TIFFStrileQuery - get strile byte count and offset

Author

       LibTIFF contributors

Copyright

       1988-2022, LibTIFF contributors

4.7                                               Apr 30, 2025                            TIFFSTRILEQUERY(3tiff)

Description

       Make  defer  strile  offset/bytecount  loading  available  at runtime and add per-strile offset/bytecount
       loading capabilities. Part of this commit makes the behaviour that was previously met  when  libtiff  was
       compiled with -DDEFER_STRILE_LOAD available for default builds.

       When  specifying the new D (Deferred) TIFFOpen() flag, the loading of strile offset/bytecount is defered.
       In that mode, the StripOffsets / StripByteCounts or TileOffsets / TileByteCounts arrays are  only  loaded
       when  first  accessed.  This  can  speed-up the opening of files stored on the network when just metadata
       retrieval is needed.

       Another addition is the capability of loading only the values of the offset/bytecount of  the  strile  of
       interest  instead of the whole array. This is enabled with the new O (Ondemand) flag of TIFFOpen() (which
       implies D).

       The   public   TIFFGetStrileOffset(),    TIFFGetStrileOffsetWithErr(),    TIFFGetStrileByteCount()    and
       TIFFGetStrileByteCountWithErr()  functions  have been added to API.  They are of particular interest when
       using sparse files (with offset==bytecount==0) and you want to detect if a strile is present  or  not
       without decompressing the data, or updating an existing sparse file.

       TIFFGetStrileByteCount()  returns  the  value  of  the  TileByteCounts  /  StripByteCounts  array for the
       specified tile/strile.

       TIFFGetStrileByteCountWithErr() additionally provides  pbErr  as  an  int  pointer  to  an  error  return
       variable, which is set to "0" for successful return or to "1" for an error return.

       TIFFGetStrileOffset()  returns  the  value  of  the  TileOffsets  /  StripOffsets array for the specified
       tile/strile.

       TIFFGetStrileOffsetWithErr() additionally provides pbErr as an int pointer to an error  return  variable,
       which is set to "0" for successful return or to "1" for an error return.

Diagnostics

       All  error messages are directed to the TIFFErrorExtR() routine.  Likewise, warning messages are directed
       to the TIFFWarningExtR() routine.

Name

       TIFFStrileQuery - get strile byte count and offset

Note

       This functionality was introduced with libtiff 4.1.

Synopsis

          #include <tiffio.h>

       uint64_tTIFFGetStrileByteCount(TIFF*tif,uint32_tstrile);uint64_tTIFFGetStrileOffset(TIFF*tif,uint32_tstrile);uint64_tTIFFGetStrileByteCountWithErr(TIFF*tif,uint32_tstrile,int*pbErr);uint64_tTIFFGetStrileOffsetWithErr(TIFF*tif,uint32_tstrile,int*pbErr);