diff mbox series

[FFmpeg-devel,6/8] avcodec/rangecoder: eliminate main branch from renorm_encoder()

Message ID 20241016194955.3627687-6-michael@niedermayer.cc
State New
Headers show
Series [FFmpeg-devel,1/8] avcodec/rangecoder: only perform renorm check/loop for callers that need it | expand

Commit Message

Michael Niedermayer Oct. 16, 2024, 7:49 p.m. UTC 
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/rangecoder.h | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/libavcodec/rangecoder.h b/libavcodec/rangecoder.h
index cdd99eff565..15217a99a3c 100644
--- a/libavcodec/rangecoder.h
+++ b/libavcodec/rangecoder.h
@@ -61,17 +61,12 @@  void ff_build_rac_states(RangeCoder *c, int factor, int max_p);
 
 static inline void renorm_encoder(RangeCoder *c)
 {
-    // FIXME: optimize
-        if (c->low <= 0xFF00) {
-            *c->bytestream = c->outstanding_byte;
+        if (c->low - 0xFF01 >= 0x10000 - 0xFF01U) {
+            int mask = c->low - 0xFF01 >> 31;
+            *c->bytestream = c->outstanding_byte + 1 + mask;
             c->bytestream += c->outstanding_byte >= 0;
             for (; c->outstanding_count; c->outstanding_count--)
-                *c->bytestream++ = 0xFF;
-            c->outstanding_byte = c->low >> 8;
-        } else if (c->low >= 0x10000) {
-            *c->bytestream++ = c->outstanding_byte + 1;
-            for (; c->outstanding_count; c->outstanding_count--)
-                *c->bytestream++ = 0x00;
+                *c->bytestream++ = mask;
             c->outstanding_byte = c->low >> 8;
         } else {
             c->outstanding_count++;