aboutsummaryrefslogtreecommitdiffhomepage
path: root/libvo/vo_svga.c
blob: 0e2f770eca74f69cd6af4ac47b9f1183ab78dba9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
/*

  Video driver for SVGAlib 
  by Zoltan Mark Vician <se7en@sch.bme.hu>
  Code started: Mon Apr  1 23:25:47 2001
  Some changes by Matan Ziv-Av <matan@svgalib.org>
  Compleat rewrite by Ivan Kalvachev 19 Mar 2003:

Wrangings:
 -  1bpp doesn't work right for me with '-double' and svgalib 1.4.3, 
    but works OK with svgalib 1.9.17
 -  The HW acceleration is not tested - svgalibs supports few chipsets, 
    and i don't have any of them. If it works for you then let me know. 
    I will remove this warning after confirm its status.
 -  retrace sync works only in doublebuffer mode.
 -  the retrace sync may slow down decoding a lot - mplayer is blocked while
    waiting for retrace
 -  denoise3d fails to find common colorspace, use -vf denoise3d,scale
   
TODO:
 - let choose_best_mode take aspect into account
 - set palette from mpi->palette or mpi->plane[1]
 - make faster OSD black bars clear - need some OSD changes
 - Make nicer CONFIG parsing
 - change video mode logical width to match img->stride[0] - for HW only 
*/

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

#include <vga.h>

#include <limits.h>

#include "config.h"
#include "video_out.h"
#include "video_out_internal.h"
#include "fastmemcpy.h"
#include "osdep/getch2.h"
#ifdef CONFIG_VIDIX
#include "vosub_vidix.h"
#endif

#include "sub.h"

#include "mp_msg.h"
#include "help_mp.h"
//#include "mp_image.h"

#include <assert.h>

//silence warnings, probably it have to go in some global header
#define UNUSED(x) ((void)(x)) 


static void draw_alpha(int x0, int y0, int w, int h, unsigned char *src,
                       unsigned char *srca, int stride);
static uint32_t get_image(mp_image_t *mpi);

#define MAXPAGES 16
#define PAGE_EMPTY 0
#define PAGE_BUSY 1

#define CAP_ACCEL_CLEAR 8
#define CAP_ACCEL_PUTIMAGE 4
#define CAP_ACCEL_BACKGR 2
#define CAP_LINEAR 1

static uint8_t zerobuf[8192];//used when clear screen with vga_draw

static int squarepix;
static int force_vm=0;
static int force_native=0;
static int sync_flip=0;
static int blackbar_osd=0;
static int cpage,max_pages,old_page;

static vga_modeinfo * modeinfo;
static int mode_stride; //keep it in case of vga_setlogicalwidth
static int stride_granularity; //not yet used
static int mode_bpp;
static int mode_capabilities;

static int image_width,image_height; // used by OSD
static int x_pos, y_pos;

static struct {
  int yoffset;//y position of the page
  int doffset;//display start of the page
  uint8_t * vbase;//memory start address of the page
  int locks;
}PageStore[MAXPAGES];

static const vo_info_t info = {
    "SVGAlib",
    "svga",
    "Ivan Kalvachev <iive@users.sf.net>",
    ""
};

#ifdef CONFIG_VIDIX
static char vidix_name[32] = "";
static vidix_grkey_t gr_key;
#endif

LIBVO_EXTERN(svga)


//return number of 1'st free page or -1 if no free one
static inline int page_find_free(void){
int i;
  for(i=0;i<max_pages;i++)
    if(PageStore[i].locks == PAGE_EMPTY) return i;
  return -1;
}

static int preinit(const char *arg)
{
int i,rez;
char s[64];

  getch2_disable();
  memset(zerobuf,0,sizeof(zerobuf));
  force_vm=force_native=squarepix=0;
  sync_flip=vo_vsync;
  blackbar_osd=0;
  
  if(arg)while(*arg) {
#ifdef CONFIG_VIDIX  
    if(memcmp(arg,"vidix",5)==0) {
      i=6;
      while(arg[i] && arg[i]!=':') i++;
      strncpy(vidix_name, arg+6, i-6);
      vidix_name[i-5]=0;
      if(arg[i]==':')i++;
      arg+=i;
      vidix_preinit(vidix_name, &video_out_svga);
    }
#endif
    if(!strncmp(arg,"sq",2)) {
      squarepix=1;
      arg+=2;
      if( *arg == ':' ) arg++;
    }
    
