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PgScalerCaps_t

Data structure that describes video overlay scaler capabilities

Synopsis:

typedef struct scaler_caps {
    unsigned    size;
    unsigned    format;
    unsigned    flags:
    short       src_max_x;
    short       src_max_y;
    short       max_mag_factor_x;
    short       max_mag_factor_y;
    short       max_shrink_factor_x;
    short       max_shrink_factor_y;
    unsigned    reserved[10];
} PgScalerCaps_t;

Description:

The PgScalerCaps_t structure describes video overlay scaler capabilities. It includes at least:

size

The size of this structure. The application should set this to sizeof (PgScalerCaps_t).

format

The video data format to which the capabilities in this structure pertain. It can be one of the following formats, which are defined in <Pg.h>:

• Pg_VIDEO_FORMAT_RGB555
• Pg_VIDEO_FORMAT_RGB565
• Pg_VIDEO_FORMAT_RGB8888
• Pg_VIDEO_FORMAT_IYU1
• Pg_VIDEO_FORMAT_IYU2
• Pg_VIDEO_FORMAT_UYVY
• Pg_VIDEO_FORMAT_YUY2
• Pg_VIDEO_FORMAT_YVYU
• Pg_VIDEO_FORMAT_V422
• Pg_VIDEO_FORMAT_CLJR
• Pg_VIDEO_FORMAT_YVU9
• Pg_VIDEO_FORMAT_YV12
• Pg_VIDEO_PLANAR_YUV_FORMAT_CLPL
• Pg_VIDEO_PLANAR_YUV_FORMAT_VBPL

flags

The flags include:

• Pg_SCALER_CAP_DST_CHROMA_KEY -- the driver can perform chroma-key testing on the desktop surface. That is, video can be made to appear only on the desktop where pixels drawn with the chroma-key color are present.
• Pg_SCALER_CAP_DOUBLE_BUFFER -- video output can be double-buffered. That is, two video buffers are provided, and the application can copy each frame into the alternative buffer. Thus, one frame can be displayed, while video data is being copied into the alternative frame. This eliminates flickering and tearing artifacts.
• Pg_SCALER_CAP_BRIGHTNESS_ADJUST -- the application can control the brightness of the video viewport.
• Pg_SCALER_CAP_CONTRAST_ADJUST -- the application can control the contrast of the video viewport.

src_max_x, src_max_y

The maximum width and height of a video data frame before scaling.

max_mag_factor_x, max_mag_factor_y

The maximum upward scaling factor in the horizontal and vertical directions.

max_shrink_factor_x, max_shrink_factor_y

The maximum downward scaling factor in the horizontal and vertical directions. Some scalers can't perform downward scaling, in which case these fields are set to 1.

Classification:

Photon

See also:

PgConfigScalerChannel(), PgCreateVideoChannel(), PgDestroyVideoChannel(), PgGetOverlayChromaColor(), PgGetScalerCapabilities(), PgNextVideoFrame(), PgScalerProps_t, PgVideoChannel_t

"Video overlay" in the Raw Drawing and Animation chapter of the Photon Programmer's Guide