R: [GRASS-dev] GRASS FFMPEG support

[Glynn Clements]

marco.pasetti at alice.it wrote:

> I succesfully built ffmpeg with the following configure options:
>  
> --enable-shared --disable-static --enable-gpl 
>  
> >Configure checks for the headers avcodec.h, avformat.h and swscale.h,
> >for the function avcodec_init with -lavcodec (and optionally
> >-lavutil), and for the function av_set_parameters with -lavformat (and
> >optionally -lavutil).
>  
> mmm... the configure log it's long to post it here, but there's a
> line that may be *interesting*:
>  
> software scaler enabled   no
>  
> you say that configure checks for swscale.h ... maybe software
> scaler must be enabled?

No, gsd_img_mpeg.c includes <swscale.h>, and creates a couple of
variables with types from that header, but the variables are never
actually used. If I remove the variables and the inclusion of
<swscale.h>, OGSF and NVIZ both compile without problems.

> another thing: vhook is not enabled, because it has been replaced by
> LibAVFilter, and because to build it I need some works around with
> libraries... so I would be very happy if GRASS would not need it :-)
> ... do you know if it is needed?

I'm fairly sure that GRASS doesn't need it. AFAICT, the vhook
libraries are only used as plugins (dynamically loaded at run time),
and never linked to directly.

-- 
Glynn Clements <glynn at gclements.plus.com>