[FFmpeg-devel] [PATCH] allow vf_drawtext to draw framenumbers

[Jean First]

On Sat Apr 09 2011 02:31:49 GMT+0200 (CET), Stefano Sabatini wrote:
> * implement a special mode, in this mode you interpret %X codes in a
>    special way, in a similar way to that of strftime(). The problem is
>    that it would be incompatible with strftime()-sequences.
>
> * implement a dynamic environment accessible through the text
>    specification, for example:
>    "month:${month} n:${frame_number:%04d}"
>    Overkill?
>
> The problem with the #f/#F system is that it is quite limited and not
> very extensible (for example what if you want to print 5 padded digits
> for the frame number)?
I prefer the second idea. But I think on the shell ${month} will also be 
replaced with environment variables.

But what do you think about splitting the text and its variables 
completely ?
f.ex: text="Date: %s,%cFrame: %05d%cPTS: %s",textvars="%Y %n 
frame_number %n pts"

I'm not sure if it is easy to implement, but at least if textvars are 
not present you do not have to parse the text with snprintf or any other 
function.