Global: make threshold of percentage colors configurable

Fix #689

src/modules/gpu/gpu.c

@@ -162,6 +162,9 @@ bool ffParseGPUCommandOptions(FFGPUOptions* options, const char* key, const char
         });
     }
 
+    if (ffPercentParseCommandOptions(key, subKey, value, &options->percent))
+        return true;
+
     return false;
 }
 
@@ -212,6 +215,9 @@ void ffParseGPUJsonObject(FFGPUOptions* options, yyjson_val* module)
             continue;
         }
 
+        if (ffPercentParseJsonObject(key, val, &options->percent))
+            continue;
+
         ffPrintError(FF_GPU_MODULE_NAME, 0, &options->moduleArgs, "Unknown JSON key %s", key);
     }
 }
@@ -247,6 +253,8 @@ void ffGenerateGPUJsonConfig(FFGPUOptions* options, yyjson_mut_doc* doc, yyjson_
                 break;
         }
     }
+
+    ffPercentGenerateJsonConfig(doc, module, defaultOptions.percent, options->percent);
 }
 
 void ffGenerateGPUJsonResult(FFGPUOptions* options, yyjson_mut_doc* doc, yyjson_mut_val* module)