Condividi tramite

IAMExtTransport::GetStatus

  • Articolo
 
Microsoft DirectShow 9.0

IAMExtTransport::GetStatus

The GetStatus method returns information about the transport's status.

Syntax

  HRESULT GetStatus(
  long StatusItem,
  long *pValue
);

Parameters

StatusItem

[in]  Specifies the status information to retrieve. See Remarks for more information.

pValue

[in, out]  Pointer to variable that either specifies or receives a long integer, whose meaning depends on the value of StatusItem. See Remarks for more information.

Return Values

When this method succeeds, it returns S_OK. Otherwise it returns an HRESULT error code.

Remarks

The StatusItem parameter is a flag that specifies which status information to retrieve. The method returns in the information in the pValue parameter. Not every device supports every status flag. The following flags are defined:

  • ED_MODE: Returns the current transport mode, such as pause or play. See IAMExtTransport::put_Mode for a list of constants that define the transport modes. As an alternative, you can set StatusItem equal to one of these constants, and pValue will receive the value OATRUE if the transport is currently in that mode, or OAFALSE otherwise.

  • ED_MEDIA_TYPE: Indicates the format of the media for this transport. Returns one of the following constants.

    Constant Description
    ED_MEDIA_VHS VHS
    ED_MEDIA_SVHS S-VHS
    ED_MEDIA_HI8 Hi-8
    ED_MEDIA_UMATIC Umatic
    ED_MEDIA_DVC DV tape (DVC)
    ED_MEDIA_1_INCH 1-inch tape
    ED_MEDIA_D1 D1 format
    ED_MEDIA_D2 D2 format
    ED_MEDIA_D3 D3 format
    ED_MEDIA_D5 D5 format
    ED_MEDIA_DBETA Digital Betacam
    ED_MEDIA_BETA Betacam
    ED_MEDIA_8MM 8-millimeter
    ED_MEDIA_DDR Digital disk recorder
    ED_MEDIA_SX Betacam SX
    ED_MEDIA_OTHER Other
    ED_MEDIA_CLV CLV (Constant Linear Velocity, or "standard play") laserdisc
    ED_MEDIA_CAV CAV (Constant Angular Velocity, or "extended play") laserdisc

  • ED_LINK_MODE: Returns OATRUE if the transport's controls are linked to the filter graph's Run, Stop, and Pause methods, and OAFALSE otherwise. See IAMExtTransport::put_Mode for more information.

  • ED_MEDIA_PRESENT: Returns OATRUE if the transport's media is present, or OAFALSE otherwise.

  • ED_MEDIA_LENGTH: Returns the length of the media, in units of the current time format (see IAMExtTransport::SetTransportBasicParameters).

  • ED_MEDIA_TRACK_COUNT: Returns the track count.

  • ED_MEDIA_TRACK_LENGTH: Returns the track length, in units of the current time format.

  • ED_MEDIA_SIDE: Indicates which side of the media is active.

DV Implementation

MSDV supports the following status flags:

  • ED_MODE: See previous remarks.

  • ED_MEDIA_TYPE: Returns one of the following values.

    Constant Description
    ED_MEDIA_VHS VHS tape.
    ED_MEDIA_DVC DV tape.
    ED_MEDIA_UNKNOWN Unknown type.
    ED_MEDIA_NOT_PRESENT The transport is empty.

  • ED_DEV_REMOVED_HEVENT_GET. Returns a handle to an event. The driver signals the event if the device is physically removed from the system.

  • ED_DEV_REMOVED_HEVENT_RELEASE. Releases the event handle obtained through the ED_DEV_REMOVED_HEVENT_GET flag. Specify the address of the handle in the pValue parameter.

  • ED_MODE_CHANGE_NOTIFY. Returns the device state in pValue. If the method returns E_PENDING, a state change is pending. You can use the ED_NOTIFY_HEVENT_GET flag to get notification when the state change is complete.

  • ED_NOTIFY_HEVENT_GET. Returns a handle to an event. The driver signals the event when the device completes a mode change.

  • ED_NOTIFY_HEVENT_RELEASE. Releases the event handle obtained through the ED_NOTIFY_HEVENT_GET flag. Specify the address of the handle in the pValue parameter.

MPEG Camcorder Implementation

MSTape supports an additional media format for the ED_MEDIA_TYPE flag.

Constant Description
ED_MEDIA_NEO Mini digital tape for MPEG-2 transport stream (D-VHS).

Some of these flags are defined in the header file Xptrdefs.h.

Windows XP Service Pack 2

In Windows XP Service Pack 2 and later, the following additional play modes are defined for ED_MODE.

Constant Description
ED_MODE_PLAY_SLOW_FWD_X Play unspecified slow forward. (Slow-forward play at vendor-specific speed.)
ED_MODE_PLAY_FAST_FWD_X Play unspecified fast forward. (Fast-forward play at vendor-specific speed.)
ED_MODE_PLAY_SLOW_REV_X Play unspecified slow reverse. (Slow-reverse play at vendor-specific speed.)
ED_MODE_PLAY_FAST_REV_X Play unspecified fast reverse. (Fast-reverse play at vendor-specific speed.)
ED_MODE_STOP_START Transport is stopped at the beginning of the tape (or other transport medium).
ED_MODE_STOP_END Transport is stopped at the end of the tape (or other transport medium).
ED_MODE_STOP_EMERGENCY Transport has stopped due to unexpected conditions or to avoid possible damage to the transport.

To use these constants, include the header file Xprtdefs.h from the Windows SDK.

Requirements

Header: Declared in Strmif.h; include Dshow.h.

Library: Use Strmiids.lib.

See Also