mm4 \n\t"
		"paddw %%mm2, %%mm4 \n\t"
		"paddw %%mm3, %%mm4 \n\t"
		
		"decl %%ecx \n\t"
		"jnz 1b \n\t"
		"movq %%mm4, (%%"REG_d") \n\t"
		"emms \n\t"
		: 
		: "S" (old), "D" (new), "a" ((long)os), "b" ((long)ns), "d" (out)
		: "memory"
		);
	return out[0]+out[1]+out[2]+out[3];
}
#endif

static int diff_C(unsigned char *old, unsigned char *new, int os, int ns)
{
	int x, y, d=0;
	for (y = 8; y; y--) {
		for (x = 8; x; x--) {
			d += abs(new[x] - old[x]);
		}
		new += ns;
		old += os;
	}
	return d;
}

static int (*diff)(unsigned char *, unsigned char *, int, int);

static int diff_to_drop_plane(int hi, int lo, float frac, unsigned char *old, unsigned char *new, int w, int h, int os, int ns)
{
	int x, y;
	int d, c=0;
	int t = (w/16)*(h/16)*frac;
	for (y = 0; y < h-7; y += 4) {
		for (x = 8; x < w-7; x += 4) {
			d = diff(old+x+y*os, new+x+y*ns, os, ns);
			if (d > hi) return 0;
			if (d > lo) {
				c++;
				if (c > t) return 0;
			}
		}
	}
	return 1;
}

static int diff_to_drop(int hi, int lo, float frac, mp_image_t *old, mp_image_t *new)
{
	if (new->flags & MP_IMGFLAG_PLANAR) {
		return diff_to_drop_plane(hi,lo,frac, old->planes[0], new->planes[0],
			new->w, new->h, old->stride[0], new->stride[0])
			&& diff_to_drop_plane(hi,lo,frac, old->planes[1], new->planes[1],
			new->chroma_width, new->chroma_height,
			old->stride[1], new->stride[1])
			&& diff_to_drop_plane(hi,lo,frac, old->planes[2], new->planes[2],
			new->chroma_width, new->chroma_height,
			old->stride[2], new->stride[2]);
	}
	return diff_to_drop_plane(hi,lo,frac, old->planes[0], new->planes[0],
		new->w*(new->bpp/8), new->h, old->stride[0], new->stride[0]);
}

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

	dmpi = vf_get_image(vf->next, mpi->imgfmt,
		MP_IMGTYPE_STATIC, MP_IMGFLAG_ACCEPT_STRIDE |
		MP_IMGFLAG_PRESERVE | MP_IMGFLAG_READABLE,
		mpi->width, mpi->height);
	dmpi->qscale = mpi->qscale;
	dmpi->qstride = mpi->qstride;
	dmpi->qscale_type = mpi->qscale_type;

	if (diff_to_drop(vf->priv->hi, vf->priv->lo, vf->priv->frac, dmpi, mpi)) {
		if (vf->priv->max == 0)
			return 0;
		else if ((vf->priv->max > 0) && (vf->priv->cnt++ < vf->priv->max))
			return 0;
		else if ((vf->priv->max < 0) && (vf->priv->last+1 >= -vf->priv->max))
			return vf->priv->last=0;
	}
	vf->priv->last++;
	vf->priv->cnt=0;
	
	memcpy_pic(dmpi->planes[0], mpi->planes[0], mpi->w, mpi->h,
		dmpi->stride[0], mpi->stride[0]);
	if (mpi->flags & MP_IMGFLAG_PLANAR) {
		memcpy_pic(dmpi->planes[1], mpi->planes[1],
			mpi->chroma_width, mpi->chroma_height,
			dmpi->stride[1], mpi->stride[1]);
		memcpy_pic(dmpi->planes[2], mpi->planes[2],
			mpi->chroma_width, mpi->chroma_height,
			dmpi->stride[2], mpi->stride[2]);
	}
	return vf_next_put_image(vf, dmpi, pts);
}

static void uninit(struct vf_instance* vf)
{
	free(vf->priv);
}

static int open(vf_instance_t *vf, char* args)
{
	struct vf_priv_s *p;
	vf->put_image = put_image;
	vf->uninit = uninit;
	vf->default_reqs = VFCAP_ACCEPT_STRIDE;
	vf->priv = p = calloc(1, sizeof(struct vf_priv_s));
	p->max = 0;
	p->hi = 64*12;
	p->lo = 64*5;
	p->frac = 0.33;
	if (args) sscanf(args, "%d:%d:%d:%f", &p->max, &p->hi, &p->lo, &p->frac);
	diff = diff_C;
#ifdef HAVE_MMX
	if(gCpuCaps.hasMMX) diff = diff_MMX;
#endif
	return 1;
}

const vf_info_t vf_info_decimate = {
    "near-duplicate frame remover",
    "decimate",
    "Rich Felker",
    "",
    open,
    NULL
};