sync with en/mplayer.1 rev. 30936

[mplayer/glamo.git] / libmpcodecs / pullup.c

/*
 * 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.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "config.h"
#include "pullup.h"
#include "cpudetect.h"



#if ARCH_X86
#if HAVE_MMX
static int diff_y_mmx(unsigned char *a, unsigned char *b, int s)
{
        int ret;
        __asm__ volatile (
                "movl $4, %%ecx \n\t"
                "pxor %%mm4, %%mm4 \n\t"
                "pxor %%mm7, %%mm7 \n\t"

                "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_a", %%"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, %%mm3 \n\t"
                "punpcklwd %%mm7, %%mm4 \n\t"
                "punpckhwd %%mm7, %%mm3 \n\t"
                "paddd %%mm4, %%mm3 \n\t"
                "movd %%mm3, %%eax \n\t"
                "psrlq $32, %%mm3 \n\t"
                "movd %%mm3, %%edx \n\t"
                "addl %%edx, %%eax \n\t"
                "emms \n\t"
                : "=a" (ret)
                : "S" (a), "D" (b), "a" (s)
                : "%ecx", "%edx"
                );
        return ret;
}

static int licomb_y_mmx(unsigned char *a, unsigned char *b, int s)
{
        int ret;
        __asm__ volatile (
                "movl $4, %%ecx \n\t"
                "pxor %%mm6, %%mm6 \n\t"
                "pxor %%mm7, %%mm7 \n\t"
                "sub  %%"REG_a", %%"REG_D" \n\t"

                "2: \n\t"

                "movq (%%"REG_D"), %%mm0 \n\t"
                "movq (%%"REG_D"), %%mm1 \n\t"
                "punpcklbw %%mm7, %%mm0 \n\t"
                "movq (%%"REG_D",%%"REG_a"), %%mm2 \n\t"
                "punpcklbw %%mm7, %%mm1 \n\t"
                "punpcklbw %%mm7, %%mm2 \n\t"
                "paddw %%mm0, %%mm0 \n\t"
                "paddw %%mm2, %%mm1 \n\t"
                "movq %%mm0, %%mm2 \n\t"
                "psubusw %%mm1, %%mm0 \n\t"
                "psubusw %%mm2, %%mm1 \n\t"
                "paddw %%mm0, %%mm6 \n\t"
                "paddw %%mm1, %%mm6 \n\t"

                "movq (%%"REG_S"), %%mm0 \n\t"
                "movq (%%"REG_D"), %%mm1 \n\t"
                "punpckhbw %%mm7, %%mm0 \n\t"
                "movq (%%"REG_D",%%"REG_a"), %%mm2 \n\t"
                "punpckhbw %%mm7, %%mm1 \n\t"
                "punpckhbw %%mm7, %%mm2 \n\t"
                "paddw %%mm0, %%mm0 \n\t"
                "paddw %%mm2, %%mm1 \n\t"
                "movq %%mm0, %%mm2 \n\t"
                "psubusw %%mm1, %%mm0 \n\t"
                "psubusw %%mm2, %%mm1 \n\t"
                "paddw %%mm0, %%mm6 \n\t"
                "paddw %%mm1, %%mm6 \n\t"

                "movq (%%"REG_D",%%"REG_a"), %%mm0 \n\t"
                "movq (%%"REG_S"), %%mm1 \n\t"
                "punpcklbw %%mm7, %%mm0 \n\t"
                "movq (%%"REG_S",%%"REG_a"), %%mm2 \n\t"
                "punpcklbw %%mm7, %%mm1 \n\t"
                "punpcklbw %%mm7, %%mm2 \n\t"
                "paddw %%mm0, %%mm0 \n\t"
                "paddw %%mm2, %%mm1 \n\t"
                "movq %%mm0, %%mm2 \n\t"
                "psubusw %%mm1, %%mm0 \n\t"
                "psubusw %%mm2, %%mm1 \n\t"
                "paddw %%mm0, %%mm6 \n\t"
                "paddw %%mm1, %%mm6 \n\t"

