Commit Graph

3 Commits

Author SHA1 Message Date
Christophe Gisquet
74c414202f x86: simple_idct10_template: use const
This avoid going through constants.c while still sharing them
with proresdsp.asm

Reviewed-by: "Ronald S. Bultje" <rsbultje@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2015-10-13 22:52:33 +02:00
Christophe Gisquet
7ece8b50b1 x86: simple_idct: 12bits versions
On 12 frames of a 444p 12 bits DNxHR sequence, _put function:
C:         78902 decicycles in idct,  262071 runs,     73 skips
avx:       32478 decicycles in idct,  262045 runs,     99 skips

Difference between the 2:
stddev:    0.39 PSNR:104.47 MAXDIFF:    2

This is unavoidable and due to the scale factors used in the x86
version, which cannot match the C ones.

In addition, the trick of adding an initial bias to the input of a
pass can overflow, as the input coefficients are already 15bits,
which is the maximum this function can handle.

Overall, however, the omse on 12 bits samples goes from 0.16916 to
0.16883. Reducing rowshift by 1 improves to 0.0908, but causes
overflows.

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2015-10-13 15:34:32 +02:00
Christophe Gisquet
4369b9dc7b x86: simple_idct(_put): 10bits versions
Modeled from the prores version. Clips to [0;1023] and is bitexact.
Bitexactness requires to add offsets in different places compared to
prores or C, and makes the function approximately 2% slower.

For 16 frames of a DNxHD 4:2:2 10bits test sequence:

C:    60861 decicycles in idct, 1048205 runs,    371 skips
sse2: 27567 decicycles in idct, 1048216 runs,    360 skips
avx:  26272 decicycles in idct, 1048171 runs,    405 skips

The add version is not implemented, so the corresponding dsp
function is set to NULL to make it clear in a code executing it.

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2015-10-13 13:32:21 +02:00