[FFmpeg-devel] [PATCH] lavfi/rotate: add angle command

[Stefano Sabatini]

On date Wednesday 2013-06-12 10:01:31 +0200, Clément Bœsch encoded:
> On Tue, Jun 11, 2013 at 04:09:37PM +0200, Stefano Sabatini wrote:
> > ---
> >  doc/filters.texi        |   13 +++++++++++++
> >  libavfilter/vf_rotate.c |   36 ++++++++++++++++++++++++++++++++++++
> >  2 files changed, 49 insertions(+)
> > 
> > diff --git a/doc/filters.texi b/doc/filters.texi
> > index 7e8fff9..c4ad494 100644
> > --- a/doc/filters.texi
> > +++ b/doc/filters.texi
> > @@ -5852,6 +5852,19 @@ rotate=2*PI*t:ow='min(iw,ih)/sqrt(2)':oh=ow
> >  @end example
> >  @end itemize
> >  
> > + at subsection Commands
> > +
> > +The filter supports the following commands:
> > +
> > + at table @option
> > + at item a, angle
> > +Set the angle expression.
> > +The command accepts the same syntax of the corresponding option.
> > +
> > +If the specified expression is not valid, it is kept at its current
> > +value.
> > + at end table
> > +
> >  @section removelogo
> >  
> >  Suppress a TV station logo, using an image file to determine which
> > diff --git a/libavfilter/vf_rotate.c b/libavfilter/vf_rotate.c
> > index da294c3..ce31a7c 100644
> > --- a/libavfilter/vf_rotate.c
> > +++ b/libavfilter/vf_rotate.c
> > @@ -425,6 +425,41 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
> >      return ff_filter_frame(outlink, out);
> >  }
> >  
> > +static int set_expr(AVExpr **pexpr, const char *expr, const char *option, void *log_ctx)
> > +{
> > +    int ret;
> > +    AVExpr *old = NULL;
> > +
> 
> > +    if (*pexpr)
> > +        old = *pexpr;
> 
> That check is wrong (dereference in the if), or at best useless.
> 
> > +    ret = av_expr_parse(pexpr, expr, var_names,
> > +                        NULL, NULL, NULL, NULL, 0, log_ctx);
> > +    if (ret < 0) {
> > +        av_log(log_ctx, AV_LOG_ERROR,
> > +               "Error when evaluating the expression '%s' for %s\n",
> > +               expr, option);
> > +        *pexpr = old;
> > +        return ret;
> > +    }
> > +
> > +    av_expr_free(old);
> > +    return 0;
> > +}
> > +
> > +static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
> > +                           char *res, int res_len, int flags)
> > +{
> > +    RotContext *rot = ctx->priv;
> > +    int ret;
> > +
> > +    if (!strcmp(cmd, "angle") || !strcmp(cmd, "a")) {
> > +        ret = set_expr(&rot->angle_expr, args, cmd, ctx);
> > +    } else
> > +        ret = AVERROR(ENOSYS);
> > +
> > +    return ret;
> > +}
> > +
> >  static const AVFilterPad rotate_inputs[] = {
> >      {
> >          .name         = "default",
> > @@ -453,4 +488,5 @@ AVFilter avfilter_vf_rotate = {
> >      .inputs      = rotate_inputs,
> >      .outputs     = rotate_outputs,
> >      .priv_class  = &rotate_class,
> > +    .process_command = process_command,
> 
> Rest LGTM

Simplified, pushed.
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