    if(!strncmp(arg,"native",6)) {
      force_native=1;
      arg+=6;
      if( *arg == ':' ) arg++;
    }

    if(!strncmp(arg,"bbosd",5)) {
      blackbar_osd=1;
      arg+=5;
      if( *arg == ':' ) arg++;
    }

    if(!strncmp(arg,"retrace",7)) {
      sync_flip=1;
      arg+=7;
      if( *arg == ':' ) arg++;
    }
    
    if(*arg) {
      i=0;
      while(arg[i] && arg[i]!=':')i++;
      if(i<64){
        strncpy(s, arg, i);
        s[i]=0;

        force_vm=vga_getmodenumber(s);
        if(force_vm>0) {
          if( mp_msg_test(MSGT_VO,MSGL_V) ) mp_msg(MSGT_VO,MSGL_V, "vo_svga: Forcing mode %i\n",force_vm);
        }else{ 
          force_vm = 0;
        }
      }
      arg+=i;
      if(*arg==':')arg++;
    }
  }
  
  rez = vga_init();
  if(rez != 0){
      mp_msg(MSGT_VO,MSGL_ERR, "vo_svga: vga_init() returned error=%d\n",rez);
  }
  return !!rez;
}

static void svga_clear_box(int x,int y,int w,int h){
uint8_t * rgbplane;
int i;

  if (mode_capabilities&CAP_ACCEL_CLEAR){
    if( mp_msg_test(MSGT_VO,MSGL_DBG3) )
      mp_msg(MSGT_VO,MSGL_DBG3, "vo_svga: clearing box %d,%d - %d,%d with HW acceleration\n",
             x,y,w,h);
    if(mode_capabilities&CAP_ACCEL_BACKGR)  
      vga_accel(ACCEL_SYNC);
    vga_accel(ACCEL_SETFGCOLOR,0);//black
    vga_accel(ACCEL_FILLBOX,x,y,w,h);
    return;
  }
  if (mode_capabilities & CAP_LINEAR){
    if( mp_msg_test(MSGT_VO,MSGL_DBG3) )
      mp_msg(MSGT_VO,MSGL_DBG3, "vo_svga: clearing box %d,%d - %d,%d with memset\n",x,y,w,h);
    rgbplane=PageStore[0].vbase + (y*mode_stride) + (x*modeinfo->bytesperpixel);
    for(i=0;i<h;i++){
//i'm afraid that memcpy is better optimized than memset;)
      fast_memcpy(rgbplane,zerobuf,w*modeinfo->bytesperpixel);
//    memset(rgbplane,0,w*modeinfo->bytesperpixel);
      rgbplane+=mode_stride;
    }
    return;
  }
  //native
  if( mp_msg_test(MSGT_VO,MSGL_DBG3) )
    mp_msg(MSGT_VO,MSGL_DBG3, "vo_svga: clearing box %d,%d - %d,%d with native draw \n",x,y,w,h);
  if(modeinfo->bytesperpixel!=0) w*=modeinfo->bytesperpixel;
  for(i=0;i<h;i++){
    vga_drawscansegment(zerobuf,x,y+i,w);
  }
};

static uint32_t svga_draw_image(mp_image_t *mpi){
int i,x,y,w,h;
int stride;
uint8_t *rgbplane, *base;
int bytesperline;
int page;

  if(mpi->flags & MP_IMGFLAG_DIRECT){
    if( mp_msg_test(MSGT_VO,MSGL_DBG3) )
      mp_msg(MSGT_VO,MSGL_DBG3, "vo_svga: drawing direct rendered surface\n");
    cpage=(uint32_t)mpi->priv;
    assert((cpage>=0)&&(cpage<max_pages));
    return VO_TRUE; //it's already done
  }
//  if (mpi->flags&MP_IMGFLAGS_DRAWBACK) 
//  return VO_TRUE;//direct render method 2

//find a free page to draw into
//if there is no one then use the current one
  page = page_find_free();
  if(page>=0) cpage=page;
  PageStore[cpage].locks=PAGE_BUSY;

