list ZMQLH7

The list command determines the number and types of video and audio inputs. Digital-video and VCR devices recognize this command.

wsprintf(lpstrCommand, "list %s %s %s", lpszDeviceID, lpszList,
lpszFlags);

Parameters

lpszDeviceID

Identifier of an MCI device. This identifier or alias is assigned when the device is opened.

lpszList

Flag that identifies the number and types of video and audio inputs. The following table lists device types that recognize the list command and the flags used by each type:

digitalvideo	audio algorithm audio quality algorithm algorithm audio stream count number index	still algorithm still quality algorithm algorithm video algorithm video quality algorithm algorithm video source video stream
vcr	audio source count audio source number index	video source count video source number index

The following table lists the flags that can be specified in the lpszList parameter and their meanings:

audio algorithm	Specifies the command should retrieve audio algorithm names.
audio quality algorithm algorithm	Specifies the command should retrieve quality levels associated with the specified algorithm. If algorithm is current , the quality level of the current algorithm is returned.
audio source count	Returns the total number of audio inputs.
audio source number index	Returns the type of audio input of source index.
audio stream	Specifies the command should retrieve the names of the audio streams associated with the workspace. These strings (such as English or German ) are embedded in the file and identify the stream.
count	Returns the number of options of the specified type.
number index	Returns a string describing a specific option (as identified by index) of the specified option type. Index must be an integer between 1 and the value returned by count .
still algorithm	Specifies the command should retrieve still algorithm names.
still quality algorithm algorithm	Specifies the command should retrieve quality levels associated with the specified still algorithm. If algorithm is current , the quality level of the current algorithm is returned.
video algorithm	Specifies the command should retrieve video algorithm names.
video quality algorithm algorithm	Specifies the command should retrieve quality levels associated with the specified video algorithm. If algorithm is current , the quality level of the current algorithm is returned.
video source	Specifies the command should return information about the video sources. When used with the count flag, it returns the number of video sources. When used with the number flag, it returns the type of a video source. MCI defines the following constants for type: ntsc , rgb , pal , secam , svideo , and generic . There might be more than one source of each type returned. The generic source type is used when more than one signal is allowed for that connector.
video source count	Returns total number of video inputs.
video source number index	Returns the type of video input of source index.
video stream	Specifies the command should retrieve the names of video streams associated with the workspace. These strings (such as funny ending or sad ending ) are embedded in the file and identify the stream.

lpszFlags

Can be wait , notify , or test . For more information about these flags, see The Wait, Notify, and Test Flags4FW.04J.

Return Values

Returns zero if successful or an error otherwise.

Remarks

For VCR devices, either video source or audio source must be specified with either the count or number flags. If count is specified, the total number of inputs of video or audio is returned. If number is specified, the driver returns a type corresponding to the input. The type can be any one of the following: tuner , line , svideo , aux , or generic . Typically, you should first query the VCR for the count and then use the count as the range for the number flag. The source numbers start from 1.