SharpExport
xtra是由Sharp Software公司发行的完全免费的xtra，可以将director内部的图象成员输出处为JPEG， PNG 和 BMP/PICT 等文件格式。目前不支持shockwave。
使用方法：
Creating an Xtra instance:
xtraInst = new (xtra "SharpExport")
Saving as a JPG (8-bit castmember or higher):
result = xtraInst.exportJPG (member "bitmap", "c:filename.jpg", 70)
parameter 1 - bitmap member reference
parameter 2 - pathname to save to
parameter 3 - jpeg compression level (higher is better quality)
Saving as a PNG:
result = xtraInst.exportPNG (member "bitmap", "c:filename.png")
Saving as a BMP (
Windows only):
result = xtraInst.exportBMP (member "bitmap", "c:filename.bmp")
Saving a PICT (Macintosh only):
result = xtraInst.exportPICT (member "bitmap", "MacHDName:filename.pct")
错误代号：
0 success
-1 destination file can not be written
-2 out of memory
-3 wrong number of args
-4 bad parameter
-5 castmember not found
-6 castmember media not found
-7 castmember is not a bitmap
-8 unsupported bitdepth (JPEG support is 8 bits or higher)
-9 JPEG compression failed (internal error with JPEG library)
-10 PNG compression failed (internal error with PNG library)
