From: Michael Niedermayer <michael@niedermayer.cc> To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org> Subject: [FFmpeg-devel] [PATCH 9/9] avcodec/vlc: simplify min/maxbits in multi VLC Date: Sun, 22 Oct 2023 23:51:13 +0200 Message-ID: <20231022215113.3469-9-michael@niedermayer.cc> (raw) In-Reply-To: <20231022215113.3469-1-michael@niedermayer.cc> 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 --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 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
next prev parent reply other threads:[~2023-10-22 21:52 UTC|newest] Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-10-22 21:51 [FFmpeg-devel] [PATCH 1/9] avcodec/vlc: merge lost 16bit end of array check Michael Niedermayer 2023-10-22 21:51 ` [FFmpeg-devel] [PATCH 2/9] avcodec/vlc: dont pass nb_elems into multi vlc code Michael Niedermayer 2023-10-22 21:51 ` [FFmpeg-devel] [PATCH 3/9] avcodec/vlc: Skip subtable entries in multi VLC Michael Niedermayer 2023-10-22 21:51 ` [FFmpeg-devel] [PATCH 4/9] avcodec/vlc: Replace mysterious max computation code in multi vlc Michael Niedermayer 2023-10-22 21:51 ` [FFmpeg-devel] [PATCH 5/9] avcodec/vlc: Pass VLC_MULTI_ELEM directly not by pointer Michael Niedermayer 2023-10-23 6:10 ` Leo Izen 2023-10-23 16:04 ` Michael Niedermayer 2023-10-24 9:54 ` Leo Izen 2023-10-31 22:22 ` Michael Niedermayer 2023-10-22 21:51 ` [FFmpeg-devel] [PATCH 6/9] avcodec/vlc: Remove mysterious jitter loop in multi VLC Michael Niedermayer 2023-10-22 21:51 ` [FFmpeg-devel] [PATCH 7/9] Revert "avcodec/vlc: add correct upper limit for recursive function" Michael Niedermayer 2023-10-22 21:51 ` [FFmpeg-devel] [PATCH 8/9] Revert "avcodec/vlc: fix off by one in limit check for multi" Michael Niedermayer 2023-10-22 21:51 ` Michael Niedermayer [this message] 2023-10-22 23:02 ` [FFmpeg-devel] [PATCH 1/9] avcodec/vlc: merge lost 16bit end of array check Paul B Mahol 2023-10-23 16:05 ` Michael Niedermayer 2023-10-26 22:35 ` Michael Niedermayer
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20231022215113.3469-9-michael@niedermayer.cc \ --to=michael@niedermayer.cc \ --cc=ffmpeg-devel@ffmpeg.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
Git Inbox Mirror of the ffmpeg-devel mailing list - see https://ffmpeg.org/mailman/listinfo/ffmpeg-devel This inbox may be cloned and mirrored by anyone: git clone --mirror https://master.gitmailbox.com/ffmpegdev/0 ffmpegdev/git/0.git # If you have public-inbox 1.1+ installed, you may # initialize and index your mirror using the following commands: public-inbox-init -V2 ffmpegdev ffmpegdev/ https://master.gitmailbox.com/ffmpegdev \ ffmpegdev@gitmailbox.com public-inbox-index ffmpegdev Example config snippet for mirrors. AGPL code for this site: git clone https://public-inbox.org/public-inbox.git