Implement av_set_options_string().

Originally committed as revision 18832 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavfilter/parseutils.c

@@ -256,10 +256,108 @@ int av_parse_color(uint8_t *rgba_color, const char *color_string, void *log_ctx)
     return 0;
 }
 
+/**
+ * Stores the value in the field in ctx that is named like key.
+ * ctx must be an AVClass context, storing is done using AVOptions.
+ *
+ * @param buf the string to parse, buf will be updated to point at the
+ * separator just after the parsed key/value pair
+ * @param key_val_sep a 0-terminated list of characters used to
+ * separate key from value
+ * @param pairs_sep a 0-terminated list of characters used to separate
+ * two pairs from each other
+ * @return 0 if the key/value pair has been successfully parsed and
+ * set, or a negative value corresponding to an AVERROR code in case
+ * of error:
+ * AVERROR(EINVAL) if the key/value pair cannot be parsed,
+ * the error code issued by av_set_string3() if the key/value pair
+ * cannot be set
+ */
+static int parse_key_value_pair(void *ctx, const char **buf,
+                                const char *key_val_sep, const char *pairs_sep)
+{
+    char *key = av_get_token(buf, key_val_sep);
+    char *val;
+    int ret;
+
+    if (*key && strspn(*buf, key_val_sep)) {
+        (*buf)++;
+        val = av_get_token(buf, pairs_sep);
+    } else {
+        av_log(ctx, AV_LOG_ERROR, "Missing key or no key/value separator found after key '%s'\n", key);
+        av_free(key);
+        return AVERROR(EINVAL);
+    }
+
+    av_log(ctx, AV_LOG_DEBUG, "Setting value '%s' for key '%s'\n", val, key);
+
+    ret = av_set_string3(ctx, key, val, 1, NULL);
+
+    av_free(key);
+    av_free(val);
+    return ret;
+}
+
+int av_set_options_string(void *ctx, const char *opts,
+                          const char *key_val_sep, const char *pairs_sep)
+{
+    int ret, count = 0;
+
+    while (*opts) {
+        if ((ret = parse_key_value_pair(ctx, &opts, key_val_sep, pairs_sep)) < 0)
+            return ret;
+        count++;
+
+        if (*opts)
+            opts++;
+    }
+
+    return count;
+}
+
 #ifdef TEST
 
 #undef printf
 
+typedef struct TestContext
+{
+    const AVClass *class;
+    int num;
+    int toggle;
+    char *string;
+    int flags;
+    AVRational rational;
+} TestContext;
+
+#define OFFSET(x) offsetof(TestContext, x)
+
+#define TEST_FLAG_COOL 01
+#define TEST_FLAG_LAME 02
+#define TEST_FLAG_MU   04
+
+static const AVOption test_options[]= {
+{"num",      "set num",        OFFSET(num),      FF_OPT_TYPE_INT,      0,              0,        100                 },
+{"toggle",   "set toggle",     OFFSET(toggle),   FF_OPT_TYPE_INT,      0,              0,        1                   },
+{"rational", "set rational",   OFFSET(rational), FF_OPT_TYPE_RATIONAL, 0,              0,        10                  },
+{"string",   "set string",     OFFSET(string),   FF_OPT_TYPE_STRING,   0,              CHAR_MIN, CHAR_MAX            },
+{"flags",    "set flags",      OFFSET(flags),    FF_OPT_TYPE_FLAGS,    0,              0,        INT_MAX, 0, "flags" },
+{"cool",     "set cool flag ", 0,                FF_OPT_TYPE_CONST,    TEST_FLAG_COOL, INT_MIN,  INT_MAX, 0, "flags" },
+{"lame",     "set lame flag ", 0,                FF_OPT_TYPE_CONST,    TEST_FLAG_LAME, INT_MIN,  INT_MAX, 0, "flags" },
+{"mu",       "set mu flag ",   0,                FF_OPT_TYPE_CONST,    TEST_FLAG_MU,   INT_MIN,  INT_MAX, 0, "flags" },
+{NULL},
+};
+
+static const char *test_get_name(void *ctx)
+{
+    return "test";
+}
+
+static const AVClass test_class = {
+    "TestContext",
+    test_get_name,
+    test_options
+};
+
 int main(void)
 {
     int i;
@@ -329,6 +427,45 @@ int main(void)
         }
     }
 
+    printf("\nTesting av_set_options_string()\n");
+    {
+        TestContext test_ctx;
+        const char *options[] = {
+            "",
+            ":",
+            "=",
+            "foo=:",
+            ":=foo",
+            "=foo",
+            "foo=",
+            "foo",
+            "foo=val",
+            "foo==val",
+            "toggle=:",
+            "string=:",
+            "toggle=1 : foo",
+            "toggle=100",
+            "toggle==1",
+            "flags=+mu-lame : num=42: toggle=0",
+            "num=42 : string=blahblah",
+            "rational=0 : rational=1/2 : rational=1/-1",
+            "rational=-1/0",
+        };
+
+        test_ctx.class = &test_class;
+        av_opt_set_defaults2(&test_ctx, 0, 0);
+        test_ctx.string = av_strdup("default");
+
+        av_log_set_level(AV_LOG_DEBUG);
+
+        for (i=0; i < FF_ARRAY_ELEMS(options); i++) {
+            av_log(&test_ctx, AV_LOG_DEBUG, "Setting options string '%s'\n", options[i]);
+            if (av_set_options_string(&test_ctx, options[i], "=", ":") < 0)
+                av_log(&test_ctx, AV_LOG_ERROR, "Error setting options string: '%s'\n", options[i]);
+            printf("\n");
+        }
+    }
+
     return 0;
 }
 

libavfilter/parseutils.h

@@ -25,6 +25,8 @@
 #ifndef AVFILTER_PARSEUTILS_H
 #define AVFILTER_PARSEUTILS_H
 
+#include "libavcodec/opt.h"
+
 /**
  * Unescapes the given string until a non escaped terminating char,
  * and returns the token corresponding to the unescaped string.
@@ -51,4 +53,23 @@ char *av_get_token(const char **buf, const char *term);
  */
 int av_parse_color(uint8_t *rgba_color, const char *color_string, void *log_ctx);
 
+/**
+ * Parses the key/value pairs list in opts. For each key/value pair
+ * found, stores the value in the field in ctx that is named like the
+ * key. ctx must be an AVClass context, storing is done using
+ * AVOptions.
+ *
+ * @param key_val_sep a 0-terminated list of characters used to
+ * separate key from value
+ * @param pairs_sep a 0-terminated list of characters used to separate
+ * two pairs from each other
+ * @return the number of successfully set key/value pairs, or a negative
+ * value corresponding to an AVERROR code in case of error:
+ * AVERROR(EINVAL) if opts cannot be parsed,
+ * the error code issued by av_set_string3() if a key/value pair
+ * cannot be set
+ */
+int av_set_options_string(void *ctx, const char *opts,
+                          const char *key_val_sep, const char *pairs_sep);
+
 #endif  /* AVFILTER_PARSEUTILS_H */