[FFmpeg-devel] [PATCH] avcodec/proresenc_anatoliy: change quantization scaling to floating point to utilize vectorization

[David Murmann]

Quantization scaling seems to be a slight bottleneck,
this change allows the compiler to more easily vectorize
the loop. This improves total encoding performance in my
tests by about 10-20%.

Signed-off-by: David Murmann <david at btf.de>
---
  libavcodec/proresenc_anatoliy.c | 12 ++++++++----
  1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/libavcodec/proresenc_anatoliy.c 
b/libavcodec/proresenc_anatoliy.c
index 0516066163..8b296f6f1b 100644
--- a/libavcodec/proresenc_anatoliy.c
+++ b/libavcodec/proresenc_anatoliy.c
@@ -232,14 +232,18 @@ static const uint8_t lev_to_cb[10] = { 0x04, 0x0A, 
0x05, 0x06, 0x04, 0x28,
  static void encode_ac_coeffs(AVCodecContext *avctx, PutBitContext *pb,
          int16_t *in, int blocks_per_slice, int *qmat)
  {
+    int16_t block[64];
      int prev_run = 4;
      int prev_level = 2;
       int run = 0, level, code, i, j;
-    for (i = 1; i < 64; i++) {
-        int indp = progressive_scan[i];
-        for (j = 0; j < blocks_per_slice; j++) {
-            int val = QSCALE(qmat, indp, in[(j << 6) + indp]);
+    for (j = 0; j < blocks_per_slice; j++) {
+        for (i = 0; i < 64; i++) {
+            block[i] = (float)in[(j << 6) + i] / (float)qmat[i];
+        }
+
+        for (i = 1; i < 64; i++) {
+            int val = block[progressive_scan[i]];
              if (val) {
                  encode_codeword(pb, run, run_to_cb[FFMIN(prev_run, 15)]);
  -- 2.16.2


-- 
btf GmbH | Leyendeckerstr. 27, 50825 Köln | +49 (0) 221 82 00 87 10
Geschäftsführer: Philipp Käßbohrer & Matthias Murmann | HR Köln | HRB 74707