/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2014 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2017 - Daniel De Matteis
 *
 *  RetroArch 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 Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  RetroArch 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 RetroArch.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <math.h>

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xatom.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <X11/extensions/XShm.h>
#include <X11/extensions/Xv.h>
#include <X11/extensions/Xvlib.h>

#include <retro_inline.h>

#ifdef HAVE_CONFIG_H
#include "../../config.h"
#endif

#ifdef HAVE_MENU
#include "../../menu/menu_driver.h"
#endif

#include "../font_driver.h"

#include "../../configuration.h"
#include "../../frontend/frontend_driver.h"
#include "../../verbosity.h"

#include "../common/x11_common.h"

/* Adapted from bSNES and MPlayer source. */

typedef struct xv
{
   GC gc;
   XShmSegmentInfo shminfo;

   XvPortID port;
   int depth;
   int visualid;

   XvImage *image;
   uint32_t fourcc;

   unsigned width;
   unsigned height;
   bool keep_aspect;
   struct video_viewport vp;

   uint8_t *ytable;
   uint8_t *utable;
   uint8_t *vtable;

   void *font;
   const font_renderer_driver_t *font_driver;

   unsigned luma_index[2];
   unsigned chroma_u_index;
   unsigned chroma_v_index;

   uint8_t font_y;
   uint8_t font_u;
   uint8_t font_v;

   void (*render_func)(struct xv*, const void *frame,
         unsigned width, unsigned height, unsigned pitch);
} xv_t;

static void xv_set_nonblock_state(void *data, bool state)
{
   xv_t *xv  = (xv_t*)data;
   Atom atom = XInternAtom(g_x11_dpy, "XV_SYNC_TO_VBLANK", true);

   if (atom != None && xv->port)
      XvSetPortAttribute(g_x11_dpy, xv->port, atom, !state);
   else
      RARCH_WARN("Failed to set SYNC_TO_VBLANK attribute.\n");
}

static INLINE void xv_calculate_yuv(uint8_t *y, uint8_t *u, uint8_t *v,
      unsigned r, unsigned g, unsigned b)
{
   int y_ = (int)(+((double)r * 0.257) + ((double)g * 0.504) 
         + ((double)b * 0.098) +  16.0);
   int u_ = (int)(-((double)r * 0.148) - ((double)g * 0.291) 
         + ((double)b * 0.439) + 128.0);
   int v_ = (int)(+((double)r * 0.439) - ((double)g * 0.368) 
         - ((double)b * 0.071) + 128.0);

   *y     = y_ < 0 ? 0 : (y_ > 255 ? 255 : y_);
   *u     = y_ < 0 ? 0 : (u_ > 255 ? 255 : u_);
   *v     = v_ < 0 ? 0 : (v_ > 255 ? 255 : v_);
}

static void xv_init_yuv_tables(xv_t *xv)
{
   unsigned i;
   xv->ytable = (uint8_t*)malloc(0x10000);
   xv->utable = (uint8_t*)malloc(0x10000);
   xv->vtable = (uint8_t*)malloc(0x10000);

   for (i = 0; i < 0x10000; i++)
   {
      /* Extract RGB565 color data from i */
      unsigned r = (i >> 11) & 0x1f;
      unsigned g = (i >> 5)  & 0x3f;
      unsigned b = (i >> 0)  & 0x1f;
      r          = (r << 3) | (r >> 2);  /* R5->R8 */
      g          = (g << 2) | (g >> 4);  /* G6->G8 */
      b          = (b << 3) | (b >> 2);  /* B5->B8 */

      xv_calculate_yuv(&xv->ytable[i],
            &xv->utable[i], &xv->vtable[i], r, g, b);
   }
}

static void xv_init_font(xv_t *xv, const char *font_path, unsigned font_size)
{
   settings_t *settings = config_get_ptr();

   if (!settings->video.font_enable)
      return;

   if (font_renderer_create_default((const void**)&xv->font_driver, 
            &xv->font, *settings->path.font 
            ? settings->path.font : NULL, settings->video.font_size))
   {
      int r, g, b;
      r = settings->video.msg_color_r * 255;
      r = (r < 0 ? 0 : (r > 255 ? 255 : r));
      g = settings->video.msg_color_g * 255;
      g = (g < 0 ? 0 : (g > 255 ? 255 : g));
      b = settings->video.msg_color_b * 255;
      b = (b < 0 ? 0 : (b > 255 ? 255 : b));

      xv_calculate_yuv(&xv->font_y, &xv->font_u, &xv->font_v,
            r, g, b);
   }
   else
      RARCH_LOG("[XVideo]: Could not initialize fonts.\n");
}

