libavfilter/libmpcodecs/pullup.c - third_party/ffmpeg - Git at Google

 /*
  * 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);
 }
	/*
	* 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] - 3b[j-s] + 3a[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 4var; / 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_leftc->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);
	}