Thread: [libdc1394-devel] IIDC proposal: define MIN_PIXEL_NUMBER_INQ
Capture and control API for IIDC compliant cameras
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From: Johann S. <j.s...@ir...> - 2007-05-29 01:45:44
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Here is a proposal for Damien's placeholder section 5.3 "Define a MinPixelNumber": Introduction The specification 1.31 has a 32-bit (16 horizontal + 16 vertical) inquiry register MAX_IMAGE_SIZE_INQ (section 4.9.1) which reports the maximum image size. It does not however support an inquiry register for the minimum number of pixels supported by the implementation. The Basler A600f series of cameras, for example, cannot set their AOIs to fewer than 4096 pixels. The camera firmware should be able to report such facts. A MIN_PIXEL_NUMBER_INQ register is needed because its value affects the smallest AOI the user can set. This in turn limits the highest available framerate in Format_7. Some users have for example tried to use area cameras as fast linescan cameras, and discovered by trial and error that some cameras will not allow one-line AOIs. This is a separate issue to the minimum image size which may have minimum horizontal and vertical numbers of pixels. MIN_PIXEL_NUMBER_INQ reports the minimum total number of pixels which appears to be a limit in its own right in some camera implementations. New registers proposed: CSR: Video Mode for Format_7 Offset: somewhere between 05Ch and 078h Name: MIN_PIXEL_NUMBER_INQ Specification changes: 1. Table of contents on page 3, 4.9.5 "PIXEL_NUMBER_INQ and TOTAL_BYTE_INQ registers" changes to "PIXEL_NUMBER_INQ, MIN_PIXEL_NUMBER_INQ and TOTAL_BYTE_INQ registers". 2. Add the new register to the table in section 4.9 Video Mode CSR for Format_7 as follows: Offset Name Field Bit Description ? MIN_PIXEL_NUMBER_INQ MinPixelPerFrame [0:31] Minimum number of pixels per frame 2. The table in section 4.9 Video Mode CSR for Format_7, page 39, Offset 07Ch, Name VALUE_SETTING, Field Setting_1, Bit [1], Description "PIXEL__NUMBER_INQ" changes to "PIXEL_NUMBER_INQ and MIN_PIXEL_NUMBER_INQ" in two places. 3. On page 41, heading of section 4.9.5 "PIXEL_NUMBER_INQ and TOTAL_BYTE_INQ registers" changes to "PIXEL_NUMBER_INQ, MIN_PIXEL_NUMBER_INQ and TOTAL_BYTE_INQ registers". 4. In section 4.9.5 on page 41, after the first paragraph which ends "... required image area", insert a new paragraph as follows: "MIN_PIXEL_NUMBER_INQ register reports the minimum total number of required image area." 5. In section 4.9.5 on page 41, between the "PIXEL_NUMBER_INQ register" tables and the "TOTAL_BYTE_HI_INQ and TOTAL_BYTE_LO_INQ registers" tables, insert tables as follows: MIN_PIXEL_NUMBER_INQ register 0-7 8-15 16-23 24-31 MinPixelPerFrame Initial values System dependent Read values Last update value Write effect Ignored Note that I have not taken into account other proposals in parallel. I am not sure how one should handle proposals that mutually affect one another when it is not known which proposals will be accepted into the standard and which not. Johann This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. |