Extract all data that I may recognize in package.
I(@HemanthJabalpuri) had ported spreadtrum PAC file extraction code to Java and Python.
See respective README in C or Python or Java folders
An example .pac file to extract can be found at here(~8MiB).
https://github.com/divinebird/pacextractor
https://spdflashtool.com/source/spd-tool-source-code
https://github.com/HenriDellal/unisoc-dloader/blob/master/include/BinPack.h
https://github.com/unisoc/dloader/blob/master/src/BinPack.cpp
https://github.com/yonglongliu/vendor/blob/master/sprd/build/buildpac/tools/unpac_perl/unpac.pl
https://github.com/newsfh/sprd_tool/blob/master/parse_pac.pl
https://github.com/Transsion-CI/7.SPRD_Compile/blob/master/Scripts/pac_via_conf.pl
https://github.com/yulinwang79/sprd-ap/blob/master/auto-pac/crc16.c
https://github.com/openLuat/LuatOS/blob/16cbbdb6a410c1116ece801f565b4b805e0e5867/bsp/air724/sdk/tools/combine_core.py
https://github.com/jingpad-bsp/vendor_sprd_tools_ota/blob/58ae4a1775854158a48ab30b0d9d006c043950e7/otatool/prebuilts/linux-x86/ota/pac_tools/unpac_perl/unpac.pl
https://github.com/Iscle/mksprdpac/blob/b6992356eda34f25336ebdbf7ed185097705bd48/main.c