VLGETNEXTVALID(3dm)VLGETNEXTVALID(3dm)NAME
vlGetNextValid, vlGetLatestValid, vlGetActiveRegion, vlGetNextFree,
vlGetDMediaInfo, vlGetImageInfo, vlPutValid, vlPutFree - VL buffer
management routines
SYNOPSIS
#include <dmedia/vl.h>
void *vlGetActiveRegion(VLServer vlServer, VLBuffer buffer, VLInfoPtr info);
DMediaInfo *vlGetDMediaInfo(VLServer vlServer, VLBuffer buffer,
VLInfoPtr info);
DMImageInfo *vlGetImageInfo(VLServer vlServer, VLBuffer buffer,
VLInfoPtr info);
VLInfoPtr vlGetLatestValid(VLServer vlServer, VLBuffer buffer);
VLInfoPtr vlGetNextFree(VLServer vlServer, VLBuffer buffer, int size);
VLInfoPtr vlGetNextValid(VLServer vlServer, VLBuffer buffer);
int vlPutFree(VLServer vlServer, VLBuffer buffer);
int vlPutValid(VLServer vlServer, VLBuffer buffer);
DESCRIPTION
vlGetActiveRegion returns a pointer to the video frame data. The region
is determined by the settings of the VL_OFFSET controls. The default is
the region of valid video data.
vlGetDMediaInfo returns a pointer to a DMediaInfo struct containing
general information.
vlGetImageInfo returns a pointer to a DMImageInfo struct containing image
specific info.
vlGetLatestValid returns the info struct of the most recently received
frame.
vlGetNextFree returns the info struct of the next free buffer.
vlGetNextValid returns the info struct of the next available frame.
vlPutFree frees any frames that were acquired via vlGetLatestValid or
vlGetNextValid.
vlPutValid marks a buffer as ready to be sent.
RETURN VALUE
Upon successful completion, vlGetLatestValid, vlGetNextFree,
vlGetNextValid return valid pointers, otherwise a value of NULL is
returned. If a value returned is NULL, the buffer should be checked with
vlBufferDone(3dm) to see if more data can be written to the buffer. It is
possible to get a NULL return value without a failure, if there is no
buffer available. In this case vlGetErrno will not return a useful error.
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VLGETNEXTVALID(3dm)VLGETNEXTVALID(3dm)
Upon successful completion vlGetActiveRegion, vlGetDMediaInfo,
vlGetImageInfo return valid pointers, otherwise they return NULL.
vlPutFree and vlPutValid return VLSuccess on successful completion,
otherwise a value of -1 is returned. In all failure cases, vlErrno is set
to indicate the error.
SEE ALSOvlCreateBuffer(3dm), vlRegisterBuffer(3dm)
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