unfreeze
The unfreeze command reenables video acquisition to the frame buffer after it has been disabled by the freeze command. Digital-video, VCR, and video-overlay devices recognize this command.
To send this command, call the mciSendString function with the lpszCommand parameter set as follows.
_stprintf_s(
lpszCommand,
TEXT("unfreeze %s %s %s"),
lpszDeviceID,
lpszUnfreeze,
lpszFlags
);
Parameters
lpszDeviceID
Identifier of an MCI device. This identifier or alias is assigned when the device is opened.
lpszUnfreeze
Flag for reenabling video acquisition to the frame buffer. The following table lists device types that recognize the unfreeze command and the flags used by each type.
| Value | Meaning |
| digitalvideo | at rectangle |
| overlay | at rectangle |
| vcr | input output |
The following table lists the flags that can be specified in the lpszUnfreeze parameter and their meanings.
| Value | Meaning |
| at rectangle | Specifies the region that will have video acquisition reenabled. The rectangle is relative to the video buffer origin and is specified as X1 Y1 X2 Y2. The coordinates X1 Y1 specify the upper left corner of the rectangle, and the coordinates X2 Y2 specify the width and height. |
| input | Unfreeze the input image. |
| output | Unfreeze the output image. If neither "input" nor "output" is given, "output" is assumed. |
lpszFlags
Can be "wait", "notify", or both. For digital-video and VCR devices, "test" can also be specified. For more information about these flags, see The Wait, Notify, and Test Flags.
Return Values
Returns zero if successful or an error otherwise.
Remarks
The following command unfreezes a region of the video buffer:
unfreeze vboard at 10 20 90 165
Requirements
** Windows NT/2000/XP:** Included in Windows NT 3.1 and later.
** Windows 95/98/Me:** Included in Windows 95 and later.
See Also