Commit b0971e47d76fdb81270e93bbf11ff5558073350d
2017-06-28T14:47:45
TurboJPEG: Document xform issue w/ big marker data If the source image for a transform operation has a lot of EXIF or ICC data embedded in it, then it may cause the output image size to exceed the worst-case size returned by tjBufSize() (because tjTransform() transfers all markers to the output image.) This is only a problem if TJFLAG_NOREALLOC is passed to the function. Since the TurboJPEG C API doesn't require the destination image size to be set in this case, it makes the documented assumption that the calling program has allocated the destination buffer to exactly the size returned by tjBufSize(). Changing this assumption would change the API behavior and necessitate a new function name (tjTransform2().) At the moment, it's easier to just document this as a known issue, since it's easy to work around in the C API. The Java API is unfortunately a different story, since it must always use TJFLAG_NOREALLOC (because, when using the TurboJPEG Java API, all buffers are allocated on the Java heap, and thus they can't be reallocated by the C code.) There is no easy way to work around this without changing the C API as discussed above, because if the source image contains large amounts of marker data, it's virtually impossible to determine how big the output image will be.