| Message ID | 20170614050318.16835-1-kmark937@gmail.com |
|---|---|
| State | Accepted |
| Commit | 05feeeb813e9f71f69b6b3a7f33856c609237c06 |
| Headers | show |
Hi, On Wed, Jun 14, 2017 at 1:03 AM, Kevin Mark <kmark937@gmail.com> wrote: > The input width and height is known at parse time so there's no > reason ow/oh should not be usable when using 0 as the width or > height expression. > > Previously in "scale=0:ow" ow would be set to "0" which works, > conveniently, as "scale=0:0" is perfectly valid input but this breaks > down when you do something like "scale=0:ow/4" which one could > reasonably expect to work as well, but does not as ow is 0 not the > real value. > > This change handles the 0 case for w/h immediately so the ow/oh > variables work as expected. Consequently, the rest of the code does > not need to handle 0 input. w/h will always be > 0 or < 0. > > The second explicit (int) cast ensures that ow/oh appear as integers > as a user might expect when dealing with pixel dimensions. > > Signed-off-by: Kevin Mark <kmark937@gmail.com> > --- > libavfilter/scale.c | 13 +++++-------- > 1 file changed, 5 insertions(+), 8 deletions(-) > > diff --git a/libavfilter/scale.c b/libavfilter/scale.c > index 03745ddcb8..eaee95fac6 100644 > --- a/libavfilter/scale.c > +++ b/libavfilter/scale.c > @@ -158,19 +158,19 @@ int ff_scale_eval_dimensions(void *log_ctx, > av_expr_parse_and_eval(&res, (expr = w_expr), > names, var_values, > NULL, NULL, NULL, NULL, NULL, 0, log_ctx); > - eval_w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res; > + eval_w = var_values[VAR_OUT_W] = var_values[VAR_OW] = (int) res == 0 > ? inlink->w : (int) res; > > if ((ret = av_expr_parse_and_eval(&res, (expr = h_expr), > names, var_values, > NULL, NULL, NULL, NULL, NULL, 0, > log_ctx)) < 0) > goto fail; > - eval_h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res; > + eval_h = var_values[VAR_OUT_H] = var_values[VAR_OH] = (int) res == 0 > ? inlink->h : (int) res; > /* evaluate again the width, as it may depend on the output height */ > if ((ret = av_expr_parse_and_eval(&res, (expr = w_expr), > names, var_values, > NULL, NULL, NULL, NULL, NULL, 0, > log_ctx)) < 0) > goto fail; > - eval_w = res; > + eval_w = (int) res == 0 ? inlink->w : (int) res; > > w = eval_w; > h = eval_h; > @@ -186,13 +186,10 @@ int ff_scale_eval_dimensions(void *log_ctx, > factor_h = -h; > } > > - if (w < 0 && h < 0) > - eval_w = eval_h = 0; > - > - if (!(w = eval_w)) > + if (w < 0 && h < 0) { > w = inlink->w; > - if (!(h = eval_h)) > h = inlink->h; > + } > > /* Make sure that the result is divisible by the factor we determined > * earlier. If no factor was set, it is nothing will happen as the > default > -- > 2.13.1 Pushed. Ronald
diff --git a/libavfilter/scale.c b/libavfilter/scale.c index 03745ddcb8..eaee95fac6 100644 --- a/libavfilter/scale.c +++ b/libavfilter/scale.c @@ -158,19 +158,19 @@ int ff_scale_eval_dimensions(void *log_ctx, av_expr_parse_and_eval(&res, (expr = w_expr), names, var_values, NULL, NULL, NULL, NULL, NULL, 0, log_ctx); - eval_w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res; + eval_w = var_values[VAR_OUT_W] = var_values[VAR_OW] = (int) res == 0 ? inlink->w : (int) res; if ((ret = av_expr_parse_and_eval(&res, (expr = h_expr), names, var_values, NULL, NULL, NULL, NULL, NULL, 0, log_ctx)) < 0) goto fail; - eval_h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res; + eval_h = var_values[VAR_OUT_H] = var_values[VAR_OH] = (int) res == 0 ? inlink->h : (int) res; /* evaluate again the width, as it may depend on the output height */ if ((ret = av_expr_parse_and_eval(&res, (expr = w_expr), names, var_values, NULL, NULL, NULL, NULL, NULL, 0, log_ctx)) < 0) goto fail; - eval_w = res; + eval_w = (int) res == 0 ? inlink->w : (int) res; w = eval_w; h = eval_h; @@ -186,13 +186,10 @@ int ff_scale_eval_dimensions(void *log_ctx, factor_h = -h; } - if (w < 0 && h < 0) - eval_w = eval_h = 0; - - if (!(w = eval_w)) + if (w < 0 && h < 0) { w = inlink->w; - if (!(h = eval_h)) h = inlink->h; + } /* Make sure that the result is divisible by the factor we determined * earlier. If no factor was set, it is nothing will happen as the default
The input width and height is known at parse time so there's no reason ow/oh should not be usable when using 0 as the width or height expression. Previously in "scale=0:ow" ow would be set to "0" which works, conveniently, as "scale=0:0" is perfectly valid input but this breaks down when you do something like "scale=0:ow/4" which one could reasonably expect to work as well, but does not as ow is 0 not the real value. This change handles the 0 case for w/h immediately so the ow/oh variables work as expected. Consequently, the rest of the code does not need to handle 0 input. w/h will always be > 0 or < 0. The second explicit (int) cast ensures that ow/oh appear as integers as a user might expect when dealing with pixel dimensions. Signed-off-by: Kevin Mark <kmark937@gmail.com> --- libavfilter/scale.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-)