[FFmpeg-cvslog] lavu: add av_usleep() function

[Reimar Döffinger]

git at videolan.org wrote:

>ffmpeg | branch: master | Mans Rullgard <mans at mansr.com> | Thu Jun 21
>17:00:25 2012 +0100| [d3d3a32c9d389cc0d6a91b389988a225ae01c948] |
>committer: Mans Rullgard
>
>lavu: add av_usleep() function
>
>This function implements a delay using the first available
>of the following functions:
>
>- nanosleep()
>- usleep()
>- Sleep() (Windows)

IMHO this function should come with a big warning in its doxygen, without special setup the sleep precision of this function at least using Sleep is at best 10ms which might render it completely unsuitable as a usleep replacement in some cases.