                "movq (%%"REG_D",%%"REG_a"), %%mm0 \n\t"
                "movq (%%"REG_S"), %%mm1 \n\t"
                "punpckhbw %%mm7, %%mm0 \n\t"
                "movq (%%"REG_S",%%"REG_a"), %%mm2 \n\t"
                "punpckhbw %%mm7, %%mm1 \n\t"
                "punpckhbw %%mm7, %%mm2 \n\t"
                "paddw %%mm0, %%mm0 \n\t"
                "paddw %%mm2, %%mm1 \n\t"
                "movq %%mm0, %%mm2 \n\t"
                "psubusw %%mm1, %%mm0 \n\t"
                "psubusw %%mm2, %%mm1 \n\t"
                "paddw %%mm0, %%mm6 \n\t"
                "paddw %%mm1, %%mm6 \n\t"

                "add  %%"REG_a", %%"REG_S" \n\t"
                "add  %%"REG_a", %%"REG_D" \n\t"
                "decl %%ecx \n\t"
                "jnz 2b \n\t"

                "movq %%mm6, %%mm5 \n\t"
                "punpcklwd %%mm7, %%mm6 \n\t"
                "punpckhwd %%mm7, %%mm5 \n\t"
                "paddd %%mm6, %%mm5 \n\t"
                "movd %%mm5, %%eax \n\t"
                "psrlq $32, %%mm5 \n\t"
                "movd %%mm5, %%edx \n\t"
                "addl %%edx, %%eax \n\t"

                "emms \n\t"
                : "=a" (ret)
                : "S" (a), "D" (b), "a" (s)
                : "%ecx", "%edx"
                );
        return ret;
}

static int var_y_mmx(unsigned char *a, unsigned char *b, int s)
{
        int ret;
        __asm__ volatile (
                "movl $3, %%ecx \n\t"
                "pxor %%mm4, %%mm4 \n\t"
                "pxor %%mm7, %%mm7 \n\t"

                "1: \n\t"

                "movq (%%"REG_S"), %%mm0 \n\t"
                "movq (%%"REG_S"), %%mm2 \n\t"
                "movq (%%"REG_S",%%"REG_a"), %%mm1 \n\t"
                "add  %%"REG_a", %%"REG_S" \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, %%mm3 \n\t"
                "punpcklwd %%mm7, %%mm4 \n\t"
                "punpckhwd %%mm7, %%mm3 \n\t"
                "paddd %%mm4, %%mm3 \n\t"
                "movd %%mm3, %%eax \n\t"
                "psrlq $32, %%mm3 \n\t"
                "movd %%mm3, %%edx \n\t"
                "addl %%edx, %%eax \n\t"
                "emms \n\t"
                : "=a" (ret)
                : "S" (a), "a" (s)
                : "%ecx", "%edx"
                );
        return 4*ret;
}
#endif
#endif

#define ABS(a) (((a)^((a)>>31))-((a)>>31))

static int diff_y(unsigned char *a, unsigned char *b, int s)
{
        int i, j, diff=0;
        for (i=4; i; i--) {
                for (j=0; j<8; j++) diff += ABS(a[j]-b[j]);
                a+=s; b+=s;
        }
        return diff;
}

static int licomb_y(unsigned char *a, unsigned char *b, int s)
{
        int i, j, diff=0;
        for (i=4; i; i--) {
                for (j=0; j<8; j++)
                        diff += ABS((a[j]<<1) - b[j-s] - b[j])
                                + ABS((b[j]<<1) - a[j] - a[j+s]);
                a+=s; b+=s;
        }
        return diff;
}

#if 0
static int qpcomb_y(unsigned char *a, unsigned char *b, int s)
{
        int i, j, diff=0;
        for (i=4; i; i--) {
                for (j=0; j<8; j++)
                        diff += ABS(a[j] - 3*b[j-s] + 3*a[j+s] - b[j]);
                a+=s; b+=s;
        }
        return diff;
}

static int licomb_y_test(unsigned char *a, unsigned char *b, int s)
{
        int c = licomb_y(a,b,s);
        int m = licomb_y_mmx(a,b,s);
        if (c != m) printf("%d != %d\n", c, m);
        return m;
}
#endif

static int var_y(unsigned char *a, unsigned char *b, int s)
{
        int i, j, var=0;
        for (i=3; i; i--) {
                for (j=0; j<8; j++) {
                        var += ABS(a[j]-a[j+s]);
                }
                a+=s; b+=s;
        }
        return 4*var; /* match comb scaling */
}









