On Fri, 1 Nov 2013 09:45:14 +0100, [email protected] wrote:
> From: Rudolf Polzer <[email protected]>
>
> Example: -vf setsar=sar="sar*9/10"
>
> Signed-off-by: Rudolf Polzer <[email protected]>
> ---
> doc/filters.texi | 54 ++++++++++++++++++++++++-
> libavfilter/vf_aspect.c | 102
> ++++++++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 152 insertions(+), 4 deletions(-)
>
> diff --git a/doc/filters.texi b/doc/filters.texi
> index e4fb57e..afb48b1 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -2049,10 +2049,35 @@ This filter accepts the following options:
> @table @option
>
> @item dar
> -Output display aspect ratio, as a rational or a decimal number.
> +Output display aspect ratio.
>
> @end table
>
> +The parameter @var{dar} is an expression containing
> +the following constants:
> +
> +@table @option
> +@item E, PI, PHI
> +the corresponding mathematical approximated values for e
> +(euler number), pi (greek PI), phi (golden ratio)
> +
> +@item w, h
> +the input width and height
> +
> +@item a
> +same as @var{w} / @var{h}
> +
> +@item sar
> +input sample aspect ratio
> +
> +@item dar
> +input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}
> +
> +@item hsub, vsub
> +horizontal and vertical chroma subsample values. For example for the
> +pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
> +@end table
> +
> For example to change the display aspect ratio to 16:9, specify:
> @example
> setdar=dar=16/9
> @@ -2158,10 +2183,35 @@ This filter accepts the following options:
> @table @option
>
> @item sar
> -Output sample aspect ratio, as a rational or decimal number.
> +Output sample aspect ratio.
>
> @end table
>
> +The parameter @var{sar} is an expression containing
> +the following constants:
> +
> +@table @option
> +@item E, PI, PHI
> +the corresponding mathematical approximated values for e
> +(euler number), pi (greek PI), phi (golden ratio)
> +
> +@item w, h
> +the input width and height
> +
> +@item a
> +same as @var{w} / @var{h}
> +
> +@item sar
> +input sample aspect ratio
> +
> +@item dar
> +input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}
> +
> +@item hsub, vsub
> +horizontal and vertical chroma subsample values. For example for the
> +pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
> +@end table
> +
> For example to change the sample aspect ratio to 10:11, specify:
> @example
> setsar=sar=10/11
> diff --git a/libavfilter/vf_aspect.c b/libavfilter/vf_aspect.c
> index 51ae27f..5309392 100644
> --- a/libavfilter/vf_aspect.c
> +++ b/libavfilter/vf_aspect.c
> @@ -26,13 +26,42 @@
> #include <float.h>
>
> #include "libavutil/common.h"
> +#include "libavutil/eval.h"
> #include "libavutil/mathematics.h"
> #include "libavutil/opt.h"
> +#include "libavutil/parseutils.h"
> +#include "libavutil/pixdesc.h"
>
> #include "avfilter.h"
> #include "internal.h"
> #include "video.h"
>
> +static const char *const var_names[] = {
> + "PI",
> + "PHI",
> + "E",
> + "w",
> + "h",
> + "a", "dar",
> + "sar",
> + "hsub",
> + "vsub",
> + NULL
> +};
> +
> +enum var_name {
> + VAR_PI,
> + VAR_PHI,
> + VAR_E,
> + VAR_W,
> + VAR_H,
> + VAR_A, VAR_DAR,
> + VAR_SAR,
> + VAR_HSUB,
> + VAR_VSUB,
> + VARS_NB
> +};
> +
> typedef struct {
> const AVClass *class;
> AVRational dar;
> @@ -40,6 +69,7 @@ typedef struct {
> #if FF_API_OLD_FILTER_OPTS
> float aspect_num, aspect_den;
> #endif
> + char *ratio_expr;
> } AspectContext;
>
> #if FF_API_OLD_FILTER_OPTS
> @@ -72,8 +102,37 @@ static int filter_frame(AVFilterLink *link, AVFrame
> *frame)
> /* for setdar filter, convert from frame aspect ratio to pixel aspect ratio
> */
> static int setdar_config_props(AVFilterLink *inlink)
> {
> + AVFilterContext *ctx = inlink->dst;
> AspectContext *s = inlink->dst->priv;
> AVRational dar;
> + const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
> + double var_values[VARS_NB], res;
> + int ret;
> +
> +#if FF_API_OLD_FILTER_OPTS
> + if (!(s->aspect_num > 0 && s->aspect_den > 0)) {
> +#endif
> + var_values[VAR_PI] = M_PI;
> + var_values[VAR_PHI] = M_PHI;
> + var_values[VAR_E] = M_E;
> + var_values[VAR_W] = inlink->w;
> + var_values[VAR_H] = inlink->h;
> + var_values[VAR_A] = (double) inlink->w / inlink->h;
> + var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
> + (double) inlink->sample_aspect_ratio.num /
> inlink->sample_aspect_ratio.den : 1;
> + var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
> + var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
> + var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
> +
> + /* evaluate new DAR */
> + if ((ret = av_expr_parse_and_eval(&res, s->ratio_expr,
> + var_names, var_values,
> + NULL, NULL, NULL, NULL, NULL, 0, ctx))
> < 0)
config_props might be called more than once, so you should free the old
expression.
