Lots of things
I haven't see your rom yet (I'm not at home... I'm in my daughter dept at the north).
Anyway, more or less:
. First to have all the binaries with *rk* in the names in /system specially those in /system/framework.
. Second to have the whole libs of codes in /system/lib those starting with libopencore* and libomx* and libstagefright* for ARMv5te or ARMv6 (froyo rel 8 or GB.2.3.1 rel 9)
. Third pick selected libraries related with media... most important libmediaplayerservice
all the binaries in /system/lib have to be for ARMv5te or ARMv6 instead of ARMv7. Check this displaying the binaries with a text reader and in the last 30 lines of garbage you'll see the word ARM followed by the version.
My suggestion is to pick this binaries from Froyo, GB.2.3.1. Just remember that nothing for RK2818 have changed since Eclaire times, then all the lib binaries are almost the same.
Other suggestion: use a comparing tool ... comparing a working rom from GB.2.3.1 with yours (GB.2.3.1 have all media working fine)
This is a starting point
From tuesday afternoon I'll be at my home and I'll take a look to your rom... for the moment I'll be playing games with RK2918
I think you won't need more advices from me
PS.: I would like to see a rom not related with mine or fun_ !!! so good luck my friend!
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Phablet Samsung Galaxy Note 3 - KK 4.4.2
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Tablet Onn 07DX (Yifang M7000DK) RK3066 7" - JB 4.1.1
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Tablet Onn 07DR (Yifang M7100KLD) RK3026 7" - JB 4.2.2
Tablet Master-G G-820c (Yifang M900HC) RK2918 8" - JB 4.2.2 (Oma)
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