Hey Jens,

I suppose the trouble here is that I'm familiar with Objective-C code and not so familiar with its parent, C.

On Jun 28, 2011, at 1:00 PM, Jens Alfke wrote:


On Jun 28, 2011, at 6:23 AM, Kevin Muldoon wrote:

As you can see from the output, the 'version' & 'reserved' isn't being read at all. Must I coerce/parse something here? Much thanks…

I’m not familiar with the PSD format, but aren’t ‘version’ and ‘reserved’ binary? You’re printing them as C strings.

Assuming ‘version’ is a 16-bit big-endian integer, you could read it like this:

const uint8_t* bytes = [signature bytes];
uint16_t version =  *(const uint16_t*)(bytes + 2);
version = NSSwapBigShortToHost(version);

Another way (that I often use) is to define a C struct that matches the fields and layout of the header, then cast the bytes to a pointer to that struct and read the fields. It makes your code look a lot cleaner, but you have to be careful to (a) make sure the compiler packs the struct fields properly, and (b) you byte-swap all integer/float fields appropriately.

—Jens


Kevin Muldoon
e: caoimgh...@gmail.com

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