/* We render @ 2x scale to combat chroma downsampling.
 * Also makes fonts more bearable. */
static void render16_yuy2(xv_t *xv, const void *input_,
      unsigned width, unsigned height, unsigned pitch)
{
   unsigned x, y;
   const uint16_t *input = (const uint16_t*)input_;
   uint8_t *output       = (uint8_t*)xv->image->data;

   for (y = 0; y < height; y++)
   {
      for (x = 0; x < width; x++)
      {
         uint16_t p         = *input++;
         uint8_t y0         = xv->ytable[p];
         uint8_t u          = xv->utable[p];
         uint8_t v          = xv->vtable[p];

         unsigned img_width = xv->width << 1;

         output[0] = output[img_width]     = y0;
         output[1] = output[img_width + 1] = u;
         output[2] = output[img_width + 2] = y0;
         output[3] = output[img_width + 3] = v;
         output += 4;
      }

      input  += (pitch >> 1) - width;
      output += (xv->width - width) << 2;
   }
}

static void render16_uyvy(xv_t *xv, const void *input_,
      unsigned width, unsigned height, unsigned pitch)
{
   unsigned x, y;
   const uint16_t *input = (const uint16_t*)input_;
   uint8_t       *output = (uint8_t*)xv->image->data;

   for (y = 0; y < height; y++)
   {
      for (x = 0; x < width; x++)
      {
         uint16_t p         = *input++;
         uint8_t y0         = xv->ytable[p];
         uint8_t u          = xv->utable[p];
         uint8_t v          = xv->vtable[p];
         unsigned img_width = xv->width << 1;

         output[0] = output[img_width]     = u;
         output[1] = output[img_width + 1] = y0;
         output[2] = output[img_width + 2] = v;
         output[3] = output[img_width + 3] = y0;
         output += 4;
      }

      input  += (pitch >> 1) - width;
      output += (xv->width - width) << 2;
   }
}

static void render32_yuy2(xv_t *xv, const void *input_,
      unsigned width, unsigned height, unsigned pitch)
{
   unsigned x, y;
   const uint32_t *input = (const uint32_t*)input_;
   uint8_t *output       = (uint8_t*)xv->image->data;

   for (y = 0; y < height; y++)
   {
      for (x = 0; x < width; x++)
      {
         uint8_t y0, u, v;
         unsigned img_width;
         uint32_t p = *input++;
         p = ((p >> 8) & 0xf800) | ((p >> 5) & 0x07e0) 
            | ((p >> 3) & 0x1f); /* ARGB -> RGB16 */

         y0        = xv->ytable[p];
         u         = xv->utable[p];
         v         = xv->vtable[p];

         img_width = xv->width << 1;
         output[0] = output[img_width] = y0;
         output[1] = output[img_width + 1] = u;
         output[2] = output[img_width + 2] = y0;
         output[3] = output[img_width + 3] = v;
         output += 4;
      }

      input  += (pitch >> 2) - width;
      output += (xv->width - width) << 2;
   }
}

static void render32_uyvy(xv_t *xv, const void *input_,
      unsigned width, unsigned height, unsigned pitch)
{
   unsigned x, y;
   const uint32_t *input = (const uint32_t*)input_;
   uint16_t *output      = (uint16_t*)xv->image->data;

   for (y = 0; y < height; y++)
   {
      for (x = 0; x < width; x++)
      {
         uint8_t y0, u, v;
         unsigned img_width;
         uint32_t p = *input++;
         p = ((p >> 8) & 0xf800) 
            | ((p >> 5) & 0x07e0) | ((p >> 3) & 0x1f); /* ARGB -> RGB16 */

