encoding.c: Support the UTF-8 encoding.

src/include/espeak-ng/espeak_ng.h

 	ESPEAKNG_ENCODING_ISO_8859_16,
 	ESPEAKNG_ENCODING_KOI8_R,
 	ESPEAKNG_ENCODING_ISCII,
+	ESPEAKNG_ENCODING_UTF_8,
 } espeak_ng_ENCODING;
 
 ESPEAK_NG_API espeak_ng_ENCODING

src/libespeak-ng/encoding.c

 #include "speech.h"
 #include "encoding.h"
 
+#define LEADING_2_BITS 0xC0 // 0b11000000
+#define UTF8_TAIL_BITS 0x80 // 0b10000000
+
 // http://www.iana.org/assignments/character-sets/character-sets.xhtml
 MNEM_TAB mnem_encoding[] = {
 	{ "ANSI_X3.4-1968",   ESPEAKNG_ENCODING_US_ASCII },
 	{ "Latin-9",          ESPEAKNG_ENCODING_ISO_8859_15 },
 	{ "TIS-620",          ESPEAKNG_ENCODING_ISO_8859_11 },
 	{ "US-ASCII",         ESPEAKNG_ENCODING_US_ASCII },
+	{ "UTF-8",            ESPEAKNG_ENCODING_UTF_8 },
 	{ "cp367",            ESPEAKNG_ENCODING_US_ASCII },
 	{ "cp819",            ESPEAKNG_ENCODING_ISO_8859_1 },
 	{ "csASCII",          ESPEAKNG_ENCODING_US_ASCII },
 	{ "csISOLatinHebrew", ESPEAKNG_ENCODING_ISO_8859_8 },
 	{ "csKOI8R",          ESPEAKNG_ENCODING_KOI8_R },
 	{ "csTIS620",         ESPEAKNG_ENCODING_ISO_8859_11 },
+	{ "csUTF8",           ESPEAKNG_ENCODING_UTF_8 },
 	{ "arabic",           ESPEAKNG_ENCODING_ISO_8859_6 },
 	{ "cyrillic",         ESPEAKNG_ENCODING_ISO_8859_5 },
 	{ "greek",            ESPEAKNG_ENCODING_ISO_8859_7 },
 	return (c >= 0x80) ? decoder->codepage[c - 0x80] : c;
 }
 
+static uint32_t
+string_decoder_getc_utf_8(espeak_ng_TEXT_DECODER *decoder)
+{
+	uint8_t  c = *decoder->current++ & 0xFF;
+	uint32_t ret;
+	switch (c & 0xF0)
+	{
+	// 1-byte UTF-8 sequence
+	case 0x00: case 0x10: case 0x20: case 0x30:
+	case 0x40: case 0x50: case 0x60: case 0x70:
+		return c;
+	// UTF-8 tail byte -- invalid in isolation
+	case 0x80: case 0x90: case 0xA0: case 0xB0:
+		return 0xFFFD;
+	// 2-byte UTF-8 sequence
+	case 0xC0: case 0xD0:
+		if (decoder->current + 1 >= decoder->end) goto eof;
+		ret = c & 0x1F;
+		if (((c = *decoder->current++ & 0xFF) & LEADING_2_BITS) != UTF8_TAIL_BITS) goto error;
+		ret = (ret << 6) + (c & 0x3F);
+		return ret;
+	// 3-byte UTF-8 sequence
+	case 0xE0:
+		if (decoder->current + 2 >= decoder->end) goto eof;
+		ret = c & 0x0F;
+		if (((c = *decoder->current++ & 0xFF) & LEADING_2_BITS) != UTF8_TAIL_BITS) goto error;
+		ret = (ret << 6) + (c & 0x3F);
+		if (((c = *decoder->current++ & 0xFF) & LEADING_2_BITS) != UTF8_TAIL_BITS) goto error;
+		ret = (ret << 6) + (c & 0x3F);
+		return ret;
+	// 4-byte UTF-8 sequence
+	case 0xF0:
+		if (decoder->current + 3 >= decoder->end) goto eof;
+		ret = c & 0x0F;
+		if (((c = *decoder->current++ & 0xFF) & LEADING_2_BITS) != UTF8_TAIL_BITS) goto error;
+		ret = (ret << 6) + (c & 0x3F);
+		if (((c = *decoder->current++ & 0xFF) & LEADING_2_BITS) != UTF8_TAIL_BITS) goto error;
+		ret = (ret << 6) + (c & 0x3F);
+		if (((c = *decoder->current++ & 0xFF) & LEADING_2_BITS) != UTF8_TAIL_BITS) goto error;
+		ret = (ret << 6) + (c & 0x3F);
+		return (ret <= 0x10FFFF) ? ret : 0xFFFD;
+	}
+error:
+	--decoder->current;
+	return 0xFFFD;
+eof:
+	decoder->current = decoder->end;
+	return 0xFFFD;
+}
+
 typedef struct
 {
 	uint32_t (*get)(espeak_ng_TEXT_DECODER *decoder);
 	{ string_decoder_getc_codepage, ISO_8859_16 },
 	{ string_decoder_getc_codepage, KOI8_R },
 	{ string_decoder_getc_codepage, ISCII },
+	{ string_decoder_getc_utf_8, NULL },
 };
 
