ITVControl::Tune

[This is preliminary documentation and subject to change.]

The Tune method advises that WebTV for Windows has tuned to a new channel.

HRESULT Tune(
  long ltsNew,  
  long lcnNew,  
  long IvsNew,  
  long lasNew,  
  BSTR bslPNew, 
  long ltsPrev, 
  long lcnPrev, 
  long IvsPrev, 
  long lasPrev, 
  BSTR bslPPrev 
);
 

Parameters

ltsNew

Tuning space of the new channel.

lcnNew

Channel number of the new channel.

IvsNew

Video subchannel of the new channel. A value of – 1 indicates the default video subchannel, as defined by the broadcast content provider.

lasNew

Audio subchannel of the new channel. A value of – 1 indicates the default audio subchannel, as defined by the broadcast content provider.

bslPNew

String that contains information about the IP stream used by triggers on the new channel. This string must be in the format "xxx.xxx.xxx.xxx yyy.yyy.yyy.yyy:zzz preloadURL&overlayCSS", where xxx.xxx.xxx.xxx specifies the netcard address, yyy.yyy.yyy.yyy specifies the announcement IP address, zzz specifies the announcement port, preloadURL specifies the preload URL and overlayCSS specifies the overlay style sheet. For example: "255.255.255.255 123.25.433.1:1701 basepage.htm&basestyle.css"

The preloadURL and overlayCSS parameters are optional, and can be left out of the string. For example, "255.255.255.255 123.25.433.1:1701".

If no trigger stream exists, this value is set to NULL.

ltsPrev

Tuning space of the previous channel.

lcnPrev

Channel number of the previous channel.

IvsPrev

Video subchannel of the previous channel. A value of – 1 indicates the default video subchannel, as defined by the broadcast content provider.

lasPrev

Audio subchannel of the previous channel. A value of – 1 indicates the default audio subchannel, as defined by the broadcast content provider.

bslPPrev

String that contains information about the IP stream used by triggers on teh previous channel. The string is formatted as described in bsIPNew.

If no trigger stream exists, this value is set to NULL.

Return Values

WebTV for Windows ignores the value returned by this method.

Remarks

WebTV for Windows calls this method when tuning information changes. This method is also called when an object first registers an ITVControl sink with WebTV for Windows.

QuickInfo

  Windows NT: Unsupported.
  Windows: Requires Windows 98.
  Windows CE: Unsupported.
  Header: Declared in tvdisp.odl.
  Import Library: User-defined.
  Unicode: Yes.

See Also

ITVViewer::Tune