         y0        = xv->ytable[p];
         u         = xv->utable[p];
         v         = xv->vtable[p];

         img_width = xv->width << 1;
         output[0] = output[img_width] = u;
         output[1] = output[img_width + 1] = y0;
         output[2] = output[img_width + 2] = v;
         output[3] = output[img_width + 3] = y0;
         output += 4;
      }

      input  += (pitch >> 2) - width;
      output += (xv->width - width) << 2;
   }
}

struct format_desc
{
   void (*render_16)(xv_t *xv, const void *input,
         unsigned width, unsigned height, unsigned pitch);
   void (*render_32)(xv_t *xv, const void *input,
         unsigned width, unsigned height, unsigned pitch);
   char components[4];
   unsigned luma_index[2];
   unsigned u_index;
   unsigned v_index;
};

static const struct format_desc formats[] = {
   {
      render16_yuy2,
      render32_yuy2,
      { 'Y', 'U', 'Y', 'V' },
      { 0, 2 },
      1,
      3,
   },
   {
      render16_uyvy,
      render32_uyvy,
      { 'U', 'Y', 'V', 'Y' },
      { 1, 3 },
      0,
      2,
   },
};

static bool xv_adaptor_set_format(xv_t *xv, Display *dpy,
      XvPortID port, video_info_t *video)
{
   int i;
   unsigned j;
   int format_count;
   XvImageFormatValues *format = XvListImageFormats(
         g_x11_dpy, port, &format_count);

   if (!format)
      return false;

   for (i = 0; i < format_count; i++)
   {
      for (j = 0; j < ARRAY_SIZE(formats); j++)
      {
         if (format[i].type == XvYUV 
               && format[i].bits_per_pixel == 16 
               && format[i].format == XvPacked)
         {
            if (format[i].component_order[0] == formats[j].components[0] &&
                  format[i].component_order[1] == formats[j].components[1] &&
                  format[i].component_order[2] == formats[j].components[2] &&
                  format[i].component_order[3] == formats[j].components[3])
            {
               xv->fourcc         = format[i].id;
               xv->render_func    = video->rgb32 
                  ? formats[j].render_32 : formats[j].render_16;

               xv->luma_index[0]  = formats[j].luma_index[0];
               xv->luma_index[1]  = formats[j].luma_index[1];
               xv->chroma_u_index = formats[j].u_index;
               xv->chroma_v_index = formats[j].v_index;
               XFree(format);
               return true;
            }
         }
      }
   }

   XFree(format);
   return false;
}

static void xv_calc_out_rect(bool keep_aspect,
      struct video_viewport *vp,
      unsigned vp_width, unsigned vp_height)
{
   settings_t *settings = config_get_ptr();

   vp->full_width       = vp_width;
   vp->full_height      = vp_height;

   if (settings->video.scale_integer)
      video_viewport_get_scaled_integer(vp, vp_width, vp_height,
            video_driver_get_aspect_ratio(), keep_aspect);
   else if (!keep_aspect)
   {
      vp->x      = 0;
      vp->y      = 0;
      vp->width  = vp_width;
      vp->height = vp_height;
   }
   else
   {
      float desired_aspect = video_driver_get_aspect_ratio();
      float device_aspect  = (float)vp_width / vp_height;

      /* If the aspect ratios of screen and desired aspect ratio 
       * are sufficiently equal (floating point stuff),
       * assume they are actually equal.
       */
      if (fabs(device_aspect - desired_aspect) < 0.0001)
      {
         vp->x       = 0;
         vp->y       = 0;
         vp->width   = vp_width;
         vp->height  = vp_height;
      }
      else if (device_aspect > desired_aspect)
      {
         float delta = (desired_aspect / device_aspect - 1.0) / 2.0 + 0.5;
         vp->x       = vp_width * (0.5 - delta);
         vp->y       = 0;
         vp->width   = 2.0 * vp_width * delta;
         vp->height  = vp_height;
      }
      else
      {
         float delta = (device_aspect / desired_aspect - 1.0) / 2.0 + 0.5;
         vp->x       = 0;
         vp->y       = vp_height * (0.5 - delta);
         vp->width   = vp_width;
         vp->height  = 2.0 * vp_height * delta;
      }
   }
}

