Use the text decoder object at the top-level Synthesize/espeak_TextToPhonemes call, not in TranslateClause.

src/libespeak-ng/speech.c

 /*
  * Copyright (C) 2005 to 2013 by Jonathan Duddington
  * email: [email protected]
- * Copyright (C) 2013-2016 Reece H. Dunn
+ * Copyright (C) 2013-2017 Reece H. Dunn
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
 	if (translator == NULL)
 		espeak_SetVoiceByName("default");
 
-	SpeakNextClause(text, 0);
+	if (p_decoder == NULL)
+		p_decoder = create_text_decoder();
+
+	espeak_ng_STATUS status;
+	status = text_decoder_decode_string_multibyte(p_decoder, text, translator->encoding, flags);
+	if (status != ENS_OK)
+		return status;
+
+	SpeakNextClause(0);
 
 	for (;;) {
 		out_ptr = outbuf;
 		} else if (synth_callback)
 			finished = synth_callback((short *)outbuf, length, event_list);
 		if (finished) {
-			SpeakNextClause(0, 2); // stop
+			SpeakNextClause(2); // stop
 			return ENS_SPEECH_STOPPED;
 		}
 
 				event_list[0].unique_identifier = my_unique_identifier;
 				event_list[0].user_data = my_user_data;
 
-				if (SpeakNextClause(NULL, 1) == 0) {
+				if (SpeakNextClause(1) == 0) {
 					finished = 0;
 					if ((my_mode & ENOUTPUT_MODE_SPEAK_AUDIO) == ENOUTPUT_MODE_SPEAK_AUDIO) {
 						if (dispatch_audio(NULL, 0, NULL) < 0)
 					} else if (synth_callback)
 						finished = synth_callback(NULL, 0, event_list); // NULL buffer ptr indicates end of data
 					if (finished) {
-						SpeakNextClause(0, 2); // stop
+						SpeakNextClause(2); // stop
 						return ENS_SPEECH_STOPPED;
 					}
 					return ENS_OK;
 	    bits 8-23:  separator character, between phoneme names
 	 */
 
-	option_multibyte = textmode & 7;
-	*textptr = TranslateClause(translator, *textptr, NULL, NULL);
+	if (p_decoder == NULL)
+		p_decoder = create_text_decoder();
+
+	if (text_decoder_decode_string_multibyte(p_decoder, *textptr, translator->encoding, textmode) != ENS_OK)
+		return NULL;
+
+	TranslateClause(translator, NULL, NULL);
+	*textptr = text_decoder_get_buffer(p_decoder);
+
 	return GetTranslatedPhonemeString(phonememode);
 }
 

src/libespeak-ng/synthesize.c

 /*
  * Copyright (C) 2005 to 2014 by Jonathan Duddington
  * email: [email protected]
- * Copyright (C) 2015-2016 Reece H. Dunn
+ * Copyright (C) 2015-2017 Reece H. Dunn
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
 	return 0; // finished the phoneme list
 }
 
-int SpeakNextClause(const void *text_in, int control)
+int SpeakNextClause(int control)
 {
 	// Speak text from memory (text_in)
 	// control 0: start
 
 	int clause_tone;
 	char *voice_change;
-	static const void *p_text = NULL;
 	const char *phon_out;
 
 	if (control == 2) {
 		// stop speaking
-		p_text = NULL;
 		n_phoneme_list = 0;
 		WcmdqStop();
 
 		return 0;
 	}
 
-	if (text_in != NULL) {
-		p_text = text_in;
-	}
-
-	if (p_text == NULL) {
+	if (text_decoder_eof(p_decoder)) {
 		skipping_text = 0;
 		return 0;
 	}
 
 	// read the next clause from the input text file, translate it, and generate
 	// entries in the wavegen command queue
-	p_text = TranslateClause(translator, p_text, &clause_tone, &voice_change);
+	TranslateClause(translator, &clause_tone, &voice_change);
 
 	CalcPitches(translator, clause_tone);
 	CalcLengths(translator);

src/libespeak-ng/synthesize.h

 void SynthesizeInit(void);
 int  Generate(PHONEME_LIST *phoneme_list, int *n_ph, int resume);
 void MakeWave2(PHONEME_LIST *p, int n_ph);
-int  SpeakNextClause(const void *text_in, int control);
+int  SpeakNextClause(int control);
 void SetSpeed(int control);
 void SetEmbedded(int control, int value);
 void SelectPhonemeTable(int number);

src/libespeak-ng/translate.c

 	return 0;
 }
 
-const void *TranslateClause(Translator *tr, const void *vp_input, int *tone_out, char **voice_change)
+void TranslateClause(Translator *tr, int *tone_out, char **voice_change)
 {
 	int ix;
 	int c;
 	int tone2;
 
 	if (tr == NULL)
-		return NULL;
-
-	if (p_decoder == NULL)
-		p_decoder = create_text_decoder();
-
-	if (text_decoder_decode_string_multibyte(p_decoder, vp_input, tr->encoding, option_multibyte) != ENS_OK)
-		return NULL;
+		return;
 
 	embedded_ix = 0;
 	embedded_read = 0;
 		else
 			*voice_change = NULL;
 	}
-
-	if (Eof() || (vp_input == NULL))
-		return NULL;
-
-	return text_decoder_get_buffer(p_decoder);
 }
 
 void InitText(int control)

src/libespeak-ng/translate.h

 void SetWordStress(Translator *tr, char *output, unsigned int *dictionary_flags, int tonic, int prev_stress);
 int TranslateRules(Translator *tr, char *p, char *phonemes, int size, char *end_phonemes, int end_flags, unsigned int *dict_flags);
 int TranslateWord(Translator *tr, char *word1, WORD_TAB *wtab, char *word_out);
-const void *TranslateClause(Translator *tr, const void *vp_input, int *tone, char **voice_change);
+void TranslateClause(Translator *tr, int *tone, char **voice_change);
 int ReadClause(Translator *tr, char *buf, short *charix, int *charix_top, int n_buf, int *tone_type, char *voice_change);
 
 void SetVoiceStack(espeak_VOICE *v, const char *variant_name);