1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-02 03:06:28 +02:00
Commit Graph

3 Commits

Author SHA1 Message Date
Martin Storsjö
bff0771590 arm: vp9mc: Calculate less unused data in the 4 pixel wide horizontal filter
Before:                    Cortex A7      A8     A9     A53
vp9_put_8tap_smooth_4h_neon:   378.1   273.2  340.7   229.5
After:
vp9_put_8tap_smooth_4h_neon:   352.1   222.2  290.5   229.5

This is cherrypicked from libav commit
fea92a4b57.

Signed-off-by: Martin Storsjö <martin@martin.st>
2017-03-11 13:14:47 +02:00
Martin Storsjö
656d910981 arm: vp9mc: Fix vertical alignment of operands
This is cherrypicked from libav commit
c536e5e869.

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2017-01-14 21:13:37 +01:00
Martin Storsjö
68caef9d48 arm: vp9: Add NEON optimizations of VP9 MC functions
This work is sponsored by, and copyright, Google.

The filter coefficients are signed values, where the product of the
multiplication with one individual filter coefficient doesn't
overflow a 16 bit signed value (the largest filter coefficient is
127). But when the products are accumulated, the resulting sum can
overflow the 16 bit signed range. Instead of accumulating in 32 bit,
we accumulate the largest product (either index 3 or 4) last with a
saturated addition.

(The VP8 MC asm does something similar, but slightly simpler, by
accumulating each half of the filter separately. In the VP9 MC
filters, each half of the filter can also overflow though, so the
largest component has to be handled individually.)

Examples of relative speedup compared to the C version, from checkasm:
                       Cortex      A7     A8     A9    A53
vp9_avg4_neon:                   1.71   1.15   1.42   1.49
vp9_avg8_neon:                   2.51   3.63   3.14   2.58
vp9_avg16_neon:                  2.95   6.76   3.01   2.84
vp9_avg32_neon:                  3.29   6.64   2.85   3.00
vp9_avg64_neon:                  3.47   6.67   3.14   2.80
vp9_avg_8tap_smooth_4h_neon:     3.22   4.73   2.76   4.67
vp9_avg_8tap_smooth_4hv_neon:    3.67   4.76   3.28   4.71
vp9_avg_8tap_smooth_4v_neon:     5.52   7.60   4.60   6.31
vp9_avg_8tap_smooth_8h_neon:     6.22   9.04   5.12   9.32
vp9_avg_8tap_smooth_8hv_neon:    6.38   8.21   5.72   8.17
vp9_avg_8tap_smooth_8v_neon:     9.22  12.66   8.15  11.10
vp9_avg_8tap_smooth_64h_neon:    7.02  10.23   5.54  11.58
vp9_avg_8tap_smooth_64hv_neon:   6.76   9.46   5.93   9.40
vp9_avg_8tap_smooth_64v_neon:   10.76  14.13   9.46  13.37
vp9_put4_neon:                   1.11   1.47   1.00   1.21
vp9_put8_neon:                   1.23   2.17   1.94   1.48
vp9_put16_neon:                  1.63   4.02   1.73   1.97
vp9_put32_neon:                  1.56   4.92   2.00   1.96
vp9_put64_neon:                  2.10   5.28   2.03   2.35
vp9_put_8tap_smooth_4h_neon:     3.11   4.35   2.63   4.35
vp9_put_8tap_smooth_4hv_neon:    3.67   4.69   3.25   4.71
vp9_put_8tap_smooth_4v_neon:     5.45   7.27   4.49   6.52
vp9_put_8tap_smooth_8h_neon:     5.97   8.18   4.81   8.56
vp9_put_8tap_smooth_8hv_neon:    6.39   7.90   5.64   8.15
vp9_put_8tap_smooth_8v_neon:     9.03  11.84   8.07  11.51
vp9_put_8tap_smooth_64h_neon:    6.78   9.48   4.88  10.89
vp9_put_8tap_smooth_64hv_neon:   6.99   8.87   5.94   9.56
vp9_put_8tap_smooth_64v_neon:   10.69  13.30   9.43  14.34

For the larger 8tap filters, the speedup vs C code is around 5-14x.

This is significantly faster than libvpx's implementation of the same
functions, at least when comparing the put_8tap_smooth_64 functions
(compared to vpx_convolve8_horiz_neon and vpx_convolve8_vert_neon from
libvpx).

Absolute runtimes from checkasm:
                          Cortex      A7        A8        A9       A53
vp9_put_8tap_smooth_64h_neon:    20150.3   14489.4   19733.6   10863.7
libvpx vpx_convolve8_horiz_neon: 52623.3   19736.4   21907.7   25027.7

vp9_put_8tap_smooth_64v_neon:    14455.0   12303.9   13746.4    9628.9
libvpx vpx_convolve8_vert_neon:  42090.0   17706.2   17659.9   16941.2

Thus, on the A9, the horizontal filter is only marginally faster than
libvpx, while our version is significantly faster on the other cores,
and the vertical filter is significantly faster on all cores. The
difference is especially large on the A7.

The libvpx implementation does the accumulation in 32 bit, which
probably explains most of the differences.

This is an adapted cherry-pick from libav commits
ffbd1d2b00,
392caa65df,
557c1675cf and
11623217e3.

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
2016-11-15 15:10:03 -05:00