avfilter/vf_tinterlace: fix linesize vs. width

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avfilter/tinterlace: split context definition into seperate header so it can be used by future optimizations

Idea from 2e1704059ae8625beda2ffde847ad22c5ba416dc from Kieran Kunhya

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avfilter/tinterlace: Move lowpass_line to a separate function and call it through a function pointer

This permits replacing it by a optimized implementation
Based-on / Idea-from: 2e1704059ae8625beda2ffde847ad22c5ba416dc by Kieran Kunhya

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avfilter/tinterlace: add Support for ff_lowpass_line_avx() & ff_lowpass_line_sse2()

Based-on: 2e1704059ae8625beda2ffde847ad22c5ba416dc by Kieran Kunhya

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avfilter/x86/vf_interlace: rewrite asm

4775 decicycles -> 3688 decicycles

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>