vcomp/cmpto_j2k: print opt hint in help

+ use unit_evaluate_dbl (instead of unit_evaluate) - **also** in decompress

src/utils/misc.cpp

@@ -92,7 +92,7 @@ unit_evaluate(const char *str, const char **endptr)
  * Converts units in format <val>[.<val>][kMG] to floating point representation.
  *
  * @param    str            string to be parsed, suffix following SI suffix is ignored (as in 1ms or 100MB)
- * @param    case_sensitive should 'm' be considered as mega
+ * @param    case_sensitive if true 'm' will be considered as milli, otherwise mega
  * @param    endptr         if not NULL, point to suffix after parse
  * @returns                 positive floating point representation of the string
  * @returns                 NAN if error

src/video_compress/cmpto_j2k.cpp

@@ -483,11 +483,13 @@ static void usage() {
               << " - use CPU for pixfmt conversion (useful if GPU\n\t\tis fully "
                  "occupied by the encoder; an option for decoder exists as "
                  "well)\n";
+        color_printf("\nOption prefixes (eg. 'q=' for quality) can be used. SI "
+                     "suffixes are recognized (eg. 'r=7.5M').\n");
 }
 
 #define ASSIGN_CHECK_VAL(var, str, minval) \
         do { \
-                long long val = unit_evaluate(str, nullptr); \
+                long long val = unit_evaluate_dbl(str, false, nullptr); \
                 if (val < (minval) || val > UINT_MAX) { \
                         LOG(LOG_LEVEL_ERROR) \
                             << "[J2K] Wrong value " << (str) \

src/video_decompress/cmpto_j2k.cpp

@@ -242,8 +242,8 @@ static void * j2k_decompress_init(void)
 
         auto *s = new state_decompress_j2k(queue_len, encoder_in_frames);
         if (get_commandline_param("j2k-dec-mem-limit") != nullptr) {
-                s->req_mem_limit = unit_evaluate(
-                    get_commandline_param("j2k-dec-mem-limit"), nullptr);
+                s->req_mem_limit = unit_evaluate_dbl(
+                    get_commandline_param("j2k-dec-mem-limit"), false, nullptr);
         }
 
         if (get_commandline_param("j2k-dec-tile-limit") != nullptr) {