| Message ID | 20180704231046.1fe7845a@telaviv1.shlomifish.org |
|---|---|
| State | New |
| Headers | show |
On Wed, 4 Jul 2018 23:10:46 +0300 Shlomi Fish <shlomif@shlomifish.org> wrote: Ping! Can this patch be reviewed please?
On Wed, 11 Jul 2018 19:42:09 +0300 Shlomi Fish <shlomif@shlomifish.org> wrote: > On Wed, 4 Jul 2018 23:10:46 +0300 > Shlomi Fish <shlomif@shlomifish.org> wrote: > > Ping! Can this patch be reviewed please? > Ping! >
On Fri, 20 Jul 2018 14:31:55 +0300 Shlomi Fish <shlomif@shlomifish.org> wrote: > On Wed, 11 Jul 2018 19:42:09 +0300 > Shlomi Fish <shlomif@shlomifish.org> wrote: > > > On Wed, 4 Jul 2018 23:10:46 +0300 > > Shlomi Fish <shlomif@shlomifish.org> wrote: > > > > Ping! Can this patch be reviewed please? > > > > Ping! bump / ping.
On Wed, 4 Jul 2018 23:10:46 +0300 Shlomi Fish <shlomif@shlomifish.org> wrote: Ping/bump! Can this patch be reviewed already?
On Wed, 7 Nov 2018, Shlomi Fish wrote: > On Wed, 4 Jul 2018 23:10:46 +0300 > Shlomi Fish <shlomif@shlomifish.org> wrote: > > Ping/bump! Can this patch be reviewed already? Does your patch has any measureable speed difference for some streams? It seems like a very micro optimialization, because ff_metadata_conv bails out early as well. Regards, Marton
Hi Marton, On Wed, 7 Nov 2018 10:29:31 +0100 (CET) Marton Balint <cus@passwd.hu> wrote: > On Wed, 7 Nov 2018, Shlomi Fish wrote: > > > On Wed, 4 Jul 2018 23:10:46 +0300 > > Shlomi Fish <shlomif@shlomifish.org> wrote: > > > > Ping/bump! Can this patch be reviewed already? > > Does your patch has any measureable speed difference for some streams? It > seems like a very micro optimialization, because ff_metadata_conv bails > out early as well. > First of all note that I recall it being the case for several function calls in succession there. Secondly, I didn't measure it, but see what I wrote at: https://en.wikibooks.org/wiki/Optimizing_Code_for_Speed/Factor_Optimizations#Are_%22Small%22_Optimizations_Desirable? non-inline function calls can be quite slow. > Regards, > Marton > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
On Thu, Nov 15, 2018 at 10:27 AM Shlomi Fish <shlomif@shlomifish.org> wrote: > > Hi Marton, > > On Wed, 7 Nov 2018 10:29:31 +0100 (CET) > Marton Balint <cus@passwd.hu> wrote: > > > On Wed, 7 Nov 2018, Shlomi Fish wrote: > > > > > On Wed, 4 Jul 2018 23:10:46 +0300 > > > Shlomi Fish <shlomif@shlomifish.org> wrote: > > > > > > Ping/bump! Can this patch be reviewed already? > > > > Does your patch has any measureable speed difference for some streams? It > > seems like a very micro optimialization, because ff_metadata_conv bails > > out early as well. > > > > First of all note that I recall it being the case for several function calls > in succession there. Secondly, I didn't measure it, but see what I wrote at: > > https://en.wikibooks.org/wiki/Optimizing_Code_for_Speed/Factor_Optimizations#Are_%22Small%22_Optimizations_Desirable? > > non-inline function calls can be quite slow. > Theoretical optimizations are all nice and well, but numbers are the only reality in the world. :) - Hendrik
From 98e0629d28394f8683abd98f80645ee63b295d24 Mon Sep 17 00:00:00 2001 From: Shlomi Fish <shlomif@shlomifish.org> Date: Wed, 4 Jul 2018 22:53:08 +0300 Subject: [PATCH] Short-circuit several calls on a condition. This is an optimization - more details in the comment in the changeset. --- libavformat/metadata.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libavformat/metadata.c b/libavformat/metadata.c index b9b6de7972..4b720efd38 100644 --- a/libavformat/metadata.c +++ b/libavformat/metadata.c @@ -60,6 +60,10 @@ void ff_metadata_conv_ctx(AVFormatContext *ctx, const AVMetadataConv *d_conv, const AVMetadataConv *s_conv) { int i; + /* We pass those to all ff_metadata_conv calls below and it returns + * immediately if they are equal, so we can short-circuit. */ + if (d_conv == s_conv) + return; ff_metadata_conv(&ctx->metadata, d_conv, s_conv); for (i=0; i<ctx->nb_streams ; i++) ff_metadata_conv(&ctx->streams [i]->metadata, d_conv, s_conv); -- 2.18.0