diff mbox series

[FFmpeg-devel,9/9] avcodec/vlc: simplify min/maxbits in multi VLC

Message ID 20231022215113.3469-9-michael@niedermayer.cc
State New
Headers show
Series [FFmpeg-devel,1/9] avcodec/vlc: merge lost 16bit end of array check | expand

Checks

Context Check Description
yinshiyou/make_loongarch64 success Make finished
yinshiyou/make_fate_loongarch64 success Make fate finished
andriy/make_x86 success Make finished
andriy/make_fate_x86 success Make fate finished

Commit Message

Michael Niedermayer Oct. 22, 2023, 9:51 p.m. UTC 
nothing uses maxbits, so its removed
minbits is just the last entry (verified with assert on fate)

This basically reverts 58d9b5caf3d332c6495f9af437158bf45531a05e for the minbits computation

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/vlc.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/libavcodec/vlc.c b/libavcodec/vlc.c
index ceabeba5408..de16424c93d 100644
--- a/libavcodec/vlc.c
+++ b/libavcodec/vlc.c
@@ -395,7 +395,7 @@  static int vlc_multi_gen(VLC_MULTI_ELEM *table, const VLC *single,
                          const int is16bit, const int nb_codes, const int numbits,
                          VLCcode *buf, void *logctx)
 {
-    int minbits, maxbits, max;
+    int minbits, max;
     unsigned count[VLC_MULTI_MAX_SYMBOLS-1] = { 0, };
     VLC_MULTI_ELEM info = { { 0, }, 0, 0, };
     int count0 = 0;
@@ -407,14 +407,9 @@  static int vlc_multi_gen(VLC_MULTI_ELEM *table, const VLC *single,
         }
     }
 
-    minbits = 32;
-    maxbits = 0;
-
-    for (int n = nb_codes - count0; n < nb_codes; n++) {
-        minbits = FFMIN(minbits, buf[n].bits);
-        maxbits = FFMAX(maxbits, buf[n].bits);
-    }
-    av_assert0(maxbits <= numbits);
+    //This is only correct if count0 > 0 and the table is sorted
+    //minbits is not used if count0 == 0 and other parts assume the table is sorted too
+    minbits = buf[nb_codes - 1].bits;
 
     for (max = nb_codes; max > nb_codes - count0; max--) {
         // We can only add a code that fits with the shortest other code into the table