mpv/libvo/vo_svga.c

/*

  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])
    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);
}