videoStreamUnprepareHeader(3mms) — Subroutines
Name
videoStreamUnprepareHeader --- Clean up the preparation performed by videoStreamPrepareHeader
Syntax
#include <mme/mme_api.h>
MMRESULT videoStreamUnprepareHeader(HVIDEO hVideo,
LPVIDEOHDR lpvideoHdr,
DWORD dwSize);
Arguments
HVIDEO hVideo
Specifies a handle to a video device channel.
LPVIDEOHDR lpvideoHdr
Specifies a pointer to a VIDEOHDR data structure identifying the data buffer to be cleaned up.
DWORD dwSize
Specifies the size of the VIDEOHDR data structure.
Description
The videoStreamUnprepareHeader function cleans up the preparation performed by the videoStreamPrepareHeader function. The videoStreamUnprepareHeader function is the complementary function to the videoStreamPrepareHeader function.
Call the videoStreamUnprepareHeader function before freeing the data buffer with the mmeFreeBuffer function. After passing a buffer to the device driver with the videoStreamAddBuffer function, wait until the driver is finished with the buffer before calling the videoStreamUnprepareHeader function. Unpreparing a buffer that has not been prepared has no effect, and the function returns the DV_ERR_OK error code.
Extensions
None.
Return Values
Returns DV_ERR_OK if the function is successful; otherwise, it returns one of the following error codes:
DV_ERR_INVALHANDLE@T{ The specified device handle is invalid. T} DV_ERR_STILLPLAYING@T{ There are buffers still in the queue. T}