[vlc-devel] Poor subtitle performance and what's causing it

[Laurent Aimar]

Hi,

On Tue, Feb 09, 2010, Rémi Denis-Courmont wrote:
> 
> On Mon, 8 Feb 2010 22:09:31 +0200, Tepe Hautamäki <tp7000 at hotmail.com>
> wrote:
> > The problem is basically that displaying subtitles takes a
> > disproportionate amount
> > of CPU time (several times the video decoding overhead, depending on
> > subtitle size)
> > and in extreme cases can cause frames to be skipped. I found this
> > function in
> > modules/video_filter/blend.c to be the culprit:
> 
> How did you determine that? It seems quite weird.
 I think he is right but only for some video outputs like win32 ones.
 In their cases, I fear that in 1.1 (1.0?) we end up reading and writing
directly into video memory. I will have a look and reintroduce the temporary
buffer when vout_display_t::info.is_slow is true.

-- 
fenrir