Forecast Channel

Forecast Channel
Version	0.7 (7)
Type	General channel
Peripherals

Forecast Channel allows weather reports and forecasts to be downloaded onto the console from the Internet via the WiiConnect24 service.

Description

The Forecast Channel displays a view of the Earth as a globe (courtesy of NASA), with which users can view weather in other regions. The user can also spin the globe. When fully zoomed out, an accurate star map is visible in the background (the Big Dipper and the constellation Orion are easily recognizable, for example). The Forecast Channel features include the current forecast, the UV index, today's overall forecast, tomorrow's forecast, a 5-day forecast (only for the selected country), and a laundry check (Japan only). The Forecast Channel first became available on December 19, 2006, one day earlier than previously advertised. Certain games (like Madden NFL 07 and NiGHTS: Journey of Dreams) can use the Forecast Channel to simulate weather conditions depending on the player's region.

Region Variations

There are slight variations of Forecast Channel versions in different regions. When viewing weather conditions in Japan, a different set of weather icons is used. The Japanese icons were originally going to be used for all regions, but Nintendo of America (NOA) requested that more life-like icons be used. NOA also requested that the current weather conditions be displayed on the start up screen. Nintendo of Europe made a request that certain icons be made more distinct, such as the storm clouds, so that it would be possible for the user to tell if an area is getting rain, snow, sleet, hail, or thunderstorms. Additionally, the laundry index was only featured in the Japanese version.

System Menu 3.0 update

After the August 6 update, Forecast Channel shows the icon for the current weather in the Wii Menu. Like the News Channel, long neglect of this channel will result in the icon not appearing, although the set time is longer than that of the News channel.

Region without the Forcast Channel

The Forecast Channel is not available in South Korea.

Technical Information

The Forecast channel download data packages from Nintendo servers via plain http connection.

Some examples:

http://weather.wapp.wii.com/1/076/short.bin
http://weather.wapp.wii.com/1/076/forecast.bin

http://news.wapp.wii.com/ displays a Red Hat Enterprise Linux Test Page.

File structure:

$0000 - $003F: padding (00)
$0040 - $013F: rsa encrypted sha-1 signature of rest of the file
$0140 - $0143: header
$0144 - .....: compressed data

The compression is very simple:

1. Read one byte
2. For each bit of the byte, msb-to-lsb,
   • if 0, copy one byte to the output
   • if 1, read 16 bits msb first in v, copy n bytes at offset m from the end of the output, n=3+(v>>12), m=v & fff

Quick and very dirty C code:

  i = 0x144;
  j = 0;
  while(i < size) {
    int k;
    int v = data[i++];
    for(k=0; k<8; k++)
      if(!(v & (1 << (7-k)))) {
        result_data[j++] = data[i++];
      } else {
        int vv = (data[i] << 8) | data[i+1];
        int nb = 3+(vv >> 12);
        int off = (vv & 0xfff);
        int l;
        i+=2;
        for(l=0; l<nb; l++) {
          result_data[j] = result_data[j-off-1];
          j++;
        }
      }
  }