VLDMBUFFERGETVALID(3dm)VLDMBUFFERGETVALID(3dm)NAME
vlDMBufferGetValid, vlDMBufferPutValid, vlDMBufferGetVideoInfo,
vlDMBufferSetVideoInfo - VL DMbuffer management routines
SYNOPSIS
#include <dmedia/vl.h>
int vlDMBufferGetValid(VLServer vlServer, VLPath path, VLNode node, DMbuffer* dmbuffer);
int vlDMBufferPutValid(VLServer vlServer, VLPath path, VLNode node, DMbuffer dmbuffer);
#include <sys/dmcommon.h>
int vlDMBufferGetVideoInfo(DMbuffer dmbuffer, DMBufferVideoInfo* vidinfo)
int vlDMBufferSetVideoInfo(DMbuffer dmbuffer, DMBufferVideoInfo* vidinfo)
DESCRIPTION
vlDMBufferGetValid returns a valid DMbuffer containing video data from
the specified node and path. This call is used in video capture-type
applications where a path is set up to route image data from a source
video device node to drain memory node.
The buffer that is returned contains one video image, either a field or a
frame. dmBufferMapData can be used to get a pointer to the image in the
buffer. The contents of the buffer should not be modified.
vlDMBufferPutValid takes a valid DMbuffer and sends it to the path via
the specified node. This call is used in video playback-type
applications where a path is set up to route image data from a source
memory node to a drain video device node.
After calling vlDMBufferPutValid, the video library and the call both
have references to the buffer. The contents of the buffer should not be
changed by the caller.
vlDMBufferGetVideoInfo copies the contents of the DMBufferVideoInfo
structure associated with a DMBuffer to the address of a
DMBufferVideoInfo structure specified by the user.
vlDMBufferSetVideoInfo copies the contents of a DMBufferVideoInfo
structure pointed to by the specified address to the DMBufferVideoInfo
structure associated with a DMBuffer.
The DMBufferVideoInfo structure is currently defined as:
typedef struct DMBufferVideoInfo_s {
DMVITCcode vitc[2];
unsigned int validinfo;
unsigned int sdti;
char pad[DMBUF_VIDINFO_PAD]; } DMBufferVideoInfo;
#define DMBUF_VIDINFO_SIZE 96 /* size in bytes of DMBufferVideoInfo
*/
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VLDMBUFFERGETVALID(3dm)VLDMBUFFERGETVALID(3dm)
#define DMBUF_VIDINFO_PAD ((DMBUF_VIDINFO_SIZE) - 2*sizeof(DMVITCcode)-
2*sizeof(unsigned int))
#define DMBUF_VIDINFO_VALID_VITC1 0x1
#define DMBUF_VIDINFO_VALID_VITC2 0x2
#define DMBUF_VIDINFO_VALID_SDTI 0x4
and is included in sys/dmcommon.h header file.
MACHINE DEPENDENCIES
When using glXAssociateDMPbufferSGIX to pass DMbuffers between video and
OpenGL on the O2 platform, VL_LAYOUT should be set to VL_LAYOUT_GRAPHICS.
This way, the video libary will expect DMbuffers in the format used
internally by OpenGL.
RETURN VALUE
Upon successful completion, vlDMBufferGetValid returns VLSuccess and
dmbuffer points to a valid DMbuffer referencing video data. Otherwise,
-1 is returned, dmbuffer is set to NULL and vlErrno is set indicating the
error. Note that vlErrno set to VLAgain does not indicate an error but
rather that there was no video data at the specified node when
vlDMBufferGetValid was called.
Upon success completion, vlDMBufferPutValid returns VLSuccess, otherwise
a value of -1 is returned and vlErrno is set indicating the error.
SEE ALSOvlDMPoolRegister(3dm), vlDMPoolDeregister(3dm), dmBufferAllocate(3dm),
dmBufferFree(3dm), dmBufferMapData(3dm)
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