// these variables are used in loops  
  x = mpi->x;
  y = mpi->y;
  w = mpi->w;
  h = mpi->h;
  stride = mpi->stride[0]; 
  rgbplane = mpi->planes[0] + y*stride + (x*mpi->bpp)/8;
  x+=x_pos;//center
  y+=y_pos;
  
  if(mpi->bpp >= 8){//for modes<8 use only native
    if( (mode_capabilities&CAP_ACCEL_PUTIMAGE) && (x==0) && (w==mpi->width) &&
        (stride == mode_stride) ){ //only monolite image can be accelerated
      w=(stride*8)/mpi->bpp;//we transfer pixels in the stride so the source
//ACCELERATE
      if( mp_msg_test(MSGT_VO,MSGL_DBG3) )
        mp_msg(MSGT_VO,MSGL_DBG3, "vo_svga: using HW PutImage (x=%d,y=%d,w=%d,h=%d)\n",x,y,w,h);
      if(mode_capabilities & CAP_ACCEL_BACKGR)
        vga_accel(ACCEL_SYNC);

      vga_accel(ACCEL_PUTIMAGE,x,y+PageStore[cpage].yoffset,w,h,rgbplane);
      return VO_TRUE;
    }
  
    if( mode_capabilities&CAP_LINEAR){
//DIRECT  
      if( mp_msg_test(MSGT_VO,MSGL_DBG3) )
        mp_msg(MSGT_VO,MSGL_DBG3, "vo_svga: using Direct memcpy (x=%d,y=%d,w=%d,h=%d)\n",x,y,w,h);
      bytesperline=(w*mpi->bpp)/8;
      base=PageStore[cpage].vbase + (y*mode_stride) + (x*mpi->bpp)/8;     

      for(i=0;i<h;i++){
        mem2agpcpy(base,rgbplane,bytesperline);
        base+=mode_stride;
        rgbplane+=stride;
      }
      return VO_TRUE;
    }  
  }//(modebpp>=8
  

//NATIVE
  {
  int length;
    length=(w*mpi->bpp)/8;
  //one byte per pixel! svgalib innovation
    if(mpi->imgfmt==IMGFMT_RG4B || mpi->imgfmt==IMGFMT_BG4B) length=w;
  
    if( mp_msg_test(MSGT_VO,MSGL_DBG3) )
      mp_msg(MSGT_VO,MSGL_DBG3, "vo_svga: using Native vga_draw(x=%d,y=%d,w=%d,h=%d)\n",x,y,w,h);
    y+=PageStore[cpage].yoffset;//y position of the page beggining
    for(i=0;i<h;i++){
      vga_drawscansegment(rgbplane,x,y+i,length);
      rgbplane+=stride;
    }
  }
  return VO_TRUE;
}

static int bpp_from_vminfo(vga_modeinfo *vminfo){
  switch(vminfo->colors){
    case 2: return 1;
    case 16: return 4;
    case 256: return 8;
    case 32768: return 15;
    case 65536: return 16;
    case 1<<24: return 8*vminfo->bytesperpixel;
  } 
  return 0;
}

static int find_best_svga_mode(int req_w,int req_h, int req_bpp){
 int badness,prev_badness;
 int bestmode,lastmode;
 int i;
 vga_modeinfo *vminfo;
//int best aspect mode // best linear mode // best normal mode (no modeX)

  prev_badness = 0;//take care of special case below
  bestmode = 0; //0 is the TEXT mode
  lastmode = vga_lastmodenumber();
  for(i=1;i<=lastmode;i++){
    vminfo = vga_getmodeinfo(i);
    if( vminfo == NULL ) continue;
    if( mp_msg_test(MSGT_VO,MSGL_DBG4) )
      mp_msg(MSGT_VO,MSGL_DBG4, "vo_svga: testing mode %d (%s)\n",i,vga_getmodename(i));
    if( vga_hasmode(i) == 0 ) continue;
    if( req_bpp != bpp_from_vminfo(vminfo) )continue;
    if( (vminfo->width < req_w) || (vminfo->height < req_h) ) continue;
    badness=(vminfo->width * vminfo->height) - (req_h * req_w);
    //put here aspect calculations
    if(squarepix) 
      if( vminfo->width*3 != vminfo->height*4 ) continue;

    if( bestmode==0 || prev_badness >= badness ){//modeX etc...
      prev_badness=badness;
      bestmode=i;
      if( mp_msg_test(MSGT_VO,MSGL_DBG4) )
        mp_msg(MSGT_VO,MSGL_DBG4, "vo_svga: found good mode %d with badness %d\n",i,badness);
    }
  }
  return bestmode;
}

static int control(uint32_t request, void *data, ...)
{
  switch (request) {
    case VOCTRL_QUERY_FORMAT:
      return query_format(*((uint32_t*)data));
    case VOCTRL_DRAW_IMAGE:
      return svga_draw_image( (mp_image_t *)data);
    case VOCTRL_GET_IMAGE:
      return get_image(data);
  }

