@@ -1645,9 +1645,21 @@ can be used to test the monowhite pixel format descriptor definition.

 @section scale

-Scale the input video to @var{width}:@var{height} and/or convert the image format.

+Scale the input video and/or convert the image format.

-The parameters @var{width} and @var{height} are expressions containing

+This filter accepts the following options:

+

+@table @option

+

+@item w

+Output video width.

+

+@item h

+Output video height.

+

+@end table

+

+The parameters @var{w} and @var{h} are expressions containing

 the following constants:

 @table @option

@@ -1682,27 +1694,27 @@ If the input image format is different from the format requested by

 the next filter, the scale filter will convert the input to the

 requested format.

-If the value for @var{width} or @var{height} is 0, the respective input

+If the value for @var{w} or @var{h} is 0, the respective input

 size is used for the output.

-If the value for @var{width} or @var{height} is -1, the scale filter will

-use, for the respective output size, a value that maintains the aspect

-ratio of the input image.

+If the value for @var{w} or @var{h} is -1, the scale filter will use, for the

+respective output size, a value that maintains the aspect ratio of the input

+image.

-The default value of @var{width} and @var{height} is 0.

+The default value of @var{w} and @var{h} is 0.

 Some examples follow:

 @example

 # scale the input video to a size of 200x100.

-scale=200:100

+scale=w=200:h=100

 # scale the input to 2x

-scale=2*iw:2*ih

+scale=w=2*iw:h=2*ih

 # the above is the same as

 scale=2*in_w:2*in_h

 # scale the input to half size

-scale=iw/2:ih/2

+scale=w=iw/2:h=ih/2

 # increase the width, and set the height to the same size

 scale=3/2*iw:ow

@@ -1712,13 +1724,13 @@ scale=iw:1/PHI*iw

 scale=ih*PHI:ih

 # increase the height, and set the width to 3/2 of the height

-scale=3/2*oh:3/5*ih

+scale=w=3/2*oh:h=3/5*ih

 # increase the size, but make the size a multiple of the chroma

 scale="trunc(3/2*iw/hsub)*hsub:trunc(3/2*ih/vsub)*vsub"

 # increase the width to a maximum of 500 pixels, keep the same input aspect ratio

-scale='min(500\, iw*3/2):-1'

+scale=w='min(500\, iw*3/2):h=-1'

 @end example

 @section select

@@ -481,6 +481,36 @@ int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque

     int ret=0;

     if (args && *args && filter->filter->priv_class) {

+#if FF_API_OLD_FILTER_OPTS

+        if (!strcmp(filter->filter->name, "scale") &&

+            strchr(args, ':') < strchr(args, '=')) {

+            /* old w:h:flags=<flags> syntax */

+            char *copy = av_strdup(args);

+            char *p;

+

+            av_log(filter, AV_LOG_WARNING, "The <w>:<h>:flags=<flags> option "

+                   "syntax is deprecated. Use either <w>:<h>:<flags> or "

+                   "w=<w>:h=<h>:flags=<flags>.\n");

+

+            if (!copy) {

+                ret = AVERROR(ENOMEM);

+                goto fail;

+            }

+

+            p = strrchr(copy, ':');

+            if (p) {

+                *p++ = 0;

+                ret = av_dict_parse_string(&options, p, "=", ":", 0);

+            }

+            if (ret >= 0)

+                ret = process_unnamed_options(filter, &options, copy);

+            av_freep(&copy);

+

+            if (ret < 0)

+                goto fail;

+        } else

+#endif

+

         if (strchr(args, '=')) {

             /* assume a list of key1=value1:key2=value2:... */

             ret = av_dict_parse_string(&options, args, "=", ":", 0);

@@ -69,6 +69,7 @@ enum var_name {

 };

 typedef struct {

+    const AVClass *class;

     struct SwsContext *sws;     ///< software scaler context

     /**

@@ -83,31 +84,23 @@ typedef struct {

     int slice_y;                ///< top of current output slice

     int input_is_pal;           ///< set to 1 if the input format is paletted

-    char w_expr[256];           ///< width  expression string

-    char h_expr[256];           ///< height expression string

+    char *w_expr;               ///< width  expression string

+    char *h_expr;               ///< height expression string

+    char *flags_str;

 } ScaleContext;

 static av_cold int init(AVFilterContext *ctx, const char *args)

 {

     ScaleContext *scale = ctx->priv;

-    const char *p;

-

-    av_strlcpy(scale->w_expr, "iw", sizeof(scale->w_expr));

-    av_strlcpy(scale->h_expr, "ih", sizeof(scale->h_expr));

-

-    scale->flags = SWS_BILINEAR;

-    if (args) {

-        sscanf(args, "%255[^:]:%255[^:]", scale->w_expr, scale->h_expr);

-        p = strstr(args,"flags=");

-        if (p) {

-            const AVClass *class = sws_get_class();

-            const AVOption    *o = av_opt_find(&class, "sws_flags", NULL, 0,

-                                               AV_OPT_SEARCH_FAKE_OBJ);

-            int ret = av_opt_eval_flags(&class, o, p + 6, &scale->flags);

-

-            if (ret < 0)

-                return ret;

-        }

+

+    if (scale->flags_str) {

+        const AVClass *class = sws_get_class();

+        const AVOption    *o = av_opt_find(&class, "sws_flags", NULL, 0,

+                                           AV_OPT_SEARCH_FAKE_OBJ);

+        int ret = av_opt_eval_flags(&class, o, scale->flags_str, &scale->flags);

+

+        if (ret < 0)

+            return ret;

     }

     return 0;

@@ -292,6 +285,22 @@ static int filter_frame(AVFilterLink *link, AVFrame *in)

     return ff_filter_frame(outlink, out);

 }

+#define OFFSET(x) offsetof(ScaleContext, x)

+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM

+static const AVOption options[] = {

+    { "w",     "Output video width",          OFFSET(w_expr),    AV_OPT_TYPE_STRING, { .str = "iw" },       .flags = FLAGS },

+    { "h",     "Output video height",         OFFSET(h_expr),    AV_OPT_TYPE_STRING, { .str = "ih" },       .flags = FLAGS },

+    { "flags", "Flags to pass to libswscale", OFFSET(flags_str), AV_OPT_TYPE_STRING, { .str = "bilinear" }, .flags = FLAGS },

+    { NULL },

+};

+

+static const AVClass scale_class = {

+    .class_name = "scale",

+    .item_name  = av_default_item_name,

+    .option     = options,

+    .version    = LIBAVUTIL_VERSION_INT,

+};

+

 static const AVFilterPad avfilter_vf_scale_inputs[] = {

     {

         .name        = "default",

@@ -320,6 +329,7 @@ AVFilter avfilter_vf_scale = {

     .query_formats = query_formats,

     .priv_size = sizeof(ScaleContext),

+    .priv_class = &scale_class,

     .inputs    = avfilter_vf_scale_inputs,

     .outputs   = avfilter_vf_scale_outputs,