static void *xv_init(video_info_t *video,
      const input_driver_t **input, void **input_data)
{
   unsigned i;
   XWindowAttributes target;
   char buf[128]                          = {0};
   char title[128]                        = {0};
   XSetWindowAttributes attributes        = {0};
   XVisualInfo visualtemplate             = {0};
   unsigned width                         = 0;
   unsigned height                        = 0;
   unsigned adaptor_count                 = 0;
   int visualmatches                      = 0;
   Atom atom                              = 0;
   void *xinput                           = NULL;
   XVisualInfo *visualinfo                = NULL;
   XvAdaptorInfo *adaptor_info            = NULL;
   const struct retro_game_geometry *geom = NULL;
   struct retro_system_av_info *av_info   = NULL;
   settings_t *settings                   = config_get_ptr();

   xv_t                               *xv = (xv_t*)calloc(1, sizeof(*xv));
   if (!xv)
      return NULL;

   XInitThreads();

   g_x11_dpy = XOpenDisplay(NULL);
   
   av_info = video_viewport_get_system_av_info();

   if (av_info)
      geom        = &av_info->geometry;

   if (!XShmQueryExtension(g_x11_dpy))
   {
      RARCH_ERR("[XVideo]: XShm extension not found.\n");
      goto error;
   }

   xv->keep_aspect = video->force_aspect;

   /* Find an appropriate Xv port. */
   xv->port = 0;
   XvQueryAdaptors(g_x11_dpy,
         DefaultRootWindow(g_x11_dpy), &adaptor_count, &adaptor_info);

   for (i = 0; i < adaptor_count; i++)
   {
      /* Find adaptor that supports both input (memory->drawable) 
       * and image (drawable->screen) masks. */

      if (adaptor_info[i].num_formats < 1)
         continue;
      if (!(adaptor_info[i].type & XvInputMask))
         continue;
      if (!(adaptor_info[i].type & XvImageMask))
         continue;
      if (!xv_adaptor_set_format(xv, g_x11_dpy,
               adaptor_info[i].base_id, video))
         continue;

      xv->port     = adaptor_info[i].base_id;
      xv->depth    = adaptor_info[i].formats->depth;
      xv->visualid = adaptor_info[i].formats->visual_id;

      RARCH_LOG("[XVideo]: Found suitable XvPort #%u\n", (unsigned)xv->port);
      break;
   }
   XvFreeAdaptorInfo(adaptor_info);

   if (xv->port == 0)
   {
      RARCH_ERR("[XVideo]: Failed to find valid XvPort or format.\n");
      goto error;
   }

   visualtemplate.visualid = xv->visualid;
   visualtemplate.screen   = DefaultScreen(g_x11_dpy);
   visualtemplate.depth    = xv->depth;
   visualtemplate.visual   = 0;
   visualinfo              = XGetVisualInfo(g_x11_dpy, VisualIDMask | 
         VisualScreenMask | VisualDepthMask, &visualtemplate, &visualmatches);

   if (!visualinfo)
      goto error;

   if (visualmatches < 1 || !visualinfo->visual)
   {
      RARCH_ERR("[XVideo]: Unable to find Xv-compatible visual.\n");
      goto error;
   }

   g_x11_cmap = XCreateColormap(g_x11_dpy,
         DefaultRootWindow(g_x11_dpy), visualinfo->visual, AllocNone);

   attributes.colormap     = g_x11_cmap;
   attributes.border_pixel = 0;
   attributes.event_mask   = StructureNotifyMask | KeyPressMask | 
      KeyReleaseMask | ButtonReleaseMask | ButtonPressMask | DestroyNotify | ClientMessage;

   if (video->fullscreen)
   {
      width      = (((video->width  == 0) && geom) ? geom->base_width : video->width);
      height     = (((video->height == 0) && geom) ? geom->base_height : video->height);
   }
   else
   {
      width      = video->width;
      height     = video->height;
   }
   g_x11_win  = XCreateWindow(g_x11_dpy, DefaultRootWindow(g_x11_dpy),
         0, 0, width, height,
         0, xv->depth, InputOutput, visualinfo->visual,
         CWColormap | CWBorderPixel | CWEventMask, &attributes);

