seek command

The seek command moves to the specified position and stops. CD audio, digital-video, MIDI sequencer, VCR, videodisc, and waveform-audio devices recognize this command.

To send this command, call the mciSendString function with the lpszCommand parameter set as follows.

_stprintf_s(
  lpszCommand, 
  TEXT("seek %s %s %s"), 
  lpszDeviceID, 
  lpszSeekFlags, 
  lpszFlags
); 

Parameters

lpszDeviceID

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

lpszSeekFlags

Flag for moving to a specified position. The following table lists device types that recognize the seek command and the flags used by each type.

Value	Meaning	Meaning
cdaudio	to end to position	to start
digitalvideo	to end to position	to start
sequencer	to end to position	to start
vcr	at timemark mark_numreverse	to end to positionto start
videodisc	reverse to end	to positionto start
waveaudio	to end to position	to start

The following table lists the flags that can be specified in the lpszSeekFlags parameter and their meanings.

Value	Meaning
at time	Indicates when the device should begin performing this command, or, if the device has been cued, when the cued command begins. For more information, see the cue command.
mark mark_num	Seeks to the relative mark indicated by mark_num, which must be a positive integer value. Marks are signals written to the VCR tape using the mark command and are used for high-speed searching.
reverse	Indicates that the seek direction on VCRs and CAV videodiscs is backward. This flag is invalid if the "to" flag is specified. For VCRs, this flag must be used with the "mark" flag.
to end	Seeks to the end of the content.
to position	Specifies the position to stop the seek. For cdaudio devices, MCI returns an out-of-range error if the specified position is greater than the length of the disc.
to start	Seeks to the start of the content.

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 Value

Returns zero if successful or an error otherwise.

Remarks

Before issuing any commands that use position values, you should set the desired time format by using the set command.

Digital-video devices support two seek modes, which you can change by using the set command. The "seek exactly on" mode causes the seek command to move to the specified frame. The "seek exactly off" mode causes the seek command to move to the closest key frame prior to the specified frame.

If a CD audio device is playing when the seek command is issued, playback is stopped. When the seek command is issued with a videodisc device, the device searches using fast forward or fast reverse with video and audio off.

When the seek command is issued with a waveform-audio device, the behavior depends on the sample size. If the sample size is 16 bits or greater, seek moves to the beginning of the nearest sample when a specified position does not coincide with the start of a sample.

Examples

The following command seeks to the start of the media file associated with the "mysound" device.

seek mysound to start

Requirements

See also

MCI

MCI Command Strings

cue

mark

set