lavfi: duplicate ff_log2_tab

Fixes compilation failures on msvc/icl shared builds

Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
lavc/flacenc: add sse4 version of the 16-bit lpc encoder

From 1.8 to 2.4 times faster.  Runtime is reduced by 2 to 39%.  The
speed-up generally increases with compression_level.

This lpc encoder is not used with levels < 3 so it provides no speed-up
in these cases.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/idctdsp: make add/put_pixels_clamped_c internal functions

This reduces code duplication and differences with the fork.

Signed-off-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
lavc/flacenc: partially unroll loop in flac_enc_lpc_16

It now does 12 samples per iteration, up from 4.

From 1.8 to 3.2 times faster again.  3.6 to 5.7 times faster overall.
Runtime is reduced by a further 2 to 18%.  Overall runtime reduced by
4 to 50%.

Same conditions as before apply.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
cvcodec/flacdsp_lpc_template: osmetic fix

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