> + goto fail;
> + s->dar = av_d2q(res, INT_MAX);
> +#if FF_API_OLD_FILTER_OPTS
> + }
> +#endif
>
> if (s->dar.num && s->dar.den) {
> av_reduce(&s->sar.num, &s->sar.den,
> @@ -91,6 +150,11 @@ static int setdar_config_props(AVFilterLink *inlink)
> inlink->sample_aspect_ratio.num, inlink->sample_aspect_ratio.den);
>
> return 0;
> +
> +fail:
> + av_log(NULL, AV_LOG_ERROR,
> + "Error when evaluating the expression '%s'\n", s->ratio_expr);
> + return ret;
> }
>
> static const AVOption setdar_options[] = {
> @@ -98,7 +162,7 @@ static const AVOption setdar_options[] = {
> { "dar_num", NULL, OFFSET(aspect_num), AV_OPT_TYPE_FLOAT, { .dbl = 0 },
> 0, FLT_MAX, FLAGS },
> { "dar_den", NULL, OFFSET(aspect_den), AV_OPT_TYPE_FLOAT, { .dbl = 0 },
> 0, FLT_MAX, FLAGS },
> #endif
> - { "dar", "display aspect ratio", OFFSET(dar), AV_OPT_TYPE_RATIONAL, {
> .dbl = 0 }, 0, INT_MAX, FLAGS },
> + { "dar", "display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING,
> { .str = "1" }, .flags = FLAGS },
> { NULL },
> };
>
> @@ -149,11 +213,45 @@ AVFilter ff_vf_setdar = {
> /* for setdar filter, convert from frame aspect ratio to pixel aspect ratio
> */
> static int setsar_config_props(AVFilterLink *inlink)
> {
> + AVFilterContext *ctx = inlink->dst;
> AspectContext *s = inlink->dst->priv;
> + double var_values[VARS_NB], res;
> + const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
> + int ret;
> +
> +#if FF_API_OLD_FILTER_OPTS
> + if (!(s->aspect_num > 0 && s->aspect_den > 0)) {
> +#endif
> + var_values[VAR_PI] = M_PI;
> + var_values[VAR_PHI] = M_PHI;
> + var_values[VAR_E] = M_E;
> + var_values[VAR_W] = inlink->w;
> + var_values[VAR_H] = inlink->h;
> + var_values[VAR_A] = (double) inlink->w / inlink->h;
> + var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
> + (double) inlink->sample_aspect_ratio.num /
> inlink->sample_aspect_ratio.den : 1;
> + var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
> + var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
> + var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
> +
> + /* evaluate new DAR */
> + if ((ret = av_expr_parse_and_eval(&res, s->ratio_expr,
> + var_names, var_values,
> + NULL, NULL, NULL, NULL, NULL, 0, ctx))
> < 0)
> + goto fail;
This code is exactly the same as above (including the comment which is wrong
here). Split it into a separate function perhaps?
Other than those details the patch looks fine.
--
Anton Khirnov
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