   XFree(visualinfo);
   XSetWindowBackground(g_x11_dpy, g_x11_win, 0);

   XMapWindow(g_x11_dpy, g_x11_win);

   video_driver_get_window_title(title, sizeof(title));

   if (title[0])
      XStoreName(g_x11_dpy, g_x11_win, title);

   x11_set_window_attr(g_x11_dpy, g_x11_win);

   if (video->fullscreen)
   {
      x11_windowed_fullscreen(g_x11_dpy, g_x11_win);
      x11_show_mouse(g_x11_dpy, g_x11_win, false);
   }

   xv->gc = XCreateGC(g_x11_dpy, g_x11_win, 0, 0);

   /* Set colorkey to auto paint, so that Xv video output is always visible. */
   atom = XInternAtom(g_x11_dpy, "XV_AUTOPAINT_COLORKEY", true);
   if (atom != None)
      XvSetPortAttribute(g_x11_dpy, xv->port, atom, 1);

   if (geom)
   {
      xv->width  = geom->max_width;
      xv->height = geom->max_height;
   }

   xv->image = XvShmCreateImage(g_x11_dpy, xv->port, xv->fourcc,
         NULL, xv->width, xv->height, &xv->shminfo);

   if (!xv->image)
   {
      RARCH_ERR("[XVideo]: XShmCreateImage failed.\n");
      goto error;
   }

   xv->width            = xv->image->width;
   xv->height           = xv->image->height;
   xv->shminfo.shmid    = shmget(IPC_PRIVATE, xv->image->data_size, IPC_CREAT | 0777);
   xv->shminfo.shmaddr  = xv->image->data = (char*)shmat(xv->shminfo.shmid, NULL, 0);
   xv->shminfo.readOnly = false;

   if (!XShmAttach(g_x11_dpy, &xv->shminfo))
   {
      RARCH_ERR("[XVideo]: XShmAttach failed.\n");
      goto error;
   }
   XSync(g_x11_dpy, False);
   memset(xv->image->data, 128, xv->image->data_size);

   x11_install_quit_atom();

   frontend_driver_install_signal_handler();

   xv_set_nonblock_state(xv, !video->vsync);

   if (input && input_data)
   {
      xinput = input_x.init(settings->input.joypad_driver);
      if (xinput)
      {
         *input = &input_x;
         *input_data = xinput;
      }
      else
         *input = NULL;
   }

   xv_init_yuv_tables(xv);
   xv_init_font(xv, settings->path.font, settings->video.font_size);

   if (!x11_input_ctx_new(true))
      goto error;

   XGetWindowAttributes(g_x11_dpy, g_x11_win, &target);
   xv_calc_out_rect(xv->keep_aspect, &xv->vp, target.width, target.height);
   xv->vp.full_width = target.width;
   xv->vp.full_height = target.height;

   return xv;

error:
   if (visualinfo)
      XFree(visualinfo);
   free(xv);
   return NULL;
}

static bool xv_check_resize(xv_t *xv, unsigned width, unsigned height)
{
   /* We render @ 2x scale to combat chroma downsampling. */
   if (xv->width != (width << 1) || xv->height != (height << 1))
   {
      xv->width  = width << 1;
      xv->height = height << 1;