static void alloc_buffer(struct pullup_context *c, struct pullup_buffer *b)
{
        int i;
        if (b->planes) return;
        b->planes = calloc(c->nplanes, sizeof(unsigned char *));
        for (i = 0; i < c->nplanes; i++) {
                b->planes[i] = malloc(c->h[i]*c->stride[i]);
                /* Deal with idiotic 128=0 for chroma: */
                memset(b->planes[i], c->background[i], c->h[i]*c->stride[i]);
        }
}

struct pullup_buffer *pullup_lock_buffer(struct pullup_buffer *b, int parity)
{
        if (!b) return 0;
        if ((parity+1) & 1) b->lock[0]++;
        if ((parity+1) & 2) b->lock[1]++;
        return b;
}

void pullup_release_buffer(struct pullup_buffer *b, int parity)
{
        if (!b) return;
        if ((parity+1) & 1) b->lock[0]--;
        if ((parity+1) & 2) b->lock[1]--;
}

struct pullup_buffer *pullup_get_buffer(struct pullup_context *c, int parity)
{
        int i;

        /* Try first to get the sister buffer for the previous field */
        if (parity < 2 && c->last && parity != c->last->parity
            && !c->last->buffer->lock[parity]) {
                alloc_buffer(c, c->last->buffer);
                return pullup_lock_buffer(c->last->buffer, parity);
        }

        /* Prefer a buffer with both fields open */
        for (i = 0; i < c->nbuffers; i++) {
                if (c->buffers[i].lock[0]) continue;
                if (c->buffers[i].lock[1]) continue;
                alloc_buffer(c, &c->buffers[i]);
                return pullup_lock_buffer(&c->buffers[i], parity);
        }

        if (parity == 2) return 0;

        /* Search for any half-free buffer */
        for (i = 0; i < c->nbuffers; i++) {
                if (((parity+1) & 1) && c->buffers[i].lock[0]) continue;
                if (((parity+1) & 2) && c->buffers[i].lock[1]) continue;
                alloc_buffer(c, &c->buffers[i]);
                return pullup_lock_buffer(&c->buffers[i], parity);
        }

        return 0;
}






static void compute_metric(struct pullup_context *c,
        struct pullup_field *fa, int pa,
        struct pullup_field *fb, int pb,
        int (*func)(unsigned char *, unsigned char *, int), int *dest)
{
        unsigned char *a, *b;
        int x, y;
        int mp = c->metric_plane;
        int xstep = c->bpp[mp];
        int ystep = c->stride[mp]<<3;
        int s = c->stride[mp]<<1; /* field stride */
        int w = c->metric_w*xstep;

        if (!fa->buffer || !fb->buffer) return;

        /* Shortcut for duplicate fields (e.g. from RFF flag) */
        if (fa->buffer == fb->buffer && pa == pb) {
                memset(dest, 0, c->metric_len * sizeof(int));
                return;
        }

        a = fa->buffer->planes[mp] + pa * c->stride[mp] + c->metric_offset;
        b = fb->buffer->planes[mp] + pb * c->stride[mp] + c->metric_offset;

        for (y = c->metric_h; y; y--) {
                for (x = 0; x < w; x += xstep) {
                        *dest++ = func(a + x, b + x, s);
                }
                a += ystep; b += ystep;
        }
}





static void alloc_metrics(struct pullup_context *c, struct pullup_field *f)
{
        f->diffs = calloc(c->metric_len, sizeof(int));
        f->comb = calloc(c->metric_len, sizeof(int));
        f->var = calloc(c->metric_len, sizeof(int));
        /* add more metrics here as needed */
}

static struct pullup_field *make_field_queue(struct pullup_context *c, int len)
{
        struct pullup_field *head, *f;
        f = head = calloc(1, sizeof(struct pullup_field));
        alloc_metrics(c, f);
        for (; len > 0; len--) {
                f->next = calloc(1, sizeof(struct pullup_field));
                f->next->prev = f;
                f = f->next;
                alloc_metrics(c, f);
        }
        f->next = head;
        head->prev = f;
        return head;
}

static void check_field_queue(struct pullup_context *c)
{
        if (c->head->next == c->first) {
                struct pullup_field *f = calloc(1, sizeof(struct pullup_field));
                alloc_metrics(c, f);
                f->prev = c->head;
                f->next = c->first;
                c->head->next = f;
                c->first->prev = f;
        }
}

void pullup_submit_field(struct pullup_context *c, struct pullup_buffer *b, int parity)
{
        struct pullup_field *f;

        /* Grow the circular list if needed */
        check_field_queue(c);