#ifdef CONFIG_VIDIX
  if (vidix_name[0]) {
    switch (request) {
    case VOCTRL_SET_EQUALIZER:
    {
      va_list ap;
      int value;
    
      va_start(ap, data);
      value = va_arg(ap, int);
      va_end(ap);

      return vidix_control(request, data, value);
    }
    case VOCTRL_GET_EQUALIZER:
    {
      va_list ap;
      int *value;
    
      va_start(ap, data);
      value = va_arg(ap, int*);
      va_end(ap);

      return vidix_control(request, data, value);
    }
    }
    return vidix_control(request, data);
  }
#endif

  return VO_NOTIMPL;
}

//
// This function is called to init the video driver for specific mode
//
static int config(uint32_t width, uint32_t height, uint32_t d_width,
                       uint32_t d_height, uint32_t flags, char *title,
                       uint32_t format) {
  int32_t req_w = width;// (d_width > 0 ? d_width : width);
  int32_t req_h = height;// (d_height > 0 ? d_height : height);
  uint16_t vid_mode = 0;
  int32_t req_bpp;
  
  uint32_t accflags;
  if( mp_msg_test(MSGT_VO,MSGL_V) )
    mp_msg(MSGT_VO,MSGL_V, "vo_svga: config(%i, %i, %i, %i, %08x, %s, %08x)\n", width, height,
           d_width, d_height, flags, title, format);
//Only RGB modes supported
  if (!IMGFMT_IS_RGB(format) && !IMGFMT_IS_BGR(format)) {assert(0);return -1;} 
  req_bpp = IMGFMT_BGR_DEPTH(format);
    
  if( vo_dbpp!=0 && vo_dbpp!=req_bpp) {assert(0);return-1;}
    
  if(!force_vm) {
    if ( mp_msg_test(MSGT_VO,MSGL_V) ) {
      mp_msg(MSGT_VO,MSGL_V, "vo_svga: Looking for the best resolution...\n");
      mp_msg(MSGT_VO,MSGL_V, "vo_svga: req_w: %d, req_h: %d, bpp: %d\n",req_w,req_h,req_bpp);
    }
    vid_mode=find_best_svga_mode(req_w,req_h,req_bpp);
    if(vid_mode==0) 
      return 1;
    modeinfo=vga_getmodeinfo(vid_mode);
  }else{//force_vm
    vid_mode=force_vm;
    if(vga_hasmode(vid_mode) == 0){
      mp_msg(MSGT_VO,MSGL_ERR, MSGTR_LIBVO_SVGA_ForcedVidmodeNotAvailable,
             vid_mode,vga_getmodename(vid_mode));
      return 1; //error;
    }
    modeinfo=vga_getmodeinfo(vid_mode);
    if( (modeinfo->width < req_w) || (modeinfo->height < req_h) ){
      mp_msg(MSGT_VO,MSGL_ERR, MSGTR_LIBVO_SVGA_ForcedVidmodeTooSmall,
             vid_mode,vga_getmodename(vid_mode));
      return 1;
    }
  }
  mode_bpp=bpp_from_vminfo(modeinfo);
     
  mp_msg(MSGT_VO,MSGL_INFO, MSGTR_LIBVO_SVGA_Vidmode,
         vid_mode,modeinfo->width,modeinfo->height,mode_bpp);
  
