Create an espeak-ng version of espeak_SetVoiceBy(Name|Properties).

src/include/espeak-ng/espeak_ng.h

 	ENS_FIFO_BUFFER_FULL         = 0x100003FF,
 	ENS_NOT_INITIALIZED          = 0x100004FF,
 	ENS_AUDIO_ERROR              = 0x100005FF,
+	ENS_VOICE_NOT_FOUND          = 0x100006FF,
 } espeak_ng_STATUS;
 
 typedef enum {
 ESPEAK_NG_API espeak_ng_STATUS
 espeak_ng_SetPunctuationList(const wchar_t *punctlist);
 
+ESPEAK_NG_API espeak_ng_STATUS
+espeak_ng_SetVoiceByName(const char *name);
+
+ESPEAK_NG_API espeak_ng_STATUS
+espeak_ng_SetVoiceByProperties(espeak_VOICE *voice_selector);
+
 ESPEAK_NG_API espeak_ng_STATUS
 espeak_ng_Synthesize(const void *text,
                      size_t size,

src/libespeak-ng/espeak_api.c

 	return status_to_espeak_error(espeak_ng_SetPunctuationList(punctlist));
 }
 
+ESPEAK_API espeak_ERROR espeak_SetVoiceByName(const char *name)
+{
+	return status_to_espeak_error(espeak_SetVoiceByName(name));
+}
+
+ESPEAK_API espeak_ERROR espeak_SetVoiceByProperties(espeak_VOICE *voice_selector)
+{
+	return status_to_espeak_error(espeak_SetVoiceByProperties(voice_selector));
+}
+
 ESPEAK_API espeak_ERROR espeak_Cancel(void)
 {
 	return status_to_espeak_error(espeak_ng_Cancel());

src/libespeak-ng/espeak_command.h

 espeak_ng_STATUS sync_espeak_Char(wchar_t character);
 void sync_espeak_SetPunctuationList(const wchar_t *punctlist);
 void sync_espeak_SetParameter(espeak_PARAMETER parameter, int value, int relative);
-int sync_espeak_SetVoiceByName(const char *name);
-int sync_espeak_SetVoiceByProperties(espeak_VOICE *voice_selector);
 espeak_ng_STATUS SetParameter(int parameter, int value, int relative);
 
 int sync_espeak_terminated_msg(unsigned int unique_identifier, void *user_data);

src/libespeak-ng/voices.c

 
 #pragma GCC visibility push(default)
 
-espeak_ERROR espeak_SetVoiceByName(const char *name)
+ESPEAK_NG_API espeak_ng_STATUS espeak_ng_SetVoiceByName(const char *name)
 {
 	espeak_VOICE *v;
 	int ix;
 		DoVoiceChange(voice);
 		voice_selector.languages = voice->language_name;
 		SetVoiceStack(&voice_selector, variant_name);
-		return EE_OK;
+		return ENS_OK;
 	}
 
 	if (n_voices_list == 0)
 			return EE_OK;
 		}
 	}
-	return EE_INTERNAL_ERROR; // voice name not found
+	return ENS_VOICE_NOT_FOUND;
 }
 
-espeak_ERROR espeak_SetVoiceByProperties(espeak_VOICE *voice_selector)
+ESPEAK_NG_API espeak_ng_STATUS espeak_ng_SetVoiceByProperties(espeak_VOICE *voice_selector)
 {
 	const char *voice_id;
 	int voice_found;
 
 	voice_id = SelectVoice(voice_selector, &voice_found);
-
 	if (voice_found == 0)
-		return EE_NOT_FOUND;
+		return ENS_VOICE_NOT_FOUND;
 
 	LoadVoiceVariant(voice_id, 0);
 	DoVoiceChange(voice);
 	SetVoiceStack(voice_selector, "");
 
-	return EE_OK;
+	return ENS_OK;
 }
 
 #pragma GCC visibility pop