        /* Cannot have two fields of same parity in a row; drop the new one */
        if (c->last && c->last->parity == parity) return;

        f = c->head;
        f->parity = parity;
        f->buffer = pullup_lock_buffer(b, parity);
        f->flags = 0;
        f->breaks = 0;
        f->affinity = 0;

        compute_metric(c, f, parity, f->prev->prev, parity, c->diff, f->diffs);
        compute_metric(c, parity?f->prev:f, 0, parity?f:f->prev, 1, c->comb, f->comb);
        compute_metric(c, f, parity, f, -1, c->var, f->var);

        /* Advance the circular list */
        if (!c->first) c->first = c->head;
        c->last = c->head;
        c->head = c->head->next;
}

void pullup_flush_fields(struct pullup_context *c)
{
        struct pullup_field *f;

        for (f = c->first; f && f != c->head; f = f->next) {
                pullup_release_buffer(f->buffer, f->parity);
                f->buffer = 0;
        }
        c->first = c->last = 0;
}








#define F_HAVE_BREAKS 1
#define F_HAVE_AFFINITY 2


#define BREAK_LEFT 1
#define BREAK_RIGHT 2




static int queue_length(struct pullup_field *begin, struct pullup_field *end)
{
        int count = 1;
        struct pullup_field *f;

        if (!begin || !end) return 0;
        for (f = begin; f != end; f = f->next) count++;
        return count;
}

static int find_first_break(struct pullup_field *f, int max)
{
        int i;
        for (i = 0; i < max; i++) {
                if (f->breaks & BREAK_RIGHT || f->next->breaks & BREAK_LEFT)
                        return i+1;
                f = f->next;
        }
        return 0;
}

static void compute_breaks(struct pullup_context *c, struct pullup_field *f0)
{
        int i;
        struct pullup_field *f1 = f0->next;
        struct pullup_field *f2 = f1->next;
        struct pullup_field *f3 = f2->next;
        int l, max_l=0, max_r=0;
        //struct pullup_field *ff;
        //for (i=0, ff=c->first; ff != f0; i++, ff=ff->next);

        if (f0->flags & F_HAVE_BREAKS) return;
        //printf("\n%d: ", i);
        f0->flags |= F_HAVE_BREAKS;

        /* Special case when fields are 100% identical */
        if (f0->buffer == f2->buffer && f1->buffer != f3->buffer) {
                f2->breaks |= BREAK_RIGHT;
                return;
        }
        if (f0->buffer != f2->buffer && f1->buffer == f3->buffer) {
                f1->breaks |= BREAK_LEFT;
                return;
        }

        for (i = 0; i < c->metric_len; i++) {
                l = f2->diffs[i] - f3->diffs[i];
                if (l > max_l) max_l = l;
                if (-l > max_r) max_r = -l;
        }
        /* Don't get tripped up when differences are mostly quant error */
        //printf("%d %d\n", max_l, max_r);
        if (max_l + max_r < 128) return;
        if (max_l > 4*max_r) f1->breaks |= BREAK_LEFT;
        if (max_r > 4*max_l) f2->breaks |= BREAK_RIGHT;
}

static void compute_affinity(struct pullup_context *c, struct pullup_field *f)
{
        int i;
        int max_l=0, max_r=0, l;
        if (f->flags & F_HAVE_AFFINITY) return;
        f->flags |= F_HAVE_AFFINITY;
        if (f->buffer == f->next->next->buffer) {
                f->affinity = 1;
                f->next->affinity = 0;
                f->next->next->affinity = -1;
                f->next->flags |= F_HAVE_AFFINITY;
                f->next->next->flags |= F_HAVE_AFFINITY;
                return;
        }
        if (1) {
                for (i = 0; i < c->metric_len; i++) {
                        int lv = f->prev->var[i];
                        int rv = f->next->var[i];
                        int v = f->var[i];
                        int lc = f->comb[i] - (v+lv) + ABS(v-lv);
                        int rc = f->next->comb[i] - (v+rv) + ABS(v-rv);
                        lc = lc>0 ? lc : 0;
                        rc = rc>0 ? rc : 0;
                        l = lc - rc;
                        if (l > max_l) max_l = l;
                        if (-l > max_r) max_r = -l;
                }
                if (max_l + max_r < 64) return;
                if (max_r > 6*max_l) f->affinity = -1;
                else if (max_l > 6*max_r) f->affinity = 1;
        } else {
                for (i = 0; i < c->metric_len; i++) {
                        l = f->comb[i] - f->next->comb[i];
                        if (l > max_l) max_l = l;
                        if (-l > max_r) max_r = -l;
                }
                if (max_l + max_r < 64) return;
                if (max_r > 2*max_l) f->affinity = -1;
                else if (max_l > 2*max_r) f->affinity = 1;
        }
}