  if (vga_setmode(vid_mode) == -1) {
    mp_msg(MSGT_VO,MSGL_ERR, MSGTR_LIBVO_SVGA_VgasetmodeFailed,vid_mode);
    uninit();
    return 1; // error
  }
  /* set 332 palette for 8 bpp */
  if(mode_bpp==8){
    int i;
    for(i=0; i<256; i++)
      vga_setpalette(i, ((i>>5)&7)*9, ((i>>2)&7)*9, (i&3)*21);
  }
  /* set 121 palette for 4 bpp */
  else if(mode_bpp==4){
    int i;
    for(i=0; i<16; i++)
      vga_setpalette(i, ((i>>3)&1)*63, ((i>>1)&3)*21, (i&1)*63);
  } 
  //if we change the logical width, we should know the granularity
  stride_granularity=8;//according to man vga_logicalwidth
  if(modeinfo->flags & EXT_INFO_AVAILABLE){
     stride_granularity=modeinfo->linewidth_unit;
  }
  //look for hardware acceleration
  mode_capabilities=0;//NATIVE;
  if(!force_native){//if we want to use only native drawers
    if(modeinfo->flags & HAVE_EXT_SET){//support for hwaccel interface
      accflags=vga_ext_set(VGA_EXT_AVAILABLE,VGA_AVAIL_ACCEL);
      if(accflags & ACCELFLAG_FILLBOX) // clear screen
        mode_capabilities|=CAP_ACCEL_CLEAR;
      if(accflags & ACCELFLAG_PUTIMAGE)//support for mem->vid transfer
        mode_capabilities|=CAP_ACCEL_PUTIMAGE;
      if((accflags & ACCELFLAG_SETMODE) && (accflags & ACCELFLAG_SYNC)){
        vga_accel(ACCEL_SETMODE,BLITS_IN_BACKGROUND);
        mode_capabilities|=CAP_ACCEL_BACKGR;//can draw in backgraund
      }
    }
    if(modeinfo->flags & IS_LINEAR){ 
      mode_capabilities|=CAP_LINEAR; //don't use bank & vga_draw
    }
    else{
      if(modeinfo->flags & CAPABLE_LINEAR){
        int vid_mem_size;
        vid_mem_size = vga_setlinearaddressing();
        if(vid_mem_size != -1){
          modeinfo=vga_getmodeinfo(vid_mode);//sometimes they change parameters
          mode_capabilities|=CAP_LINEAR;
        }
      }
    }
  }//fi force native
  if(mode_capabilities&CAP_LINEAR){
    mp_msg(MSGT_VO,MSGL_INFO, MSGTR_LIBVO_SVGA_VideoModeIsLinearAndMemcpyCouldBeUsed);
  }
  if(mode_capabilities&CAP_ACCEL_PUTIMAGE){
    mp_msg(MSGT_VO,MSGL_INFO, MSGTR_LIBVO_SVGA_VideoModeHasHardwareAcceleration);
    mp_msg(MSGT_VO,MSGL_INFO, MSGTR_LIBVO_SVGA_IfItWorksForYouIWouldLikeToKnow);
  }
  
//here is the place to handle strides for accel_ modes;
  mode_stride=modeinfo->linewidth;
//we may try to set a bigger stride for video mode that will match the mpi->stride, 
//this way we will transfer more data, but HW put_image can do it in backgraund!

//now let's see how many pages we can use  
  max_pages = modeinfo->maxpixels/(modeinfo->height * modeinfo->width);
  if(max_pages > MAXPAGES) max_pages = MAXPAGES;
  if(!vo_doublebuffering) max_pages=1;
//fill PageStore structs
  {
  int i;
  uint8_t * GRAPH_MEM;
  int dof;
    GRAPH_MEM=vga_getgraphmem();
    for(i=0;i<max_pages;i++){
    //calculate display offset
      dof = i * modeinfo->height * modeinfo->width;
      if(modeinfo->bytesperpixel != 0) dof*=modeinfo->bytesperpixel;
    //check video chip limitations
      if( dof != (dof & modeinfo->startaddressrange) ){
        max_pages=i;//page 0 will never come here
        break;
      }
      PageStore[i].yoffset = i * modeinfo->height;//starting y offset
      PageStore[i].vbase = GRAPH_MEM + i*modeinfo->height*mode_stride; //memory base address
      PageStore[i].doffset = dof; //display offset    
      PageStore[i].locks = PAGE_EMPTY;
    }
  }
  assert(max_pages>0);
  mp_msg(MSGT_VO,MSGL_INFO, MSGTR_LIBVO_SVGA_VideoModeHas,max_pages);
  //15bpp
  if(modeinfo->bytesperpixel!=0)
    vga_claimvideomemory(max_pages * modeinfo->height * modeinfo->width * modeinfo->bytesperpixel);
  else
    vga_claimvideomemory(max_pages * modeinfo->height * modeinfo->width * mode_bpp / 8);

  cpage=old_page=0;
  svga_clear_box(0,0,modeinfo->width,modeinfo->height * max_pages);

  image_height=req_h;
  image_width=req_w;
  x_pos = (modeinfo->width  - req_w) / 2;
  y_pos = (modeinfo->height - req_h) / 2;
  x_pos &= ~(15); //align x offset position to 16 pixels
  mp_msg(MSGT_VO,MSGL_INFO, MSGTR_LIBVO_SVGA_CenteringImageStartAt,x_pos,y_pos);

