Caption Insertion
Every video channel of Picolo U4 H.264 PCI-104 embeds a text caption insertion function.
Up to 5(*) lines of up to 47 characters can be engraved in the image. The same text is inserted on both the formatted and compressed streams.
(*)The number of caption text lines may be limited to 2 according to the driver's specification. For example, 5 lines is applicable with the version 2.0 of the Virtual File System driver.
The character set is the 7-bit ASCII character set. Non-printable characters are displayed as small rectangles. The font is not configurable. The character cell size is 16x26 pixels.
The text can be located at four pre-defined positions, or anywhere in the active area (custom position):
- Top left: the text line is top justified with a top margin of 16 rows of pixels. The text line is left justified with a left margin of 16 columns of pixels.
- Top right: the text line is top justified with a top margin of 16 rows of pixels. The text line is right justified with a right margin of 16 columns of pixels.
- Bottom left: the text line is bottom justified with a bottom margin of 16 rows of pixels. The text line is left justified with a left margin of 16 columns of pixels.
- Bottom right: the text line is bottom justified with a bottom margin of 16 rows of pixels. The text line is right justified with a right margin of 16 columns of pixels.
- Custom: the text line is left justified. The position of the top-left pixel of the first character is freely configurable.
The caption foreground is white. The character background is semi-transparent: the excursion of the video luminance is limited upwards
You can control the caption insertion by using the Caption0, Caption1 element.
Picolo U4 H.264 PCI-104 can achieve 4 caption text updates per second for all inputs.