static void foo(struct pullup_context *c)
{
        struct pullup_field *f = c->first;
        int i, n = queue_length(f, c->last);
        for (i = 0; i < n-1; i++) {
                if (i < n-3) compute_breaks(c, f);
                compute_affinity(c, f);
                f = f->next;
        }
}

static int decide_frame_length(struct pullup_context *c)
{
        struct pullup_field *f0 = c->first;
        struct pullup_field *f1 = f0->next;
        struct pullup_field *f2 = f1->next;
        int l;

        if (queue_length(c->first, c->last) < 4) return 0;
        foo(c);

        if (f0->affinity == -1) return 1;

        l = find_first_break(f0, 3);
        if (l == 1 && c->strict_breaks < 0) l = 0;

        switch (l) {
        case 1:
                if (c->strict_breaks < 1 && f0->affinity == 1 && f1->affinity == -1)
                        return 2;
                else return 1;
        case 2:
                /* FIXME: strictly speaking, f0->prev is no longer valid... :) */
                if (c->strict_pairs
                        && (f0->prev->breaks & BREAK_RIGHT) && (f2->breaks & BREAK_LEFT)
                        && (f0->affinity != 1 || f1->affinity != -1) )
                        return 1;
                if (f1->affinity == 1) return 1;
                else return 2;
        case 3:
                if (f2->affinity == 1) return 2;
                else return 3;
        default:
                /* 9 possibilities covered before switch */
                if (f1->affinity == 1) return 1; /* covers 6 */
                else if (f1->affinity == -1) return 2; /* covers 6 */
                else if (f2->affinity == -1) { /* covers 2 */
                        if (f0->affinity == 1) return 3;
                        else return 1;
                }
                else return 2; /* the remaining 6 */
        }
}


static void print_aff_and_breaks(struct pullup_context *c, struct pullup_field *f)
{
        int i;
        struct pullup_field *f0 = f;
        const char aff_l[] = "+..", aff_r[] = "..+";
        printf("\naffinity: ");
        for (i = 0; i < 4; i++) {
                printf("%c%d%c", aff_l[1+f->affinity], i, aff_r[1+f->affinity]);
                f = f->next;
        }
        f = f0;
        printf("\nbreaks:   ");
        for (i=0; i<4; i++) {
                printf("%c%d%c", f->breaks & BREAK_LEFT ? '|' : '.', i, f->breaks & BREAK_RIGHT ? '|' : '.');
                f = f->next;
        }
        printf("\n");
}





struct pullup_frame *pullup_get_frame(struct pullup_context *c)
{
        int i;
        struct pullup_frame *fr = c->frame;
        int n = decide_frame_length(c);
        int aff = c->first->next->affinity;

        if (!n) return 0;
        if (fr->lock) return 0;

        if (c->verbose) {
                print_aff_and_breaks(c, c->first);
                printf("duration: %d    \n", n);
        }

        fr->lock++;
        fr->length = n;
        fr->parity = c->first->parity;
        fr->buffer = 0;
        for (i = 0; i < n; i++) {
                /* We cheat and steal the buffer without release+relock */
                fr->ifields[i] = c->first->buffer;
                c->first->buffer = 0;
                c->first = c->first->next;
        }

        if (n == 1) {
                fr->ofields[fr->parity] = fr->ifields[0];
                fr->ofields[fr->parity^1] = 0;
        } else if (n == 2) {
                fr->ofields[fr->parity] = fr->ifields[0];
                fr->ofields[fr->parity^1] = fr->ifields[1];
        } else if (n == 3) {
                if (aff == 0)
                        aff = (fr->ifields[0] == fr->ifields[1]) ? -1 : 1;
                /* else if (c->verbose) printf("forced aff: %d    \n", aff); */
                fr->ofields[fr->parity] = fr->ifields[1+aff];
                fr->ofields[fr->parity^1] = fr->ifields[1];
        }
        pullup_lock_buffer(fr->ofields[0], 0);
        pullup_lock_buffer(fr->ofields[1], 1);

