Add log_patterns to process config

log_patterns allow to filter the FFmpeg log messages based on regular
expressions. Each entry of log_patterns is interpreted as regular
expression and matched against every non-progress log line emitted from
FFmpeg. All matching lines are returned in the matches array of the
report.

docs/docs.go

@@ -711,7 +711,7 @@ const docTemplate = `{
                     "v16.7.2"
                 ],
                 "summary": "Remove a file from a filesystem",
-                "operationId": "filesystem-3-delete-files",
+                "operationId": "filesystem-3-delete-file",
                 "parameters": [
                     {
                         "type": "string",
@@ -3402,6 +3402,12 @@ const docTemplate = `{
                 "limits": {
                     "$ref": "#/definitions/api.ProcessConfigLimits"
                 },
+                "log_patterns": {
+                    "type": "array",
+                    "items": {
+                        "type": "string"
+                    }
+                },
                 "options": {
                     "type": "array",
                     "items": {
@@ -3537,6 +3543,12 @@ const docTemplate = `{
                         }
                     }
                 },
+                "matches": {
+                    "type": "array",
+                    "items": {
+                        "type": "string"
+                    }
+                },
                 "prelude": {
                     "type": "array",
                     "items": {
@@ -3571,6 +3583,12 @@ const docTemplate = `{
                         }
                     }
                 },
+                "matches": {
+                    "type": "array",
+                    "items": {
+                        "type": "string"
+                    }
+                },
                 "prelude": {
                     "type": "array",
                     "items": {