@@ -5,6 +5,7 @@ version <next>

 - HNM version 4 demuxer and video decoder

 - Live HDS muxer

+- setsar/setdar filters now support variables in ratio expressions

 version 2.1:

@@ -6970,6 +6970,31 @@ Default value is @code{100}.

 @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

+

 @subsection Examples

 @itemize

@@ -30,11 +30,38 @@

 #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;

@@ -43,7 +70,7 @@ typedef struct {

 #if FF_API_OLD_FILTER_OPTS

     float aspect_den;

 #endif

-    char *ratio_str;

+    char *ratio_expr;

 } AspectContext;

 static av_cold int init(AVFilterContext *ctx)

@@ -52,28 +79,20 @@ static av_cold int init(AVFilterContext *ctx)

     int ret;

 #if FF_API_OLD_FILTER_OPTS

-    if (s->ratio_str && s->aspect_den > 0) {

+    if (s->ratio_expr && s->aspect_den > 0) {

         double num;

         av_log(ctx, AV_LOG_WARNING,

                "num:den syntax is deprecated, please use num/den or named options instead\n");

-        ret = av_expr_parse_and_eval(&num, s->ratio_str, NULL, NULL,

+        ret = av_expr_parse_and_eval(&num, s->ratio_expr, NULL, NULL,

                                      NULL, NULL, NULL, NULL, NULL, 0, ctx);

         if (ret < 0) {

-            av_log(ctx, AV_LOG_ERROR, "Unable to parse ratio numerator \"%s\"\n", s->ratio_str);

+            av_log(ctx, AV_LOG_ERROR, "Unable to parse ratio numerator \"%s\"\n", s->ratio_expr);

             return AVERROR(EINVAL);

         }

         s->sar = s->dar = av_d2q(num / s->aspect_den, s->max);

-    } else

-#endif

-    if (s->ratio_str) {

-        ret = av_parse_ratio(&s->sar, s->ratio_str, s->max, 0, ctx);

-        if (ret < 0 || s->sar.num < 0 || s->sar.den <= 0) {

-            av_log(ctx, AV_LOG_ERROR,

-                   "Invalid string '%s' for aspect ratio\n", s->ratio_str);

-            return AVERROR(EINVAL);

-        }

-        s->dar = s->sar;

     }

+#endif

+

     return 0;

 }

@@ -97,6 +116,48 @@ static inline void compute_dar(AVRational *dar, AVRational sar, int w, int h)

     }

 }

+static int get_aspect_ratio(AVFilterLink *inlink, AVRational *aspect_ratio)

+{

+    AVFilterContext *ctx = inlink->dst;

+    AspectContext *s = inlink->dst->priv;

+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);

+    double var_values[VARS_NB], res;

+    int ret;

+

+    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 aspect ratio*/

+    ret = av_expr_parse_and_eval(&res, s->ratio_expr,

+                                      var_names, var_values,

+                                      NULL, NULL, NULL, NULL, NULL, 0, ctx);

+    if (ret < 0) {

+        ret = av_parse_ratio(aspect_ratio, s->ratio_expr, s->max, 0, ctx);

+    } else

+        *aspect_ratio = av_d2q(res, s->max);

+

+    if (ret < 0) {

+        av_log(ctx, AV_LOG_ERROR,

+               "Error when evaluating the expression '%s'\n", s->ratio_expr);

+        return ret;

+    }

+    if (aspect_ratio->num < 0 || aspect_ratio->den <= 0) {

+        av_log(ctx, AV_LOG_ERROR,

+                "Invalid string '%s' for aspect ratio\n", s->ratio_expr);

+        return AVERROR(EINVAL);

+    }

+    return 0;

+}

+

 #if CONFIG_SETDAR_FILTER

 static int setdar_config_props(AVFilterLink *inlink)

@@ -105,6 +166,16 @@ static int setdar_config_props(AVFilterLink *inlink)

     AVRational dar;

     AVRational old_dar;

     AVRational old_sar = inlink->sample_aspect_ratio;

+    int ret;

+

+#if FF_API_OLD_FILTER_OPTS

+    if (!(s->ratio_expr && s->aspect_den > 0)) {

+#endif

+    if ((ret = get_aspect_ratio(inlink, &s->dar)))

+        return ret;

+#if FF_API_OLD_FILTER_OPTS

+    }

+#endif

     if (s->dar.num && s->dar.den) {

         av_reduce(&s->sar.num, &s->sar.den,

@@ -126,9 +197,9 @@ static int setdar_config_props(AVFilterLink *inlink)

 }

 static const AVOption setdar_options[] = {

-    { "dar",   "set display aspect ratio", OFFSET(ratio_str), AV_OPT_TYPE_STRING, {.str="0"}, .flags=FLAGS },

-    { "ratio", "set display aspect ratio", OFFSET(ratio_str), AV_OPT_TYPE_STRING, {.str="0"}, .flags=FLAGS },

-    { "r",     "set display aspect ratio", OFFSET(ratio_str), AV_OPT_TYPE_STRING, {.str="0"}, .flags=FLAGS },

+    { "dar",   "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },

+    { "ratio", "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },

+    { "r",     "set display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },

 #if FF_API_OLD_FILTER_OPTS

     { "dar_den", NULL, OFFSET(aspect_den), AV_OPT_TYPE_FLOAT, { .dbl = 0 }, 0, FLT_MAX, FLAGS },

 #endif

@@ -175,6 +246,16 @@ static int setsar_config_props(AVFilterLink *inlink)

     AspectContext *s = inlink->dst->priv;

     AVRational old_sar = inlink->sample_aspect_ratio;

     AVRational old_dar, dar;

+    int ret;

+

+#if FF_API_OLD_FILTER_OPTS

+    if (!(s->ratio_expr && s->aspect_den > 0)) {

+#endif

+    if ((ret = get_aspect_ratio(inlink, &s->sar)))

+        return ret;

+#if FF_API_OLD_FILTER_OPTS

+    }

+#endif

     inlink->sample_aspect_ratio = s->sar;

@@ -188,9 +269,9 @@ static int setsar_config_props(AVFilterLink *inlink)

 }

 static const AVOption setsar_options[] = {

-    { "sar",   "set sample (pixel) aspect ratio", OFFSET(ratio_str), AV_OPT_TYPE_STRING, {.str="0"}, .flags=FLAGS },

-    { "ratio", "set sample (pixel) aspect ratio", OFFSET(ratio_str), AV_OPT_TYPE_STRING, {.str="0"}, .flags=FLAGS },

-    { "r",     "set sample (pixel) aspect ratio", OFFSET(ratio_str), AV_OPT_TYPE_STRING, {.str="0"}, .flags=FLAGS },

+    { "sar",   "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },

+    { "ratio", "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },

+    { "r",     "set sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },

 #if FF_API_OLD_FILTER_OPTS

     { "sar_den", NULL, OFFSET(aspect_den), AV_OPT_TYPE_FLOAT, { .dbl = 0 }, 0, FLT_MAX, FLAGS },

 #endif