#ifdef CONFIG_VIDIX

  if(vidix_name[0]){ 
    vidix_init(width, height, x_pos, y_pos, modeinfo->width, modeinfo->height, 
        format, mode_bpp, modeinfo->width,modeinfo->height);
    mp_msg(MSGT_VO,MSGL_INFO, MSGTR_LIBVO_SVGA_UsingVidix,width,height,
           modeinfo->width,modeinfo->height);
    vidix_start();
    /*set colorkey*/       
    if(vidix_grkey_support()){
      vidix_grkey_get(&gr_key);
      gr_key.key_op = KEYS_PUT;
      if (!(vo_colorkey & 0xFF000000)) {
	gr_key.ckey.op = CKEY_TRUE;
	gr_key.ckey.red = (vo_colorkey & 0x00FF0000) >> 16;
	gr_key.ckey.green = (vo_colorkey & 0x0000FF00) >> 8;
	gr_key.ckey.blue = vo_colorkey & 0x000000FF;
      } else
	gr_key.ckey.op = CKEY_FALSE;
      vidix_grkey_set(&gr_key);
    }         
  }
#endif    

  vga_setdisplaystart(0);
  return 0;
}

static int draw_slice(uint8_t *image[],int stride[],
               int w, int h, int x, int y) {
assert(0);
UNUSED(image);UNUSED(stride);
UNUSED(w);UNUSED(h);
UNUSED(x);UNUSED(y);

  return VO_ERROR;//this is yv12 only -> vf_scale should do all transforms
}

static int draw_frame(uint8_t *src[]) {
assert(0);
UNUSED(src);
  return VO_ERROR;//this one should not be called
}

static void draw_osd(void)
{
  if( mp_msg_test(MSGT_VO,MSGL_DBG4) )
     mp_msg(MSGT_VO,MSGL_DBG4, "vo_svga: draw_osd()\n");
  //only modes with bytesperpixel>0 can draw OSD
  if(modeinfo->bytesperpixel==0) return;
  if(!(mode_capabilities&CAP_LINEAR)) return;//force_native will remove OSD
    
  if(blackbar_osd){
//111
//3 4
//222
    svga_clear_box(0,0 + PageStore[cpage].yoffset, 
                   modeinfo->width, y_pos);
    svga_clear_box(0, image_height + y_pos + PageStore[cpage].yoffset,
                   modeinfo->width, modeinfo->height-(image_height+ y_pos));
    svga_clear_box(0, y_pos + PageStore[cpage].yoffset,
                   x_pos, image_height);
    svga_clear_box(image_width + x_pos, y_pos + PageStore[cpage].yoffset, 
                   modeinfo->width-(x_pos+image_width), image_height);
//    vo_remove_text(modeinfo->width, modeinfo->height, clear_alpha);
    vo_draw_text(modeinfo->width, modeinfo->height, draw_alpha);
  }else{
    vo_draw_text(image_width, image_height, draw_alpha);
  }
}

static void flip_page(void) {
  PageStore[old_page].locks=PAGE_EMPTY;
  PageStore[cpage].locks=PAGE_BUSY;

  if( mp_msg_test(MSGT_VO,MSGL_DBG3) )
    mp_msg(MSGT_VO,MSGL_DBG3, "vo_svga: viewing page %d\n",cpage);
  if(sync_flip && old_page!=cpage){
    if( mp_msg_test(MSGT_VO,MSGL_DBG3) ) mp_msg(MSGT_VO,MSGL_DBG3, "vo_svga:vga_waitretrace\n");
    vga_waitretrace();
  }
  vga_setdisplaystart(PageStore[cpage].doffset);
  
  old_page=cpage;//cpage will be overwriten on next draw_image
}

static void check_events(void) {
}

static void uninit(void) {

#ifdef CONFIG_VIDIX
  if(vidix_name[0])vidix_term();
#endif
  vga_setmode(TEXT);
}

/* --------------------------------------------------------------------- */
static int query_format(uint32_t format) {
int32_t req_bpp,flags;
int i,lastmode;
vga_modeinfo * vminfo;

  if ( mp_msg_test(MSGT_VO,MSGL_DBG4) )
    mp_msg(MSGT_VO,MSGL_DBG4, "vo_svga: query_format=%X \n",format);
//only RGB modes supported
  if( (!IMGFMT_IS_RGB(format)) && (!IMGFMT_IS_BGR(format)) ) return 0; 

