SwScaler performance help (was Re: [MPlayer-dev-eng] [PATCH] vf_osd updates - fully baked?)

[Reimar Döffinger]

Hi,
On Mon, Sep 12, 2005 at 10:34:58PM -0400, Jason Tackaberry wrote:
>     sws_getFlagsAndFilterFromCmdLine(&sws_flags, &srcFilterParam,
> &dstFilterParam);

Btw. this function isn't in any header, so don't use it in the final
version (use sws_getContextFromCmdLine), though I'm not sure if you
really want to respect the -sws command line option.

>     priv->sws_bgr32 = sws_getContext(priv->w, priv->h, IMGFMT_BGR32, width, height, IMGFMT_YV12,
>                                        get_sws_cpuflags() | sws_flags | SWS_PRINT_INFO,
>                                        srcFilterParam, dstFilterParam, NULL);

>         SwScaler: using unscaled Planar YV12 -> Planar YV12 special converter
>         
>         SwScaler: BICUBIC scaler, from Planar YV12 to Planar YV12 using MMX2

I wonder where these come from?

>         SwScaler: BICUBIC scaler, from BGRA to Planar YV12 using MMX2

Why does it get scaled? And BICUBIC is probably overkill, see -sws
option.

Greetings,
Reimar Döffinger

btw.2: since the scaler supports strides, it is possible to convert only a
rectangle by setting up a new context and doing a bit of pointer
arithmetic.