go : support "auto" as an option when set language (#462)

Co-authored-by: Ming <ming@localhost>

bindings/go/params.go

@@ -49,6 +49,10 @@ func (p *Params) SetSpeedup(v bool) {
 
 // Set language id
 func (p *Params) SetLanguage(lang int) error {
+	if lang == -1 {
+		p.language = nil
+		return nil
+	}
 	str := C.whisper_lang_str(C.int(lang))
 	if str == nil {
 		return ErrInvalidLanguage

bindings/go/pkg/whisper/context.go

@@ -46,7 +46,10 @@ func (context *context) SetLanguage(lang string) error {
 	if !context.model.IsMultilingual() {
 		return ErrModelNotMultilingual
 	}
-	if id := context.model.ctx.Whisper_lang_id(lang); id < 0 {
+
+	if lang == "auto" {
+		context.params.SetLanguage(-1)
+	} else if id := context.model.ctx.Whisper_lang_id(lang); id < 0 {
 		return ErrUnsupportedLanguage
 	} else if err := context.params.SetLanguage(id); err != nil {
 		return err
@@ -61,6 +64,10 @@ func (context *context) IsMultilingual() bool {
 
 // Get language
 func (context *context) Language() string {
+	id := context.params.Language()
+	if id == -1 {
+		return "auto"
+	}
 	return whisper.Whisper_lang_str(context.params.Language())
 }
 

bindings/go/pkg/whisper/interface.go

@@ -29,7 +29,7 @@ type Model interface {
 
 // Context is the speach recognition context.
 type Context interface {
-	SetLanguage(string) error // Set the language to use for speech recognition.
+	SetLanguage(string) error // Set the language to use for speech recognition, use "auto" for auto detect language.
 	SetTranslate(bool)        // Set translate flag
 	IsMultilingual() bool     // Return true if the model is multilingual.
 	Language() string         // Get language