[FFmpeg-devel] [PATCH 9/9] avcodec/vlc: simplify min/maxbits in multi VLC
Michael Niedermayer
michael at niedermayer.cc
Mon Oct 23 00:51:13 EEST 2023
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 at niedermayer.cc>
---
libavcodec/vlc.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
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
--
2.17.1
More information about the ffmpeg-devel
mailing list