MCI_SETVIDEO
The MCI_SETVIDEO
command sets values associated with video playback. Digital-video and VCR
devices recognize this command.
MCIERROR mciSendCommand(MCIDEVICEID wDeviceID,
MCI_SETVIDEO,
DWORD dwFlags, (DWORD)
(LPMCI_GENERIC_PARMS) lpSetVideo);
Parameters
wDeviceID
Device identifier
of the MCI device that is to receive the command message.
dwFlags
MCI_NOTIFY,
MCI_WAIT, or MCI_TEST. For information about these flags, see The Wait,
Notify, and Test Flags.
lpSetVideo
Address of an
MCI_GENERIC_PARMS
structure. (Devices with extended command sets might replace this structure
with a device-specific structure.)
Return Values
Returns zero
if successful or an error otherwise.
Remarks
The following
additional flags are used with the digitalvideo device type:
MCI_DGV_SETVIDEO_ALG
The lpstrAlgorithm
member of the structure identified by lpSetVideo contains an address of
a buffer containing the name of a video compression algorithm. The compression
algorithm is used by subsequent MCI_RESERVE or MCI_RECORDBEWKAT commands. The available algorithms are
device dependent.
If the
specified algorithm is incompatible with the current file format, the file
format is changed to the default format for the algorithm.
MCI_DGV_SETVIDEO_CLOCKTIME
When used
with MCI_DGV_SETVIDEO_OVER, indicates time is specified in milliseconds and is
absolute time. (This time is not in step with the playing of the workspace.)
MCI_DGV_SETVIDEO_INPUT
Modifies the
MCI_DGV_SETVIDEO_BRIGHTNESS, MCI_DGV_SETVIDEO_COLOR, MCI_DGV_SETVIDEO_CONTRAST,
MCI_DGV_SETVIDEO_GAMMA, MCI_DGV_SETVIDEO_SHARPNESS, or MCI_DGV_SETVIDEO_TINT so
that it affects the input signal and modifies what is recorded. If possible,
this is the default when monitoring the input.
MCI_DGV_SETVIDEO_ITEM
A video
constant is specified in the dwItem member of the structure identified
by lpSetVideo. The constant identifies the value that is being set. You
can specify the following constants with this flag:
MCI_AVI_SETVIDEO_DRAW_PROCEDURE
A new drawing
procedure address is specified in the dwValue member of the structure
identified by lpSetVideo. You can specify a new drawing procedure only
when the device is idle. This flag is recognized only by the MCIAVI
digital-video driver. There is no equivalent to this flag in the string command
interface.
MCI_AVI_SETVIDEO_PALETTE_COLOR
A new palette
color is specified in the dwOver and dwValue members of the
structure identified by lpSetVideo. The dwOver member specifies
the palette index of the color to be changed and the dwValue member
specifies the new color, as an RGB value. You must also specify the MCI_DGV_SETVIDEO_OVER and
MCI_DGV_SETVIDEO_VALUE flags with MCI_DGV_SETVIDEO_ITEM when you use this
constant. This flag is recognized only by the MCIAVI digital-video driver.
MCI_AVI_SETVIDEO_PALETTE_HALFTONE
Indicates
that the halftone palette should be used, instead of the default palette. This
flag is recognized only by the MCIAVI digital-video driver.
MCI_DGV_SETVIDEO_BITSPERPEL
The number of
bits per pixel is specified in the dwValue member of the structure
identified by lpSetVideo. The number of bits per pixel is used for
saving captured or recorded data
MCI_DGV_SETVIDEO_BRIGHTNESS
The video
brightness level is specified as a factor in the dwValue member of the
structure identified by lpSetVideo.
MCI_DGV_SETVIDEO_COLOR
The video
color saturation level is specified as a factor in the dwValue member of
the structure identified by lpSetVideo.
MCI_DGV_SETVIDEO_CONTRAST
The video
contrast level is specified as a factor in the dwValue member of the
structure identified by lpSetVideo.