        if (fr->ofields[0] == fr->ofields[1]) {
                fr->buffer = fr->ofields[0];
                pullup_lock_buffer(fr->buffer, 2);
                return fr;
        }
        return fr;
}

static void copy_field(struct pullup_context *c, struct pullup_buffer *dest,
        struct pullup_buffer *src, int parity)
{
        int i, j;
        unsigned char *d, *s;
        for (i = 0; i < c->nplanes; i++) {
                s = src->planes[i] + parity*c->stride[i];
                d = dest->planes[i] + parity*c->stride[i];
                for (j = c->h[i]>>1; j; j--) {
                        memcpy(d, s, c->stride[i]);
                        s += c->stride[i]<<1;
                        d += c->stride[i]<<1;
                }
        }
}

void pullup_pack_frame(struct pullup_context *c, struct pullup_frame *fr)
{
        int i;
        if (fr->buffer) return;
        if (fr->length < 2) return; /* FIXME: deal with this */
        for (i = 0; i < 2; i++)
        {
                if (fr->ofields[i]->lock[i^1]) continue;
                fr->buffer = fr->ofields[i];
                pullup_lock_buffer(fr->buffer, 2);
                copy_field(c, fr->buffer, fr->ofields[i^1], i^1);
                return;
        }
        fr->buffer = pullup_get_buffer(c, 2);
        copy_field(c, fr->buffer, fr->ofields[0], 0);
        copy_field(c, fr->buffer, fr->ofields[1], 1);
}

void pullup_release_frame(struct pullup_frame *fr)
{
        int i;
        for (i = 0; i < fr->length; i++)
                pullup_release_buffer(fr->ifields[i], fr->parity ^ (i&1));
        pullup_release_buffer(fr->ofields[0], 0);
        pullup_release_buffer(fr->ofields[1], 1);
        if (fr->buffer) pullup_release_buffer(fr->buffer, 2);
        fr->lock--;
}






struct pullup_context *pullup_alloc_context(void)
{
        struct pullup_context *c;

        c = calloc(1, sizeof(struct pullup_context));

        return c;
}

void pullup_preinit_context(struct pullup_context *c)
{
        c->bpp = calloc(c->nplanes, sizeof(int));
        c->w = calloc(c->nplanes, sizeof(int));
        c->h = calloc(c->nplanes, sizeof(int));
        c->stride = calloc(c->nplanes, sizeof(int));
        c->background = calloc(c->nplanes, sizeof(int));
}

void pullup_init_context(struct pullup_context *c)
{
        int mp = c->metric_plane;
        if (c->nbuffers < 10) c->nbuffers = 10;
        c->buffers = calloc(c->nbuffers, sizeof (struct pullup_buffer));

        c->metric_w = (c->w[mp] - ((c->junk_left + c->junk_right) << 3)) >> 3;
        c->metric_h = (c->h[mp] - ((c->junk_top + c->junk_bottom) << 1)) >> 3;
        c->metric_offset = c->junk_left*c->bpp[mp] + (c->junk_top<<1)*c->stride[mp];
        c->metric_len = c->metric_w * c->metric_h;

        c->head = make_field_queue(c, 8);

        c->frame = calloc(1, sizeof (struct pullup_frame));
        c->frame->ifields = calloc(3, sizeof (struct pullup_buffer *));

        switch(c->format) {
        case PULLUP_FMT_Y:
                c->diff = diff_y;
                c->comb = licomb_y;
                c->var = var_y;
#if ARCH_X86
#if HAVE_MMX
                if (c->cpu & PULLUP_CPU_MMX) {
                        c->diff = diff_y_mmx;
                        c->comb = licomb_y_mmx;
                        c->var = var_y_mmx;
                }
#endif
#endif
                /* c->comb = qpcomb_y; */
                break;
#if 0
        case PULLUP_FMT_YUY2:
                c->diff = diff_yuy2;
                break;
        case PULLUP_FMT_RGB32:
                c->diff = diff_rgb32;
                break;
#endif
        }
}

void pullup_free_context(struct pullup_context *c)
{
        struct pullup_field *f;
        free(c->buffers);
        f = c->head;
        do {
                if (!f) break;
                free(f->diffs);
                free(f->comb);
                f = f->next;
                free(f->prev);
        } while (f != c->head);
        free(c->frame);
        free(c);
}