With the appropriate hardware, the digital video device is able to monitor a TV channel. The WinTV card is an overlay card that has video capture support as well as television signal support. The monitor window displays the TV signal. The tuner is selected by setting the digital video device connector type to video in and the connector number to the tuner connector number of the adapter. The tuner connector number varies from adapter to adapter. On the WinTV adapter, this is connector number 2.
connector digitalvideo02 enable type video in number 2 wait
An application can use the settuner command to set the region, channel, and fine-tuning values. These flags are valid when used individually or in any combination. The digital video device uses these three values to calculate a frequency to send to the device. See the following example.
open digitalvideo03 alias mytuner wait settuner mytuner tv channel 3 region usa finetune plus 1 wait
The following example illustrates setting the frequency directly. Setting the frequency directly causes channel, region, and fine-tuning values to be ignored.
settuner mytuner frequency 80 wait
The region value must have a corresponding ASCII file (region.RGN) located in the \MMOS2\REGION subdirectory. When an application selects the region with the settuner command, the digital video device reads in the region file and fills a region array. The channel is used as an index into this array, which identifies the frequency. Fine-tuning is then added to the frequency. Region files are keyword-driven and have the following format:
[tuner] description=USA Cable lowchannel=2 highchannel=99 frequencies=0,0, 10050, -1, ... 29000
The description keyword identifies a descriptive string displayed on the corresponding Multimedia Setup page. The lowchannel and highchannel keywords indicate the range of channels available for the region. The frequencies correspond to the channel values, beginning with channel 0 and continuing to the highest available channel. The frequencies must be listed in columns of nine; otherwise, the region is invalid. A frequency value of 0 indicates the channel is out of range. A frequency value of -1 indicates a skipped channel, allowing the user to "block" certain channels from being viewed.