      XShmDetach(g_x11_dpy, &xv->shminfo);
      shmdt(xv->shminfo.shmaddr);
      shmctl(xv->shminfo.shmid, IPC_RMID, NULL);
      XFree(xv->image);

      memset(&xv->shminfo, 0, sizeof(xv->shminfo));
      xv->image = XvShmCreateImage(g_x11_dpy, xv->port, xv->fourcc,
            NULL, xv->width, xv->height, &xv->shminfo);

      if (xv->image == None)
      {
         RARCH_ERR("[XVideo]: Failed to create image.\n");
         return false;
      }

      xv->width  = xv->image->width;
      xv->height = xv->image->height;

      xv->shminfo.shmid = 
         shmget(IPC_PRIVATE, xv->image->data_size, IPC_CREAT | 0777);

      if (xv->shminfo.shmid < 0)
      {
         RARCH_ERR("[XVideo]: Failed to init SHM.\n");
         return false;
      }

      xv->shminfo.shmaddr  = xv->image->data = 
         (char*)shmat(xv->shminfo.shmid, NULL, 0);
      xv->shminfo.readOnly = false;

      if (!XShmAttach(g_x11_dpy, &xv->shminfo))
      {
         RARCH_ERR("[XVideo]: Failed to reattch XvShm image.\n");
         return false;
      }
      XSync(g_x11_dpy, False);
      memset(xv->image->data, 128, xv->image->data_size);
   }
   return true;
}

/* TODO: Is there some way to render directly like GL?
 * Hacky C code is hacky. */
static void xv_render_msg(xv_t *xv, const char *msg,
      unsigned width, unsigned height)
{
   int x, y, msg_base_x, msg_base_y;
   unsigned i, luma_index[2], pitch;
   unsigned chroma_u_index, chroma_v_index;
   settings_t *settings = config_get_ptr();
   const struct font_atlas *atlas = NULL;

   if (!xv->font)
      return;

   atlas          = xv->font_driver->get_atlas(xv->font);

   msg_base_x     = settings->video.msg_pos_x * width;
   msg_base_y     = height * (1.0f - settings->video.msg_pos_y);

   luma_index[0]  = xv->luma_index[0];
   luma_index[1]  = xv->luma_index[1];

   chroma_u_index = xv->chroma_u_index;
   chroma_v_index = xv->chroma_v_index;

   pitch          = width << 1; /* YUV formats used are 16 bpp. */

   for (; *msg; msg++)
   {
      int base_x, base_y, glyph_width, glyph_height, max_width, max_height;
      const uint8_t *src             = NULL;
      uint8_t *out                   = NULL;
      const struct font_glyph *glyph = 
         xv->font_driver->get_glyph(xv->font, (uint8_t)*msg);

      if (!glyph)
         continue;

      /* Make sure we always start on the correct boundary 
       * so the indices are correct. */
      base_x          = (msg_base_x + glyph->draw_offset_x + 1) & ~1; 
      base_y          = msg_base_y + glyph->draw_offset_y;

      glyph_width     = glyph->width;
      glyph_height    = glyph->height;

      src             = atlas->buffer + glyph->atlas_offset_x + 
                        glyph->atlas_offset_y * atlas->width;

      if (base_x < 0)
      {
         src          -= base_x;
         glyph_width  += base_x;
         base_x = 0;
      }

      if (base_y < 0)
      {
         src          -= base_y * (int)atlas->width;
         glyph_height += base_y;
         base_y = 0;
      }

      max_width        = width - base_x;
      max_height       = height - base_y;

      if (max_width <= 0 || max_height <= 0)
         continue;

      if (glyph_width > max_width)
         glyph_width   = max_width;
      if (glyph_height > max_height)
         glyph_height  = max_height;

      out = (uint8_t*)xv->image->data + base_y * pitch + (base_x << 1);

      for (y = 0; y < glyph_height; y++, src += atlas->width, out += pitch)
      {
         /* 2 input pixels => 4 bytes (2Y, 1U, 1V). */

         for (x = 0; x < glyph_width; x += 2)
         {
            unsigned alpha[2], alpha_sub, blended;
            int out_x = x << 1;

            alpha[0] = src[x + 0];
            alpha[1] = 0;

            if (x + 1 < glyph_width)
               alpha[1] = src[x + 1];

            /* Blended alpha for the sub-sampled U/V channels. */
            alpha_sub = (alpha[0] + alpha[1]) >> 1; 

            for (i = 0; i < 2; i++)
            {
               unsigned blended = (xv->font_y * alpha[i] 
                     + ((256 - alpha[i]) * out[out_x + luma_index[i]])) >> 8;
               out[out_x + luma_index[i]] = blended;
            }

