IDvdControl2::PlayBackwards
| Microsoft DirectShow 9.0 |
IDvdControl2::PlayBackwards
The PlayBackwards method plays backward at the specified speed from the current location.
Syntax
HRESULT PlayBackwards( double dwSpeed, DWORD dwFlags, IDvdCmd **ppCmd );
Parameters
dwSpeed
[in] Value that specifies the speed of backward play. This value is a multiplier, where 1.0 is the authored speed. So, a value of 2.5 plays backward at two and one-half times the authored speed, while a value of 0.5 plays backward at half the authored speed. The actual speed of playback depends on the video decoder's capabilities and might differ from the specified rate. For reverse play, audio is muted and no subpicture is displayed. Any speed below 0.00001 is converted to 0.00001.
dwFlags
[in] Bitwise OR of one or more flags from the DVD_CMD_FLAGS enumeration, specifying how to synchronize the command.
ppCmd
[out] Receives a pointer to an IDvdCmd object that can be used to synchronize DVD commands. The caller must release the interface. This parameter can be NULL. For more information, see Synchronizing DVD Commands.
Return Values
Returns one of the following values.
| Return code | Description |
| S_OK | Success. |
| VFW_E_DVD_OPERATION_INHIBITED | UOP control prohibits the operation. |
Remarks
This method is demonstrated in the DVDSample application in CDvdCore::Rewind.
The following table shows the Annex J command name to which this method name corresponds, and the domains in which this method is valid.
| Annex J Command Name | Valid Domains |
| Backward_Scan | DVD_DOMAIN_VideoManagerMenu DVD_DOMAIN_VideoTitleSetMenu DVD_DOMAIN_Title |
Requirements
Header: Declared in Strmif.h; include Dshow.h.
Library: Use Strmiids.lib.
See Also