Make pix{Read,Write}MemJp2k work via direct memory access #732
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* On platforms lacking open_memstream(), pix{Read,Write}MemJp2k()
worked via a temporary file, but this overhead is unnecessary
as openjpeg2000's opj_stream allows one to read/write directly
from a memory buffer by supplying it with appropriate callbacks.
* This commit makes pix{Read,Write}MemJp2k() use this more direct
mechanism on all platforms.
* In addition, since pixReadStreamJp2k() always read the whole
stream into memory when it called fgetJp2kResolution(),
this commit saves a bit of compute resources by in effect making
pixReadStreamJp2k() into a wrapper for pixReadMemJp2k().
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This is very nice work! |
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On platforms lacking
open_memstream(),pix{Read,Write}MemJp2k()worked via a temporary file, but this overhead is unnecessary as openjpeg2000'sopj_streaminterface allows one to read/write directly from a memory buffer by supplying it with appropriate callbacks. This PR makespix{Read,Write}MemJp2k()use this more direct mechanism on all platforms.In addition, since
pixReadStreamJp2k()always reads the whole stream into memory when it calledfgetJp2kResolution(), this PR saves a bit of compute resources by in effect makingpixReadStreamJp2k()into a wrapper forpixReadMemJp2k().