            /* Blend chroma channels */
            blended = (xv->font_u * alpha_sub 
                  + ((256 - alpha_sub) * out[out_x + chroma_u_index])) >> 8;
            out[out_x + chroma_u_index] = blended;

            blended = (xv->font_v * alpha_sub 
                  + ((256 - alpha_sub) * out[out_x + chroma_v_index])) >> 8;
            out[out_x + chroma_v_index] = blended;
         }
      }

      msg_base_x += glyph->advance_x;
      msg_base_y += glyph->advance_y;
   }
}

static bool xv_frame(void *data, const void *frame, unsigned width,
      unsigned height, uint64_t frame_count,
      unsigned pitch, const char *msg, video_frame_info_t *video_info)
{
   XWindowAttributes target;
   xv_t *xv                  = (xv_t*)data;

   if (!frame)
      return true;

   if (!xv_check_resize(xv, width, height))
      return false;

   XGetWindowAttributes(g_x11_dpy, g_x11_win, &target);
   xv->render_func(xv, frame, width, height, pitch);

   xv_calc_out_rect(xv->keep_aspect, &xv->vp, target.width, target.height);
   xv->vp.full_width  = target.width;
   xv->vp.full_height = target.height;

#ifdef HAVE_MENU
   menu_driver_frame(video_info);
#endif

   if (msg)
      xv_render_msg(xv, msg, width << 1, height << 1);

   XvShmPutImage(g_x11_dpy, xv->port, g_x11_win, xv->gc, xv->image,
         0, 0, width << 1, height << 1,
         xv->vp.x, xv->vp.y, xv->vp.width, xv->vp.height,
         true);
   XSync(g_x11_dpy, False);

   x11_update_title(NULL, video_info);

   return true;
}

static bool xv_suppress_screensaver(void *data, bool enable)
{
   (void)data;

   if (video_driver_display_type_get() != RARCH_DISPLAY_X11)
      return false;

   x11_suspend_screensaver(video_driver_window_get(), enable);
   return true;
}

static bool xv_has_windowed(void *data)
{
   (void)data;

   /* TODO - verify. */
   return true;
}

static void xv_free(void *data)
{
   xv_t *xv = (xv_t*)data;

   if (!xv)
      return;

   x11_input_ctx_destroy();

   XShmDetach(g_x11_dpy, &xv->shminfo);
   shmdt(xv->shminfo.shmaddr);
   shmctl(xv->shminfo.shmid, IPC_RMID, NULL);
   XFree(xv->image);

   x11_window_destroy(true);
   x11_colormap_destroy();

   XCloseDisplay(g_x11_dpy);

   free(xv->ytable);
   free(xv->utable);
   free(xv->vtable);

   if (xv->font)
      xv->font_driver->free(xv->font);

   free(xv);
}

static void xv_viewport_info(void *data, struct video_viewport *vp)
{
   xv_t *xv = (xv_t*)data;
   *vp = xv->vp;
}

static void xv_set_rotation(void *data, unsigned rotation)
{
   (void)data;
   (void)rotation;
}

static bool xv_read_viewport(void *data, uint8_t *buffer, bool is_idle)
{
   (void)data;
   (void)buffer;

   return true;
}

static void xv_get_poke_interface(void *data,
      const video_poke_interface_t **iface)
{
   (void)data;
   (void)iface;
}

static bool xv_set_shader(void *data,
      enum rarch_shader_type type, const char *path)
{
   (void)data;
   (void)type;
   (void)path;

   return false; 
}

video_driver_t video_xvideo = {
   xv_init,
   xv_frame,
   xv_set_nonblock_state,
   x11_alive,
   x11_has_focus_internal,
   xv_suppress_screensaver,
   xv_has_windowed,
   xv_set_shader,
   xv_free,
   "xvideo",
   NULL, /* set_viewport */
   xv_set_rotation,
   xv_viewport_info,
   xv_read_viewport,
   NULL, /* read_frame_raw */
#ifdef HAVE_OVERLAY
  NULL, /* overlay_interface */
#endif
  xv_get_poke_interface
};