MCI_DGV_SETVIDEO_FRAME_RATE
A frame rate
is specified in the dwValue member of the structure identified by lpSetVideo.
The rate is specified in units of frames per second times 1000. For example,
29.97 frames per second is specified as 29970.
MCI_DGV_SETVIDEO_GAMMA
A gamma
correction exponent value is specified in the dwValue member of the
structure identified by lpSetVideo. Gamma correction adjusts the mapping
between the intensity encoded in the presentation source and the displayed
brightness. The value is the exponent multiplied by 1000. For example, 2200
indicates an exponent of 2.2. A value of 1000 indicates an exponent of 1, which
applies no gamma correction.
MCI_DGV_SETVIDEO_KEY_COLOR
A key color
is specified in the dwValue member of the structure identified by lpSetVideo.
The key color is a Windows RGB
value.
MCI_DGV_SETVIDEO_KEY_INDEX
A key index
value is specified in the dwValue member of the structure identified by lpSetVideo.
The index parameter is a physical palette index.
MCI_DGV_SETVIDEO_PALHANDLE
A palette
handle is specified in the dwValue member of the structure identified by
lpSetVideo. The palette handle is contained in the low-order word.
Digital-video devices should not free the palette passed with this command.
Applications should free it after they close the device. This flag is supported
only by devices that use palettes. If this specified palette handle is zero,
then the default palette is used.
MCI_DGV_SETVIDEO_SHARPNESS
A video
sharpness value is specified as a factor in the dwValue member of the
structure identified by lpSetVideo.
MCI_DGV_SETVIDEO_SOURCE
A constant
specifying the source of the video input is specified in the dwValue
member of the structure identified by lpSetVideo. The following
constants are defined:
MCI_DGV_SETVIDEO_SRC_NTSC
Specifies NTSC.
MCI_DGV_SETVIDEO_SRC_PAL
Specifies PAL.
MCI_DGV_SETVIDEO_SRC_RGB
Specifies RGB959Q0EE.
MCI_DGV_SETVIDEO_SRC_SECAM
Specifies SECAM.
MCI_DGV_SETVIDEO_SRC_SVIDEO
Specifies SVIDEO.
MCI_DGV_SETVIDEO_STREAM
A video
stream is specified in the dwValue member of the structure identified by
lpSetVideo. The integer value specifies the video stream played back
from the workspace. If the stream is not specified and the file format does not
define a default stream, the first physically interleaved video stream is
played.
MCI_DGV_SETVIDEO_TINT
A video tint
value is specified as a factor in the dwValue member of the structure
identified by lpSetVideo. Typically, this adjustment is modeled after
the tint control of many color television sets, with 250 defined as green, 750
defined as red, and 0 (or 1000) defined as blue. The nominal value is always
500.
MCI_DGV_SETVIDEO_OUTPUT
The
MCI_DGV_SETVIDEO_BRIGHTNESS, MCI_DGV_SETVIDEO_COLOR, MCI_DGV_SETVIDEO_CONTRAST,
MCI_DGV_SETVIDEO_GAMMA, MCI_DGV_SETVIDEO_SHARPNESS, or MCI_DGV_SETVIDEO_TINT
flag is modified so that it affects only the displayed signal and not what is
recorded. If possible, this is the default when monitoring a file.
MCI_DGV_SETVIDEO_OVER
A transition
length parameter is included in the dwOver member of the structure
identified by lpSetVideo. The transition length specifies how long (in
the current time format) it should take to make a change. If this flag is not
used, the change occurs immediately.
MCI_DGV_SETVIDEO_QUALITY
The lpstrQuality
member of the structure identified by lpSetVideo contains an address of
a buffer describing the video quality. A text-string in the buffer specifies
the characteristics of the video compression algorithm.
The
MCI_DGV_SETVIDEO_ALG flag can be used to select a quality descriptor for the
specified algorithm. If this flag is omitted, then the current algorithm is
used.
