Do you have time and interest in enhancing your software-only MPEG2 decoder by implementing more modern and effective deblocking algorithms than the existing one?
I will not copy and paste »Didée's explanation why Nic's deblocking is not recommendable anymore, despite its advantage of knowing the quantization factors« – so please read it in detail again in doom9's forum, using this link.
Just in brief:
- An MPEG2Source() internal deblocker has the advantage of knowing the source video's quantization to tune its strength and threshold on its own.
- The currently used deblocker related to CPU and CPU2 parameters (Nic's algorithm) fails taking this advantage by being less efficient than other more modern algorithms.
- The additionally available Deblock() filter, based on a H.264 implementation by Manao, has the advantage of being more efficient, but the disadvantages of not knowing the source quantization and requiring a manual strength parameter, and operating on MPEG4-AVC/H.264 quantization parameters instead of MPEG2/H.262
- For some cases with rather fine quantization and little blocking, the pure Deblock() result can be too strong, an attenuation as implemented in deblock_qed() would be recommendable.
MPEG2Source(..., bool useDeblock, float qed)
(just a suggestion; practical reasons may prove it wrong or not...)
Please don't miss that it would have to work with interlaced sources too. Find Deblock_QED with a modification by Bi11 in »this thread on doom9's forum«.