// Reject different endian
#ifdef WORDS_BIGENDIAN
  if (IMGFMT_IS_BGR(format)) return 0;
#else
  if (IMGFMT_IS_RGB(format)) return 0;
#endif

  //svgalib supports only BG4B! if we want BGR4 we have to emulate it (sw)
  if( format==IMGFMT_BGR4 || format==IMGFMT_RGB4) return 0;
  req_bpp = IMGFMT_RGB_DEPTH(format);
  if( vo_dbpp>0 && vo_dbpp!=req_bpp ) return 0; //support -bpp options
//scan all modes
  lastmode = vga_lastmodenumber();
  for(i=1;i<=lastmode;i++){
    vminfo = vga_getmodeinfo(i);
    if( vminfo == NULL ) continue;
    if( vga_hasmode(i) == 0 ) continue;
    if( req_bpp != bpp_from_vminfo(vminfo) ) continue;
    if( (force_vm > 0) && (force_vm != i) )  continue;//quick hack
    flags = VFCAP_CSP_SUPPORTED|
      VFCAP_CSP_SUPPORTED_BY_HW|
      VFCAP_ACCEPT_STRIDE|
      0;
    if(req_bpp>8) flags|=VFCAP_OSD;
    return flags;
  }
  return 0;
}

static void draw_alpha(int x0, int y0, int w, int h, unsigned char *src,
                       unsigned char *srca, int stride) {
  char* base;

  if( mp_msg_test(MSGT_VO,MSGL_DBG3) )
    mp_msg(MSGT_VO,MSGL_DBG3, "vo_svga: draw_alpha(x0=%d,y0=%d,w=%d,h=%d,src=%p,srca=%p,stride=%d\n",
           x0,y0,w,h,src,srca,stride);
  if(!blackbar_osd) {
    //drawing in the image, so place the stuff there
    x0+=x_pos;
    y0+=y_pos;
  }
  
  if( mp_msg_test(MSGT_VO,MSGL_DBG4) )
    mp_msg(MSGT_VO,MSGL_DBG4, "vo_svga: OSD draw in page %d\n",cpage);
  base=PageStore[cpage].vbase + y0*mode_stride + x0*modeinfo->bytesperpixel;
  switch (mode_bpp) {
    case 32: 
      vo_draw_alpha_rgb32(w, h, src, srca, stride, base, mode_stride);
      break;
    case 24: 
      vo_draw_alpha_rgb24(w, h, src, srca, stride, base, mode_stride);
      break;
    case 16:
      vo_draw_alpha_rgb16(w, h, src, srca, stride, base, mode_stride);
      break;
    case 15:
      vo_draw_alpha_rgb15(w, h, src, srca, stride, base, mode_stride);
      break;
  }
}

static uint32_t get_image(mp_image_t *mpi){
int page;

  if(!IMGFMT_IS_BGR(mpi->imgfmt) && !IMGFMT_IS_RGB(mpi->imgfmt) ){ 
    assert(0);//should never happen
    return VO_FALSE;
  }
  
  if (
   ( (mpi->type != MP_IMGTYPE_STATIC) && (mpi->type != MP_IMGTYPE_TEMP)) ||
   (mpi->flags & MP_IMGFLAG_PLANAR) ||
   (mpi->flags & MP_IMGFLAG_YUV)
      )
    return VO_FALSE;

//reading from video memory is horribly slow
  if( !(mpi->flags & MP_IMGFLAG_READABLE) && vo_directrendering &&
       (mode_capabilities & CAP_LINEAR) ){

//find free page and reserve it
    page=page_find_free();
    if(page >= 0){
      PageStore[page].locks=PAGE_BUSY;

      mpi->flags |= MP_IMGFLAG_DIRECT;
      mpi->stride[0] = mode_stride;
      mpi->planes[0] = PageStore[page].vbase + 
             y_pos*mode_stride + (x_pos*mpi->bpp)/8;
      mpi->priv=(void *)page;
      if( mp_msg_test(MSGT_VO,MSGL_DBG3) )
        mp_msg(MSGT_VO,MSGL_DBG3, "vo_svga: direct render allocated! page=%d\n",page);
      return VO_TRUE;
    }
  }

  return VO_FALSE;
}