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DLPC900: RLE padding

Part Number: DLPC900

Hi,

what are the rules for padding? According to the DLPC programmers guide rev G. You write that all padding needs to end at a 4 byte boundary. So, is there a reason you add 10 bytes of padding after the End of Image in tabel 2-108?

Why does it look like the end-of-image command is repeated in the last row of Table 1-108? Is padding not necessarily 0?

  • Thomas,

    It may be possible that the example in the is incorrect.  The software team will look at this and get back to you.

    Fizix

  • Hi Thomas,

     

    Padding after End of Image is not necessary.

    The last row from the Table 2-108 will be deleted. Thanks for highlighting this.

     

     

    Decompression algorithm expects each line information in the compressed data should starts at 4 byte boundary address.

     

    Eg:

    From the above table, till the first End Of Line command (row 5) there are total 25 bytes. This will occupy from address 0-24 of internal storage memory.

    Controller will expect Next line information (Row 7) to start at address 28. Three bytes of padding (Row 6) is added for this purpose.

     

    For additional information, Source files for compression and decompression functions are available at GUI installation directory.

    Refer to "compress.c" file from installation directory -
    C:\Texas Instruments-DLP\DLPC900REF-SW-5.0.0\DLPC900REF-SW-5.0.0\DLPC900REF-GUI\Source\HiresLib

     

    Thanks,

    Shivakumar

  • This 4 byte boundary is only required for normal RLE compression, as end-of-line + padding is marked optional for enhanced RLE?

    I guess end-of-image padding in enhanced RLE, last line in Table 2-110, is also optional?

  • Hi Thomas,

    Yes. 4 byte boundary is only required for normal RLE compression.

    For the Enhanced RLE compression, on the table 2-110, last row(00 01 00) is the actual End of Image command. The word "padding" must be removed from that sentence.

    End of image command must be included for proper exit of decompression function.

    Thanks,
    Shivakumar