The
algorithms and descriptor names available depend on the device. Each device
supplies documentation for the available algorithms and a description of the
applicable descriptor names. The MCI_QUALITYVDIDKL command can define additional descriptor
names. All devices support the descriptors low , medium , and high . The
default is driver specific.
MCI_DGV_SETVIDEO_RECORD
Specifies
whether recording includes or excludes video data. When combined with
MCI_SET_ON, video data is recorded. When combined with MCI_SET_OFF, video data
is excluded. The default includes video data.
MCI_DGV_SETVIDEO_SRC_NUMBER
A number for
the video source is specified in the dwSourceNumber member of the
structure identified by lpSetVideo. If there is more than one input of
the type specified by MCI_DGV_SETVIDEO_VALUE, the value selects the input. This
flag must always be used with MCI_DGV_SETVIDEO_SOURCE. If MCI_DGV_SETVIDEO_VALUE
is omitted, however, the specified source number indicates the absolute source
to use as specified in the MCI_LIST command.
MCI_DGV_SETVIDEO_STILL
The algorithm
name or quality value specified applies to still images.
Every device
driver must support an algorithm of none , which means no compression. This is
the default. In this case, digital-video devices save still images as RGB format device-independent
bitmaps (DIBs).
MCI_DGV_SETVIDEO_VALUE
A value is
included in the dwValue member of the structure identified by lpSetVideo.
The meaning of the value is specified by the MCI_DGV_SETVIDEO_ITEM flag.
MCI_SET_OFF
Disables
video output. For digital-video devices, disabling video sets the pixels in the
destination rectangle defined by the MCI_PUTBO5B3C command (or its default, the client region
of the current window) to a solid color, but it has no effect on the frame
buffer. You can hide the window with the MCI_WINDOW command if desired. The
source of video, whether it s the workspace or an external input, might
continue to store new images in the frame buffer, but they are not displayed
until the video is enabled. While applications should use the MCI_SETVIDEO
command to control this function, digital-video devices must still support this
flag. The default value after an open is on.
MCI_SET_ON
Enables video
output.
For
digital-video devices, the lpSetVideo parameter points to an MCI_DGV_SETVIDEO_PARMS structure.
The following
additional flags are used with the vcr device type:
MCI_VCR_SETVIDEO_RECORD
Sets the
video recording to on or off. Used in conjunction with one of following flags:
MCI_SET_ON
Video
recording on.
MCI_SET_OFF
Video
recording off. It might be necessary to first turn off the assemble recording
(using the MCI_SET
command with the MCI_VCR_SET_ASSEMBLE_RECORD flag set to off) before the video
recording can be turned off.
MCI_TRACK
The
dwTrack member of the structure identified by lpSetVideo specifies
which track is affected by the command.
MCI_VCR_SETVIDEO_SOURCE
Sets the
video source, and must be used with the MCI_VCR_SETVIDEO_TO flag.
MCI_VCR_SETVIDEO_MONITOR
Sets the
video source monitor, and must be used with the MCI_VCR_SETVIDEO_TO flag.
MCI_VCR_SETVIDEO_TO
The dwTo member
of the structure identified by lpSetVideo contains one of the following
constants:
MCI_VCR_SRC_TYPE_TUNER
MCI_VCR_SRC_TYPE_LINE
MCI_VCR_SRC_TYPE_AUX
MCI_VCR_SRC_TYPE_GENERIC
MCI_VCR_SRC_TYPE_MUTE
MCI_VCR_SRC_TYPE_OUTPUT
MCI_VCR_SRC_TYPE_RGB
MCI_VCR_SETVIDEO_NUMBER
The
dwNumber member of the structure identified by lpSetVideo contains
the video input (of the type specified in the dwTo member) to use.
For VCR
devices, the lpSetVideo parameter points to an MCI_VCR_SETVIDEO_PARMS structure.
See Also