 espeak_ng_TEXT_DECODER *
                            int length,
                            espeak_ng_ENCODING encoding)
 {
-	if (encoding > ESPEAKNG_ENCODING_ISCII)
+	if (encoding > ESPEAKNG_ENCODING_UTF_8)
 		return ENS_UNKNOWN_TEXT_ENCODING;
 
 	const encoding_t *enc = string_decoders + encoding;

tests/encoding.c

 	destroy_text_decoder(decoder);
 }
 
+void
+test_utf_8_encoding()
+{
+	printf("testing UTF-8 encoding\n");
+
+	assert(espeak_ng_EncodingFromName("UTF-8") == ESPEAKNG_ENCODING_UTF_8);
+	assert(espeak_ng_EncodingFromName("csUTF8") == ESPEAKNG_ENCODING_UTF_8);
+
+	espeak_ng_TEXT_DECODER *decoder = create_text_decoder();
+
+	// 1-byte UTF-8 sequences
+	assert(text_decoder_decode_string(decoder, "\x0D\x1E\x20\x35\x42\x57\x65\x77", 8, ESPEAKNG_ENCODING_UTF_8) == ENS_OK);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x000D);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x001E);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x0020);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x0035);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x0042);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x0057);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x0065);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x0077);
+	assert(text_decoder_eof(decoder) == 1);
+
+	// UTF-8 tail bytes without an initial length indicator character
+	assert(text_decoder_decode_string(decoder, "\x84\x92\xA8\xB5", 4, ESPEAKNG_ENCODING_UTF_8) == ENS_OK);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0xFFFD);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0xFFFD);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0xFFFD);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0xFFFD);
+	assert(text_decoder_eof(decoder) == 1);
+
+	// 2-byte UTF-8 sequences
+	assert(text_decoder_decode_string(decoder, "\xC2\xA0\xD0\xB0\xC5\x65\xC2\xA0", 7, ESPEAKNG_ENCODING_UTF_8) == ENS_OK);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x00A0);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x0430);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0xFFFD); // \x65 is not a continuation byte, so \xC5 is invalid
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x0065);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0xFFFD); // incomplete: \xA0 is past the end of the string
+	assert(text_decoder_eof(decoder) == 1);
+
+	// 3-byte UTF-8 sequences
+	assert(text_decoder_decode_string(decoder, "\xE4\xBA\x8C\xE8\x42\xE2\x93\x44\xE4\xA0\x80", 9, ESPEAKNG_ENCODING_UTF_8) == ENS_OK);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x4E8C);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0xFFFD); // \x42 is not a continuation byte, so \xE8 is invalid
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x0042);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0xFFFD); // \x44 is not a continuation byte, so \xE2\x93 is invalid
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x0044);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0xFFFD); // incomplete: \xA0 is past the end of the string
+	assert(text_decoder_eof(decoder) == 1);
+
+	// 4-byte UTF-8 sequences
+	assert(text_decoder_decode_string(decoder, "\xF0\x90\x8C\x82\xF4\x8F\xBF\xBF\xF3\x61\xF3\xA5\x32\xF3\x87\xB2\x36\xF1\xA0\x80\x80", 18, ESPEAKNG_ENCODING_UTF_8) == ENS_OK);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x10302);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x10FFFF);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0xFFFD); // \x61 is not a continuation byte, so \xF3 is invalid
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x0061);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0xFFFD); // \x32 is not a continuation byte, so \xF3\xA5 is invalid
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x0032);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0xFFFD); // \x36 is not a continuation byte, so \xF3\x87\xB2 is invalid
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0x0036);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0xFFFD); // incomplete: \xA0 is past the end of the string
+	assert(text_decoder_eof(decoder) == 1);
+
+	// out of range (> 0x10FFFF)
+	assert(text_decoder_decode_string(decoder, "\xF4\x90\x80\x80", 4, ESPEAKNG_ENCODING_UTF_8) == ENS_OK);
+	assert(text_decoder_eof(decoder) == 0);
+	assert(text_decoder_getc(decoder) == 0xFFFD);
+	assert(text_decoder_eof(decoder) == 1);
+
+	destroy_text_decoder(decoder);
+}
+
 int
 main(int argc, char **argv)
 {
 	test_iso_8859_15_encoding();
 	test_iso_8859_16_encoding();
 
+	test_utf_8_encoding();
+
 	printf("done\n");
 
 	return EXIT_SUCCESS;