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| author | Kevin Mark <kmark937@gmail.com> | 2017-06-14 01:03:18 -0400 |
|---|---|---|
| committer | Ronald S. Bultje <rsbultje@gmail.com> | 2017-06-19 14:27:52 -0400 |
| commit | 05feeeb813e9f71f69b6b3a7f33856c609237c06 (patch) | |
| tree | 73f8668ea490f37599967cb27877f49b18118cb4 | |
| parent | 5aea18cbd8828da885d76d528fcbf5b2fd6834ca (diff) | |
| download | ffmpeg-05feeeb813e9f71f69b6b3a7f33856c609237c06.tar.gz | |
libavfilter/scale: Populate ow/oh when using 0 as w/h
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>
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
| -rw-r--r-- | libavfilter/scale.c | 13 |
1 files 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 |